Multiple conduction defects with markedly prolonged ventricular depolarization in cardiomyopathy

J. ELECTROCARDIOLOGY, 10 (3), 1977, 275-278

Case Studies:

Multiple Conduction Defects with Markedly Prolonged Ventricular Depolarization in Cardiomyopathy BY ZUBAIR UL HASSAN, M.B., ROLANDOA. MENDOZA, M.D., WILLIAM E. STEINKE, M.D. AND DAVID B. PROPERT, M.D.

normal resting pressures, poor left ventricular contractility and no significant coronary lesions.

SUMMARY Electrophysiologic investigation of a diffuse and bizarre conduction abnormality in a patient with cardiomyopathy revealed profound slowing of the impulse in the right ventricular outflow region. The resultant 220 msec QRS duration is the longest reported in right bundle branch block.

Electrophysiologic Studies: The ECG (Fig. 1) shows first degree atrioventricular block (P-R interval 240 msec), left axis deviation and loss of anterior forces. The initial QRS spike is followed by an unusual and prolonged slurring which in some leads resembles a retrograde P wave or possible displacement of the ST segment. The QRS vectorcardiogram (Fig. 2) best depicts left anterior hemiblock and the loss of anteroseptal forces in the frontal and horizontal loops respectively. The anterior, rightward and superior terminal QRS forces reveal an extreme degree of slowing with little displacement from the E point. The corresponding terminal deflections in the intracardiac electrogram (Fig. 3), maximal in the pulmonary artery, were consistent with this vector pattern. The total QRS complex, therefore, is compatible with a right bundle branch block pattern of 220 msec duration. The His bundle electrogram (Fig. 4) further documented this 220 msec v e n t r i c u l a r depolarization, which consisted of a relatively normal (63-75 msec) initial complex followed by an apparently quiescent 95 msec period and a second set of ventricular deflections. The A-H (141 msec) and H-V (58 msec) intervals were slightly prolonged, but atrial pacing at rates up to 180/min produced only modest and gradual A-H prolongation without second degree atrioventricular block or angina. In view of t h i s n o r m a l r e s p o n s e a p a c e m a k e r was considered u n n e c e s s a r y at that time.

The QRS d u r a t i o n of t h e r i g h t b u n d l e branch block p a t t e r n demonstrated by the present case is well beyond the 200 msec previously documented. 1 A v e c t o r c a r d i o g r a m (VCG), intracardiac and His bundle electrogram were employed to further define the diffuse conduction abnormality.

CASE REPORT The patient was a 46 year old black foreman who had been drinking an average of 11~ pints of whiskey per day for several years and described recurrent episodes of heavy substernal discomfort related to alcoholic excesses, but not to exertion, for two years before admission. Progressive heart failure necessit a t e d a d m i s s i o n to t h e VA H o s p i t a l , Richmond, Virginia, in J u l y 1973. Physical e x a m i n a t i o n r e v e a l e d a blood p r e s s u r e of 140/95, pulse 100/min, slight cardiomegaly and a ventricular gallop rhythm. Routine laboratory studies including serum electrolytes and fasting blood s u g a r were normal on repeated examinations. The pat i e n t w a s t a k i n g no m e d i c a t i o n s . Electrophysiologic studies are described below. Treatment with digoxin was then initiated. In the next several months the patient was admitted elsewhere for chest pain and during one of these hospitalizations a t e m p o r a r y pacemaker was inserted because of the abnormal electrocardiogram (ECG). The persistence of chest pain and dyspnea prompted readmission to this hospital in Febr u a r y 1974. Cardiac catheterization revealed

DISCUSSION Dodge and Grant 2 found a QRS duration of 120-140 msec in the great majority of right bundle block cases. It was prolonged to 160 msec in nine out of 80 and to 180 msec in only one. Kastor, Goldreyer, Moore et al 3 found two of 37 right bundle branch blocks over 160 msec, but none over 170 msec. Lepeschkin, in his book Modern Electrocardiography, has stated that "in very large hearts the QRS (in r i g h t b u n d l e b r a n c h block) m a y e x c e e d

From the Cardiology Division, McGuire Veterans Administration Hospital, Richmond, Virginia, and Medical College of Virginia, Richmond, Virginia. Reprint requests to: Zubair ul Hassan, M.D., P.O. Box 6, MCV Station, Richmond, VA 23298. 275

276

HASSAN ET AL

~

t! it~!i~:!t!!I I!!I !i~: ~'~',iH 111 iI~:t ...................... ;::,:: ......... ............. ;i:::i: : ,~,:::~:;;

' ~ ~

~iiiil::ii::::::ii::::i::::li::ii~iiii~!::~':~lill

F i g . 1. E l e c t r o c a r d i o g r a m .

xJ ~

TRANSVERSE

PLANE ~

...................... :: : .::::.:::: .....................

_i:.::::.i...i

. il ~ ' '

i

See text for details.

~

~

u

!1', illl

x

~

J

~

--~,

/

/

!

f

/

t

•

Z-J FRONTAL PLAN E

SAGITTAL PLAN E

Fig. 2. Vectorcardiogram and Frank leads x, y, and z. P and T loops are not included.

J. ELECTROCARDIOLOGY, VOL. 10, NO. 3, 1977

MARKEDLY

PROLONGED

Q R S IN R B B B

277

~Uiiiiiiiii!iiiiiiiiiiiiiiiii!iiiiiii~ . . . . ::.:._..... ...::::: ....................................... .L.'!!!!!!!!!!!!!~!!!!~!!![!!!!!j!!!!!!!!!!!!!!!~ZZ~:ZS---Ei =============================================================== l.t~;;;;;~l ::::::::::::::::::::::::::::::::::::::::: SUPERIOR ~

CAVA

.-.~.--iii'iiiii~iiil;iliEi!~Ei!iiii!!!!ilillt~

ii~iiiiii

tllGR e I G H T ATP,IUM

IIID l I G H T A ' l ~ ' ~

i::::::::::~:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ~ili::iil~!=J 9

~:: ::::::i:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: ~::::::::::::i::::l:::-!::::::~ii::::1;l:.i::~ti::i::lii::::liiiil~ii~t ~1~

! !J!;22!!!~]ii~ ili!i!ii!i!i!ii !iiii!!!!!,

IV OUTFLOW

iJlliiiiiiiiiill

PK,TH P&

Fig. 3. Recording of the intracardiac electrogram at various sites. See text for details.

Fig. 4. Catheter electrode recording of the His bundle electrogram (HBR) recorded simultaneously with high intra-atrial electrogram (HRA) and surface electrocardiogram, leads I, II, and III. One second time lines. See text for details. 0.20 sec," and cited an example 4 showing a QRS d u r a t i o n of approximately 0.20 sec in a p a t i e n t w i t h gross h y p e r t r o p h i c cardiomyopathy. The ECG in our case satisfied the criteria for right bundle branch block ~ and also demonstrated left anterior hemiblock and loss of J. ELECTROCARDIOLOGY,

VOL. 10, NO. 3, 1977

i n i t i a l a n t e r i o r forces. E l e c t r o p h y s i o l o g i c studies clearly show t h a t the bizarre-looking t e r m i n a l forces were not retrograde P waves but components of the QRS complex which presented a double set of ventricular deflections of the His bundle electrogram with a total QRS duration up to 220 msec.

278

HASSAN ET AL

The i n t r a v e n t r i c u l a r electrographic complexes resemble t h e r i g h t b u n d l e b r a n c h block pattern described by Sodi-Pallares et al, 6 except for the profound delay of t e r m i n a l forces. This delay suggests muscle-to-muscle conduction in the region of the crista supraventricularis, which is the area n o r m a l l y depolarized last. Such remarkable slowing is in accord with Kastor's finding of a linear relationship between QRS duration and delay in activation time of the right ventricular outflow tract. 3 Generalized slowing of i n t r a v e n t r i c u l a r c o n d u c t i o n c a n be p r o d u c e d by s e v e r e metabolic changes and Quinidine-like antia r r h y t h m i c drugs. However, none of these was present in this patient whose history, physical examination and angiographic data a r e m o s t c o m p a t i b l e w i t h alcoholic cardiomyopathy. This diagnosis explains not only the diffuse myocardial and conduction abnormalities but also the loss of initial anterior forces despite essentially normal coron a r y arteriograms. Gau et al 7 found t h a t loss of anterior force in cardiomyopathy was not necessarily associated with a diffuse fibrotic process but may represent a form of conduction defect. In the present case the loss of anterior forces in conjunction with the slight prolongation of the A-H and H-V intervals, left anterior hemiblock and extreme slowing of mid and terminal QRS forces, suggests t h a t the diffuse cardiomyopathic process involves the nodal, His-Purkinje and ventricular tissues. The particularly bizarre complex presented here is apparently produced by the

m a r k e d l y abnormal depolarization sequence in the His-purkinje system and the ventricles. Acknowledgments: We gratefully acknowledge the assistance of Dr. Charles Lewis Baird, Jr., in providing us the vectorcardiogram of this patient.

1.

2.

3.

4. 5. 6.

7.

REFERENCES DHINGRA,R C, DENES, P, WV, D, CHUQUIMIA,R, AMAT-Y-LEON,F, WYNDHAM,C ANDROSEN,K M: Chronic right bundle branch block and left posterior hemiblock. Am J Cardiol 36:867, 1975 DODGE, H T AND GRANT, R P: Mechanisms of QRS complex prolongation in man. Right ventricular conduction defects. Am J Med 21:534, 1956 KASTOR, J A, GOLDREYER, B N, MOORE, E N, SHELBURNE, J C AND MANCHESTER, J H: Intraventricular conduction in man studied with an endocardial electrode catheter mapping technique. Circulation 51:786, 1975 EVANS, W: Familial cardiomegaly. Br Heart J 11:68, 1949 ROSENBAUM,M B: The hemiblocks: Diagnostic criteria and clinical significance. Mod Concepts Cardiovasc Dis 39:141, 1970 SODI-PALLARES,D, THOMSEN,P ANDSOBERON,J: New contributions to the study of the intracavity potential in cases of right bundle branch block in the human heart. Am Heart J 36:1, 1948 GAU,G, GOODWIN,J F, OAKLEY,C, RAPHAEL,M J ANDSTEINER,R E: Q waves and coronary angiography in cardiomyopathy (abstract). Br Heart J 32:554, 1970

J. ELECTROCARDIOLOGY, VOL. 10, NO. 3, 1977