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Remission and recovery from chronic, established, complete heart block
Remission and recovery from chronic, established, complete heart block David A. Rytand, M.D. Edward Stinson, M.D. John J. Kelly, Jr., M.D.
Stanford and San Francisco, Calif.
Temporary or prolonged return of atrioventricular (A-V) conduction after many years of established, complete heart block seems virtually prohibited by the very name of the disorder. Such an event does occur, however, with reports of remission or recovery in five patients with cong e n i t a l h e a r t b l o c k . 1-5 W i t h a c q u i r e d b l o c k , p u b lished evidence of this phenomenon is m u c h l e s s c o n v i n c i n g a n d c o n c e r n s o n l y t w o p a t i e n t s . 3, ~ T h i s is t o r e c o r d o b s e r v a t i o n s upon spontaneous recovery in a young man with congenital block and on a brief remission in an elderly one after seven years of acquired, established complete A-V block. These experiences led us to make inquiries which resulted in documents, also to be presented, on remissions in three additional elderly patients who had had complete, acquired block from four to ten years. All observations were made some time ago, unfortunately without His bundle recordings.
Case reports Case 1, NA, kindly referred by Ann Purdy, M.D., was born two months prematurely on May 20, 1929. When but a few weeks of age, he had a heart rate of 52 to 60 and there was a loud apical systolic murmur; there was no cyanosis. Occasional brief episodes of syncope were reported up to two years of age, but were not observed by a physician. Three-lead electrocardiograms on April 15, 1931, a n d on May 24, Aug. 30, and Sept. 20, 1933, were alike in showing (Fig. 1, A ) w h a t someone then interpreted as 2:1 A-V block; the short strips available failed to establish or eliminate the possibility of complete A-V block with synchronization (R-R 1.20, 1.24, 1.42,
From the Departments of Medicine (Cardiology Division) and Surgery (Cardiovascular Division), Stanford University School of Medicine, Stanford, Calif., and the Department of Medicine, Presbyterian Hospital, Pacific Medical Center, San Francisco, Calif. Received for publication Feb. 14, 1974. Reprint requests: Dr. David A. Rytand, Department of Medicine, Stanford University Medical Center, Stanford, Calif. 94305.
May, 1976, Vol. 91, No. 5, pp. 645-652
and 1.32 sec.; P-R 0.16, 0.20, 0.22, a n d 0.24 sec., respectively). In June, 1936, the heart rate was reportedly 80 to 90 per minute during a febrile bout of pneumonia and empyema. Nine electrocardiograms from Jan. 9, 1936, to Jan. 15, 1949, showed complete A-V block; the P-P intervals were 0.60 to 0.85 sec., the R-R intervals were 1.20 to 1.58 sec., and the ventricular complexes were normal and regular but for the presence of the supernormal phase of conduction in 'records taken after 1936 (Fig. 1, B). A-V synchronization was present at times. Meanwhile, chorea in 1941 was followed by a rough diastolic murmur at the apex for about two years. An early systolic apical murmur was constant, and at times an early diastolic sound was heard and recorded. Growth and development were normal, as were roentgenograms of the chest. This patient is Case 2 of another report 7 in which Fig. 2B shows the wide range of P-R intervals of complete A:V block recorded on Jan. 15, 1949. At a pre-induction Army examination in Feb. 1949, the heart rate allegedly was normal. This was confirmed March 29, 1949, when an otherwise unchanged electrocardiogram showed a rate of 90 per minute, with sinus r h y t h m and P-R 0.40 sec. An electrocardiogram (Fig. 1, C) on July 1, 1949, was virtually identical, with P-R 0.40 sec. and rate 75 per minute, except for failure of conduction in a single cycle. On July 22, 1949, complete A-V block reappeared, with occasional conduction in a supernormal phase at R-P intervals of 0.50 to 0.60 sec. (P-P, 0.54; R-R, 1.09 sec.); after exercise, complete A-V block persisted (P-P, 0.46; R-R, 0.85 sec.). Complete A-V block with a supernormal phase of conduction was present in an electrocardiogram Dec. 18, 1950 (P-P, 0.77; R-R, 1.43 sec.); the ventricular complexes remained normal and unchanged {Fig. 1, D). After 14 asymptomatic years, he was examined in Nov. 1964, by Dr. Richard Merchant who recorded an electrocardiogram which showed sinus r h y t h m with a rate of 75 per minute, a P-R interval of 0.40 sec., and a QRS of 0.09 sec. An occasional P-wave was blocked when its onset occurred within 0.28 sec. of the preceding QRS. In Dec. 1965, he entered a hospital because of a fractured right hip: Again he denied symptoms of cardiac disease. His heart rate was 80 per minute, arterial pressure 115/75. The cardiac examination was said to be normal, b u t no electrocardiogram was recorded. In Aug. 1967, he was examined by One of us: The patient
American Heart Journal
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Rytand, Stinson, and Kelly
B 5/4/58
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E 8A5/67 Fig. 1. Case 1. NA. Lead II inA, B, and C. Lead V, in D and E. A-V conduction appears in C and E.
stated t h a t he led a normal life without effort intolerance, and denied any s y m p t o m s of faintness or of syncope. Physical examination revealed an arterial pressure of 120/75. a normal cardiac size, normal sounds, and no m u r m u r s or gallops. An electrocardiogram (Fig. 1. E) was u n c h a n g e d from t h a t of Nov. 1964. Sinus r h y t h m was present with a race of 80 per minute. T h e P-R interval was 0.36 to 0.40 sec., the QRS interval was 0.09 sec. Again, an occasional P-wave failed to evoke a ventricular response when its onset fell within 0.28 sec. of the preceding QRS. On this occasion, he exercised vigorously for three minutes; his heart rate rose to 130 per minute, and remained regular. Neither exercise nor carotid sinus stimulation altered the P-R interval. On J u n e 24, 1970, an electrocardiogram recorded for Richard R. Babb, M.D., showed uniform conduction with a P-R interval of 0.33 sec. Case 2. Marc Eckstein, M.D., wrote as follows: " K T . age 72, was seen by me for the first time in 1953. She was observed by another physician prior to m y examination and was known to have had complete heart block for five years. Her electrocardiogram revealed a pattern of complete heart block with a ventricular rate of 40 per minute. QRS complex measured 0.09 sec. and there was left-axis deviation. Patient did very well until Dec. 1958, age 77, when she suddenly developed substernal pain, dyspnea, and orthopnea. On hospital admis-
646
sion, h e r electrocardiogram revealed t h e same pattern of complete heart block, b u t ST s e g m e n t s were elevated. Ventricular rate was 38. Sedimentation rate a n d enzymes were increased. Patient was given Demerol, oxygen, and a mercurial and she was started on anticoagulants. Since signs of congestive failure increased, it was decided to digitalize her. She received 2.5 mg. of digoxin within 24 hours, then 0:75 mg. in the next 24 hours. An electrocardiogram, taken after this 48-hour period, revealed a regular sinus r h y t h m with a rate of 75 per minute. P R interval was 0.18 sec. a n d QRS 0.10 sec. T h e axis remained the same, b u t there were T-wave changes, consistent with an acute process. This r h y t h m persisted for two days then reverted to its original pattern, when digoxin was stopped due to gastric complaints. P a t i e n t recovered from this acute bout of myocardial infarction with congestive heart failure and lived until 1966 when, at 85, she died during a Stokes-Adams seizure. Between 1958 a n d her demise she experienced several bouts of Stokes-Adams seizures with documented runs of ventricular fibrillation interchanging with cardiac asystole, but responded always to Isuprel a n d oxygen. From 1961, she developed a right bundle branch block in addition to complete heart block which persisted to her demise in 1966. T h e ventricular rate remained around 38 a n d the QRS complex measured 0.12 sec. ''~ Case 3. Sidney P. Schwartz, M.D., wrote as follows: "HB, aged 79, was known to have complete h e a r t block for seven years before she was operated upon for carcinoma of the vagina. Shortly after operation, she developed normal sinus r h y t h m [P-R 0.20 sec.] which was present when she died at 8 6 . . . She represents the only patient out of a series of upward of 500 patients with all forms of heart block in whom an established type of complete heart block reverted to sinus r h y t h m without any medication. ''9 Case 4. CW (No. 08-58-80) was 63 in 1960, when a single episode of syncope led to the discovery of complete A-V block documented by electrocardiograms recorded Sept. 28, 1960 (Fig. 2, A ) and Oct. 6, 1960 (P-P, 1.04 sec.; R-R, 1.6 to 1.8 sec.; QRS, 0.12 sec.; left axis deviation; and a pattern of right bundle branch block). On Oct. 3, 1961, an electrocardiogram showed 2:1 A-V block without other change, both before and after mild exercise (P-P, 0.78 to 0.62; R-R, 1.56 to 1.24 sec., respectively, and P-R, 0.32 sec.). Past history included diphtheria w i t h o u t recognized complications in childhood, diabetes mellitus, duodenal peptic ulcer, and one paroxysm of tachycardia about 1942. No further episodes of syncope occurred until early in 1962, when there were a series of t h e m for which he was seen by T h o m a s P. Lyon, M.D., on April 18, 1962. He appeared healthy, and was without detectable abnormalities other t h a n cardiovascular ones. T h e ventricular rate was 32 per minute, r h y t h m regular b u t for a few p r e m a t u r e beats; the first sound varied in amplitude, there was a m o d e r a t e , blowing, apical systolic murmur, and atrial sounds were present in diastole. Arterial pressure was 235/100 m m . Hg at first, later i~50 to 180/70 to 75. An electrocardiogram of March 6, 1962, showed complete A-V block (P-P, 1.0 sec.; R-R, 2.2 sec.; QRS, 0.12 sec.) with occasional ventricular premature beats b u t no other change since the earlier ones. Electrocardiograms of May 18 and 25 and Oct. 22, 1962 (Fig. 2, B), revealed the same r h y t h m and comparable rates; however, m o s t ventricular complexes showed right-axis deviation rather t h a n the previous left
May, 1976, Vol. 91, No. 5
Remission and recovery from complete heart block
variety (without changes in Leads V~ through V6) and premature beats were rare. The serum potassium was 5.0 mEq. per liter before, and 4.6 mEq. per liter during, a trial of chlorothiazide up to 1.5 Gm. per day; the trial was stopped because of nausea, another episode of giddiness, and no improvement in A-V block. Isuprel, 15 mg. in repeated daily doses made him feel jittery, caused no improvement, and was discontinued. Erythrityl, tetranitrate produced a sensation of tongue burning, and also was stopped. No further cardiovascular therapy was offered subsequent to Oct. 1962, when he was hospitalized for gastric retention with an exacerbation of peptic ulcer; antacids were used freely. He was examined twice in 1963, four times each in 1964 and 1965, and five times in 1966. Syncope and related symptoms were denied at each visit, and on every occasion the ventricular rhythm was regular at rates of 32 to 40. An electrocardiogram of Feb. 15, 1965, closely resembled that of Sept. 28, 1960 (there had been inconstant inversion of T-waves in Leads V4 through V~), with P-P 0.86 sec. and R-R 2.06 sec. and complete A-V block. A rhythm strip on June 15, 1965, was similar. The supernormal phase of conduction was never present. X-rays of the chest failed to reveal intracardiac calcification. In Dec. 1966, he had coryza followed by herpes labialis, and on Feb. 3, 1967, he was given propoxyphene hydrochloride because of low back ache. There was no other change in therapy or in his status. On Feb. 18, 1967, however, he noticed that his heart rate was an unaccustomed 60 per minute, counting it because of the nocturnal sensation of pounding. This rate reportedly persisted, and two days later he began to have Stokes-Adams attacks for the first time since 1962. At examination on Feb. 20, 1967, the heart indeed was regular at 60 per minute, and an electrocardiogram (Fig. 2, C) confirmed the presence of 1:1 A-V conduction (R-R. 1.0 sec.; P-R, 0.32 sec.; QRS was unchanged since Feb. 15, 1965, in showing a right bundle branch block pattern and left-axis deviation, but the unstable T-waves in Leads V~ through V6 were not so deeply inverted). With sustained deep respiration, 2:1 A-V block (Fig. 2, D) appeared repeatedly (P-P. 0.84 sec.; P-R, 0.28 sec.). An electrocardiogram Feb. 21, 1967, was identical to that of the preceding day in all respects including the clear addition of a notch in the P-wave, of which there had been some earlier suggestion. On Feb. 22, 1967, a transvenous fixed-rate pacemaker was installed. On subsequent examination, it was functioning perfectly at a rate of 72 per minute. No further syncope or giddiness had occurred up to a visit on April 3, 1967, but on Aug. 31, 1967. he reported occasional orthostatic giddiness and had noted that the pulse was sometimes irregular. The latter was confirmed by an electrocardiogram (Fig. 2, E), which showed competition of natural and artificial pacemakers with inconstant conduction at a P-R of 0.34 sec. This episode cleared rapidly, and on Oct. 6, 1967, the ventricular rhythm was regular again and independent of P-waves. On Dec. 15, 1967, he continued well and the r h y t h m was regular. Apparently with chest pain. he died suddenly on Jan. 11, 1968. At autopsy, the pacemaker unit was firing regularly at 62 per minute. Calcification of the mitral fibrous anulus was present, coronary atherosclerosls was only mild, and there were no gross anatomic reasons for death. Fibrosis of the A-V nodal region and the bundle of HIS, but not of the bundle branches, was present (Dr. Charles P. Bieber).
American Heart Journal
Fig. 2. Case 4, CW. Lead II throughout. The first cycle of B is not premature. A-V conduction appears in C, with 2:1 block in D.
Case 5. SK (No. 11-62-04) was brought co our attention by Ralph J. Spiegl, M.D., who kindly allowed us to summarize his records. He was 63 years of age in 1948, when he first visited another physician with a history suggestive of angina pectoris and paroxysmal tachycardia, but these never were present or prominent subsequently. Mild arterial hypertension and obesity were the chief findings. Nine electrocardiograms from Dec. 6, 1948, to March 5, 1962, were alike in showing sinus rhythm, rate, 50 to 82; P-R, 0.18 to 0.24 sec.; and QRS, 0.08 sec.; suggestion of P-wave notching in Lead 2, prominent Q-wave in Leads 3 and aVF, and normal Leads V1 through V6; only the last two records showed prolonged A-V conduction. The heart rate was normal in each of a dozen examinations to June 1, 1962. Asymptomatic heart block was discovered at another visit Dec. 28, 1962, and confirmed by an electrocardiogram (Fig. 3, A): P-P. 1.00 sec.; R-R, 1.64 sec.; and QRS, 0.10 sec. with Q-wave in Leads 3 and aV F as before but now, for the first time, with poor R-wave progression through Lead V4; P had become more clearly notched in Lead 2 and diphasic in Lead V , A similar record April 8, 1963, and a few episodes of giddiness, led to the temporary use of prednisone up to 80 rag.
647
Rytand, Stinson, and Kelly
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block asympt,omatically returned on Feb 1(t. 1.968. al~d syncopa! episodes late in 1968 led ~o th~ use ot a ~ransvenous demand pacemaker. There was ne A-V ,.:onduction in any el 14 electrocardiograms recorded between 3an. 2(I. 1969. and ,lan. 23. 1974. On the iar.t,er date. bo~h pacemake~ and pauem were functioning well. Discussion
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I !liliVit!iiil!i il ililil Fig. 3. Case 5, SK. Lead V~ in A, G, and D. Lead 1I in B. A-V conduction appears in B and D.
daily. Complete heart block was present and the serum potassium was 4.1 mEq. per liter when Dr. Spiegl first saw the patient May 13, 1963. Except as noted below, the heart rate was 40 to 48 per minute at three dozen examinations from that date through Dec. 27, 1966 (Fig. 3, C), during which period five unchanged electrocardiograms showed complete block. An electrocardiogram on Nov. 10, 1964, also showed complete block for the most part, but a few cycles seemed to be conducted at a P-R of 0.32 see. On April 17, 1965, the heart rate was 73 per minute, and an electrocardiogram revealed sinus rhythm with P-R of 0.30 sec. (Fig. 3, B ). There were rare cycles of 2:1 block; a few supraventricular premature beats were conducted. The heart rate was 42 per minute both two weeks before and two weeks after that record. Similar bradycardia persisted during and following an operation for repair of a Natal hernia, July 28, 1965, when gout appeared. Diuretics with potassium replacement were used for mild edema through much of 1965 and 1966; the serum potassium was 4.? mEq: per liter on Nov. 14, 1966. On March 3, 1967, the heart rate was 62 per minute, and rates of 82 to 88 per minute were found in many subsequent examinations and electrocardiograms from that date (Fig. 3. D) through Jan. 1968. In these records, the P-R was usually 0.28 see. (0.20 to 0.32 see.); one atrial premature beat was blocked but many others were conducted; for the first time, left bundle branch block with left-axis deviation appeared constantly on Aug. 4, 1967, and both were intermittent together a month later, when normai ventrieular complexes followed the pauses which succeeded ventricular premature beats. But for the more rapid rates with sinus rhythm, no other clinical changes were apparent. However, complete A-V
648
r a t e l y fi'om 1;bose w i t h a c q u i r e d b l o c k : in e a c h type, ~he cases are lis~ ed a c c o r d i n g ~.o d u r a t i o n of complel;e b l o c k prior t.o r e m i s s i o n . R e c o v e r y h a s p e r s i s t e d for ahnos~ t w o d e c a d e s e a c h in t h e pat i e n t s of Gilchrist a n d C a m p b e l l a n d for y e a r s in o t h e r ~ w i t h congenit, al block; r e m i s s i o n s u e r e m u c h more, b r i e f in t.be a c q u i r e d f o r m , a l t h o u g h one's duratior~ was t o t seve~ y e a r s u n t i l d e ~ ; h . S t o k e s - A d a m s e p i s o d e s ~e~'e n o t o b s e r v e d in a n y of ghe c o n g e n i t a l g r o u p , but, did o c c u r in C a s e 4 bo~h b e t o r e a n d a t t h e o n s e t of' r e m i s s i o n , as well as in Cases 2 a n d 5 subsequen'~ t o r e m i s sion. A t its onset:, a c q u i r e d b l o c k o f t e n a p p e a r s in p a r o x y s m s a~ first. T h i s ~toes n o t s e e m to o c c u r ~ t h congetdt, at block, a~d in g e n e r a l we h a v e t r i e d to a v o i d t h i s p r o b l e m b y t h e a r b i t r a r y e x c l u s i o n f r o m c o n s i d e r a n o n of r e m i s s i o n s w i t h i n t o u r y e a r s of t h e e s t a b l i s h m e n t of b l o c k ( a l t h o u g h Case 5 m a y be an e x c e p t i o n ) . B u t for a few cases described by O i l c h r i s t " as t o l l o w i n g his C o u r s e A, w i t h l i a b i l i t y to r e c u r r e n t s y n c o p a l att, acks, t h a t p h a s e in w h i c h p a r o x y s m s o c c u r p r i o r ~o t h e a c q u i r e d e s t a b l i s h m e n t of c o m p l e t e b l o c k s e e m s t o be o n l y t w o or t h r e e y e a r s ? . . . . . :~ Males and females are divided a b o u t equally. Age a t r e m i s s i o n was f r o m 20 t o a n e x t r a o r d i n a r y 76 y e a r s w i t h c o n g e n i t a l block, 64 t o 82 a f t e r f o u r t o t e n y e a r s of a c q u i r e d b l o c k . In. v i e w of t h e u s u a l age r a n g e w i t h i n w h i c h a c q u i r e d b l o c k is f o u n d , it is n o t a l t o g e t h e r s u r p r i s i n g t h a t r e m i s sions are m o r e b r i e f in t h i s g r o u p t h a n in t h o s e w h o s e b l o c k is c o n g e n i t a l . R e m i s s i o n s e e m s m o r e f r e q u e n t in t h e c o n g e n i t a l v a r i e t y , e s p e c i a l l y in ~Jew of t h e fact t h a t a c q u i r e d b l o c k is m o r e c o m m o n than congenital block. All b u t C a s e 4 h a d n a r r o w v e n t r i c u l a r c o m p l e x e s d u r i n g b l o c k , w h i l e p a t t e r n s of d e f e c t i v e i n t r a v e n t r i c u l a r cot)duc~ion c o n t i n u e d in h i m a n d first a p p e a r e d i n t h r e e o t h e r s w i t h r e m i s s i o n from acquired, b u t n o t congenital, block. In t h e c o n g e n i t a l group, t h e s h o r t e s t P - R i n t e r v a l in
May, 1976, i,~)l. 91, No. 5
R e m i s s i o n a n d recovery f r o m c o m p l e t e h e a r t b l o c k
Table I. R e m i s s i o n or r e c o v e r y in e s t a b l i s h e d h i g h - g r a d e or c o m p l e t e h e a r t b l o c k Restoration of A- V conduction Dr~ulolz8
duration of A- V biock ~vears)
Pa~ent
Age at onset (years)
Duration
Nature
43-76
76
4 years, to d e a t h
42
42
L6 years, continuing
:~5-.42 22-2!)
35-42 29
Nadas and Fyier Case L, NA
21)
20
Case 2, KT Case 3, HB Case 4. CW
[0 7 7
77 79 70
Campbell" ~Case 125)
5
64
Case 5. SK
~
$2
LenSgre, et al, *
Gilch~st;
Campbell, e~ aL Lenegre, e~, ai.
-
12-L9 years, c o n t i n u i n g
13 years, continuing 5 m o n t h s k n o w n , t h e n relapse u n k n o w n d u r a t i o n (18 mo. to 15 yr.) t h e n 6 yrs. or more, c o n t i n u i n g . 2 day s o n l y 7 years, to d e a t h 4 days or more, p l u s t r a n s i e n t c o m p e t i t i o n 6 mo. a ft e r p a c e m a k e r insertion. Sudden d e a t h Brief; 2 occasions 1 yr. a p a r t
1I too. until relapse; plus brief remission 2 yrs. earlier
P-R, 0.22 to 0.30 sec., no blocked cycles. P-R, 0.28 to 0.32 sec. and 3:2 Wenckebach block at first; P-R, 0.24 sec. with no blocked cycles 10-16 years later (Oct. 31, 1967, and Aug. 30, 1973; personal communications from A. R. Gilchrist and R. M. Marquis). P-R, 0.32 to 0.48 sec., no blocked cycles. P-R, 0.32 to 0.37 sec., no blocked cycles. P-R, 0.40 sec., rare blocked cycle at first. Later, P-R 0.33 see. with no blocked cycles.
P-R, 0.18 sec. P-R, 0.18 sec. P-R, 0.32 see.; 2:1 A-V block with deep inspiration.
P-R, 0.23 see.; no blocked cycles; later 2:I and 3:1 A-V block (P-R, 0.40 and 0.26 sec.) P-R, 0.28 (0.20 to 0.32) sec.).
*De~ails not available.
r e m i s s i o n was 0.22 sec.. the l o n g e s t 0.48 see. G i l c h r i s t ' s '; p a t i e n t had W e n c k e b a c h p e r i o d s i n e a r l v r e m i s s i o n b u t n o t later, a n d t h e P - R i n t e r val d e c r e a s e d w i t h time. Of t h e o t h e r c o n g e n i t a l cases i n remission, b l o c k e d cycles were r e c o r d e d o n l y i n Case i. C o n d u c t i o n t i m e i n t h e a c q u i r e d g r o u p was 0.18 Go 0.40 sec.. w i t h 2:1 a n d 3:1 A-V block i n two p a t i e n t s . N o d e l t a - w a v e s a p p e a r e d in arlv.
T h e a n a t o m i c d e t e c t was A-V n o d a l r e g i o n fibrosis a n d c a l c i f i c a t i o n of the micra] fibrous a n u l u s in Case 4, in w h o m t h e c o r o n a r y a r t e r i e s were p a t e n t a n d o n l y m o d e r a t e l y a t h e r o s c l e r o t i c . Calcific lesions in the v i c i n i t y of t h e c o n d u c t i o n s y s t e m , k n o w n e a r l i e r to b e p r e s e n t e v e n w i t h b l o c k w h i c h k~ p a r o x y s m a l , TM were n o t s h o w n r a d i o l o g i c a l l y in a n y case. b u t of c o u r s e m a y h a v e b e e n p r e s e n t i n fact as t h e y were in C a s e 4. I n t h e first p a t i e n t of L e n ~ g r e a n d c o - w o r k e r s : a rem a r k a b l e fibroadipose lesion v i r t u a l l y e n c a p s u l a t e d t h e A-V node. T h e p a t i e n t of C a m p b e l l a n d
American Heart Journal
S u z m a n 1~ a t o n e t i m e was t h o u g h t to h a v e h a d a v e n t r i c u l a r - s e p t a l defect, b u t t h i s d i a g n o s i s w a s given u p later. ~" ~ N e i t h e r t h e s e o b s e r v a t i o n s , n o r those of o t h e r s o n t h e l e s i o n s of h e a r t b l o c k as r e c e n t l y reviewed, TM s e e m a t all h e l p f u l i n u n d e r s t a n d i n g t h e s e r e m i s s i o n s . W e h a v e n o e v i d e n c e as to t h e c a u s e of b l o c k i n t h e o t h e r p a t i e n t s . N o n e h a d m y x e d e m a , n o r did a n y receive t h y r o i d Y A-V c o n d u c t i o n s o m e t i m e s r e t u r n s a f t e r t h e p r o d u c t i o n of c o m p l e t e A - V b l o c k as a c o m p l i c a t i o n of o p e n - h e a r t s u r g e r y for c o n g e n i t a l defects. S u c h r e m i s s i o n s a r e r a r e a f t e r f o u r weeks, b u t i n e x c e p t i o n a l i n s t a n c e s m a y b e d e l a y e d for a s l o n g as two y e a r s a n d p o s s i b l y e v e n f o u r y e a r s . TM 19 I n t e r m i t t e n t 2:1 a n d 3:1 A - V c o n d u c t i o n w a s recorded b y E r l a n g e r a n d B l a c k m a n :~ s u b s e q u e n t to the p r o d u c t i o n of c o m p l e t e b l o c k i n dog No. 3 i n t h e i r classic e x p e r i m e n t s . I n m o r e a c u t e e x p e r i m e n t s , Biggs :1 also n o t e d r e c o v e r y of A - V c o n d u c tion a f t e r " a c o n s i d e r a b l e t i m e . " Remission took place in Case 2 shortly after
{}49
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myocardial infarction. In Case 3, it occurred during a postoperative phase, and in Case 1, the initial remission was related temporally to an Army pre-induction examination. These events, of course, suggest a consideration of endogenous adrenal corticosteroid release in stressful situations, with consequent improvement in A-V conduction. It is difficult to understand how this could lead to prolonged remissions, and in other patients remissions occurred in the apparent absence of unusual stress. The return of sinus r h y t h m in A-V block has been reported to follow the use of isoproterenol hydrochloride, prednisone, chlorothiazide, or electronic pacemakers. ~~8 Prior to remission, a trial of chlorothiazide had failed in Case 4, and one of prednisone had failed in Case 5. One must point out th at many of the relevant case reports fail to note the prior duration of heart block; available data strongly suggest t h a t most, if not all, of these patients were within two, or rarely three, years of onset and thus might have been in the paroxysmal phase. A pacemaker was inserted in our Case 4 for the paradoxical reason t h a t episodes thought to be Stokes-Adams ones recurred with his spontaneous remission; relapse into complete block followed this operation, but six months later A-V conduction reappeared briefly, and a year later he died suddenly. Considerations of this sort support the use of a demand pacemaker, for the incidence of paroxysmal ventricular arrhythmias and the chance of death increase in the face of competition between endogenous and exogenous pacemakers. 2s, 29 We now use only the demand type of pacemaker. ~9'-~2 We have reviewed our own early cases of pacemaker insertion in order better to define any relationship between return of conduction and preoperative duration of complete block. T he results show th at intermittent A-V conduction is common following pacemaker implantation. In the present series it was documented in 23 out of 91 cases (25 per cent). This compares with an incidence of temporary return to sinus r h y t h m of 20 to 23 per cent in other reports. ~-~9 In our series, sinus r h y t h m was present in four cases at the time of pacemaker insertion, was the dominant r h yth m with occasional episodes of sinus arrest and slow idioventricular r h y t h m in two instances, and in another was present except during anginal attacks when heart block developed. This last
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patient demonstrated continuous sinus-pacemaker competition and died suddenly three months following pacemaker insertion without evidence of recent infarction. The remaining 19 case histories were examined to determine if postoperative sinus-pacemaker competition in fact represented remission of established heart block following the institution of cardiac pacing. The longest interval between the onset of heart block and pacemaker insertion in these patients was 27 months with an average interval of 10 months, except Case 4 described above. Thus, 18 of the 19 patients who demonstrated occasional A-V conduction postoperatively may be considered to have been in the paroxysmal phase of complete heart block. Indeed, 10 of the 19 patients showed A-V conduction immediately prior to or at the time of pacemaker insertion. None of the patients with a history of complete heart block longer t han two years developed A-V conduction postoperatively {except Case 4, above}. These considerations fail to support the thesis t h a t cardiac pacing p e r s e promotes the return of sinus r h y t h m in established heart block. Controversy has attended the existence of two particular types of conduction, A-V conduction within a supernormal phase and A-V retrograde conduction, in patients with high-grade or otherwise complete A-V block. 33 3~ We detected the latter in none of our patients, while the former was recorded occasionally only in Case 1. Finally, we have considered the possibility t h a t remission mav depend upon the establishment of accessory pathways. Accelerated A-V conduction has been reported as appearing in association with myocardial infarction and other insults. 35 Our patients, however, lacked delta-waves and none had P-R intervals shorter t han 0.18 sec. so that this hypothesis lacks support. Although His bundle studies were not obtained in any of the patients discussed here, results of such studies in others may be relevant. In congenital block without associated cardiac disease, block is almost invariably proximal to the bundle of His? 6-38 In acquired high-grade or complete A-V block with narrow ventricular complexes it usually is proximal, with wide ones distal29 Therefore, it would appear t h a t in all of the congenital cases presented here the block should have been proximal, a speculation receiving some
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Remission and recovery from complete heart block
s u p p o r t f r o m t h e a b s e n c e of S t o k e s - A d a m s s y n c o p e a n d t h e p r e s e n c e of n a r r o w Q R S c o m plexes ( a n d W e n c k e b a c h p e r i o d s i n one) d u r i n g r e m i s s i o n 2 ~ All of t h e a c q u i r e d - b l o c k p a t i e n t s e x c e p t Case 4 also h a d n a r r o w c o m p l e x e s d u r i n g h i g h - g r a d e block, b u t i n t h i s g r o u p t h e Q R S w a s i n v a r i a b l y w i d e n e d d u r i n g r e m i s s i o n (no i n f o r m a t i o n a v a i l a b l e i n Case 3), S t o k e s - A d a m s episodes first a p p e a r e d i n two, a n d M o b i t z T y p e I I w a s recorded in two patients; this suggests t h a t the site of b l o c k m a y h a v e s h i f t e d d i s t a l l y i n r e m i s sion 39 i n t h o s e w i t h a c q u i r e d disease.
12. 13. 14. 15. 16. 17.
Summary T h e r e t u r n of A - V c o n d u c t i o n is d e s c r i b e d in a p a t i e n t a f t e r t w o d e c a d e s of h i g h - g r a d e or c o m p l e t e c o n g e n i t a l h e a r t block. S i m i l a r cases h a v e b e e n r e p o r t e d b y o t h e r s , w i t h r e m i s s i o n or e v e n r e c o v e r y c o m m e n c i n g u p t o t h e f o u r t h d e c a d e or later. A s i m i l a r p h e n o m e n o n is also d e s c r i b e d i n f o u r p a t i e n t s w i t h a c q u i r e d h e a r t b l o c k of f o u r to ten years' duration; in them, remission was u s u a l l y b r i e f b u t p e r s i s t e d for s e v e n y e a r s i n o n e p a t i e n t . N o f u l l r e p o r t of t h i s s e e m s t o h a v e b e e n p u b l i s h e d p r e v i o u s l y . P o s s i b l e e x p l a n a t i o n s are discussed, b u t n o c o n c l u s i o n is r e a c h e d . A p a r t f r o m its i n t e r e s t , t h e p h e n o m e n o n is of i m p o r t a n c e w i t h r e s p e c t to t h e s e l e c t i o n of d e m a n d t y p e e l e c t r o n i c p a c e m a k e r s i n t h e m a n a g e m e n t of p a t i e n t s w i t h h e a r t block.
18.
19.
20. 21. 22.
23. 24.
REFERENCES 1. Campbell, M., and Thorne, M. G.: Congenital heart block, Br. Heart J. 18:90, 1956. 2. Campbell, M., and Emanuel, R.: Six Cases of congenital complete heart block followed for 34-40 years, Br. Heart J. 29:577, 1967. 3. Gilchrist, A. R.: Clinical aspects of high-grade heartblock, Scot. Med. J. 3"53, 1958. 4. Len~gre,J.i Deparis, M., Auz~py, Ph., and Gay, J.: Deux cas (run anatomo-clinique) de bloc auriculo-ventriculaire probablement congenital et d'~volution r~gressive. Arch. Mal. Coeur 63:749, 1970. 5. Nadas, A. N., and Fyler, D. C.: Pediatric Cardiology, Ed. 3. Philadelphia, 1972, W. B. Saunders Company, p. 212. 6. Campbell, M.: Complete heart block, Br. Heart J. 6:69, 1944. 7. Shearn, M. A., Tarr, E., and Rytand, D. A.: The significance of changes in amplitude of the first heart sound in children with A-V block, Circulation 7:839, 1953. 8. Eckstein, M.: Personal communication, April 19. 1967. 9. Schwartz, S. P.: Personal communication, March 28, 1967. 10. Spiegl, R. J.: Personal communications, Oct. 19, 1967, and subsequently. 11. Comeau, W. J.: Paroxysmal complete heart block alter-
American Heart Journal
25.
26. 27. 28. 29. 30. 31. 32. 33.
nating with normal rhythm and conduction, Am. J. Med. Sci. 194:43, 1937. Roos, A.: Paroxysmal complete heart block produced by ischemia of the auriculoventricular node. AM. HEARTJ. 30:238, 1945. Lawrence, J. S., and Forbes, G. W.: Paroxysmal heart block and ventricular standstill, Br. Heart J. 6:53. 1944. Rytand. D. A., and Lipsitch. L. S.: Clinical aspects of calcification of the mitral annulus fibrosus, Arch. Intern. Med. 78:544. 1946. Campbell, M., and Suzman, S. S.: Congenital complete heart block. An account of eight eases, AM. HEART J. 9:304, 1934. Davies, M. J.: Pathology of Conducting Tissue of the Heart. New York, 1971, Appleton-Century-Crofts. Singh, J. B., Starobin, O. E., Guerfant, R. C., and Manders. E. K.: Reversible atrioventricular block in myxedema, Chest 63:582, 1973. Averill, K. H., Vogel, J. H. K., Pryor. R., and Blount, S. G., Jr.: Complete heart block following intracardiac surgery. Reversion to normal sinus rhythm after twentyfive months, Am. J. Cardiol. 14:556, 1964. Murphy, D. A., Graham, G. R., Tynan, M., and BonhamCarter, R. E.: Prognosis of complete atrioven~ricular dissociation in children after open-heart surgery, Lancet 1:750, 1970. Erlanger, J., and Blackman, J. R.: Further studies in the physiology of heart-block in mammals. Chronic auriculoventricular heart-block in the dog, Heart 1:177, 1910. Biggs, L. N. H.: Investigation of the bundle of His in rabbits' excised hearts perfused with Locke's fluid. Br. Med. J. 1:1419, 1908. Friedberg, C. K., Kahn, M., Scheuer. J.. Bleifer, S.. and Dack, S.: Adams-Stokes syndrome associated with chronic heart block. Treatment with corticosteroids, J. A. M. A. 1 72:1146, 1960. Lown, B., Arons, W. L., Ganong, W. F., Vazifdar, J. P., and Levine, S. A.: Adrenal steroids and auriculoventricular conduction, AM. HEARTJ. 50:760, 1955. Dall, J. L. C.: The effect of steroid therapy on normal and abnormal atrio-ventricular conduction, Br. Heart J, 26:537, 1964. Schwartz, S. P., and Schwartz, L. S.: Adams-Stokes syndrome during normal sinus rhythm and transient heart block. I. Effects of Isuprel on patients with AdamsStokes syndrome during normal sinus rhythm and ~ransient heart block, AM. HEARTJ. 57:849, 1959. Tobian, L.: Prevention of Stokes-Adams seizures with chlorothiazide, N. Engl. J. Med. 265:623, 1961. Sowton, E.: Artificial pacemaking and sinus rhythm, Br. Heart J. 27:311, 1965. Chardack, W. M., Gage, A. A., Federico, A. J., Schimert. G., and Greatbatch, W.: The long-term treatment of heart block, Progr. Cardiovasc. Dis. 9:105. 1966. Bilitch, M., Cosby, R. S., and Cafferky, E. A.:' Ventricular fibrillation and competitive pacing, N. Engl. J. Med. 276:589, 1967. Siddons, H., and Sowton, E.: Cardiac Pacemakers, Springfield, Ill., 1967, Charles C Thomas, Publisher. Sowton, E.: Clinical application of demand pacemakers, Br. Med. J. 3:576, 1967. Castellanos, A., Jr., Lemberg, L., Jude. J. R., MobinUddin. K., and Berkovits, B. V.: Implantable demand pacemaker, Br. Heart J. 30:29, 1968. Williams, D. O.: Supernormal phase of A-V conduction. A study during heart block and endocardial pacing, Br. Heart J. 35:365, 1973.
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34. Gupta, P. K., and Haft, J. I.: Retrograde ventriculoatrial conduction in complete heart block. Studies with His bundle electrocardiography, Am. J. Cardiol. 30:408, 1972. 35. Mathew, G., and Raftery, E. B.: Accelerated atrioventricular conduction after myocardial infarction. A study using His bundle electrograms, Br. Heart J. 35:985, 1973. 36. Rosen, K. M., Mehta, A., Rahimtoola, S. H., and Miller, R. A.: Sites of congenital and surgical heart block as defined by His bundle electrocardiography, Circulation 44:833, 1971.
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37. Kelly, D. T., Brodsky, S. J., Mirowski, M., Krovetz, J., and Rowe, R. D.: Bundle of His recordings in congenital complete heart block, Circulation 45-277, 1972. 38. Wolff, G. S., Freed, M. D., and Ellison, R. C.: Bundle of His recordings in congenital heart disease, Br. Heart J. 35:805, 1973. 39. Dreifus, L. S., Watanabe, Y., Haiat, R., and Kimbiris, D.: Atrioventricular block, Am J. Cardiol. 28:371, I971. 40. Reichek, N., Jackson, L., Ronan, J. A., Jr., and Perloff, J. K.: Advanced congenital first-degree atrioventricular block. A His bundle electrocardiographic study, Arch. Intern. Med. !30:765, 1972.
May, 1976, Vol. 91, No. 5
Stanford and San Francisco, Calif.
Temporary or prolonged return of atrioventricular (A-V) conduction after many years of established, complete heart block seems virtually prohibited by the very name of the disorder. Such an event does occur, however, with reports of remission or recovery in five patients with cong e n i t a l h e a r t b l o c k . 1-5 W i t h a c q u i r e d b l o c k , p u b lished evidence of this phenomenon is m u c h l e s s c o n v i n c i n g a n d c o n c e r n s o n l y t w o p a t i e n t s . 3, ~ T h i s is t o r e c o r d o b s e r v a t i o n s upon spontaneous recovery in a young man with congenital block and on a brief remission in an elderly one after seven years of acquired, established complete A-V block. These experiences led us to make inquiries which resulted in documents, also to be presented, on remissions in three additional elderly patients who had had complete, acquired block from four to ten years. All observations were made some time ago, unfortunately without His bundle recordings.
Case reports Case 1, NA, kindly referred by Ann Purdy, M.D., was born two months prematurely on May 20, 1929. When but a few weeks of age, he had a heart rate of 52 to 60 and there was a loud apical systolic murmur; there was no cyanosis. Occasional brief episodes of syncope were reported up to two years of age, but were not observed by a physician. Three-lead electrocardiograms on April 15, 1931, a n d on May 24, Aug. 30, and Sept. 20, 1933, were alike in showing (Fig. 1, A ) w h a t someone then interpreted as 2:1 A-V block; the short strips available failed to establish or eliminate the possibility of complete A-V block with synchronization (R-R 1.20, 1.24, 1.42,
From the Departments of Medicine (Cardiology Division) and Surgery (Cardiovascular Division), Stanford University School of Medicine, Stanford, Calif., and the Department of Medicine, Presbyterian Hospital, Pacific Medical Center, San Francisco, Calif. Received for publication Feb. 14, 1974. Reprint requests: Dr. David A. Rytand, Department of Medicine, Stanford University Medical Center, Stanford, Calif. 94305.
May, 1976, Vol. 91, No. 5, pp. 645-652
and 1.32 sec.; P-R 0.16, 0.20, 0.22, a n d 0.24 sec., respectively). In June, 1936, the heart rate was reportedly 80 to 90 per minute during a febrile bout of pneumonia and empyema. Nine electrocardiograms from Jan. 9, 1936, to Jan. 15, 1949, showed complete A-V block; the P-P intervals were 0.60 to 0.85 sec., the R-R intervals were 1.20 to 1.58 sec., and the ventricular complexes were normal and regular but for the presence of the supernormal phase of conduction in 'records taken after 1936 (Fig. 1, B). A-V synchronization was present at times. Meanwhile, chorea in 1941 was followed by a rough diastolic murmur at the apex for about two years. An early systolic apical murmur was constant, and at times an early diastolic sound was heard and recorded. Growth and development were normal, as were roentgenograms of the chest. This patient is Case 2 of another report 7 in which Fig. 2B shows the wide range of P-R intervals of complete A:V block recorded on Jan. 15, 1949. At a pre-induction Army examination in Feb. 1949, the heart rate allegedly was normal. This was confirmed March 29, 1949, when an otherwise unchanged electrocardiogram showed a rate of 90 per minute, with sinus r h y t h m and P-R 0.40 sec. An electrocardiogram (Fig. 1, C) on July 1, 1949, was virtually identical, with P-R 0.40 sec. and rate 75 per minute, except for failure of conduction in a single cycle. On July 22, 1949, complete A-V block reappeared, with occasional conduction in a supernormal phase at R-P intervals of 0.50 to 0.60 sec. (P-P, 0.54; R-R, 1.09 sec.); after exercise, complete A-V block persisted (P-P, 0.46; R-R, 0.85 sec.). Complete A-V block with a supernormal phase of conduction was present in an electrocardiogram Dec. 18, 1950 (P-P, 0.77; R-R, 1.43 sec.); the ventricular complexes remained normal and unchanged {Fig. 1, D). After 14 asymptomatic years, he was examined in Nov. 1964, by Dr. Richard Merchant who recorded an electrocardiogram which showed sinus r h y t h m with a rate of 75 per minute, a P-R interval of 0.40 sec., and a QRS of 0.09 sec. An occasional P-wave was blocked when its onset occurred within 0.28 sec. of the preceding QRS. In Dec. 1965, he entered a hospital because of a fractured right hip: Again he denied symptoms of cardiac disease. His heart rate was 80 per minute, arterial pressure 115/75. The cardiac examination was said to be normal, b u t no electrocardiogram was recorded. In Aug. 1967, he was examined by One of us: The patient
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645
Rytand, Stinson, and Kelly
B 5/4/58
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C 7/!149
E 8A5/67 Fig. 1. Case 1. NA. Lead II inA, B, and C. Lead V, in D and E. A-V conduction appears in C and E.
stated t h a t he led a normal life without effort intolerance, and denied any s y m p t o m s of faintness or of syncope. Physical examination revealed an arterial pressure of 120/75. a normal cardiac size, normal sounds, and no m u r m u r s or gallops. An electrocardiogram (Fig. 1. E) was u n c h a n g e d from t h a t of Nov. 1964. Sinus r h y t h m was present with a race of 80 per minute. T h e P-R interval was 0.36 to 0.40 sec., the QRS interval was 0.09 sec. Again, an occasional P-wave failed to evoke a ventricular response when its onset fell within 0.28 sec. of the preceding QRS. On this occasion, he exercised vigorously for three minutes; his heart rate rose to 130 per minute, and remained regular. Neither exercise nor carotid sinus stimulation altered the P-R interval. On J u n e 24, 1970, an electrocardiogram recorded for Richard R. Babb, M.D., showed uniform conduction with a P-R interval of 0.33 sec. Case 2. Marc Eckstein, M.D., wrote as follows: " K T . age 72, was seen by me for the first time in 1953. She was observed by another physician prior to m y examination and was known to have had complete heart block for five years. Her electrocardiogram revealed a pattern of complete heart block with a ventricular rate of 40 per minute. QRS complex measured 0.09 sec. and there was left-axis deviation. Patient did very well until Dec. 1958, age 77, when she suddenly developed substernal pain, dyspnea, and orthopnea. On hospital admis-
646
sion, h e r electrocardiogram revealed t h e same pattern of complete heart block, b u t ST s e g m e n t s were elevated. Ventricular rate was 38. Sedimentation rate a n d enzymes were increased. Patient was given Demerol, oxygen, and a mercurial and she was started on anticoagulants. Since signs of congestive failure increased, it was decided to digitalize her. She received 2.5 mg. of digoxin within 24 hours, then 0:75 mg. in the next 24 hours. An electrocardiogram, taken after this 48-hour period, revealed a regular sinus r h y t h m with a rate of 75 per minute. P R interval was 0.18 sec. a n d QRS 0.10 sec. T h e axis remained the same, b u t there were T-wave changes, consistent with an acute process. This r h y t h m persisted for two days then reverted to its original pattern, when digoxin was stopped due to gastric complaints. P a t i e n t recovered from this acute bout of myocardial infarction with congestive heart failure and lived until 1966 when, at 85, she died during a Stokes-Adams seizure. Between 1958 a n d her demise she experienced several bouts of Stokes-Adams seizures with documented runs of ventricular fibrillation interchanging with cardiac asystole, but responded always to Isuprel a n d oxygen. From 1961, she developed a right bundle branch block in addition to complete heart block which persisted to her demise in 1966. T h e ventricular rate remained around 38 a n d the QRS complex measured 0.12 sec. ''~ Case 3. Sidney P. Schwartz, M.D., wrote as follows: "HB, aged 79, was known to have complete h e a r t block for seven years before she was operated upon for carcinoma of the vagina. Shortly after operation, she developed normal sinus r h y t h m [P-R 0.20 sec.] which was present when she died at 8 6 . . . She represents the only patient out of a series of upward of 500 patients with all forms of heart block in whom an established type of complete heart block reverted to sinus r h y t h m without any medication. ''9 Case 4. CW (No. 08-58-80) was 63 in 1960, when a single episode of syncope led to the discovery of complete A-V block documented by electrocardiograms recorded Sept. 28, 1960 (Fig. 2, A ) and Oct. 6, 1960 (P-P, 1.04 sec.; R-R, 1.6 to 1.8 sec.; QRS, 0.12 sec.; left axis deviation; and a pattern of right bundle branch block). On Oct. 3, 1961, an electrocardiogram showed 2:1 A-V block without other change, both before and after mild exercise (P-P, 0.78 to 0.62; R-R, 1.56 to 1.24 sec., respectively, and P-R, 0.32 sec.). Past history included diphtheria w i t h o u t recognized complications in childhood, diabetes mellitus, duodenal peptic ulcer, and one paroxysm of tachycardia about 1942. No further episodes of syncope occurred until early in 1962, when there were a series of t h e m for which he was seen by T h o m a s P. Lyon, M.D., on April 18, 1962. He appeared healthy, and was without detectable abnormalities other t h a n cardiovascular ones. T h e ventricular rate was 32 per minute, r h y t h m regular b u t for a few p r e m a t u r e beats; the first sound varied in amplitude, there was a m o d e r a t e , blowing, apical systolic murmur, and atrial sounds were present in diastole. Arterial pressure was 235/100 m m . Hg at first, later i~50 to 180/70 to 75. An electrocardiogram of March 6, 1962, showed complete A-V block (P-P, 1.0 sec.; R-R, 2.2 sec.; QRS, 0.12 sec.) with occasional ventricular premature beats b u t no other change since the earlier ones. Electrocardiograms of May 18 and 25 and Oct. 22, 1962 (Fig. 2, B), revealed the same r h y t h m and comparable rates; however, m o s t ventricular complexes showed right-axis deviation rather t h a n the previous left
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Remission and recovery from complete heart block
variety (without changes in Leads V~ through V6) and premature beats were rare. The serum potassium was 5.0 mEq. per liter before, and 4.6 mEq. per liter during, a trial of chlorothiazide up to 1.5 Gm. per day; the trial was stopped because of nausea, another episode of giddiness, and no improvement in A-V block. Isuprel, 15 mg. in repeated daily doses made him feel jittery, caused no improvement, and was discontinued. Erythrityl, tetranitrate produced a sensation of tongue burning, and also was stopped. No further cardiovascular therapy was offered subsequent to Oct. 1962, when he was hospitalized for gastric retention with an exacerbation of peptic ulcer; antacids were used freely. He was examined twice in 1963, four times each in 1964 and 1965, and five times in 1966. Syncope and related symptoms were denied at each visit, and on every occasion the ventricular rhythm was regular at rates of 32 to 40. An electrocardiogram of Feb. 15, 1965, closely resembled that of Sept. 28, 1960 (there had been inconstant inversion of T-waves in Leads V4 through V~), with P-P 0.86 sec. and R-R 2.06 sec. and complete A-V block. A rhythm strip on June 15, 1965, was similar. The supernormal phase of conduction was never present. X-rays of the chest failed to reveal intracardiac calcification. In Dec. 1966, he had coryza followed by herpes labialis, and on Feb. 3, 1967, he was given propoxyphene hydrochloride because of low back ache. There was no other change in therapy or in his status. On Feb. 18, 1967, however, he noticed that his heart rate was an unaccustomed 60 per minute, counting it because of the nocturnal sensation of pounding. This rate reportedly persisted, and two days later he began to have Stokes-Adams attacks for the first time since 1962. At examination on Feb. 20, 1967, the heart indeed was regular at 60 per minute, and an electrocardiogram (Fig. 2, C) confirmed the presence of 1:1 A-V conduction (R-R. 1.0 sec.; P-R, 0.32 sec.; QRS was unchanged since Feb. 15, 1965, in showing a right bundle branch block pattern and left-axis deviation, but the unstable T-waves in Leads V~ through V6 were not so deeply inverted). With sustained deep respiration, 2:1 A-V block (Fig. 2, D) appeared repeatedly (P-P. 0.84 sec.; P-R, 0.28 sec.). An electrocardiogram Feb. 21, 1967, was identical to that of the preceding day in all respects including the clear addition of a notch in the P-wave, of which there had been some earlier suggestion. On Feb. 22, 1967, a transvenous fixed-rate pacemaker was installed. On subsequent examination, it was functioning perfectly at a rate of 72 per minute. No further syncope or giddiness had occurred up to a visit on April 3, 1967, but on Aug. 31, 1967. he reported occasional orthostatic giddiness and had noted that the pulse was sometimes irregular. The latter was confirmed by an electrocardiogram (Fig. 2, E), which showed competition of natural and artificial pacemakers with inconstant conduction at a P-R of 0.34 sec. This episode cleared rapidly, and on Oct. 6, 1967, the ventricular rhythm was regular again and independent of P-waves. On Dec. 15, 1967, he continued well and the r h y t h m was regular. Apparently with chest pain. he died suddenly on Jan. 11, 1968. At autopsy, the pacemaker unit was firing regularly at 62 per minute. Calcification of the mitral fibrous anulus was present, coronary atherosclerosls was only mild, and there were no gross anatomic reasons for death. Fibrosis of the A-V nodal region and the bundle of HIS, but not of the bundle branches, was present (Dr. Charles P. Bieber).
American Heart Journal
Fig. 2. Case 4, CW. Lead II throughout. The first cycle of B is not premature. A-V conduction appears in C, with 2:1 block in D.
Case 5. SK (No. 11-62-04) was brought co our attention by Ralph J. Spiegl, M.D., who kindly allowed us to summarize his records. He was 63 years of age in 1948, when he first visited another physician with a history suggestive of angina pectoris and paroxysmal tachycardia, but these never were present or prominent subsequently. Mild arterial hypertension and obesity were the chief findings. Nine electrocardiograms from Dec. 6, 1948, to March 5, 1962, were alike in showing sinus rhythm, rate, 50 to 82; P-R, 0.18 to 0.24 sec.; and QRS, 0.08 sec.; suggestion of P-wave notching in Lead 2, prominent Q-wave in Leads 3 and aVF, and normal Leads V1 through V6; only the last two records showed prolonged A-V conduction. The heart rate was normal in each of a dozen examinations to June 1, 1962. Asymptomatic heart block was discovered at another visit Dec. 28, 1962, and confirmed by an electrocardiogram (Fig. 3, A): P-P. 1.00 sec.; R-R, 1.64 sec.; and QRS, 0.10 sec. with Q-wave in Leads 3 and aV F as before but now, for the first time, with poor R-wave progression through Lead V4; P had become more clearly notched in Lead 2 and diphasic in Lead V , A similar record April 8, 1963, and a few episodes of giddiness, led to the temporary use of prednisone up to 80 rag.
647
Rytand, Stinson, and Kelly
S.K.
Nq:r ~!1I, .,li~ I;'if:I"+,:..I.,-I I~.,:" . ..........
1212 8 1 6 2
block asympt,omatically returned on Feb 1(t. 1.968. al~d syncopa! episodes late in 1968 led ~o th~ use ot a ~ransvenous demand pacemaker. There was ne A-V ,.:onduction in any el 14 electrocardiograms recorded between 3an. 2(I. 1969. and ,lan. 23. 1974. On the iar.t,er date. bo~h pacemake~ and pauem were functioning well. Discussion
B
4/17/65
~fi!l~i!!I!ilil!ii!l!ilIl}}!{H~iI~liiI~If!~}i;i!!i~Id~!;!lfi!iIih ii~!hlii~ ~ S a l i e n t p o i n t s are se~ f o r t h in T a b l e I. in w h i c h .d!tl!i!ili!i!l!;~il~tiit!i;i~fi,iil!;iiill]lt!i![llfilt!iiit~titl i1!1~-~!IIi,ir t h e c o n g e n i t a l cases are p r e s e n t e d a b o v e , sepa:.!!.! .....
i!
C 12/27/66
I !liliVit!iiil!i il ililil Fig. 3. Case 5, SK. Lead V~ in A, G, and D. Lead 1I in B. A-V conduction appears in B and D.
daily. Complete heart block was present and the serum potassium was 4.1 mEq. per liter when Dr. Spiegl first saw the patient May 13, 1963. Except as noted below, the heart rate was 40 to 48 per minute at three dozen examinations from that date through Dec. 27, 1966 (Fig. 3, C), during which period five unchanged electrocardiograms showed complete block. An electrocardiogram on Nov. 10, 1964, also showed complete block for the most part, but a few cycles seemed to be conducted at a P-R of 0.32 see. On April 17, 1965, the heart rate was 73 per minute, and an electrocardiogram revealed sinus rhythm with P-R of 0.30 sec. (Fig. 3, B ). There were rare cycles of 2:1 block; a few supraventricular premature beats were conducted. The heart rate was 42 per minute both two weeks before and two weeks after that record. Similar bradycardia persisted during and following an operation for repair of a Natal hernia, July 28, 1965, when gout appeared. Diuretics with potassium replacement were used for mild edema through much of 1965 and 1966; the serum potassium was 4.? mEq: per liter on Nov. 14, 1966. On March 3, 1967, the heart rate was 62 per minute, and rates of 82 to 88 per minute were found in many subsequent examinations and electrocardiograms from that date (Fig. 3. D) through Jan. 1968. In these records, the P-R was usually 0.28 see. (0.20 to 0.32 see.); one atrial premature beat was blocked but many others were conducted; for the first time, left bundle branch block with left-axis deviation appeared constantly on Aug. 4, 1967, and both were intermittent together a month later, when normai ventrieular complexes followed the pauses which succeeded ventricular premature beats. But for the more rapid rates with sinus rhythm, no other clinical changes were apparent. However, complete A-V
648
r a t e l y fi'om 1;bose w i t h a c q u i r e d b l o c k : in e a c h type, ~he cases are lis~ ed a c c o r d i n g ~.o d u r a t i o n of complel;e b l o c k prior t.o r e m i s s i o n . R e c o v e r y h a s p e r s i s t e d for ahnos~ t w o d e c a d e s e a c h in t h e pat i e n t s of Gilchrist a n d C a m p b e l l a n d for y e a r s in o t h e r ~ w i t h congenit, al block; r e m i s s i o n s u e r e m u c h more, b r i e f in t.be a c q u i r e d f o r m , a l t h o u g h one's duratior~ was t o t seve~ y e a r s u n t i l d e ~ ; h . S t o k e s - A d a m s e p i s o d e s ~e~'e n o t o b s e r v e d in a n y of ghe c o n g e n i t a l g r o u p , but, did o c c u r in C a s e 4 bo~h b e t o r e a n d a t t h e o n s e t of' r e m i s s i o n , as well as in Cases 2 a n d 5 subsequen'~ t o r e m i s sion. A t its onset:, a c q u i r e d b l o c k o f t e n a p p e a r s in p a r o x y s m s a~ first. T h i s ~toes n o t s e e m to o c c u r ~ t h congetdt, at block, a~d in g e n e r a l we h a v e t r i e d to a v o i d t h i s p r o b l e m b y t h e a r b i t r a r y e x c l u s i o n f r o m c o n s i d e r a n o n of r e m i s s i o n s w i t h i n t o u r y e a r s of t h e e s t a b l i s h m e n t of b l o c k ( a l t h o u g h Case 5 m a y be an e x c e p t i o n ) . B u t for a few cases described by O i l c h r i s t " as t o l l o w i n g his C o u r s e A, w i t h l i a b i l i t y to r e c u r r e n t s y n c o p a l att, acks, t h a t p h a s e in w h i c h p a r o x y s m s o c c u r p r i o r ~o t h e a c q u i r e d e s t a b l i s h m e n t of c o m p l e t e b l o c k s e e m s t o be o n l y t w o or t h r e e y e a r s ? . . . . . :~ Males and females are divided a b o u t equally. Age a t r e m i s s i o n was f r o m 20 t o a n e x t r a o r d i n a r y 76 y e a r s w i t h c o n g e n i t a l block, 64 t o 82 a f t e r f o u r t o t e n y e a r s of a c q u i r e d b l o c k . In. v i e w of t h e u s u a l age r a n g e w i t h i n w h i c h a c q u i r e d b l o c k is f o u n d , it is n o t a l t o g e t h e r s u r p r i s i n g t h a t r e m i s sions are m o r e b r i e f in t h i s g r o u p t h a n in t h o s e w h o s e b l o c k is c o n g e n i t a l . R e m i s s i o n s e e m s m o r e f r e q u e n t in t h e c o n g e n i t a l v a r i e t y , e s p e c i a l l y in ~Jew of t h e fact t h a t a c q u i r e d b l o c k is m o r e c o m m o n than congenital block. All b u t C a s e 4 h a d n a r r o w v e n t r i c u l a r c o m p l e x e s d u r i n g b l o c k , w h i l e p a t t e r n s of d e f e c t i v e i n t r a v e n t r i c u l a r cot)duc~ion c o n t i n u e d in h i m a n d first a p p e a r e d i n t h r e e o t h e r s w i t h r e m i s s i o n from acquired, b u t n o t congenital, block. In t h e c o n g e n i t a l group, t h e s h o r t e s t P - R i n t e r v a l in
May, 1976, i,~)l. 91, No. 5
R e m i s s i o n a n d recovery f r o m c o m p l e t e h e a r t b l o c k
Table I. R e m i s s i o n or r e c o v e r y in e s t a b l i s h e d h i g h - g r a d e or c o m p l e t e h e a r t b l o c k Restoration of A- V conduction Dr~ulolz8
duration of A- V biock ~vears)
Pa~ent
Age at onset (years)
Duration
Nature
43-76
76
4 years, to d e a t h
42
42
L6 years, continuing
:~5-.42 22-2!)
35-42 29
Nadas and Fyier Case L, NA
21)
20
Case 2, KT Case 3, HB Case 4. CW
[0 7 7
77 79 70
Campbell" ~Case 125)
5
64
Case 5. SK
~
$2
LenSgre, et al, *
Gilch~st;
Campbell, e~ aL Lenegre, e~, ai.
-
12-L9 years, c o n t i n u i n g
13 years, continuing 5 m o n t h s k n o w n , t h e n relapse u n k n o w n d u r a t i o n (18 mo. to 15 yr.) t h e n 6 yrs. or more, c o n t i n u i n g . 2 day s o n l y 7 years, to d e a t h 4 days or more, p l u s t r a n s i e n t c o m p e t i t i o n 6 mo. a ft e r p a c e m a k e r insertion. Sudden d e a t h Brief; 2 occasions 1 yr. a p a r t
1I too. until relapse; plus brief remission 2 yrs. earlier
P-R, 0.22 to 0.30 sec., no blocked cycles. P-R, 0.28 to 0.32 sec. and 3:2 Wenckebach block at first; P-R, 0.24 sec. with no blocked cycles 10-16 years later (Oct. 31, 1967, and Aug. 30, 1973; personal communications from A. R. Gilchrist and R. M. Marquis). P-R, 0.32 to 0.48 sec., no blocked cycles. P-R, 0.32 to 0.37 sec., no blocked cycles. P-R, 0.40 sec., rare blocked cycle at first. Later, P-R 0.33 see. with no blocked cycles.
P-R, 0.18 sec. P-R, 0.18 sec. P-R, 0.32 see.; 2:1 A-V block with deep inspiration.
P-R, 0.23 see.; no blocked cycles; later 2:I and 3:1 A-V block (P-R, 0.40 and 0.26 sec.) P-R, 0.28 (0.20 to 0.32) sec.).
*De~ails not available.
r e m i s s i o n was 0.22 sec.. the l o n g e s t 0.48 see. G i l c h r i s t ' s '; p a t i e n t had W e n c k e b a c h p e r i o d s i n e a r l v r e m i s s i o n b u t n o t later, a n d t h e P - R i n t e r val d e c r e a s e d w i t h time. Of t h e o t h e r c o n g e n i t a l cases i n remission, b l o c k e d cycles were r e c o r d e d o n l y i n Case i. C o n d u c t i o n t i m e i n t h e a c q u i r e d g r o u p was 0.18 Go 0.40 sec.. w i t h 2:1 a n d 3:1 A-V block i n two p a t i e n t s . N o d e l t a - w a v e s a p p e a r e d in arlv.
T h e a n a t o m i c d e t e c t was A-V n o d a l r e g i o n fibrosis a n d c a l c i f i c a t i o n of the micra] fibrous a n u l u s in Case 4, in w h o m t h e c o r o n a r y a r t e r i e s were p a t e n t a n d o n l y m o d e r a t e l y a t h e r o s c l e r o t i c . Calcific lesions in the v i c i n i t y of t h e c o n d u c t i o n s y s t e m , k n o w n e a r l i e r to b e p r e s e n t e v e n w i t h b l o c k w h i c h k~ p a r o x y s m a l , TM were n o t s h o w n r a d i o l o g i c a l l y in a n y case. b u t of c o u r s e m a y h a v e b e e n p r e s e n t i n fact as t h e y were in C a s e 4. I n t h e first p a t i e n t of L e n ~ g r e a n d c o - w o r k e r s : a rem a r k a b l e fibroadipose lesion v i r t u a l l y e n c a p s u l a t e d t h e A-V node. T h e p a t i e n t of C a m p b e l l a n d
American Heart Journal
S u z m a n 1~ a t o n e t i m e was t h o u g h t to h a v e h a d a v e n t r i c u l a r - s e p t a l defect, b u t t h i s d i a g n o s i s w a s given u p later. ~" ~ N e i t h e r t h e s e o b s e r v a t i o n s , n o r those of o t h e r s o n t h e l e s i o n s of h e a r t b l o c k as r e c e n t l y reviewed, TM s e e m a t all h e l p f u l i n u n d e r s t a n d i n g t h e s e r e m i s s i o n s . W e h a v e n o e v i d e n c e as to t h e c a u s e of b l o c k i n t h e o t h e r p a t i e n t s . N o n e h a d m y x e d e m a , n o r did a n y receive t h y r o i d Y A-V c o n d u c t i o n s o m e t i m e s r e t u r n s a f t e r t h e p r o d u c t i o n of c o m p l e t e A - V b l o c k as a c o m p l i c a t i o n of o p e n - h e a r t s u r g e r y for c o n g e n i t a l defects. S u c h r e m i s s i o n s a r e r a r e a f t e r f o u r weeks, b u t i n e x c e p t i o n a l i n s t a n c e s m a y b e d e l a y e d for a s l o n g as two y e a r s a n d p o s s i b l y e v e n f o u r y e a r s . TM 19 I n t e r m i t t e n t 2:1 a n d 3:1 A - V c o n d u c t i o n w a s recorded b y E r l a n g e r a n d B l a c k m a n :~ s u b s e q u e n t to the p r o d u c t i o n of c o m p l e t e b l o c k i n dog No. 3 i n t h e i r classic e x p e r i m e n t s . I n m o r e a c u t e e x p e r i m e n t s , Biggs :1 also n o t e d r e c o v e r y of A - V c o n d u c tion a f t e r " a c o n s i d e r a b l e t i m e . " Remission took place in Case 2 shortly after
{}49
Rytand, Stinson, and Kelly
myocardial infarction. In Case 3, it occurred during a postoperative phase, and in Case 1, the initial remission was related temporally to an Army pre-induction examination. These events, of course, suggest a consideration of endogenous adrenal corticosteroid release in stressful situations, with consequent improvement in A-V conduction. It is difficult to understand how this could lead to prolonged remissions, and in other patients remissions occurred in the apparent absence of unusual stress. The return of sinus r h y t h m in A-V block has been reported to follow the use of isoproterenol hydrochloride, prednisone, chlorothiazide, or electronic pacemakers. ~~8 Prior to remission, a trial of chlorothiazide had failed in Case 4, and one of prednisone had failed in Case 5. One must point out th at many of the relevant case reports fail to note the prior duration of heart block; available data strongly suggest t h a t most, if not all, of these patients were within two, or rarely three, years of onset and thus might have been in the paroxysmal phase. A pacemaker was inserted in our Case 4 for the paradoxical reason t h a t episodes thought to be Stokes-Adams ones recurred with his spontaneous remission; relapse into complete block followed this operation, but six months later A-V conduction reappeared briefly, and a year later he died suddenly. Considerations of this sort support the use of a demand pacemaker, for the incidence of paroxysmal ventricular arrhythmias and the chance of death increase in the face of competition between endogenous and exogenous pacemakers. 2s, 29 We now use only the demand type of pacemaker. ~9'-~2 We have reviewed our own early cases of pacemaker insertion in order better to define any relationship between return of conduction and preoperative duration of complete block. T he results show th at intermittent A-V conduction is common following pacemaker implantation. In the present series it was documented in 23 out of 91 cases (25 per cent). This compares with an incidence of temporary return to sinus r h y t h m of 20 to 23 per cent in other reports. ~-~9 In our series, sinus r h y t h m was present in four cases at the time of pacemaker insertion, was the dominant r h yth m with occasional episodes of sinus arrest and slow idioventricular r h y t h m in two instances, and in another was present except during anginal attacks when heart block developed. This last
650
patient demonstrated continuous sinus-pacemaker competition and died suddenly three months following pacemaker insertion without evidence of recent infarction. The remaining 19 case histories were examined to determine if postoperative sinus-pacemaker competition in fact represented remission of established heart block following the institution of cardiac pacing. The longest interval between the onset of heart block and pacemaker insertion in these patients was 27 months with an average interval of 10 months, except Case 4 described above. Thus, 18 of the 19 patients who demonstrated occasional A-V conduction postoperatively may be considered to have been in the paroxysmal phase of complete heart block. Indeed, 10 of the 19 patients showed A-V conduction immediately prior to or at the time of pacemaker insertion. None of the patients with a history of complete heart block longer t han two years developed A-V conduction postoperatively {except Case 4, above}. These considerations fail to support the thesis t h a t cardiac pacing p e r s e promotes the return of sinus r h y t h m in established heart block. Controversy has attended the existence of two particular types of conduction, A-V conduction within a supernormal phase and A-V retrograde conduction, in patients with high-grade or otherwise complete A-V block. 33 3~ We detected the latter in none of our patients, while the former was recorded occasionally only in Case 1. Finally, we have considered the possibility t h a t remission mav depend upon the establishment of accessory pathways. Accelerated A-V conduction has been reported as appearing in association with myocardial infarction and other insults. 35 Our patients, however, lacked delta-waves and none had P-R intervals shorter t han 0.18 sec. so that this hypothesis lacks support. Although His bundle studies were not obtained in any of the patients discussed here, results of such studies in others may be relevant. In congenital block without associated cardiac disease, block is almost invariably proximal to the bundle of His? 6-38 In acquired high-grade or complete A-V block with narrow ventricular complexes it usually is proximal, with wide ones distal29 Therefore, it would appear t h a t in all of the congenital cases presented here the block should have been proximal, a speculation receiving some
May, 1976, Vol. 91, No. 5
Remission and recovery from complete heart block
s u p p o r t f r o m t h e a b s e n c e of S t o k e s - A d a m s s y n c o p e a n d t h e p r e s e n c e of n a r r o w Q R S c o m plexes ( a n d W e n c k e b a c h p e r i o d s i n one) d u r i n g r e m i s s i o n 2 ~ All of t h e a c q u i r e d - b l o c k p a t i e n t s e x c e p t Case 4 also h a d n a r r o w c o m p l e x e s d u r i n g h i g h - g r a d e block, b u t i n t h i s g r o u p t h e Q R S w a s i n v a r i a b l y w i d e n e d d u r i n g r e m i s s i o n (no i n f o r m a t i o n a v a i l a b l e i n Case 3), S t o k e s - A d a m s episodes first a p p e a r e d i n two, a n d M o b i t z T y p e I I w a s recorded in two patients; this suggests t h a t the site of b l o c k m a y h a v e s h i f t e d d i s t a l l y i n r e m i s sion 39 i n t h o s e w i t h a c q u i r e d disease.
12. 13. 14. 15. 16. 17.
Summary T h e r e t u r n of A - V c o n d u c t i o n is d e s c r i b e d in a p a t i e n t a f t e r t w o d e c a d e s of h i g h - g r a d e or c o m p l e t e c o n g e n i t a l h e a r t block. S i m i l a r cases h a v e b e e n r e p o r t e d b y o t h e r s , w i t h r e m i s s i o n or e v e n r e c o v e r y c o m m e n c i n g u p t o t h e f o u r t h d e c a d e or later. A s i m i l a r p h e n o m e n o n is also d e s c r i b e d i n f o u r p a t i e n t s w i t h a c q u i r e d h e a r t b l o c k of f o u r to ten years' duration; in them, remission was u s u a l l y b r i e f b u t p e r s i s t e d for s e v e n y e a r s i n o n e p a t i e n t . N o f u l l r e p o r t of t h i s s e e m s t o h a v e b e e n p u b l i s h e d p r e v i o u s l y . P o s s i b l e e x p l a n a t i o n s are discussed, b u t n o c o n c l u s i o n is r e a c h e d . A p a r t f r o m its i n t e r e s t , t h e p h e n o m e n o n is of i m p o r t a n c e w i t h r e s p e c t to t h e s e l e c t i o n of d e m a n d t y p e e l e c t r o n i c p a c e m a k e r s i n t h e m a n a g e m e n t of p a t i e n t s w i t h h e a r t block.
18.
19.
20. 21. 22.
23. 24.
REFERENCES 1. Campbell, M., and Thorne, M. G.: Congenital heart block, Br. Heart J. 18:90, 1956. 2. Campbell, M., and Emanuel, R.: Six Cases of congenital complete heart block followed for 34-40 years, Br. Heart J. 29:577, 1967. 3. Gilchrist, A. R.: Clinical aspects of high-grade heartblock, Scot. Med. J. 3"53, 1958. 4. Len~gre,J.i Deparis, M., Auz~py, Ph., and Gay, J.: Deux cas (run anatomo-clinique) de bloc auriculo-ventriculaire probablement congenital et d'~volution r~gressive. Arch. Mal. Coeur 63:749, 1970. 5. Nadas, A. N., and Fyler, D. C.: Pediatric Cardiology, Ed. 3. Philadelphia, 1972, W. B. Saunders Company, p. 212. 6. Campbell, M.: Complete heart block, Br. Heart J. 6:69, 1944. 7. Shearn, M. A., Tarr, E., and Rytand, D. A.: The significance of changes in amplitude of the first heart sound in children with A-V block, Circulation 7:839, 1953. 8. Eckstein, M.: Personal communication, April 19. 1967. 9. Schwartz, S. P.: Personal communication, March 28, 1967. 10. Spiegl, R. J.: Personal communications, Oct. 19, 1967, and subsequently. 11. Comeau, W. J.: Paroxysmal complete heart block alter-
American Heart Journal
25.
26. 27. 28. 29. 30. 31. 32. 33.
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May, 1976, Vol. 91, No. 5