Stokes-Adams attacks nonspecific myocarditis
due to acute
Chin-Hock Lim, M.B.B.S., M.R.A.C.P., M.Med., A.M. Charles C. S. Toh, M.B.B.S., F.R.C.P., F.R.A.C.P., F.A.C.C., A.M. Boon-Lock Chia, A.M., M.B.B.S., F.R.A.C.P., F.A.C.C. Lip-Ping Low, M.B.B.S., M.R.A.C.P., A.M. Singapore, Singapore
Acute nonspecific or viral myocarditis producing Stokes-Adams attacks due to complete heart block is uncommon. As far as we are aware, only 16 cases have been described so far.1-8 The majority of these reported cases were in male adults more than 30 years old, although Loh’ and Johnson and Lee5 (1971) described three patients who were less than 9 years old. The purpose of this paper is to describe 10 patients, the majority of whom were female, less than 20 years old, with acute nonspecific myocarditis developing StokesAdams attacks due to complete heart block. Material and methods
From December, 1970, to June, 1974, 10 patients with acute nonspecific myocarditis and complete heart block, presenting with StokesAdams (S.-A.) attacks, were referred to the coronary-care unit, Department of Medicine, University of Singapore, for cardiac pacing and intensive-care management. All these patients had a detailed clinical workup and were monitored continuously in the coronary-care unit until their cardiac rhythm was stable or their general condition improved. Laboratory investigations included the following: serial blood counts, erythrocyte sedimentation rate (ESR), urine analysis, blood sugar, serum electrolytes, blood urea, tissue cultures for Coxsackie B virus in five patients, serum enzymes-creatine phosphokinase (SCPK), glutamic oxaloacetic transFrom the Department of Medicine, University Lines, Singapore 3, Singapore. Received for publication July 23, 1974. Reprint requests to: Dr. Chin Hock Lii, Medical of Medicine, University of Singapore, Sepoy Singapore.
172
of Singapore,
Sepoy
Unit II, Department Lines, Singapore 3,
aminase (SGOT), lactic dehydrogenase (SLDH), antistreptolysin-0 titer (ASOT), hemagglutination tests for toxoplasma, anti-heart antibodies, antinuclear factor, serial electrocardiograms (ECG), and chest x-rays. T3 and T” uptake studies were done in two patients. All these patients have been followed up after discharge for periods ranging from 2 to 42 months. Results (Table I)
The patients’ ages ranged from 11 to 27 years and the majority of them (60 per cent) were less than 20 years. There were more females than males (F:M = 4:l) and only one patient was not of Chinese descent. Fever, present in nine patients, was the earliest symptom in five patients and it was usually present for 5 days before admission to hospital. Gastrointestinal (GI) symptoms were common (eight patients), and these usually preceded the syncopal episodes. The GI symptoms were abdominal pain, vomiting, or diarrhea, and the abdominal pain was either present all over the abdomen or localized in the epigastrium. Minimal hepatomegaly was seen in only two patients. None of the patients had splenomegaly or significant lymphadenopathy. Vague abdominal tenderness was present in six patients. Chest pain was present in only two patients and it was described as crushing and was situated in the retrosternal region. All 10 patients had signs of complete heart block (CHB) at admission and four were in cardiogenic shock. Two patients had clinical evidence of cardiomegaly which has persisted even at follow-up. An apical soft ejection systolic murmur was heard in all 10 patients and a third heart sound was heard in four. Two
August,
1975, Vol. 90, No. 2, pp. 172-178
Stokes-Adams
Fig.
1. Case 8. ECG
Fig. 2. Case 4. ECG shows depression in V, and V,.
RBBB
showing
with
LPH
complete
(+ 1300).
female patients were obviously thyrotoxic with visibly enlarged thyroid glands. One patient was untreated and the other stopped treatment on her own accord several weeks before the onset of acute myocarditis. A macular erythematous rash was seen in one patient (Case 2). Laboratory investigations. Four patients had leukocytosis but in only one was the total white count greater than 13,000 per cubic millimeter. One patient (Case 2) had leukopenia (1,500 per cubic millimeter) and thrombocytopenia. All 10 patients, except one, had elevated ESR values ranging from 16 to 75 mm. per hour (Westergren). Three patients had normal serum enzymes
American
Heart
Journal
heart
block
There
with
junctional
is ST segment
pacemaker
elevation
attacks
ctnd myocarditis
focus
in Leads
V, to V and ST
(SCPK, SGOT, or SLDH) and the rest had elevated values (Table I). The ASOT values were raised in four patients, their values ranging from 300 to 7,500 Todd Units, and these were normal before discharge. Throat swabs for bacterial culture did not reveal the presence of streptococci or diphtheria. None of the patients had a positive test for toxoplasmosis, anti-heart antibodies, or antinuclear factor. The serum electrolytes were abnormal in three patients who had elevated blood urea leveb. These patients had raised urea levels due most probably to cardiogenic shock, their values ranging from 100 to 300 mg. per 100 ml. The
173
Lim
et al.
Table
I. Findings in 10 patients symptoms
Case No.
Age
Sex
Fever
1
20
F
+
-
2 3
27 15
F F
+
Chest pain Headache
4
11
F
+
5
26
M
+
6
19
F
+
7 8
23 11
F F
+ +
9
14
F
+
10
10
M
+
*SGOT
normal
Pain
Gastrointestinal
-
+
-
+
Vomiting -
+ +
-
+ -
Epigastric pain
Diarrhea
+
60/40
-
Epigastric pain Abdominal; headache
Vomiting; diarrhea Vomiting
+
60/40
-
+
50/?
-
Chest
Vomiting Vomiting
+ +
Vomiting
+
Abdominal distension
+
or < 33 UL; SCPK
normal
pain
-
Abdominal pain
values are < 125 King’s Units (KU)
patient with the highest blood urea was anuric for 4 days and was dialyzed peritoneally. All had normal renal functions at discharge. Tissue cultures for Coxsackie B virus were negative in all five patients; Patient 3 had significant titers of antibodies to arborviruses. Electrocardiogram. On admission, CHB with a slow ventricular rate ranging from 28 to 48 per minute, was seen in all patients (Fig. 1). Two had CHB with narrow QRS complexes, indicating a high pacemaker focus. The remaining eight patients showed widened QRS complexes, suggesting the presence of trifascicular disease of the conducting system. ST segment depression and T wave inversion were seen in eight patients, giant T wave inversion was present in Patient 3, and Patient 4 showed an acute anteroseptal infarction pattern with right bundle branch block (RBBB) and left posterior hemiblock (LPH) (+ 130°, Fig. 2). Patient 4 developed ventricular tachycardia
174
Peak level of enzymes
- Shock ThyroS.-A. (lowest toxiattacks B.P.) cosis
-
50/?
-
ECG CHB (LBBB pattern); ST in II, III, aV, CHB (LBBB pattern) CHB (narrow QRS complexes); giant T wave inversion CHB, RBBB with LPH (+X0’) and first-degree heart block, acute anteroseptal infarct pattern CHB (narrow QRS complexes); ST II, III, aV, CHB, RBBB, and LAH (-45”); ventricular tachycardia; ventricular premature beats CHB (RBBB pattern) CHB (first-degree heart block and RBBB pattern); transient LPH CHB with LBBB pattern; nonspecific T wave inversion, V, to V, CHB (RBBB with LPH pattern); atria1 standstill; atria1 flutter; premature ventricular beats
SGOP
SCPK*
39 U/L
2.1
175 KU 327 KU
3.5
>20
278 KU
46 U/L ~400
KU
7.8 > 20
117 KU 112 KU
1.3 18.5
370 KU
11.6
128 KU
1.3
values are < 4.5 Units.
and fibrillation during CHB and she was treated with DC cardioversion and intravenous lignoCaine. Patient 6 had premature ventricular beats and ventricular tachycardia. Nine patients had temporary transvenous cardiac pacing because of Stokes-Adams attacks (Fig. 3). One patient was not paced as the idioventricular rate responded satisfactorily to isoprenaline infusion. Progress. Four patients had cardiogenic shock while in CHB; three remained in shock while being paced but responded to vasopressor therapy. Of these three, one developed ventricular tachycardia and one had ventricular tachycardia and fibrillation successfully treated with D.C. cardioversion. Two patients (cases 3 and lo), followed up over 12 and 8 months, respectively, remain in CHB but are well compensated and able to cope with their usual daily activities. Except for these two patients, normal A-V conduction returned in the
August,
1975, Vol. 90, No. 2
Stokes-Adams
Laboratory
investigations
(peak level)
Urea (mg. / 100 ml.)
ASOT (Todd Units)
CXR
Tw
ESR (mm./hrJ
N
11,200
64
36
604
N N
11,300 1,500
75 17
55 25
7,500 Neg.
+
6,~
73
132
300
N
17,600
16
110
Neg.
N
5,ooo
40
300
Neg.
W3’3
N +
13,000
47 48
20 27
342 Neg.
N
8,500
5
46
Neg.
+
7,900
50
26
Neg.
rest. In seven patients, this occurred between 1 to 12 hours after the institution of cardiac pacing and in one patient (Fig. 4), after 12 hours of isoprenaline therapy. Temporary relapse into CHB was seen in 3 patients. At follow-up, six patients have normal ECG’s, one has an old anteroseptal infarction pattern with permanent LPH (+ 120”, Fig. 5), and the other has a permanent RBBB with alternating LAH and LPH. Discussion
Acute nonspecific myocarditis has been described in Singapore previously.‘, 9 Chao’s autopsied cases were all young adults below 30 years, half of whom were admitted to the surgical units for fever, abdominal pain, and vomiting or diarrhea simulating acute appendicitis. The other half were admitted to the acute psychiatric wards for psychotic symptoms. The clinical features
American
Heart
Journal
attacks
and myocarditis
were similar to those seen in some of our patients, all of whom have survived their acute illness. In this series, there was predominance of young females, the majority lessthan 20 years old. Other author@‘, ‘I have reported the common occurrence of this condition in males and Pruitt’” believed that males are more susceptible because of their increased physical activity during infection. Two patients were frankly thyrotoxic, but we believe that the development of CHB was unrelated to their thyrotoxic state and that it was due to an acute nonspecific infective myocarditis. Davis and Smith’ reported six cases of CHB in thyrotoxic patients, but the A-V conduction disturbance was attributed to acute infection in four and to digoxin administration in two patients. Muggia, Stjernholm, and Houle” attributed the CHB to thyrotoxic myocarditis in the patient they described. Our belief is supported by Goel, Hanson, and Han,” who have shown experimentally that in dogs made thyrotoxic the A-V conduction time and functional refractory period were shortened, facilitating impulse transmission through the A-V conducting system. This would indicate that thyrotoxicosis per se is unlikely to produce heart block. It is unlikely that coronary artery disease was the cause of CHB in our series because of the preponderance of young female patients, although in Whitehead’s series one patient had severe atherosclerosis. Rheumatic fever is also an unlikely cause, although this cannot be excluded in Patient 2, who had an extremely high ASOT level. Freidberg’” believed, and most physicians will agree, that CHB is very uncommon in patients with rheumatic fever and serious conduction disturbances may not be directly due to rheumatic fever. High ASOT levels have been described in patients with Coxsackie myocarditis.‘” In two of our patients, the high ASOT level (more than 350 Todd Units) could be due to a coexisting streptococcal infection. Diphtheria is unlikely to be responsible as, in our experience, diphtheric myocarditis never occurs in the absence of throat manifestations. The acute presentation of fever, abdominal pain, chest pain, diarrhea, vomiting, and mild leukocytosis suggests that an infective process, probably an acute virus infection, was the cause of myocarditis. Although tissue culture for Coxsackie B virus was negative in the five patients who had it done, this does not exclude a
175
Lim
et al.
Fig. 3. The second strip illustrates of ventricular arrest.
Fig. 4. The pacing.
176
last rhythm
strip
the effect
of a thump
IlAY
t@ln. :‘Ip Ia@6
shows
the restoration
on the chest
of normal
stimulating
ventricular
activity
after
a period
m IMt-min. A-V
conduction
after
a brief
period
August,
of ventricular
1975, Vol. 90, No. 2
Fig. 5. A 12 lead ECG
of Patient
5 showing
a recent
viral etiology, as animal inoculations were not done. Cardiomegaly is considered to be one of the hallmarks of acute myocarditis,‘3 but it is of interest to note that this was seen in only two patients (20 per cent) and has persisted in one. The degree of cardiomegaly is usually related to the extent of myocardial inflammation. In those cases without cardiomegaly, there could be selective involvement of strategic parts of the heart, such as the conducting system. Two patients with extensive myocardial damage developed shock, prerenal renal failure, and malignant ventricular arrhythmias. Involvement of the conducting system in these two patients is considered to be due to the extensive myocardial inflammation (cases 4 and 6). Two patients developed permanent CHB and another patient (case 6) who has bifascicular disease of the AV conducting system may develop complete heart block or asystole at a later date. All three patients are being considered for implantation of permanent pacemakers. The first case of transient “pure” LPH in acute myocarditis was described by Forfang and Lippestead.3 In our series we have one patient (case 4) with permanent LPH and another (case 8) with transient LPH. Normal A-V conduction in eight patients appeared soon after cardiac pacing was started and this may have been the result of an increased
American
Heart
Journal
anteroseptal
infarction
Stokes-Adams
attacks
pattern
L,PH
wit.h
anti
(+
myocarditis
13)“1
cardiac output and concomitant increased coronary artery perfusion. However, CHB can recur as late as 14 days after initial restoration of A-V conduction and because of this pacemaker electrodes should not be removed until at least 2 weeks after restoration of normal .4-V conduction. The mode of death in patients with acute nonspecific or viral myocarditis may be severe cardiac failure, ventricular asystole, or ventricular fibrillation. Death from CHB leading to ventricular arrest of asystole as a result of A-V nodal disease or trifascicular disease of the conducting system is said to be uncommon.2. :‘. lo However, our experience demonstrates that acute myocarditis may be a more important cause of CHB and other life-threatening arrhythmias than has been hitherto suspected. All these 10 patients could have died if they had not been paced and treated in an intensive-care area where continuous ECG monitoring and prompt therapy can be carried out. Summary
Ten patients, all below 30 years of age (8 females and 2 males) developed Stokes-Adams attacks from complete heart block due to acute nonspecific myocarditis. Coexisting thyrotoxicosis was present in two patients and cardiogenic shock was seen in four. Temporary transvenous
777
Llm et al.
pacing was instituted in all but one patient. Except for two patients who developed permanent complete heart block, normal A-V conduction returned in between 1 to 12 hours after ventricular pacing in seven patients and after 12 hours of isoprenaline therapy in the final patient. The ECG returned to normal in six patients and all 10 patients survived their acute illness. REFERENCES 1.
2. 3. 4. 5.
178
Loh, T. F.: Acute myocarditis in children, Proceedings of the Fourth Singapore-Malaysia Congress, p. 1, 1969. Whitehead, R.: Isolated myocarditis, Br. Heart J. 27:220, 1965. Forfang, K., and Lippstead, C. T.: Transient left posterior hemiblock in acute myocarditis, J. Electrocardiol7:83, 1974. Monif, R. F., Lee, C. W., Hsung, G. D.: Isolated myocarditis with recovery of Echo type 9 virus from the myocsrdium, N. Engl. J. Med. 277:1353, 1967. Johnson, J. L., and Lee, L. P.: Complete atrioventricular heart block secondary to acute myocarditis requiring intracardiac pacing, J. Paediatr. 78:312, 1971.
6. Muggia, A. L., Stjemhohn, M., and Houle, T.: Complete heart block with thyrotoxic myocarditis, N. Engl. J. Med. 283:1099, 1970. 7. Davis, A. C. and Smith, A. L.: Complete heart block in hyperthyroidism following acute infection, AM. HEART J. 9:81, 1933. 8. Harvey, W. P., Segal, J. P., and Gurel, T.: The clinical spectrum of primary myocardial disease, Progr. Cardiovast. Dis. 7:17, 1964. 9. Chao, T. C.: Unpublished observations (1970). 10. Pruitt, R. D.: Acute myocarditis in the adult, Progr. Cardiovasc. Dis. 7:73, 1964. 11. Sainani, G. S., Krompotic, E., and Slodki, S. J.: Adult heart disease due to Coxsackie virus B infection, Medicine 47:133, 1968. 12. Goel, B. J., Hanson, C. S., and Han, J.: AV conduction in hypo- and hyperthyroid dogs, AM. HEART J. 83:504, 1972.
13. Friedberg, C. K.: Diseases of the Heart, Ed. 3, Philadelphia, 1969, W. B. Saunders Company. 14. Helin, M., Savola, I., Sapulerumu, K.: Cardiac manifestation during a Coxsackie B5 epidemic, Br. Med. J. 3:97, 1968.
August, 1975, Vol. 90, No. 2
due to acute
Chin-Hock Lim, M.B.B.S., M.R.A.C.P., M.Med., A.M. Charles C. S. Toh, M.B.B.S., F.R.C.P., F.R.A.C.P., F.A.C.C., A.M. Boon-Lock Chia, A.M., M.B.B.S., F.R.A.C.P., F.A.C.C. Lip-Ping Low, M.B.B.S., M.R.A.C.P., A.M. Singapore, Singapore
Acute nonspecific or viral myocarditis producing Stokes-Adams attacks due to complete heart block is uncommon. As far as we are aware, only 16 cases have been described so far.1-8 The majority of these reported cases were in male adults more than 30 years old, although Loh’ and Johnson and Lee5 (1971) described three patients who were less than 9 years old. The purpose of this paper is to describe 10 patients, the majority of whom were female, less than 20 years old, with acute nonspecific myocarditis developing StokesAdams attacks due to complete heart block. Material and methods
From December, 1970, to June, 1974, 10 patients with acute nonspecific myocarditis and complete heart block, presenting with StokesAdams (S.-A.) attacks, were referred to the coronary-care unit, Department of Medicine, University of Singapore, for cardiac pacing and intensive-care management. All these patients had a detailed clinical workup and were monitored continuously in the coronary-care unit until their cardiac rhythm was stable or their general condition improved. Laboratory investigations included the following: serial blood counts, erythrocyte sedimentation rate (ESR), urine analysis, blood sugar, serum electrolytes, blood urea, tissue cultures for Coxsackie B virus in five patients, serum enzymes-creatine phosphokinase (SCPK), glutamic oxaloacetic transFrom the Department of Medicine, University Lines, Singapore 3, Singapore. Received for publication July 23, 1974. Reprint requests to: Dr. Chin Hock Lii, Medical of Medicine, University of Singapore, Sepoy Singapore.
172
of Singapore,
Sepoy
Unit II, Department Lines, Singapore 3,
aminase (SGOT), lactic dehydrogenase (SLDH), antistreptolysin-0 titer (ASOT), hemagglutination tests for toxoplasma, anti-heart antibodies, antinuclear factor, serial electrocardiograms (ECG), and chest x-rays. T3 and T” uptake studies were done in two patients. All these patients have been followed up after discharge for periods ranging from 2 to 42 months. Results (Table I)
The patients’ ages ranged from 11 to 27 years and the majority of them (60 per cent) were less than 20 years. There were more females than males (F:M = 4:l) and only one patient was not of Chinese descent. Fever, present in nine patients, was the earliest symptom in five patients and it was usually present for 5 days before admission to hospital. Gastrointestinal (GI) symptoms were common (eight patients), and these usually preceded the syncopal episodes. The GI symptoms were abdominal pain, vomiting, or diarrhea, and the abdominal pain was either present all over the abdomen or localized in the epigastrium. Minimal hepatomegaly was seen in only two patients. None of the patients had splenomegaly or significant lymphadenopathy. Vague abdominal tenderness was present in six patients. Chest pain was present in only two patients and it was described as crushing and was situated in the retrosternal region. All 10 patients had signs of complete heart block (CHB) at admission and four were in cardiogenic shock. Two patients had clinical evidence of cardiomegaly which has persisted even at follow-up. An apical soft ejection systolic murmur was heard in all 10 patients and a third heart sound was heard in four. Two
August,
1975, Vol. 90, No. 2, pp. 172-178
Stokes-Adams
Fig.
1. Case 8. ECG
Fig. 2. Case 4. ECG shows depression in V, and V,.
RBBB
showing
with
LPH
complete
(+ 1300).
female patients were obviously thyrotoxic with visibly enlarged thyroid glands. One patient was untreated and the other stopped treatment on her own accord several weeks before the onset of acute myocarditis. A macular erythematous rash was seen in one patient (Case 2). Laboratory investigations. Four patients had leukocytosis but in only one was the total white count greater than 13,000 per cubic millimeter. One patient (Case 2) had leukopenia (1,500 per cubic millimeter) and thrombocytopenia. All 10 patients, except one, had elevated ESR values ranging from 16 to 75 mm. per hour (Westergren). Three patients had normal serum enzymes
American
Heart
Journal
heart
block
There
with
junctional
is ST segment
pacemaker
elevation
attacks
ctnd myocarditis
focus
in Leads
V, to V and ST
(SCPK, SGOT, or SLDH) and the rest had elevated values (Table I). The ASOT values were raised in four patients, their values ranging from 300 to 7,500 Todd Units, and these were normal before discharge. Throat swabs for bacterial culture did not reveal the presence of streptococci or diphtheria. None of the patients had a positive test for toxoplasmosis, anti-heart antibodies, or antinuclear factor. The serum electrolytes were abnormal in three patients who had elevated blood urea leveb. These patients had raised urea levels due most probably to cardiogenic shock, their values ranging from 100 to 300 mg. per 100 ml. The
173
Lim
et al.
Table
I. Findings in 10 patients symptoms
Case No.
Age
Sex
Fever
1
20
F
+
-
2 3
27 15
F F
+
Chest pain Headache
4
11
F
+
5
26
M
+
6
19
F
+
7 8
23 11
F F
+ +
9
14
F
+
10
10
M
+
*SGOT
normal
Pain
Gastrointestinal
-
+
-
+
Vomiting -
+ +
-
+ -
Epigastric pain
Diarrhea
+
60/40
-
Epigastric pain Abdominal; headache
Vomiting; diarrhea Vomiting
+
60/40
-
+
50/?
-
Chest
Vomiting Vomiting
+ +
Vomiting
+
Abdominal distension
+
or < 33 UL; SCPK
normal
pain
-
Abdominal pain
values are < 125 King’s Units (KU)
patient with the highest blood urea was anuric for 4 days and was dialyzed peritoneally. All had normal renal functions at discharge. Tissue cultures for Coxsackie B virus were negative in all five patients; Patient 3 had significant titers of antibodies to arborviruses. Electrocardiogram. On admission, CHB with a slow ventricular rate ranging from 28 to 48 per minute, was seen in all patients (Fig. 1). Two had CHB with narrow QRS complexes, indicating a high pacemaker focus. The remaining eight patients showed widened QRS complexes, suggesting the presence of trifascicular disease of the conducting system. ST segment depression and T wave inversion were seen in eight patients, giant T wave inversion was present in Patient 3, and Patient 4 showed an acute anteroseptal infarction pattern with right bundle branch block (RBBB) and left posterior hemiblock (LPH) (+ 130°, Fig. 2). Patient 4 developed ventricular tachycardia
174
Peak level of enzymes
- Shock ThyroS.-A. (lowest toxiattacks B.P.) cosis
-
50/?
-
ECG CHB (LBBB pattern); ST in II, III, aV, CHB (LBBB pattern) CHB (narrow QRS complexes); giant T wave inversion CHB, RBBB with LPH (+X0’) and first-degree heart block, acute anteroseptal infarct pattern CHB (narrow QRS complexes); ST II, III, aV, CHB, RBBB, and LAH (-45”); ventricular tachycardia; ventricular premature beats CHB (RBBB pattern) CHB (first-degree heart block and RBBB pattern); transient LPH CHB with LBBB pattern; nonspecific T wave inversion, V, to V, CHB (RBBB with LPH pattern); atria1 standstill; atria1 flutter; premature ventricular beats
SGOP
SCPK*
39 U/L
2.1
175 KU 327 KU
3.5
>20
278 KU
46 U/L ~400
KU
7.8 > 20
117 KU 112 KU
1.3 18.5
370 KU
11.6
128 KU
1.3
values are < 4.5 Units.
and fibrillation during CHB and she was treated with DC cardioversion and intravenous lignoCaine. Patient 6 had premature ventricular beats and ventricular tachycardia. Nine patients had temporary transvenous cardiac pacing because of Stokes-Adams attacks (Fig. 3). One patient was not paced as the idioventricular rate responded satisfactorily to isoprenaline infusion. Progress. Four patients had cardiogenic shock while in CHB; three remained in shock while being paced but responded to vasopressor therapy. Of these three, one developed ventricular tachycardia and one had ventricular tachycardia and fibrillation successfully treated with D.C. cardioversion. Two patients (cases 3 and lo), followed up over 12 and 8 months, respectively, remain in CHB but are well compensated and able to cope with their usual daily activities. Except for these two patients, normal A-V conduction returned in the
August,
1975, Vol. 90, No. 2
Stokes-Adams
Laboratory
investigations
(peak level)
Urea (mg. / 100 ml.)
ASOT (Todd Units)
CXR
Tw
ESR (mm./hrJ
N
11,200
64
36
604
N N
11,300 1,500
75 17
55 25
7,500 Neg.
+
6,~
73
132
300
N
17,600
16
110
Neg.
N
5,ooo
40
300
Neg.
W3’3
N +
13,000
47 48
20 27
342 Neg.
N
8,500
5
46
Neg.
+
7,900
50
26
Neg.
rest. In seven patients, this occurred between 1 to 12 hours after the institution of cardiac pacing and in one patient (Fig. 4), after 12 hours of isoprenaline therapy. Temporary relapse into CHB was seen in 3 patients. At follow-up, six patients have normal ECG’s, one has an old anteroseptal infarction pattern with permanent LPH (+ 120”, Fig. 5), and the other has a permanent RBBB with alternating LAH and LPH. Discussion
Acute nonspecific myocarditis has been described in Singapore previously.‘, 9 Chao’s autopsied cases were all young adults below 30 years, half of whom were admitted to the surgical units for fever, abdominal pain, and vomiting or diarrhea simulating acute appendicitis. The other half were admitted to the acute psychiatric wards for psychotic symptoms. The clinical features
American
Heart
Journal
attacks
and myocarditis
were similar to those seen in some of our patients, all of whom have survived their acute illness. In this series, there was predominance of young females, the majority lessthan 20 years old. Other author@‘, ‘I have reported the common occurrence of this condition in males and Pruitt’” believed that males are more susceptible because of their increased physical activity during infection. Two patients were frankly thyrotoxic, but we believe that the development of CHB was unrelated to their thyrotoxic state and that it was due to an acute nonspecific infective myocarditis. Davis and Smith’ reported six cases of CHB in thyrotoxic patients, but the A-V conduction disturbance was attributed to acute infection in four and to digoxin administration in two patients. Muggia, Stjernholm, and Houle” attributed the CHB to thyrotoxic myocarditis in the patient they described. Our belief is supported by Goel, Hanson, and Han,” who have shown experimentally that in dogs made thyrotoxic the A-V conduction time and functional refractory period were shortened, facilitating impulse transmission through the A-V conducting system. This would indicate that thyrotoxicosis per se is unlikely to produce heart block. It is unlikely that coronary artery disease was the cause of CHB in our series because of the preponderance of young female patients, although in Whitehead’s series one patient had severe atherosclerosis. Rheumatic fever is also an unlikely cause, although this cannot be excluded in Patient 2, who had an extremely high ASOT level. Freidberg’” believed, and most physicians will agree, that CHB is very uncommon in patients with rheumatic fever and serious conduction disturbances may not be directly due to rheumatic fever. High ASOT levels have been described in patients with Coxsackie myocarditis.‘” In two of our patients, the high ASOT level (more than 350 Todd Units) could be due to a coexisting streptococcal infection. Diphtheria is unlikely to be responsible as, in our experience, diphtheric myocarditis never occurs in the absence of throat manifestations. The acute presentation of fever, abdominal pain, chest pain, diarrhea, vomiting, and mild leukocytosis suggests that an infective process, probably an acute virus infection, was the cause of myocarditis. Although tissue culture for Coxsackie B virus was negative in the five patients who had it done, this does not exclude a
175
Lim
et al.
Fig. 3. The second strip illustrates of ventricular arrest.
Fig. 4. The pacing.
176
last rhythm
strip
the effect
of a thump
IlAY
t@ln. :‘Ip Ia@6
shows
the restoration
on the chest
of normal
stimulating
ventricular
activity
after
a period
m IMt-min. A-V
conduction
after
a brief
period
August,
of ventricular
1975, Vol. 90, No. 2
Fig. 5. A 12 lead ECG
of Patient
5 showing
a recent
viral etiology, as animal inoculations were not done. Cardiomegaly is considered to be one of the hallmarks of acute myocarditis,‘3 but it is of interest to note that this was seen in only two patients (20 per cent) and has persisted in one. The degree of cardiomegaly is usually related to the extent of myocardial inflammation. In those cases without cardiomegaly, there could be selective involvement of strategic parts of the heart, such as the conducting system. Two patients with extensive myocardial damage developed shock, prerenal renal failure, and malignant ventricular arrhythmias. Involvement of the conducting system in these two patients is considered to be due to the extensive myocardial inflammation (cases 4 and 6). Two patients developed permanent CHB and another patient (case 6) who has bifascicular disease of the AV conducting system may develop complete heart block or asystole at a later date. All three patients are being considered for implantation of permanent pacemakers. The first case of transient “pure” LPH in acute myocarditis was described by Forfang and Lippestead.3 In our series we have one patient (case 4) with permanent LPH and another (case 8) with transient LPH. Normal A-V conduction in eight patients appeared soon after cardiac pacing was started and this may have been the result of an increased
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cardiac output and concomitant increased coronary artery perfusion. However, CHB can recur as late as 14 days after initial restoration of A-V conduction and because of this pacemaker electrodes should not be removed until at least 2 weeks after restoration of normal .4-V conduction. The mode of death in patients with acute nonspecific or viral myocarditis may be severe cardiac failure, ventricular asystole, or ventricular fibrillation. Death from CHB leading to ventricular arrest of asystole as a result of A-V nodal disease or trifascicular disease of the conducting system is said to be uncommon.2. :‘. lo However, our experience demonstrates that acute myocarditis may be a more important cause of CHB and other life-threatening arrhythmias than has been hitherto suspected. All these 10 patients could have died if they had not been paced and treated in an intensive-care area where continuous ECG monitoring and prompt therapy can be carried out. Summary
Ten patients, all below 30 years of age (8 females and 2 males) developed Stokes-Adams attacks from complete heart block due to acute nonspecific myocarditis. Coexisting thyrotoxicosis was present in two patients and cardiogenic shock was seen in four. Temporary transvenous
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pacing was instituted in all but one patient. Except for two patients who developed permanent complete heart block, normal A-V conduction returned in between 1 to 12 hours after ventricular pacing in seven patients and after 12 hours of isoprenaline therapy in the final patient. The ECG returned to normal in six patients and all 10 patients survived their acute illness. REFERENCES 1.
2. 3. 4. 5.
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Loh, T. F.: Acute myocarditis in children, Proceedings of the Fourth Singapore-Malaysia Congress, p. 1, 1969. Whitehead, R.: Isolated myocarditis, Br. Heart J. 27:220, 1965. Forfang, K., and Lippstead, C. T.: Transient left posterior hemiblock in acute myocarditis, J. Electrocardiol7:83, 1974. Monif, R. F., Lee, C. W., Hsung, G. D.: Isolated myocarditis with recovery of Echo type 9 virus from the myocsrdium, N. Engl. J. Med. 277:1353, 1967. Johnson, J. L., and Lee, L. P.: Complete atrioventricular heart block secondary to acute myocarditis requiring intracardiac pacing, J. Paediatr. 78:312, 1971.
6. Muggia, A. L., Stjemhohn, M., and Houle, T.: Complete heart block with thyrotoxic myocarditis, N. Engl. J. Med. 283:1099, 1970. 7. Davis, A. C. and Smith, A. L.: Complete heart block in hyperthyroidism following acute infection, AM. HEART J. 9:81, 1933. 8. Harvey, W. P., Segal, J. P., and Gurel, T.: The clinical spectrum of primary myocardial disease, Progr. Cardiovast. Dis. 7:17, 1964. 9. Chao, T. C.: Unpublished observations (1970). 10. Pruitt, R. D.: Acute myocarditis in the adult, Progr. Cardiovasc. Dis. 7:73, 1964. 11. Sainani, G. S., Krompotic, E., and Slodki, S. J.: Adult heart disease due to Coxsackie virus B infection, Medicine 47:133, 1968. 12. Goel, B. J., Hanson, C. S., and Han, J.: AV conduction in hypo- and hyperthyroid dogs, AM. HEART J. 83:504, 1972.
13. Friedberg, C. K.: Diseases of the Heart, Ed. 3, Philadelphia, 1969, W. B. Saunders Company. 14. Helin, M., Savola, I., Sapulerumu, K.: Cardiac manifestation during a Coxsackie B5 epidemic, Br. Med. J. 3:97, 1968.
August, 1975, Vol. 90, No. 2
