Arch Dis Child: first published as 10.1136/adc.19.100.178 on 1 December 1944. Downloaded from MYOCARDITIS IN ACUTE INFECTIVE DISEASES A REVIEW OF 200 CASES BY C. NEUBAUER, M.D. Resident Medical Officer, City Hospital for Infectious Diseases, Newcastle upon Tyne The acute infective diseases constitute the most voltage in all three limb leads together. This sign important cause of myocarditis, the commonest occurs especially in cases of severe myocarditis. heart disease in childhood. Increasing amount of Pathological anatomy. Whenever possible the evidence from electrocardiographic investigations heart of a fatal case was examined in the Patho- of the heart in acute infective diseases shows that logical Department (Prof. B. Shaw) ofKing's College, there can be a myocarditis when clinical signs and Newcastle upon Tyne. Two illustrative cases are symptoms are slight, doubtful or completely absent. given: These investigations further revealed that many 1. convalescent cases whose unsatisfactory condition Sheila F., ten years, died on the eleventh day of diphtheria. Immediately beneath the ven- was accounted for by post-infective or secondary tricular anaemia were endocardium and also in the inner third of actually suffering from myocarditis. the wall are some scattered small foci of lymphoid Therefore, since this involvement of the myocardium and histiocytic cells. These foci sometimes occur is so common an event and liable to be missed or in association with shrunken muscle fibres and what misdiagnosed, it seems justifiable to give an account appear to be small delicate recent scars. of 200 cases of myocarditis occuring in acute 2. Iris N., eight years old,'died on the fourth day infectious diseases. of diphtheria. Beneath the endocardium of the General signs. The children do not complain of left ventricle there are a few patches of interstitial any pains ; sometimes there is myocarditis in which the muscle fibres are dis- abdominal dis- and there is comfort. They do not resent examination and are appearing accumulation of mobile not irritable. histiocytes and lymphocytes.' Clinical signs. There is always some pallor and In the present series of 200 cases there are listlessness. Not infrequently vomiting occurs and 122 cases of diphtheria; http://adc.bmj.com/ may be the first sign. The urine often shows 10 cases of diphtheria in inoculated children albuminuria, varying from the presence of a trace 40 cases of scarlet fever; to a heavy deposit. The principal clinical signs are 24 cases of whooping cough; and diminution in intensity of the first sound at the apex, 4 cases of measles. indicating a weakness of the myocardium. The The diagnosis of myocarditis was made on first sound becomes equal in intensity to the second clinical grounds in 55 per cent. of the present series, means apical sound, later on it becomes weaker and may by of an electrocardiogram with doubtful on September 24, 2021 by guest. Protected copyright. even become entirely inaudible. Changes in the clinical signs in 20 per cent. and on electrocardio- character of the cardiac rhythm take place, as graphic findings with no clinical signs present in shown by persistent tachycardia, less frequently 24 per cent. The duration of the .myocarditis in bradycardia, embryocardia or gallop rhythm. the present series was two to three weeks in 17 per Some degree of cardiac enlargement is common in cent., five to nine weeks in 58 per cent., three to severe cases of myocarditis. An important sign is four months in 25 per cent. The termination of a low blood pressure, the diastolic reading being the myocarditis was ascertained clinically in 13 per often extremely low. The electrocardiogram is an cent., clinically and by means of an electrocardio- important aid in the diagnosis of a myocarditis. gram in 12 per cent., and by means of a graphic The first sign is a flattened T wave; later on the T record alone in 75 per cent., when the clinical signs wave becomes isoelectric and eventually inverted. had subsided or they had not been present at all. A second sign of myocarditis is an S-T segment Frequency of clinical below the isoelectric line in lead I and II or in both. signs (percentage) It Vomiting .. .. .. .. 23 is conclusive evidence of a myocarditis when Albuminuria .. .. .. .. 38 found together with a change in the T wave. A Enlargement of cardiac dullness .. 21 third sign of myocarditis is a diminution of voltage Heart sounds: of the ventricular I = 2nd apical sound .. .. 15 deflections to less than 1.5 mV 2>1st apical sound .. .. .. 29 178 Arch Dis Child: first published as 10.1136/adc.19.100.178 on 1 December 1944. Downloaded from MYOCARDITIS IN ACUTE INFECTIVE DISEASES 179 Rhythm: Diphtheria Persistent tachycardia 36 Bradycardia 17 It would be superfluous to discuss in detail here Embryocardia (tic-tac rhythm) . 9 the myocarditis in diphtheria. Vomiting, changes Gallop rhythm 6 in the quality of the first apical sound, changes in the Extrasytoles 16 heart rhythm, and low blood pressure are clinically the most suggestive evidence of a myocarditis. Blood pressure (mm. Hg) Severe albuminuria early in the disease has always Lowest readings In severe Age Normal in present series been regarded as a signum mali ominis. in years systolic diastolic systolic diastolic cases not only the myocardium but also the con- 3 90-100 70 48 30 ducting tissue is involved resulting in partial or 4 100-115 70 40 30 complete heart block or intraventricular block. 5-6 110-120 75-80 40 20 In the present series, however, only cases of pure 7-10 115-120 80-90 62 24 12-17 120-130 90 70 38 myocarditis are represented. In 7 per cent. of the cases there was a slightly prolonged P-R interval. Frequency of electrocardiographic signs. (Percentage) It is important to underline the occurrence of LIMB-LEADS myocarditis in diphtheria in inoculated children. Changes of T wave: Severe complications are rare in diphtheria in the T of less than 0 I mV voltage, round 47 inoculated, but myocarditis does occur. General T isoelectric .. 18 54 signs and symptoms, and clinical findings are the T inverted .. 6J same as in the non-inoculated but occur in milder S-T segment below the base line'' 27 5 QRS of less than 15 mV voltage in all degrees and the electrocardiogram gives a good three leads .. 38 clue to the diagnosis ; involvement of the con- Extrasystoles .. 12 ducting tissue is rare in these cases. Sinus tachycardia 32 CHEST-LEADS Scarlet fever QRS inverted .. 64 Voltage of QRS less than 0-8 mV 80 Heart complications in scarlet fever occur towards S-T segment depressed 17 the end of the second week, more frequently during S-T segment below the base line 6 the third week of disease and even later. The first Changes of the T wave: symptom is pallor, the temperature is slightly raised T of less than 0 I mV voltage 17 T inverted .. 18 for a few days or is normal. The pallor becomes T isoelectric .. 36 86 more intense after a week or two and persists into T diphasic .. 5 late convalescence. The patient often loses weight. The cardiac dullness is enlarged, but only The changes of the T wave in the chest-leads in severe cases is the dilatation extensive. The enumerated above cannot be interpreted as a intensity of the first apical sound becomes less than http://adc.bmj.com/ myocarditis if not combined with other alterations that of the second and accompanying or following occur infants and because they often in healthy this change, a murmur develops. The development young children. of murmurs is common in scarlet fever and it is Once a myocarditis has been present there is the important to distinguish functional murmurs from danger of its recurring in the course of another or endocarditis or infective disease. Each of these subsequent attacks those caused by myocarditis by both. Generally speaking myocarditis is more may cause to the heart and may prove further injury common than endocarditis in scarlet fever. Hence was in the majority of on September 24, 2021 by guest. Protected copyright. fatal. Actually it found that murmurs which occur in the course of scarlet fever cases the patient had one, two or more the 200 have to be regarded as due to a diseased myocardium acute within the last year and in infective diseases in the first place and to an endocarditis in the some instances up to five acute diseases within the second place. There are three criteria of a carditis last three years. blood sedimentation rate in 200 in scarlet fever : (1) The Incidence of preceding infective diseases is markedly increased as in rheumatic fever; (2) The cases of acute myocarditis (percentage). electrocardiogram shows definite signs of a myo- carditis and signs of a valvular disease, e.g. a mitral Measles .. 25 Measles and whooping cough 22 stenosis in some instances, later on; (3) the x-ray Measles and chickenpox 9 examination reveals the enlargement of the heart. Whooping cough 7 since the clinical are varied and Scarlet fever .. 6 However, signs Lobar and bronchopneumonia 15 poor at the onset, diagnosis might be difficult. The clinical and electrocardiographic signs are similar Death occurred in 4 per cent. of the present series. to those seen in rheumatic fever and last for several It is noteworthy that the fatal event occurred in weeks or even months. When the myocarditis two cases of diphtheria, where the history reported subsides the murmur disappears and the patient four infective diseases within three years (whooping makes so complete a recovery that all evidence of cough, chickenpox, measles, scarlet fever) in one the disease vanishes.