Surgical treatment of refractory life-threatening ventricular tachycardia

Surgical Treatment of Refractory Life-Threatening Ventricular Tachycardia

ANTHONY F. GRAHAM, MD, FRCP(C)* D. CRAIG MILLER, MD EDWARD B. STINSON. MD PAT O. DAILY, MD THOMAS J. FOGARTY, MD DONALD C. HARRISON, MD, FACC Stanford, California

Aortocoronary bypass, with or without myocardial resection, was used to treat eight patients with refractory life-threatening ventricular tachycardia. All patients had documented evidence of coronary artery disease without recent myocardial infarction and were totally disabled by recurrent ventricular tachycardia while receiving aggressive medical treatment. Angiographic studies showed abnormalities of left ventricular contractions in all patients, including aneurysms in four, localized hypokinetic areas in two and diffusely poor contractility in two. Operative treatment consIsted of resection of the aneurysm or localized hypokinetic area in six patients and aortocoronary bypass grafting to at least one major coronary artery in all eight patients. Seven patients are alive an average of 17 months after operation and all are free of major ventricular arrhythmias. We conclude that surgical treatment should be considered in patients with coronary artery disease who have life-threatening ventricular arrhythmias that cannot be prevented or controlled with drug therapy.

Ventricular tachycardia in patients with coronary artery disease has an ominous prognosis, and effective control by medical means may be difficult. 1 ,2 Conventional methods of treatment include administration of antiarrhythmic agents, either alone or in combination with overdrive atrial pacing and direct-current countershock. 3 Such interventions are directed toward the suppression of these arrhythmias rather than the underlying ischemic process with its associated areas of dyskinetic, focally scarred or aneurysmal myocardium. The development of operative procedures that permit direct myocardial revascularization as well as the resection of abnormal myocardium has provided an alternative approach to the treatment of these arrhythmias and possibly their underlying cause. This report presents our experience with sur~ical treatment in a group of patients with refractory ventricular tachycardia, and stresses the types of patients who may be considered for this aggressive approach.

Material and Methods Patient Population

From the Division of Cardiology and Cardiovascular Surgery, Stanford University School of Medicine, Stanford, Calif. This work was supported in part by National Institutes of Health Grants HL-5709 and HL-5866. *Supported in part by the Medical Research Council of Canada. Manuscript accepted June 6, 1973. Address for reprints: Donald C. Harrison, MD, Cardiology Division, Stanford University School of Medicine, Stanford, Calif. 94305.

Eight patients underwent operative treatment for recurrent ventricular arrhythmias at St.anford Universit.y Medical Center between December 1970 and January 1973. The average age of the group was 52 years (range 47 to 79 years) (Table n. There were seven men in the group. Recurrent syncope was the most common clinical presentation and occurred in six patients. Five patients also had New York Heart Association class II symptoms of congestive heart failure, and three had mild angina pectoris. Seven had a history of documented previous myocardial infarction between 1 month and 25 years before presentation. No patient had evidence of recent myocardial infarction. Although all patients were receiving intensive medical therapy, all continued to have recurrent ventricular tachycardia considered to he life-threatening. Serial electrocardiograms showed evidence of previous

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TABLE I Patient Data Clinical Profile

Case no.

Age (yr) & Sex

1

50M

2

Symptoms

Time from Previous Infarction

ECG Site of Infarction

Angiographic Data S-T Segment Eleva· tion

Documented Arrhythmia

Maior Coronary Arterial Narrowing

LV Angiographic Data

Mitral Insuffi· ciency

11 yr.

Inf.

VT

RCA, LAD, LCA

Hypokinetlc info wall

+2

49M

Syncope, angina, CHF Syncope

10 mo.

lnf.

VT

RCA

+1

3

79M

Syncope,

2!i yr.

Inf., ant.

VT

LAD, LCA, RCA

Inf. wall aneurysm Diffuse hypokinesis

4

47F

8 mo.

Ant.

Vi -V4

VT

LAD

5

51M

7 yr.

Ant.

Vi-V,

VT, VF

LAD, RCA

6

57M

angina Angina, CHF Syncope, CHF CHF

VT

7

47M 50M

Syncope Syncope

2mo. 1 mo.

Subendo· cardlal? Ant. Ant.

LAD, LCA, RCA LAD, RCA LAD, RCA

8 Ant.

CHF,

V1-V 4 V1-V 4

VT, VF VT

Apical & ant. wall aneurysm Apical, ant. walls akinetic Diffuse hypokinesis Apical aneu rysm Apical aneurysm

+1

= anterior; CH F = congestive heart failure; Inf. = inferior; LAD = left anterior descending coronary artery; LeA = left circumflex

transmural myocardial infarction in seven of the patients. Four had had an anterior wall infarction, and the anterior precordial leads showed persistent S-T segment elevation suggestive of ventricular aneurysm. In the other three patients, the electrocardiograms showed inferior or lateral wall infarction without associated S-T changes suggestive of an aneurysm. One patient did not have evidence of a transmural infarction but had S-T and T wave changes suggesting myocardial ischemia or subendocardial infarction, or both. Each patient had a variety of ventricular ectopic beats; in six the beats were multifocal and in two unifocal. In addition, as many as 100 episodes of ventricular tachycardia were documented in each patient, and two patients also had ventricular fibrillation.

ed by recurrent ventricular tachycardia while receiving maximally tolerated medical treatment. Anglographic and Hemodynamic Data Coronary arteriography was subsequently performed with use of the Judkins technique and revealed coronary arterial narrowing of greater than 70 percent in at least one major coronary .artery in all patients. Three patients had significant triple vessel disease, three had disease involving the left anterior descending and right coronary arteries and two had single vessel disease.

Medical Treatment

TABLE II

Each patient underwent intensive medical treatment before operative intervention was considered. The five patients with mild congestive heart failure had been receiving maintenance doses of digoxin with serum levels documented within the therapeutic range (1.2 to 1.8 J.l g/liter). Serum electrolytes and the acid-base balance were maintained within normal limits. Various combinations of antiarrhythmic agents were used in each patient (Table II). These included procainamide, quinidine, diphenylhydantoin, bretylium tOBYlate and propranolol. Each patient was treated with combinations of at least four of these agents. Lidocaine was given both by bolus injection and by' constant infusion in doses of 3 to 6 mg/min in each patient for more than 24 hours. Overdrive suppression with atrial pacing was attempted in five patients but was only temporarily effective in two. All the patients had alBo received direct-current countershock on multiple occasions as emergency treatment for their arrhythmias. In spite of these meB5ures, each patient continued to be incapacitat-

Medical Treatment for Patients with Ventricular Tachycardia

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Preoperative Maximal Patients Dose/Day (no.) (mg) Drug trea tment Procalnamide Quinidine Diphenylhydantoin Bretylium tosylate Propra nolol Lidocaine Overdrive atrial pacing Direct·current countershock

Volume 32

3000 2000 400 4 1200 6 720 8 3-6 mg/min

Postoperative

Patients (no.)

7

5

6 8

2

5 8

Maximal Dose/Day

2000 1200

SURGERY FOR VENTRICULAR TACHYCARDIA-GRAHAM ET AL.

Hemodynamic Data LV Pressure

Cardiac Index (liters/min per m2)

Operative Procedure

Results

Case no,

(S/D/ED)

1

130/0/25

Inf. wall scar

RCA

31

2

140/0/15

RCA

27

3

130/0/17

Inf. wal! aneurysm (calcium)

4

130/6/10

3.8

Apical aneurysm

RCA

19

5

130/6/28

2.3

LAD

15

6

140/0/25

Apical & ant. aneurysm (calcium)

1.6

LAD, LeA, RCA

13

7 8

125/0/23 90/0/20

2..9

LAD LAD, RCA

10

(mm Hg)

Myocardial Resection

Bypass Grafts

RCA, LAD

artery; LV = left ventricular; RCA ventricular tachycardia.

Apical aneurysm Apical aneurysm

Survival (mo)

Symptoms

Died, 1 day

Mild angina

7

= right coronary artery; S/D/ED = systolic/diastolic/end·diaslolic; VF = ventricular fibrillation; VT =

Single plane left uentricular cineangiography was performed in the right anterior oblique projection, using an injection of 50 cc of 70 percent Renografinill , under pressure of 250 lb/sq. in. Three of the four patients with previous anterior wall infarction had a discrete apical or an· terior wall aneurysm; the other had an akinetic area in the anterior wall without paradoxical movement. Two patients had contraction abnormalities involving the inferior wall of the left ventricular chamber and associated with various degree~ of mitral insufficiency. One of these had an akinetic inferior wall, and the other had a localized inferior wall aneurysm. Two patients had diffusely poor contractility of the entire left ventricle without any localized hypokinetic areas. Hemodynamic studies were performed at the time of angiography before injection of contrast medium. Abnormalities in left ventricular function were present in six of the patients with elevations of end·diastolic pressure levels as high as 28 mm Hg. The resting cardiac output was also reduced in two of the four patients in whom it was measured (Table I). Operative Technique

At the time of operation, each patient was placed under cardiopulmonary bypass, using standard techniques and central cannulation. Examination of the heart confirmed the presence of severe coronary atherosclerosis in seven patients and fibromuscular hyperplasia in the eighth. Localized aneurysms were composed of fibrous connective tissue, and two also contained various amounts of calcium. The localized hypokinetic area in two patients was a patchy fibrotic scar involving the full thickness of the heart wall, surrounded by myocardial tissue that was grossly normal in appearance. In each of these patients the aneurysm or hypokinetic area was resected. The free edges of the myocardium were then apposed with mattress sutures

supported by Teflon @ felt bolsters. Coronary artery bypass grafts utilizing autologous reversed saphenous veins were also inserted in each patient. The two patients showing only diffusely poor left ventricular contractility with no localized resectable areas underwent only bypass grafting. Triple grafts were used in two patients, double grafts in another two and a single graft to the right coronary artery in the other four.

Results One patient died within 24 hours after operation. He was a 79 year old man with diffusely poor left ventricular contractility, in whom only coronary artery bypass grafting had been performed. The other seven patients are currently alive 7 to 31 months after operation. Postoperative assessment in these patients included clinical evaluation, resting electrocardiograms and ambulatory Holter electrocardiographic monitoring. These studies showed that four patients are free from documented ventricular arrhythmias and the other three have only occasional unifocal ventricular premature contractions. FiVe patients are currently receiving antiarrhythmic medication as a prophylactic measure (Table Il). All patients are free of clinically evident congestive heart failure, and only one continues to have mild exertional angina pectoris. Discussion The application of the different forms of operative treatment for the various complications of coronary heart disease is expanding rapidly. Currently the most frequent indications for operation in a patient with postinfarction ventriCular aneurysm are intrac-

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table congestive heart failure or systemic emboli. The association between refractory ventricular tachycardia and ventricular aneurysm was first noted by Wasserman and Yules 4 in 1953. The first successful surgical resection of a ventricular aneurysm as treatment for recurrent ventricular tachycardia'was reported by Cough 5 in 1959. Since then, similar case reports have appeared, describing aneurysmectomy alone as successful treatment for refractory ventricular tachycard~a.6-9 In each of these cases, operation was performed in patients with well defined aneurysms occurring as a complication of ischemic heart disease, and aneurysmectomy was not combined with direct myocardial revascularization. The introduction of procedures allowing direct myocardial revascularization has further extended the applicability of surgical interventions for the complications of ischemic heart disease. The technique of direct aortocoronary bypass grafting has been shown to provide significantly increased blood flow to localized ischemic areas. Ecker et a1. 10 reported the successful use of aortocoronary bypass grafting along with plication of a right ventricular aneurysm in a patient with refractory ventricular tachycardia. The successful use of bypass grafting alone without myocardial resection in a patient with ventricular tachycardia was recently reported by Nakhjavan et a1. 11 Pathogenesis: The pathogenesis of recurrent ventricular arrhythmias in patients with coronary artery disease is still unclear. A mechanism of reentry circuits located around areas of focal scar tissue or ventricular a~eurysms has been postulated. Studies in isolated muscle segments made ischemic support this hypothesis, but as yet no documentation for this reentry mechanism exists in man. Increased ventricular diameter as a result of aneurysmal formation or ischemic left ventricular dysfunction is known to incrfi!ase oxygen consumption and may further aggravate focal areas of ischemia peripheral to the infarcted area in certain patients. In both these situations the removal of an aneurysm or focal scar may remove the underlying cause of the arrhythmia. In ad-

dition, the use of coronary artery bypass grafting alone to appropriate vessels may be useful in certain patients with reversible ischemic left ventricular dysfunction. Recommended medicat" and surgical treatment: All patients in this series had evidence of significant coronary artery disease and, with the recurrent ventricular arrhythmias, were thought to be in a high risk group for sudden death. 1 All of the patients had failed to respond to conventional treatment with large doses of antiarrhythmic agents. Frequently, three or more drugs had been tried in combination, utilizing the recommended kinetic program for administration (Table ll). Ideally, one should demonstrate that adequate blood levels of the antiarrhythmic agent had been achieved at the time a therapeutic failure was declared. In several cases, this practice was followed for administration of lidocaine and quinidine, with blood levels of 10 ,ug/ml and 8 mg/ liter, respectively, being the upper limits tolerated. Angiographic studies showed severe left ventricular dysfunction in each patient. As a result, at operation it was considered appropriate to combine necessary myocardial resection of localized aneurysm or focal scar with direct aortocoronary bypass grafts to major diseased vessels. Of particular interest are two patients who underwent only bypass grafting because of the absence of localized resectable areas of myocardium. The survival of one of these patients supports the concept that reversible ischemic left ventricular dysfunction with associated refractory ventricular tachycardia can be successfully treated by myocardial revascularization alone, although additional factors may be operative. At present, it is our policy to combine direct aortocoronary bypass procedures with appropriate myocardial resection in patients with refractory ventricular tachycardia. Myocardial resection should always be considered in patients with localized ventricular aneurysms or focal hypokinetic areas. However, myocardial revascularization alone may be therapeutic in selected cases.

References 1. Armbrust CA Jr, Levine SA: Paroxysmal ventricular tachycardia: a study of one hundred and seven cases. Circulation

1:28-34,1950

2. Day fiW: Progress In cardiology: acute coronary care. a five year report. Am J Cardiol 21 :252-257, 1968 3. Friedberg CK, Lyon W, Donoso E: Suppression of refractory recurrent ventricular tachycardia by transvenous rapid cardiac pacing and antiarrhythmic drugs. Report of seven cases. Am Heart J 79:44-50, 1970 4. Wasserman E, Yules J: Cardiac aneurysm with ventricular tachycardia. Ann Intern Mad 39:948-956, 1953 5. Cough OA: Cardiac aneurysm with ventricular tachycardia and subsequent excision of aneurysm. Circulation 20:251-

253,1959

6. Hunt 0, Sloman G, Westlake G: Ventricular aneurysmectomy for recurrent tachycardia. Sr Heart J 31 :264-266,

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1969 7. Ritter ER: Intractable ventricular tachycardia due to venirlcular aneurysm with surgical cure. Ann Intern Med

71:1155-1157.1969

8. Rolette E, Webster S, Avioli LF: Surgical management of ventricular aneurysm. JAMA 210:122-125, 1969 9. Wardekar A, Lon B, Gosaynie CD, et al: Recurrent ventricular tachycardia successfully treated by excision of ventricular aneurysm. Chest 62:505-508. 1972 10. Ecker RE, Mullins CB, Grammer JC, el 81: Control of intractable ventricular tachycardia by coronary revascularizatlon. Circulation 44:666-671. 1971 11. NakhJavan EK, Morse DP, Nichols HT, el al: Emergency aortocoronary bypass: treatment of ventricular tachycardia due to Ischemic heart disease. JAMA 216:2138-2140,

1971

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