- Email: [email protected]
Medical problems in total correction of tetralogy of fallot
Medical Problems in Total Correction of Tetralogy of Fallot By SYLVIAP. GRIFFITHS AND JAMES R. MALM
N THE REHABILITATION of patients with congenital heart disease, probably the most exciting achievement is total surgical correction of the tetralogy of Fallot. Complete management of the patient for whom surgical repair of this anomaly is planned requires close cooperation between the cardiologist (pediatric or medical) and the cardiovascular surgeon. This basic team approach should begin with the consideration of the indications for surgery and continue into the evaluation of postoperative status. The discussion presented here, with respect to case selection for surgery, management in the preoperative, operative and postoperative periods, and follow-up evaluation, is based on 5 years' experience with the tetralogy at the Columbia-Presbyterian Medical Center. v3
I
Definition
The tetralogy of Fallot consists of (1) ventricular septal defect, (2) pulmonic stenosis, (3) overriding of the aorta, and (4) hypertrophy of the right ventricle. It is apparent that in this anomaly a wide range of anatomic variation may exist, the essential features being the ventricular septal defect, which is usually large, and the pulmonie stenosis or obstruction of the outflow tract of the right ventric|e. Since the right ventricular systolic pressure is similar to the systemic arterial pressure a right-to-left shunt occurs through the ventricular defect. The physiologic effects of the malformation are shown on lateral angiograms in figure 1: during systole, obstnlction of the right ventricular outflow tract is present and there is right-to-left shunting through the ventricular septal defect and into the aorta; during diastole, widening of the infundibulum occurs. Clinical Picture and Course
In patients with cyanotic congenital heart disease, tetralogy of Fallot represents the most common lesion in those who survive beyond infancy. The time of initial appearance of cyanosis, however, is variable: as summarized by Nadas, approximately one-third the patients show cyanosis at birth, onethird exhibit cyanosis between 1 month and 1 year of age, and the remainder do not manifest arterial oxygen desaturation until well after the first year of life. 4 Clubbing of the digits eventually accompanies the cyanosis. From the Departments of Pediatrics and Surgery of the Columbia Uravers~ College of Physicians and Surgeons, and the Babies and Presbyterian Hospitals, New York, New York. This work was supported in part blr the Health Research Council of the City of New York, 1-289 (S. P. G.) and the ]ohn A. Hartford Foundation, Inc.
64 PI~OGRESSIN CARDIOVASCULARDISEASES,VOL.8, NO. 1 (JULY), 1965
.NIEDICAL
I'ROBLE.~S
:: ii:/::(ii!~'
IN
TETRALOGY
OF
FALLOT
65
::9 ::i, ::i:~,::i~i~ii:i~:,:i~i~iiii::!i;J:
9
9
9 ...
..;~.~'~.;,,i~?~!~?~!~!~.:.~!~:~i:/.: .~:..:}:i.........~. ... !..!:.:.:.:::..:./ : ...... :.. 9
:
.:.
9
....
.9:::;.~:::. ~..:: i.!.::..:..: :.~..:
9.:.:~. . . . . .
.
:i:.i:.~:.:
........
~ . . . .
.....::~:..:..::... . . . . .
....~,......
.:.
..
9
Fig. 1.--Selective angiograms in lateral view in systole and diastole showing right-to-left shunt through the ventricular septal defect and into the aorta. The marked change in the diameter of the outflow tract at the level of the infundibulum clearly demonstrates the functional obstruction during systole. Puhnonary valvular stenosis is also visualized. Inf. sten, infimdibular stenosisi PV, pulmonary valve; PA, pulmonary artery, Ao, aorta. Physical examination reveals a systolic thrill and murmur, usually grade 3/6 or louder, which is maximal at the mid to low left sternal border. The murmur is stenotic in character and is related to the right ventricular or pulmonary obstruction. In the patients with the most severe obstruction, or pulmonary atresia, no mm'mur may be audible. The second sound at the pulmonary area is diminished or absent; a single, loud second sound, corresponding to aortie valve closure, may be heard at the low left sternal border. Chest roentgenograms reveal a small heart with elevation of the apex, or right ventricular enlargement, and diminished pulmonary vascular markings. Electrocardiograms indicate right axis deviation and right ventricular hypertrophy. Symptoms may become manifest in infancy with exertional dyspnea, squatting, or hypoxic spells. The severity of distress in infancy may be exaggerated by the presence of a relative anemia the treatment of which with iron or blood transfusion often results in marked improvement in clinical status. Limitation of exercise is the most conspicuous symptom in childhood and early adult life and varies from inability to walk half a block to tolerance for a mile or more. Congestive heart failure does not occur except in infants with associated pulmonary atresia or in patients who acquire bacterial endoearditis. Cerebral complications, which include thrombosis, embolism, or profound anoxia, may be life threatening or terminal..Most patients with the tetralogy die before the end of the second decade, though a few have lived into the fourth decade and beyond.
66
GRIFFITHS AND MAL1V[
Indications [or Surgery The selection of patients with tetralogy of Fallot for open heart surgery should be made on the basis of age, severity of symptoms, and anatomy of the anomaly. At the present time, elective primary repair of the malformation is recommended in cyanotic patients over the age of 5 years; more particularly, total correction should be deferred until the age of approximately 8 to 12 years if the child is able to attend school regularly. A palliative shunting procedure, namely a subclavian to pulmonary artery anastomosis (BlalockTaussig), is recommended in all severely symptomatic infants and children under 5 years of age. A previously constructed Blalock-Taussig shunt does not increase the operative risk of total correction. The presence, however, of a direct aortic to pulmonary arterial anastomosis (Potts) poses more of a problem from the standpoint of (1) liability to produce pulmonary hypertension, and (2) technical difficulty in taking down the shunt at the time of open heart surgery. It is unlikely that the balance between the ventricular shunt and t h e constructed systemic-pulmonary artery shunt will sustain a normal life expectancy;~,6 hence, total correction of the anomaly should be planned prior to the end of the second decade. Cardiovascular studies should be scheduled by the cardiologist when the patient with the tetralogy is considered a candidate for primary repair. Venous angiograms or studies carried out in infancy or early childhood may be i n adequate for clear delineation of the anatomic abnormality so that further examinatien is indicated. Selective biplane angiocardiography performed from the right ventricle in conjunction with cardiac Catheterization provides the most useful information. The type and extent of obstruction of the right ventricular outflow tract is the most variable feature of this anomaly and influences the completeness of the surgical repair that can be anticipated. The anatomic obstruction can be classified into 5 types which are diagrammatically illustrated in figure 2: (1) infundibular muscle hypertrophy is the most common single obstruction to pulmonary blood flow; (2) pulmonic valvular stenosis is the second most common obstruction and is always accompanied by a significant degree of infundibular stenosis; (3) narrowing or fibrosis of the pulmonary annulus may be present in some patients with valvular pulmonic stenosis and results in a fixed rigid diameter; (4) narrowing or stenosis of the main pulmonary artery is less commonly encountered, but may occur in combination with either infundibular or valvular stenosis; and (5) atresia of the pulmonary artery represents the most severe form of obstruction, the pulmonary blood flow being sustained by an associated patent ductus arteriosus. In the last 3 types (No. 3-5) usually reconstruction of the right ventricnlar outflow tract with a prosthetic graft is required, and pulmonary valvular insufficiency is an invariable result. A limiting factor in the completeness of the repair of the outflow tract may be the presence of an anomalous right coronary artery, often visualized on angiocardiogram, which crosses the site of ventriculotomy and may impede the surgical resection of the infundibular hypertrophic muscle.
MEDICAL FROBLEMS IN TETRALOGY OF FALLOT
~7
The cardiologist and cardiovascular surgeon should review the catheterization and angiographic data with the laboratory staff, including the radiologist, who performed the studies. If open heart surgery is indicated, it is the responsibility of the physician and the surgeon, separately or together; to discuss with the patient's family the risks of the procedure and the postoperative results that can be anticipated from a knowledge of the anatomic abnormalities. Operative mortality, including late deaths, is estimated at 10 per cent or less (in our experience with 85 consecutive patients with tetralogy of Fallot, 8 deaths have occurred).2'r Good to excellent hemodynamie results can be expected in most patients postoperatively. (See Follow-up and Evaluation).
Preoperative Care Since fresh heparinized whole blood is utilized during eardiopulmonary bypass for all patients with tetralogy of Fallot, certain blood requirements are imposed which are not necessary for patients with acyanotic types of heart disease. Blood and donor typing should be done several weeks prior to surgery. Compatibility in major and minor blood groups including D, C, E, c, and Kell factors must be checked. The patient is admitted to the surgical service 3 days before operation. It is the cardiologist's responsibility to ascertain that the patient is free of infection and has not been exposed to contagious diseases (a not infrequent problem in tile pediatric age group), and that the laboratory data are satisfactory. The determinations and examinations routinely obtained on the patient, besides a complete blood count and urinalysis, include: hematocrit, platelet count, prothrombin time, serum potassium, sodium, chlorides, and carbon dioxide, blood urea nitrogen, chest roentgenogram, and electrocardiogram. Measurements of height and weight are recorded to calculate body surface area which is used as reference (1) during cardiopulmonary bypass in establishing flow rate, and (2) postoperatively in parenteral fluid prescription. Psychologic preparation of the patient and his family should be initiated when the decision is made for surgery. Since many of the patients have had years of medical follow-up and are well known to the cardiologist, he may expect to be responsible for this aspect of management. Further support from the surgeon may be indicated in the immediate preoperative period. At this time a visit from one of the nurses in the recovery room is arranged so that the patient may learn what to expect on awakening from anesthesia and how he will be cared for postoperatively.
Operative Period Cardiopulmonary bypass is employed utilizing a disc oxygeuator primed with heparinized blood and low molecular weight dextran. Flow rates between 2,000 and 2,400 ml./M~ and hypothermia to 28 C are utilized. Perfusion time averages 90 minutes. The conduct of the operation is monitored by the electrocardiogram and
68
GlqlFFITIIS
...
~-'~IAL3I
'..
9 ;..:.. :i: .: :.:.:....
".
9..~':iiii.:i.li:.:i i~~- .,,.....i!.i;. put :. ::~ A nnulus~ 9 : ..,~ ~ . ; ~
AND
"~
9149149
. ~--- ..ii:"...:.:.
!
;i:
"
- . . . . . - . ,Z -. :"
- : ' ~ i : .
'~c.9~-.q/,W.~;
'
~7; Fig. 2.--See legend oil facing
" page.
venous and systemic blood pressures. These parameters are invaluable to the surgeon who is responsible for their interpretation. The arterial blood acid-base status (pH, CO,, and base excess) in the immediate preperfusion period is assessed) Correction of any metabolic acidosis at this point or during extraeorporeal circulation can be carried out by the quantitative titration with 0.3 M Tris (hydroxymethyl) amino methane
MEDICAL PBOBLEMS IN TETRALOGY OF FALLOT
69
Fig. 2.--Diagrammatic illustration of range of right ventricular and pulmonary artery obstruction in tetralogy of Fallot: (1) infundibular stenosis, (2) pulmonary valvular stenosis, (3) fibrosis of pulmonary annulus, (4) peripheral pulmonary artery stenosis, and (5) pulmonary atresia. RV, right venta'icle; Ao, aorta; PA, pulmonary artery; VSD, ventricular septal defect; CSV, crista supraventrieularis. (THAM).9 After completion of bypass, acid-base status is again determined and additional THAM given if necessary. A simple derived formula for the administration of THAM is: Milliliters of 0.3 THAM ---- negative base excess ( m E q . / L . ) x body weight (Kg.)
Most patients managed in this manner demonstrate no significant metabolic acidosis during the immediate postoperative period unless problems in the operating room have required prolonged cardiopulmonary bypass. Upon completion of total correction, direct measurement is made of the right ventricular and pulmonary artery pressures. A systolic pressure gradient above 40 mm. Hg indicates that additional reconstruction is required to insure a satisfactory hemodynamic outcome. It is essential that a complete anatomic and physiologic correction be can'ied out. Major complications during the postoperative period are usually related to unsatisfactory repair. The presence of the cardiologist in the operating room or gallery is that of an interested spectator; he should know tile anatomic findings and the nature of the repair in order to anticipate the postoperative course.
Postoperative Care Immediately on discharge from the operating room, the patient is best managed in a specialized intensive care area or recovery room restricted to
70
GRIFFITIIS AND MALzNI
cardiac surgical cases. This unit should be equipped with all supportive mechanical aids such as oxygen-humidity tents, respirators, pacemaker units, and bedside stretcher seale. A permanent assignment nursing staff insures optimal patient eare. The patient is placed in a high humidity oxygen tent for 48 hours postoperatively. Monitoring of the electrocardiogram, blood pressure, blood gases, and chemistries are carried out but the findings are usually not significantly abnormal or useful in the routine management of patients without complications. The electrocardiogram is continuously monitored for 2 to 3 days after which it is discontinued if no problem with arrhythmia is manifest. Arterial blood gases (oxygen saturation, pCO2), pH, and base excess are determined on arrival in the recovery room and again 4 hours later. An indwelling catheter in the femoral vein permits blood sampling and venous pressure determinations. The hematocrit is checked at frequent intervals in the first 18 hours following surgery. Urine output is measured hourly from an indwelling catheter for the first 48 hours. A flow sheet at the bedside is useful for recording fluids administered, blood losses, urine output, daily weight, and laboratory determinations. Fluids are administered intravenously for 48 hours in the amount of 500 ml./M~/24 hours with urinary volume losses added to the fluid prescription with 5 per eent dextrose in water at 12-hour intervals. Sodium is supplied in the amount of 50 reg./M2/24 hours. Potassium, 40 reg./M2/24 hours, is administered if the serum potassium is below 4.0 mEq./L. Blood loss is replaced volume for volume according to amounts withdrawn for laboratory determinations and drainage from the chest. Oral fluids are started on the second day with gradual progression to a regular low sodium (500 rag.) diet by the fourth day. Antibiotics are given parenterally with aqueous penicillin 10 million units/ day intravenously, for the first 48 hours, and 1-2 million units/day intramuscularly for the next 8 days. Streptomycin (20 mg./Kg, day) is prescribed for 5 days. Gamma globulin is administered immediately postoperatively as prophylaxis against serum hepatitis: a single dose of 0.02 ml./Kg, is given to a child or a total of 10 ml. to an adult, a~ Sedation with Demerol is given as needed beginning in the immediate postoperative period. Ambulation is started on the seventh day when the patient usually leaves the recovery room, and may be ad lib' by the fourteenth day. Strenuous exertion or playing is restricted for 6 weeks postoperatively.
Management of Complications The cardiologist participates with the surgeon in the care of those few patients who experience postoperative complications. Most of the problems following repair of tetralogy of Fallot are not unique to this anomaly but are potential risks of cardiotomy employing technics of eardiopulmonary bypass. In some respects, patients with tetralogy of Fallot represent especially favorable candidates for open heart surgery because most of them have had good
MEDICAL PROBLEIV~S IN TETRALOGY OF F A L L O T
71
myocardial function and have never required digitalis or other cardiotonic drugs. Furthermore, postoperative problems associated with pulmonary hypertension in other congenital malformations are obviously not encountered. Congestive Heart Failure: This complication may be regarded as inherent in the repair of the tetralogy in a small number of patients. The development of right-sided heart failure, which is usually mild, is predictable in 2 circumstances in which surgical correction has not resulted in optimal hemodynamics: (1) presence of an outflow patch across the pulmonary valve resulting in pulmonary valvular insufficiency, or (2) incomplete surgical relief of outflow tract obstruction resulting in a significant gradient between the body of the right ventricle and the pulmonary artery. Recognition of right-sided heart failure following surgery is often fraught with difficulties because neck vein distention and hepatomegaly are difficult to evaluate especially in children. Elevated central venous pressure recorded from an indwelling catheter through the femoral vein has been the most helpful index for diagnosis. Venous pressure measurements of 150 to 200 ram. H20 are common in the first 8 hours postoperatively; higher values would be of special concern. Digitalization of patients with surgically acquired pulmonary valvular insufficiency is usually begun in the first 4 hours postoperatively, whereas in patients with a residual gradient the digitalization may not be started until the third or fourth postoperative day. A rapidly utilized, rapidly excreted drug, digoxin, available for parenteral administration, is satisfactory in this situation. Acute digitalization can be achieved and controlled for maintenance. In children, the calculated digitalizing dose is 0.05 mg./Kg.: one-third the dose is given intramuscularly at once and the remainder administered in 12 to 14 hours depending upon the urgency of the situation; maintenance therapy is given orally or by the intramuscular route as one-third the total digitalizing dose. Since the most common manifestation of digitalis intoxication in children is arrhythmia, eareful electrocardiographic monitoring is indicated during this period. Most of the patients with pulmonary insufficiency are maintained on digoxin for 4 to 6 months postoperatively, whereas those with residual obstruction are usually compensated without digoxin by the sixth to eighth postoperative week. Arrhythmia: In the first few hours or days postoperatively transient arrhythmias occasionally appear in these patients as well as in others subjected to open heart surgery. The factors implicated include surgical trauma, acidosis, electrolyte imbalance, hypoxia, and hypothermia. Nodal or His bundle rhythms are not uncommon and are probably due to trauma in the region of the A-V node. Spontaneous reversion essentially always occurs in these patients so that even with so-called "nodal tachycardia" the duration of rapid heart rate has not been sufficient to cause cardiac decompensation. Since right bundle-branch block patterns invariably ensue following repair of the ventricular defect in tetralogy of Fallot, it may sometimes be difficult to distinguish between aberrant ventricular conduction and ventricular tachycardia in the presence of a rapid rate. If frequent ventricular premature systoles are noted in the absence of advanced atrioventricular block, quinidine or procaine amide may be in-
72
G R I F F I T H S AND MAL.-'VI
dicated. When these drugs are employed the patient's blood pressure should be frequently checked since electrocardiographic evidence of toxicity may be difficult to determine. Complete atrioventricular block is rare and has occurred in only 2 of our 85 patients following repair of tetralogy of Fallot. If complete heart block is noted while the patient is still on the operating table, an electrode lead wire is implanted into the epicardium of the right ventricle and another is inserted subcutaneously for external pacemaker control. Isoproterenol may be used as adiunctive therapy but cannot be relied upon alone for maintenance in the early postoperative period or for long-term management. If the heart block appears to be permanent, particularly with an idioventricular rhythm, it is recommended that an internal cardiac pacemaker be implanted before the patient is discharged from the hospital. 12 Bleeding: Preoperative studies on the clotting mechanism in patients with the tetralogy have shown no consistent alteration though fibrinogen levels are frequently low (in the range of 150 to 250 mg./100 ml. as opposed to the normal of 200 to 400 mg./100 ml.) and have no correlation to postoperative bleeding problems. Extensive collateral circulation to the lungs is encountered in many patients with tetralogy of Fallot, especially in adolescents and young adults following previous palliative surgery, and poses need for extra surgical care in securing hemostasis. Extracorporeal circulation presents a special problem in hemostasis associated with heparin. 1:~ If neutralization of heparin is incomplete with the use of protamine sulfate, in normally required doses, the drug may be safely increased in amounts up to 30 per cent of the original calculated dose. n Excessive protamine acts as an activator of the fibrinolytic system and additional dosages should be determined by protamine titration. Postoperative bleeding in excess of 500 ml./M"/hour is usually a result of (1) insecure hemostasis, or (2) coagulation defect. Prior to reexploration, laboratory studies should be done to rule out a coagulation defect and should include: (1) venous clotting time; (2) partial thromboplastin time; (3) prothrombin time; and (4) fibrinogen. 13,14 Abnormalities of the partial thrumboplastin time respond to replacement of labile factors (i.e., factors V and VIII) by fresh blood. Vitamin K is prescribed for a prolonged prothrombin time. A low fibrinogen level (less than 150 to 175 mg./100 ml.) associated with bleeding indicates an active fibrinolysis and the prompt administration of fibrinogen (initial dose 4 Gm. in adults) is necessary. The use of epsilonaminocaprolc acid or trasyol appears warranted but the final role of these agents in the treatment of fibrinolysis is unsettled. ~,1~ Oliguria: Postoperative oliguria (urine flow less than 15 to 20 ml./hour) most commonly results from hypotension. If adequate whole blood replacement does not correct the situation, low cardiac output as a consquence of incomplete surgical repair should be suspected. Renal function will not improve unless cardiac function is improved. Under these circumstances the administration of base is indicated since metabolic acidosis (base excess over - 4 mEq./L.) is usually present and progressive. Sodium bicarbonate is the base
MEDICAL PROBLEMS
IN T E T R A L O G Y O F F A L L O T
73
of choice during the postoperative period, for THAM may depress the respiratory cen,ter. Simple oliguria may respond to a water load of 100 m]. of 5 per cent dextrose in water/M 2 given over a 10 to 15 minute period when blood pressure is stable and urinary flow is patent: an increase in urine flow indicates inadequate hydration and additional water in the fluid prescription is necessary. Reversible functional renal failure often precedes organic renal failure. If acute renal failure occurs following the use of incompatible blood or from progressive functional failure, a renal shut-down regimen should be initiated.16,1r Postpericardiotomy Syndrome: In contrast to the potential problems described above, which usually occur within the first 3 postoperative days, postpericardiotomy syndrome may be manifest near the end of the second week38 Electrocardiographic evidence of pericardial inflammation in the absence of digitalis therapy may be seen as deviations in the ST segment and T wave from the fourth day onwards. The frequency with which these changes are noted is probably directly related to the extent of electrocardiographic monitoring. It is not uncommon to hear a perieardial friction rub, especially over the lower preeordium between the apex and the midline sternotomy sear. The appearance of fever after antibiotics have been discontinued on the tenth day is of concern and suggests a diagnosis of postpericardiotomy syndrome. Most frequently the temperature is elevated to around 101 to 102 F and there may be associated subjective complaints of chest or shoulder pain. Splenomegaly may be noted as well as abnormal lymphoeytes in the peripheral blood smear. Although this entity may be clinically suspected, suffleient blood cultures should be obtained to exclude bacterial or myeotiq endocarditis. In most patients postpericardiotomy syndrome is self-limitod after 4 or 5 days and requires no specific therapy though ambulation should be restricted. If, however, fever is persistent, the patient is placed on salieylates in the dosage of 100 Gm./Kg./24 hours, for a period of about 5 days. No recurrences of postpericardiotomy syndrome have been encountered following hospital discharge.
Follow-up and Evaluation After the patient has been discharged from the hospital, usually about 2% to 3 weeks following open heart surgery, full activity is allowed for daily living, but strenuous exertion and sports should be restricted. He is reexamined by the cardiovascular surgeon in 1 months' time, and then his progress and rehabilitation is usually checked by the cardiologist. If the patient is on digitalis maintenance therapy, the cardiologist is responsible for its cessation. By the end o.f the sixth postoperative month, most patients are allowed to engage in unrestricted activity. Physical examination in these patients reveals a systolic murmur, grade 1-3/6 in intensity, which is rough to mildly harsh and maximal at the mid to upper left sternal border. There is no predictable relationship between auscultation of loud murmurs and the presence or absence of a small residual gradient or shunt, ag~ In the patient who acquires pulmonary valvular in suf-
74
CRIFFITIIS
PULMONIC
AND
INSUFFICIENCY
I,
P.C., 9'/2 YEARS, MALE
-#6-216
2-13-62 0.4
z
= SM
PHONO -
j....... i.....~.
..~ +r(.m ......
CARDIOGRAM,, mm Hg
I ...... +~.r. . . . .
L" "
/VIALlk~
LJ,~ _,i ..... +P ' " r " " r r ' ' r ' + "
9
=
DM
SM
l+~t++L_ "Ip'~ ....
SIC
I
I
DM
,.t~.,.._., ~ m m , , ,~ill,,.....,.~ m~~ & +y~: I ~ " . . . . . . i," r f r r . . . . .
k .... )+. . . . . .
,, j ' , , l . . }+m+m"- . . . .
" ,e-- PA
RV - - ~
~
/~
Fig. 3.--Phonocardiogram from the second left intercostal space indicating crescendo-decrescendo diastolic murmur (DM) postoperatively in patient with
pulmonary valvular insufficiency. A low amplitude systolic murmur (SM) is also noted. The tracing was recorded during withdrawal of intracardiac catheter from pnlmonary artery to right ventricle. 9,. i:: ,..i.,
.i 84i .~-..
,.-).i! I, i ~..I.I!A r !-.. ~:i
i!~i,,~J~,
+
~:.i:!..!:i.i... ! :.:i:...:::~, !.. ~;!t. i;!iiiihii!::~ili .l ; :!;;L
'~
"I
' ......... i +
Pre -Op
I0 days
9
:
+
P
9
5 weeks
i
9months
Fig. 4.--Electrocardiographic follow-up with selected leads (I, aVR and V1) in a 10 year old boy. (1) Preoperative tracing, right axis deviation and right ventricular hypertrophy; (2) 10 days postoperative, complete right bundle branch block; (3) 5 weeks postoperative, intermittent RBBB in V1; and (4) 9 months postoperative, normal conduction time and axis. Leads I and aVR are simultaneously recorded at full standardization; lead Vx is recorded at 1/2 standardization. ficiency, a short, early, low-pitched diastolic murmur is audible in the second left intercostal space. This murmur is illustrated in figure 3 on a phonecardiogram recorded during postoperative cardiac catheterization in a-patient with an outflow tract prosthesis and pulmonary insufficiency. Radiologic evaluation of patients following complete surgical repair indicates the over-all heart size to be normal in the posteroanterior film, i.e., similar to the preoperative picture. In the lateral view, there may be some increase in the posterior projection of the heart in the area of the left atrium and left ventricle,s An increased prominence of the peripheral pulmonary
MEDICAL PROBLEMS IN TETRALOGY OF FALLOT
75
Fig. 5.--Postoperative lateral angiogram showing position of an outflow patch across pulmonary valve resulting in pulmonary valvular insufficiency. The prosthesis was required because of peripheral pulmonary artery stenosis. vascular markings is also evident. Any significant increase in cardiac size postoperatively suggests the presence of a residual anatomic defect. The electrocardiogram usually shows an incomplete or complete right bundle branch block pattern (QRS duration 0.12 sec. or more). Follow-up tracings in one patient with tetralogy of Fallot, however, who had right axis deviation and right vcntricular hypertrophy preoperatively, and who acquired complete right bundle branch block immediately postoperatively, revealed an essentially normal electrocardiogram 9 months later (fig. 4). The electrocardiogram is still within normal limits 31/2 years following surgery. No late complications or unexpected infections have been encountered following open heart surgery in our series. It may be noted, however, that one death occurred 6 months postoperatively with Aspergillus endocarditis. 2 Prophylaxis against bacterial endocarditis should be carried out with suitable antibiotics prior to dental or other surgery in patients who have had total correction of tetralogy of Fallot. All living patients in our series are clinically improved with normal or
76
GBIFI, TI'I-IS A N D M A L M
Table 1.--Results of Postoperative Catheterization in 47 Patients with Tetralogy of FaUot H e m o d y n a m i c Result
Observations
No. P a t i e n t s
30
Excellent
No residual shunt and a right ventricle to pulmonary artery gradient less than 20 ram. Hg Good
11 Gradient of 20-50 mm. Hg Small L-B shunt (QPa/QS 1.5/1) Pulmonary valvular insulficiency Small gradient and small L-R shunt
(3) (5) (2) 1)
Gradient of 50 ram. Hg and L-R shunt (2.0/1) Heart block Pulmonary hypertension Late deaths
1) 1) (2) (2)
Poor
m
Total
47
QPa/QS, ratio of pulmonary to systemic blood flow. L-R, left to right. nearly normal exercise tolerance. A physiologic and anatomic re-evaluation by cardiovascular study is, however, planned for all patients approximately 1 year following surgery. Selective angiocardiography from the right ventricle is carried out to visualize the repair of the outflow tract and/or pulmonary artery obstruction. Figure 5 illustrates by angiocardiogram the use of an extensive outflow patch for reconstruction of stenosis of the main pulmonary artery: pulmonary valvular insufficiency is produced as the prosthesis extends beyond the pulmonary valve. Surgically acquired pulmonary incompetence appears to be well tolerated clinically. Right heart and pulmonary artery pressures are measured both at rest and during exercise in addition to the determination of any residual gradient or shunting at the ventricular level. The postoperative catheterization data on 47 of the 85 patients with tetralogy are summarized in table I and categorized as excellent, good or poor: excellent, if there is no residual shunt and a residual right ventricle/pulmonary artery gradient less than 20 ram. Hg; good, if there is a small left-to-right shunt or a residual gradient of 20 to 50 ram. Hg; and poor, if a shunt and gradient are both present. These figures suggest that 41 of 47 patients (87 per cent) have normal or nearly normal hemodynamics. The importance of clinical follow-up in the evaluation of the long-term results of total correction of tetralogy of Fallot cannot be overemphasized. It is the responsibility of the cardiologist to continue observation of the patient so that assessment of the effects of surgical repair on cardiac performance and life-expectancy can be made38 REFERENCES
1. Maim, J. R.: Surgical treatment of retralogy of Fallot. In Cooper, P. (Ed.): The Craft of Surgery. Bos-
ton, Little, Brown and Company, 1964, pp. 520-530. 2. --, Bowman, F. O., Jr., Jameson, A. G.,
77
MEDICAL PROBLEMS IN TETRALOGY OF FALLOT
3.
4.
5.
6.
7.
8.
9.
1O.
11.
Ellis, K., Griffiths, S. P., and Blumenthal, S.: An evaluation of total correction of tetralogy of Fallot. Circulation 27:805, 1963, . . . . and Blumenthal, S.: Current concepts in treatment of tetralogy of Fallot. Dis. Chest 45:86, 1964. Nadas, A. S.: Pediatric Cardiology. Philadelphia, W. B. Saunders, 2nd ed. 1963, pp. 638-662. Paul, M., Miller, R. A., and Potts, W. J.: Long-term results of aortic pulmonary anastomosis for tetralogy of Fallot. An analysis of the first 100 cases eleven to thirteen years after operation. Circulation 23:525, 1961. Taussig, H. B., Crawford, H., Pelargonio, S., and Zacharioudakis, S.: Ten to thirteen year follow-up on patients after a Blalock-Taussig operation. Circulation 25:630, 1962. Kay, E. B., Nogueira, C,, Mendelsohn, D., Jr., and Zimmerman, H. A.: Corrective surgery for tetralogy of Fallot. Circulation 24:1342, 1961. Anderson, O. S., and Engel, K.: A new acid-base nomogram. Scandinav. J. Clin. & Lab. Invest. 12:177, 1960. Maim, J. R., Sullivan, S. F., Patterson, R. W., Bowman, F. O., Jr., and Nahas, G. S.: Effect of THAM on urine flow during extra-corporeal circulation. S. Forum 14:107-108, 1963. Allen, J. G..: Immunization against serum hepatitis from blood transfusion. Ann. Surg. 160:752, 1964. Humphreys, G. H., II, Blumenthal, S., Bowman, F. O., Jr., Malm, J. R., Singer, D. H., and Sullivan, S. F.: hnmediate complications of thoracot-
12.
13.
14.
15.
16.
17.
18.
19,
20.
omy for heart disease. S. Clin. North America 44:335, 1964. McGoon, D. C., Ongley, P. A., and Kirklin, J. W.: Surgical heart block. Am. J. Med. 37:749, 1964. Phillips, L. L., Maim, J. R., and Deterling, R. A., Jr.: Coagulation defects following extra-corporeal circulation. Ann. Surg. 157:317, 1963. Nye, S. W., Graham, J. B., and Brinhous, K. M.: The partial thromboplastin time as a screening test for the detection of late bleeders. Am. J. M. Sci. 243:279, 1962. Gans, H., and Krinit, W.: Problems in hemostasis during open heart surgery. Epsilonaminocaproic acid as an inhibitor of plasminogen activation activity. Ann. Surg. 155:268, 1962. Barry, K. G., and Malloy, J. P.: Oligttric renal failure. J. A. M. A. 179:510, 1962. Doberneck, R. C., Reiser, P. M., and Lillehei, C. W.: Acute renal failure after open heart surgery utilizing extra-corporeal circulation and total body peffusion. J. Thoracic & Cardiovasc. Surg.. 43:441, 1962. Engle, M. A., and Ito, T.: The postpericardiotomy syndrome. Am. J. Cardiol. 7:73, 1961. Allison, P. R., Gunning, A. J.: Hamill, J., and Mody, S. M.: Fallot's tetralogy: a post-operative study. Circulation 28: 525, 1963. Albertal, G., Swan, H. J. C., and Kirklin, J. W.: Hemodynamic studies two weeks to six years after repair of tetralogy of Fallot. Circulation 29: 583, 1964.
Sylvia P. GriI~ths, M.D., Dept. of Pediatrics, Columbia University College of Physiciansand Surgeons, New York, N. Y. ]ames R. Malm, M.D., Dept. of Surgery, Columbia University College of Physicians and Surgeons, New York, N, Y.
N THE REHABILITATION of patients with congenital heart disease, probably the most exciting achievement is total surgical correction of the tetralogy of Fallot. Complete management of the patient for whom surgical repair of this anomaly is planned requires close cooperation between the cardiologist (pediatric or medical) and the cardiovascular surgeon. This basic team approach should begin with the consideration of the indications for surgery and continue into the evaluation of postoperative status. The discussion presented here, with respect to case selection for surgery, management in the preoperative, operative and postoperative periods, and follow-up evaluation, is based on 5 years' experience with the tetralogy at the Columbia-Presbyterian Medical Center. v3
I
Definition
The tetralogy of Fallot consists of (1) ventricular septal defect, (2) pulmonic stenosis, (3) overriding of the aorta, and (4) hypertrophy of the right ventricle. It is apparent that in this anomaly a wide range of anatomic variation may exist, the essential features being the ventricular septal defect, which is usually large, and the pulmonie stenosis or obstruction of the outflow tract of the right ventric|e. Since the right ventricular systolic pressure is similar to the systemic arterial pressure a right-to-left shunt occurs through the ventricular defect. The physiologic effects of the malformation are shown on lateral angiograms in figure 1: during systole, obstnlction of the right ventricular outflow tract is present and there is right-to-left shunting through the ventricular septal defect and into the aorta; during diastole, widening of the infundibulum occurs. Clinical Picture and Course
In patients with cyanotic congenital heart disease, tetralogy of Fallot represents the most common lesion in those who survive beyond infancy. The time of initial appearance of cyanosis, however, is variable: as summarized by Nadas, approximately one-third the patients show cyanosis at birth, onethird exhibit cyanosis between 1 month and 1 year of age, and the remainder do not manifest arterial oxygen desaturation until well after the first year of life. 4 Clubbing of the digits eventually accompanies the cyanosis. From the Departments of Pediatrics and Surgery of the Columbia Uravers~ College of Physicians and Surgeons, and the Babies and Presbyterian Hospitals, New York, New York. This work was supported in part blr the Health Research Council of the City of New York, 1-289 (S. P. G.) and the ]ohn A. Hartford Foundation, Inc.
64 PI~OGRESSIN CARDIOVASCULARDISEASES,VOL.8, NO. 1 (JULY), 1965
.NIEDICAL
I'ROBLE.~S
:: ii:/::(ii!~'
IN
TETRALOGY
OF
FALLOT
65
::9 ::i, ::i:~,::i~i~ii:i~:,:i~i~iiii::!i;J:
9
9
9 ...
..;~.~'~.;,,i~?~!~?~!~!~.:.~!~:~i:/.: .~:..:}:i.........~. ... !..!:.:.:.:::..:./ : ...... :.. 9
:
.:.
9
....
.9:::;.~:::. ~..:: i.!.::..:..: :.~..:
9.:.:~. . . . . .
.
:i:.i:.~:.:
........
~ . . . .
.....::~:..:..::... . . . . .
....~,......
.:.
..
9
Fig. 1.--Selective angiograms in lateral view in systole and diastole showing right-to-left shunt through the ventricular septal defect and into the aorta. The marked change in the diameter of the outflow tract at the level of the infundibulum clearly demonstrates the functional obstruction during systole. Puhnonary valvular stenosis is also visualized. Inf. sten, infimdibular stenosisi PV, pulmonary valve; PA, pulmonary artery, Ao, aorta. Physical examination reveals a systolic thrill and murmur, usually grade 3/6 or louder, which is maximal at the mid to low left sternal border. The murmur is stenotic in character and is related to the right ventricular or pulmonary obstruction. In the patients with the most severe obstruction, or pulmonary atresia, no mm'mur may be audible. The second sound at the pulmonary area is diminished or absent; a single, loud second sound, corresponding to aortie valve closure, may be heard at the low left sternal border. Chest roentgenograms reveal a small heart with elevation of the apex, or right ventricular enlargement, and diminished pulmonary vascular markings. Electrocardiograms indicate right axis deviation and right ventricular hypertrophy. Symptoms may become manifest in infancy with exertional dyspnea, squatting, or hypoxic spells. The severity of distress in infancy may be exaggerated by the presence of a relative anemia the treatment of which with iron or blood transfusion often results in marked improvement in clinical status. Limitation of exercise is the most conspicuous symptom in childhood and early adult life and varies from inability to walk half a block to tolerance for a mile or more. Congestive heart failure does not occur except in infants with associated pulmonary atresia or in patients who acquire bacterial endoearditis. Cerebral complications, which include thrombosis, embolism, or profound anoxia, may be life threatening or terminal..Most patients with the tetralogy die before the end of the second decade, though a few have lived into the fourth decade and beyond.
66
GRIFFITHS AND MAL1V[
Indications [or Surgery The selection of patients with tetralogy of Fallot for open heart surgery should be made on the basis of age, severity of symptoms, and anatomy of the anomaly. At the present time, elective primary repair of the malformation is recommended in cyanotic patients over the age of 5 years; more particularly, total correction should be deferred until the age of approximately 8 to 12 years if the child is able to attend school regularly. A palliative shunting procedure, namely a subclavian to pulmonary artery anastomosis (BlalockTaussig), is recommended in all severely symptomatic infants and children under 5 years of age. A previously constructed Blalock-Taussig shunt does not increase the operative risk of total correction. The presence, however, of a direct aortic to pulmonary arterial anastomosis (Potts) poses more of a problem from the standpoint of (1) liability to produce pulmonary hypertension, and (2) technical difficulty in taking down the shunt at the time of open heart surgery. It is unlikely that the balance between the ventricular shunt and t h e constructed systemic-pulmonary artery shunt will sustain a normal life expectancy;~,6 hence, total correction of the anomaly should be planned prior to the end of the second decade. Cardiovascular studies should be scheduled by the cardiologist when the patient with the tetralogy is considered a candidate for primary repair. Venous angiograms or studies carried out in infancy or early childhood may be i n adequate for clear delineation of the anatomic abnormality so that further examinatien is indicated. Selective biplane angiocardiography performed from the right ventricle in conjunction with cardiac Catheterization provides the most useful information. The type and extent of obstruction of the right ventricular outflow tract is the most variable feature of this anomaly and influences the completeness of the surgical repair that can be anticipated. The anatomic obstruction can be classified into 5 types which are diagrammatically illustrated in figure 2: (1) infundibular muscle hypertrophy is the most common single obstruction to pulmonary blood flow; (2) pulmonic valvular stenosis is the second most common obstruction and is always accompanied by a significant degree of infundibular stenosis; (3) narrowing or fibrosis of the pulmonary annulus may be present in some patients with valvular pulmonic stenosis and results in a fixed rigid diameter; (4) narrowing or stenosis of the main pulmonary artery is less commonly encountered, but may occur in combination with either infundibular or valvular stenosis; and (5) atresia of the pulmonary artery represents the most severe form of obstruction, the pulmonary blood flow being sustained by an associated patent ductus arteriosus. In the last 3 types (No. 3-5) usually reconstruction of the right ventricnlar outflow tract with a prosthetic graft is required, and pulmonary valvular insufficiency is an invariable result. A limiting factor in the completeness of the repair of the outflow tract may be the presence of an anomalous right coronary artery, often visualized on angiocardiogram, which crosses the site of ventriculotomy and may impede the surgical resection of the infundibular hypertrophic muscle.
MEDICAL FROBLEMS IN TETRALOGY OF FALLOT
~7
The cardiologist and cardiovascular surgeon should review the catheterization and angiographic data with the laboratory staff, including the radiologist, who performed the studies. If open heart surgery is indicated, it is the responsibility of the physician and the surgeon, separately or together; to discuss with the patient's family the risks of the procedure and the postoperative results that can be anticipated from a knowledge of the anatomic abnormalities. Operative mortality, including late deaths, is estimated at 10 per cent or less (in our experience with 85 consecutive patients with tetralogy of Fallot, 8 deaths have occurred).2'r Good to excellent hemodynamie results can be expected in most patients postoperatively. (See Follow-up and Evaluation).
Preoperative Care Since fresh heparinized whole blood is utilized during eardiopulmonary bypass for all patients with tetralogy of Fallot, certain blood requirements are imposed which are not necessary for patients with acyanotic types of heart disease. Blood and donor typing should be done several weeks prior to surgery. Compatibility in major and minor blood groups including D, C, E, c, and Kell factors must be checked. The patient is admitted to the surgical service 3 days before operation. It is the cardiologist's responsibility to ascertain that the patient is free of infection and has not been exposed to contagious diseases (a not infrequent problem in tile pediatric age group), and that the laboratory data are satisfactory. The determinations and examinations routinely obtained on the patient, besides a complete blood count and urinalysis, include: hematocrit, platelet count, prothrombin time, serum potassium, sodium, chlorides, and carbon dioxide, blood urea nitrogen, chest roentgenogram, and electrocardiogram. Measurements of height and weight are recorded to calculate body surface area which is used as reference (1) during cardiopulmonary bypass in establishing flow rate, and (2) postoperatively in parenteral fluid prescription. Psychologic preparation of the patient and his family should be initiated when the decision is made for surgery. Since many of the patients have had years of medical follow-up and are well known to the cardiologist, he may expect to be responsible for this aspect of management. Further support from the surgeon may be indicated in the immediate preoperative period. At this time a visit from one of the nurses in the recovery room is arranged so that the patient may learn what to expect on awakening from anesthesia and how he will be cared for postoperatively.
Operative Period Cardiopulmonary bypass is employed utilizing a disc oxygeuator primed with heparinized blood and low molecular weight dextran. Flow rates between 2,000 and 2,400 ml./M~ and hypothermia to 28 C are utilized. Perfusion time averages 90 minutes. The conduct of the operation is monitored by the electrocardiogram and
68
GlqlFFITIIS
...
~-'~IAL3I
'..
9 ;..:.. :i: .: :.:.:....
".
9..~':iiii.:i.li:.:i i~~- .,,.....i!.i;. put :. ::~ A nnulus~ 9 : ..,~ ~ . ; ~
AND
"~
9149149
. ~--- ..ii:"...:.:.
!
;i:
"
- . . . . . - . ,Z -. :"
- : ' ~ i : .
'~c.9~-.q/,W.~;
'
~7; Fig. 2.--See legend oil facing
" page.
venous and systemic blood pressures. These parameters are invaluable to the surgeon who is responsible for their interpretation. The arterial blood acid-base status (pH, CO,, and base excess) in the immediate preperfusion period is assessed) Correction of any metabolic acidosis at this point or during extraeorporeal circulation can be carried out by the quantitative titration with 0.3 M Tris (hydroxymethyl) amino methane
MEDICAL PBOBLEMS IN TETRALOGY OF FALLOT
69
Fig. 2.--Diagrammatic illustration of range of right ventricular and pulmonary artery obstruction in tetralogy of Fallot: (1) infundibular stenosis, (2) pulmonary valvular stenosis, (3) fibrosis of pulmonary annulus, (4) peripheral pulmonary artery stenosis, and (5) pulmonary atresia. RV, right venta'icle; Ao, aorta; PA, pulmonary artery; VSD, ventricular septal defect; CSV, crista supraventrieularis. (THAM).9 After completion of bypass, acid-base status is again determined and additional THAM given if necessary. A simple derived formula for the administration of THAM is: Milliliters of 0.3 THAM ---- negative base excess ( m E q . / L . ) x body weight (Kg.)
Most patients managed in this manner demonstrate no significant metabolic acidosis during the immediate postoperative period unless problems in the operating room have required prolonged cardiopulmonary bypass. Upon completion of total correction, direct measurement is made of the right ventricular and pulmonary artery pressures. A systolic pressure gradient above 40 mm. Hg indicates that additional reconstruction is required to insure a satisfactory hemodynamic outcome. It is essential that a complete anatomic and physiologic correction be can'ied out. Major complications during the postoperative period are usually related to unsatisfactory repair. The presence of the cardiologist in the operating room or gallery is that of an interested spectator; he should know tile anatomic findings and the nature of the repair in order to anticipate the postoperative course.
Postoperative Care Immediately on discharge from the operating room, the patient is best managed in a specialized intensive care area or recovery room restricted to
70
GRIFFITIIS AND MALzNI
cardiac surgical cases. This unit should be equipped with all supportive mechanical aids such as oxygen-humidity tents, respirators, pacemaker units, and bedside stretcher seale. A permanent assignment nursing staff insures optimal patient eare. The patient is placed in a high humidity oxygen tent for 48 hours postoperatively. Monitoring of the electrocardiogram, blood pressure, blood gases, and chemistries are carried out but the findings are usually not significantly abnormal or useful in the routine management of patients without complications. The electrocardiogram is continuously monitored for 2 to 3 days after which it is discontinued if no problem with arrhythmia is manifest. Arterial blood gases (oxygen saturation, pCO2), pH, and base excess are determined on arrival in the recovery room and again 4 hours later. An indwelling catheter in the femoral vein permits blood sampling and venous pressure determinations. The hematocrit is checked at frequent intervals in the first 18 hours following surgery. Urine output is measured hourly from an indwelling catheter for the first 48 hours. A flow sheet at the bedside is useful for recording fluids administered, blood losses, urine output, daily weight, and laboratory determinations. Fluids are administered intravenously for 48 hours in the amount of 500 ml./M~/24 hours with urinary volume losses added to the fluid prescription with 5 per eent dextrose in water at 12-hour intervals. Sodium is supplied in the amount of 50 reg./M2/24 hours. Potassium, 40 reg./M2/24 hours, is administered if the serum potassium is below 4.0 mEq./L. Blood loss is replaced volume for volume according to amounts withdrawn for laboratory determinations and drainage from the chest. Oral fluids are started on the second day with gradual progression to a regular low sodium (500 rag.) diet by the fourth day. Antibiotics are given parenterally with aqueous penicillin 10 million units/ day intravenously, for the first 48 hours, and 1-2 million units/day intramuscularly for the next 8 days. Streptomycin (20 mg./Kg, day) is prescribed for 5 days. Gamma globulin is administered immediately postoperatively as prophylaxis against serum hepatitis: a single dose of 0.02 ml./Kg, is given to a child or a total of 10 ml. to an adult, a~ Sedation with Demerol is given as needed beginning in the immediate postoperative period. Ambulation is started on the seventh day when the patient usually leaves the recovery room, and may be ad lib' by the fourteenth day. Strenuous exertion or playing is restricted for 6 weeks postoperatively.
Management of Complications The cardiologist participates with the surgeon in the care of those few patients who experience postoperative complications. Most of the problems following repair of tetralogy of Fallot are not unique to this anomaly but are potential risks of cardiotomy employing technics of eardiopulmonary bypass. In some respects, patients with tetralogy of Fallot represent especially favorable candidates for open heart surgery because most of them have had good
MEDICAL PROBLEIV~S IN TETRALOGY OF F A L L O T
71
myocardial function and have never required digitalis or other cardiotonic drugs. Furthermore, postoperative problems associated with pulmonary hypertension in other congenital malformations are obviously not encountered. Congestive Heart Failure: This complication may be regarded as inherent in the repair of the tetralogy in a small number of patients. The development of right-sided heart failure, which is usually mild, is predictable in 2 circumstances in which surgical correction has not resulted in optimal hemodynamics: (1) presence of an outflow patch across the pulmonary valve resulting in pulmonary valvular insufficiency, or (2) incomplete surgical relief of outflow tract obstruction resulting in a significant gradient between the body of the right ventricle and the pulmonary artery. Recognition of right-sided heart failure following surgery is often fraught with difficulties because neck vein distention and hepatomegaly are difficult to evaluate especially in children. Elevated central venous pressure recorded from an indwelling catheter through the femoral vein has been the most helpful index for diagnosis. Venous pressure measurements of 150 to 200 ram. H20 are common in the first 8 hours postoperatively; higher values would be of special concern. Digitalization of patients with surgically acquired pulmonary valvular insufficiency is usually begun in the first 4 hours postoperatively, whereas in patients with a residual gradient the digitalization may not be started until the third or fourth postoperative day. A rapidly utilized, rapidly excreted drug, digoxin, available for parenteral administration, is satisfactory in this situation. Acute digitalization can be achieved and controlled for maintenance. In children, the calculated digitalizing dose is 0.05 mg./Kg.: one-third the dose is given intramuscularly at once and the remainder administered in 12 to 14 hours depending upon the urgency of the situation; maintenance therapy is given orally or by the intramuscular route as one-third the total digitalizing dose. Since the most common manifestation of digitalis intoxication in children is arrhythmia, eareful electrocardiographic monitoring is indicated during this period. Most of the patients with pulmonary insufficiency are maintained on digoxin for 4 to 6 months postoperatively, whereas those with residual obstruction are usually compensated without digoxin by the sixth to eighth postoperative week. Arrhythmia: In the first few hours or days postoperatively transient arrhythmias occasionally appear in these patients as well as in others subjected to open heart surgery. The factors implicated include surgical trauma, acidosis, electrolyte imbalance, hypoxia, and hypothermia. Nodal or His bundle rhythms are not uncommon and are probably due to trauma in the region of the A-V node. Spontaneous reversion essentially always occurs in these patients so that even with so-called "nodal tachycardia" the duration of rapid heart rate has not been sufficient to cause cardiac decompensation. Since right bundle-branch block patterns invariably ensue following repair of the ventricular defect in tetralogy of Fallot, it may sometimes be difficult to distinguish between aberrant ventricular conduction and ventricular tachycardia in the presence of a rapid rate. If frequent ventricular premature systoles are noted in the absence of advanced atrioventricular block, quinidine or procaine amide may be in-
72
G R I F F I T H S AND MAL.-'VI
dicated. When these drugs are employed the patient's blood pressure should be frequently checked since electrocardiographic evidence of toxicity may be difficult to determine. Complete atrioventricular block is rare and has occurred in only 2 of our 85 patients following repair of tetralogy of Fallot. If complete heart block is noted while the patient is still on the operating table, an electrode lead wire is implanted into the epicardium of the right ventricle and another is inserted subcutaneously for external pacemaker control. Isoproterenol may be used as adiunctive therapy but cannot be relied upon alone for maintenance in the early postoperative period or for long-term management. If the heart block appears to be permanent, particularly with an idioventricular rhythm, it is recommended that an internal cardiac pacemaker be implanted before the patient is discharged from the hospital. 12 Bleeding: Preoperative studies on the clotting mechanism in patients with the tetralogy have shown no consistent alteration though fibrinogen levels are frequently low (in the range of 150 to 250 mg./100 ml. as opposed to the normal of 200 to 400 mg./100 ml.) and have no correlation to postoperative bleeding problems. Extensive collateral circulation to the lungs is encountered in many patients with tetralogy of Fallot, especially in adolescents and young adults following previous palliative surgery, and poses need for extra surgical care in securing hemostasis. Extracorporeal circulation presents a special problem in hemostasis associated with heparin. 1:~ If neutralization of heparin is incomplete with the use of protamine sulfate, in normally required doses, the drug may be safely increased in amounts up to 30 per cent of the original calculated dose. n Excessive protamine acts as an activator of the fibrinolytic system and additional dosages should be determined by protamine titration. Postoperative bleeding in excess of 500 ml./M"/hour is usually a result of (1) insecure hemostasis, or (2) coagulation defect. Prior to reexploration, laboratory studies should be done to rule out a coagulation defect and should include: (1) venous clotting time; (2) partial thromboplastin time; (3) prothrombin time; and (4) fibrinogen. 13,14 Abnormalities of the partial thrumboplastin time respond to replacement of labile factors (i.e., factors V and VIII) by fresh blood. Vitamin K is prescribed for a prolonged prothrombin time. A low fibrinogen level (less than 150 to 175 mg./100 ml.) associated with bleeding indicates an active fibrinolysis and the prompt administration of fibrinogen (initial dose 4 Gm. in adults) is necessary. The use of epsilonaminocaprolc acid or trasyol appears warranted but the final role of these agents in the treatment of fibrinolysis is unsettled. ~,1~ Oliguria: Postoperative oliguria (urine flow less than 15 to 20 ml./hour) most commonly results from hypotension. If adequate whole blood replacement does not correct the situation, low cardiac output as a consquence of incomplete surgical repair should be suspected. Renal function will not improve unless cardiac function is improved. Under these circumstances the administration of base is indicated since metabolic acidosis (base excess over - 4 mEq./L.) is usually present and progressive. Sodium bicarbonate is the base
MEDICAL PROBLEMS
IN T E T R A L O G Y O F F A L L O T
73
of choice during the postoperative period, for THAM may depress the respiratory cen,ter. Simple oliguria may respond to a water load of 100 m]. of 5 per cent dextrose in water/M 2 given over a 10 to 15 minute period when blood pressure is stable and urinary flow is patent: an increase in urine flow indicates inadequate hydration and additional water in the fluid prescription is necessary. Reversible functional renal failure often precedes organic renal failure. If acute renal failure occurs following the use of incompatible blood or from progressive functional failure, a renal shut-down regimen should be initiated.16,1r Postpericardiotomy Syndrome: In contrast to the potential problems described above, which usually occur within the first 3 postoperative days, postpericardiotomy syndrome may be manifest near the end of the second week38 Electrocardiographic evidence of pericardial inflammation in the absence of digitalis therapy may be seen as deviations in the ST segment and T wave from the fourth day onwards. The frequency with which these changes are noted is probably directly related to the extent of electrocardiographic monitoring. It is not uncommon to hear a perieardial friction rub, especially over the lower preeordium between the apex and the midline sternotomy sear. The appearance of fever after antibiotics have been discontinued on the tenth day is of concern and suggests a diagnosis of postpericardiotomy syndrome. Most frequently the temperature is elevated to around 101 to 102 F and there may be associated subjective complaints of chest or shoulder pain. Splenomegaly may be noted as well as abnormal lymphoeytes in the peripheral blood smear. Although this entity may be clinically suspected, suffleient blood cultures should be obtained to exclude bacterial or myeotiq endocarditis. In most patients postpericardiotomy syndrome is self-limitod after 4 or 5 days and requires no specific therapy though ambulation should be restricted. If, however, fever is persistent, the patient is placed on salieylates in the dosage of 100 Gm./Kg./24 hours, for a period of about 5 days. No recurrences of postpericardiotomy syndrome have been encountered following hospital discharge.
Follow-up and Evaluation After the patient has been discharged from the hospital, usually about 2% to 3 weeks following open heart surgery, full activity is allowed for daily living, but strenuous exertion and sports should be restricted. He is reexamined by the cardiovascular surgeon in 1 months' time, and then his progress and rehabilitation is usually checked by the cardiologist. If the patient is on digitalis maintenance therapy, the cardiologist is responsible for its cessation. By the end o.f the sixth postoperative month, most patients are allowed to engage in unrestricted activity. Physical examination in these patients reveals a systolic murmur, grade 1-3/6 in intensity, which is rough to mildly harsh and maximal at the mid to upper left sternal border. There is no predictable relationship between auscultation of loud murmurs and the presence or absence of a small residual gradient or shunt, ag~ In the patient who acquires pulmonary valvular in suf-
74
CRIFFITIIS
PULMONIC
AND
INSUFFICIENCY
I,
P.C., 9'/2 YEARS, MALE
-#6-216
2-13-62 0.4
z
= SM
PHONO -
j....... i.....~.
..~ +r(.m ......
CARDIOGRAM,, mm Hg
I ...... +~.r. . . . .
L" "
/VIALlk~
LJ,~ _,i ..... +P ' " r " " r r ' ' r ' + "
9
=
DM
SM
l+~t++L_ "Ip'~ ....
SIC
I
I
DM
,.t~.,.._., ~ m m , , ,~ill,,.....,.~ m~~ & +y~: I ~ " . . . . . . i," r f r r . . . . .
k .... )+. . . . . .
,, j ' , , l . . }+m+m"- . . . .
" ,e-- PA
RV - - ~
~
/~
Fig. 3.--Phonocardiogram from the second left intercostal space indicating crescendo-decrescendo diastolic murmur (DM) postoperatively in patient with
pulmonary valvular insufficiency. A low amplitude systolic murmur (SM) is also noted. The tracing was recorded during withdrawal of intracardiac catheter from pnlmonary artery to right ventricle. 9,. i:: ,..i.,
.i 84i .~-..
,.-).i! I, i ~..I.I!A r !-.. ~:i
i!~i,,~J~,
+
~:.i:!..!:i.i... ! :.:i:...:::~, !.. ~;!t. i;!iiiihii!::~ili .l ; :!;;L
'~
"I
' ......... i +
Pre -Op
I0 days
9
:
+
P
9
5 weeks
i
9months
Fig. 4.--Electrocardiographic follow-up with selected leads (I, aVR and V1) in a 10 year old boy. (1) Preoperative tracing, right axis deviation and right ventricular hypertrophy; (2) 10 days postoperative, complete right bundle branch block; (3) 5 weeks postoperative, intermittent RBBB in V1; and (4) 9 months postoperative, normal conduction time and axis. Leads I and aVR are simultaneously recorded at full standardization; lead Vx is recorded at 1/2 standardization. ficiency, a short, early, low-pitched diastolic murmur is audible in the second left intercostal space. This murmur is illustrated in figure 3 on a phonecardiogram recorded during postoperative cardiac catheterization in a-patient with an outflow tract prosthesis and pulmonary insufficiency. Radiologic evaluation of patients following complete surgical repair indicates the over-all heart size to be normal in the posteroanterior film, i.e., similar to the preoperative picture. In the lateral view, there may be some increase in the posterior projection of the heart in the area of the left atrium and left ventricle,s An increased prominence of the peripheral pulmonary
MEDICAL PROBLEMS IN TETRALOGY OF FALLOT
75
Fig. 5.--Postoperative lateral angiogram showing position of an outflow patch across pulmonary valve resulting in pulmonary valvular insufficiency. The prosthesis was required because of peripheral pulmonary artery stenosis. vascular markings is also evident. Any significant increase in cardiac size postoperatively suggests the presence of a residual anatomic defect. The electrocardiogram usually shows an incomplete or complete right bundle branch block pattern (QRS duration 0.12 sec. or more). Follow-up tracings in one patient with tetralogy of Fallot, however, who had right axis deviation and right vcntricular hypertrophy preoperatively, and who acquired complete right bundle branch block immediately postoperatively, revealed an essentially normal electrocardiogram 9 months later (fig. 4). The electrocardiogram is still within normal limits 31/2 years following surgery. No late complications or unexpected infections have been encountered following open heart surgery in our series. It may be noted, however, that one death occurred 6 months postoperatively with Aspergillus endocarditis. 2 Prophylaxis against bacterial endocarditis should be carried out with suitable antibiotics prior to dental or other surgery in patients who have had total correction of tetralogy of Fallot. All living patients in our series are clinically improved with normal or
76
GBIFI, TI'I-IS A N D M A L M
Table 1.--Results of Postoperative Catheterization in 47 Patients with Tetralogy of FaUot H e m o d y n a m i c Result
Observations
No. P a t i e n t s
30
Excellent
No residual shunt and a right ventricle to pulmonary artery gradient less than 20 ram. Hg Good
11 Gradient of 20-50 mm. Hg Small L-B shunt (QPa/QS 1.5/1) Pulmonary valvular insulficiency Small gradient and small L-R shunt
(3) (5) (2) 1)
Gradient of 50 ram. Hg and L-R shunt (2.0/1) Heart block Pulmonary hypertension Late deaths
1) 1) (2) (2)
Poor
m
Total
47
QPa/QS, ratio of pulmonary to systemic blood flow. L-R, left to right. nearly normal exercise tolerance. A physiologic and anatomic re-evaluation by cardiovascular study is, however, planned for all patients approximately 1 year following surgery. Selective angiocardiography from the right ventricle is carried out to visualize the repair of the outflow tract and/or pulmonary artery obstruction. Figure 5 illustrates by angiocardiogram the use of an extensive outflow patch for reconstruction of stenosis of the main pulmonary artery: pulmonary valvular insufficiency is produced as the prosthesis extends beyond the pulmonary valve. Surgically acquired pulmonary incompetence appears to be well tolerated clinically. Right heart and pulmonary artery pressures are measured both at rest and during exercise in addition to the determination of any residual gradient or shunting at the ventricular level. The postoperative catheterization data on 47 of the 85 patients with tetralogy are summarized in table I and categorized as excellent, good or poor: excellent, if there is no residual shunt and a residual right ventricle/pulmonary artery gradient less than 20 ram. Hg; good, if there is a small left-to-right shunt or a residual gradient of 20 to 50 ram. Hg; and poor, if a shunt and gradient are both present. These figures suggest that 41 of 47 patients (87 per cent) have normal or nearly normal hemodynamics. The importance of clinical follow-up in the evaluation of the long-term results of total correction of tetralogy of Fallot cannot be overemphasized. It is the responsibility of the cardiologist to continue observation of the patient so that assessment of the effects of surgical repair on cardiac performance and life-expectancy can be made38 REFERENCES
1. Maim, J. R.: Surgical treatment of retralogy of Fallot. In Cooper, P. (Ed.): The Craft of Surgery. Bos-
ton, Little, Brown and Company, 1964, pp. 520-530. 2. --, Bowman, F. O., Jr., Jameson, A. G.,
77
MEDICAL PROBLEMS IN TETRALOGY OF FALLOT
3.
4.
5.
6.
7.
8.
9.
1O.
11.
Ellis, K., Griffiths, S. P., and Blumenthal, S.: An evaluation of total correction of tetralogy of Fallot. Circulation 27:805, 1963, . . . . and Blumenthal, S.: Current concepts in treatment of tetralogy of Fallot. Dis. Chest 45:86, 1964. Nadas, A. S.: Pediatric Cardiology. Philadelphia, W. B. Saunders, 2nd ed. 1963, pp. 638-662. Paul, M., Miller, R. A., and Potts, W. J.: Long-term results of aortic pulmonary anastomosis for tetralogy of Fallot. An analysis of the first 100 cases eleven to thirteen years after operation. Circulation 23:525, 1961. Taussig, H. B., Crawford, H., Pelargonio, S., and Zacharioudakis, S.: Ten to thirteen year follow-up on patients after a Blalock-Taussig operation. Circulation 25:630, 1962. Kay, E. B., Nogueira, C,, Mendelsohn, D., Jr., and Zimmerman, H. A.: Corrective surgery for tetralogy of Fallot. Circulation 24:1342, 1961. Anderson, O. S., and Engel, K.: A new acid-base nomogram. Scandinav. J. Clin. & Lab. Invest. 12:177, 1960. Maim, J. R., Sullivan, S. F., Patterson, R. W., Bowman, F. O., Jr., and Nahas, G. S.: Effect of THAM on urine flow during extra-corporeal circulation. S. Forum 14:107-108, 1963. Allen, J. G..: Immunization against serum hepatitis from blood transfusion. Ann. Surg. 160:752, 1964. Humphreys, G. H., II, Blumenthal, S., Bowman, F. O., Jr., Malm, J. R., Singer, D. H., and Sullivan, S. F.: hnmediate complications of thoracot-
12.
13.
14.
15.
16.
17.
18.
19,
20.
omy for heart disease. S. Clin. North America 44:335, 1964. McGoon, D. C., Ongley, P. A., and Kirklin, J. W.: Surgical heart block. Am. J. Med. 37:749, 1964. Phillips, L. L., Maim, J. R., and Deterling, R. A., Jr.: Coagulation defects following extra-corporeal circulation. Ann. Surg. 157:317, 1963. Nye, S. W., Graham, J. B., and Brinhous, K. M.: The partial thromboplastin time as a screening test for the detection of late bleeders. Am. J. M. Sci. 243:279, 1962. Gans, H., and Krinit, W.: Problems in hemostasis during open heart surgery. Epsilonaminocaproic acid as an inhibitor of plasminogen activation activity. Ann. Surg. 155:268, 1962. Barry, K. G., and Malloy, J. P.: Oligttric renal failure. J. A. M. A. 179:510, 1962. Doberneck, R. C., Reiser, P. M., and Lillehei, C. W.: Acute renal failure after open heart surgery utilizing extra-corporeal circulation and total body peffusion. J. Thoracic & Cardiovasc. Surg.. 43:441, 1962. Engle, M. A., and Ito, T.: The postpericardiotomy syndrome. Am. J. Cardiol. 7:73, 1961. Allison, P. R., Gunning, A. J.: Hamill, J., and Mody, S. M.: Fallot's tetralogy: a post-operative study. Circulation 28: 525, 1963. Albertal, G., Swan, H. J. C., and Kirklin, J. W.: Hemodynamic studies two weeks to six years after repair of tetralogy of Fallot. Circulation 29: 583, 1964.
Sylvia P. GriI~ths, M.D., Dept. of Pediatrics, Columbia University College of Physiciansand Surgeons, New York, N. Y. ]ames R. Malm, M.D., Dept. of Surgery, Columbia University College of Physicians and Surgeons, New York, N, Y.