Pediatr Cardiol 11:229-230, 1990
Pediatric Cardiology 9 Springer-VerlagNew York Inc. 1990
Fatal Thyrotoxic Heart Disease in a 7-Year-Old Girl
Case History A 7-year-old Arab girl presented with complaints of tiredness, palpitations, shortness of breath, sweating, and steady weight loss for more than a year. She had no recent fever or cough, and all five siblings were well. She had no history of rheumatic fever, and there was no family history of thyroidrelated disease, or of myasthenia gravis, pernicious anemia, diabetes mellitus, ulcerative colitis, or collagen disorders. On examination, she was emaciated with a weight of 17.5 kg (10th percentile) and a height of 117 cm (75th percentile) with very prominent ribs, sternum and iliac crests, and marked exophthalmos with proptosis. Her temperature was 38~ (oral), she had a waterhammer pulse of 180/min and blood pressure of 130/50 with the heart apex beat (HAB) in the anterior axillary line in the left 6th intercostal space. There was no gallop rhythm, murmur, or pericardial friction rub. The jugular venous pressure was raised 2 cm above the suprasternal notch; there were numerous crepitations at both lung bases, arid the liver was palpable 3 cm below the right costal margin. The thyroid gland was smooth and diffusely and symmetrically enlarged, and a moderate bruit was audible. The palms of her hands were warm and moist, and there was a fine tremor of the outstretched hands. There was generalized weakness of the limb muscles, particularly of the arms and trunk. A provisional diagnosis of thyrotoxicosis with congestive cardiac failure (CCF) was made and confirmed by a chest x-ray, which showed a grossly enlarged cardiomediastinal shadow and C/T ratio of 150/185 mm (81%) (Fig. 1). There was also an area of radiodensity in the right mid-zone; pneumonic consolidation was considered most likely, but there was no cough and only mild fever, and crepitations were heard only at the bases, consistent with CCF. Other investigations showed a hemoglobin level of
10.3 g/dl, film normochromic, total white blood cell count 6.6 • 109 (neutrophils 43%. Lymphocytes 46%, monocytes 9% and eosinophils 2%), PBI 13.6 p~g/100 ml (normal, 4-8), and an electrocardiogram (ECG) showed a sinus tachycardia and a left ventricular hypertrophy pattern (voltage criteria) and nonspecific flattening of T waves. She was admitted urgently to the ward, and treatment started with oral 5 mg carbimazole t.d.s., 20 mg propranolol t.d.s., 40 mg furosemide o.d., and antibiotics (250 mg flucloxacillin i.v. 6 hourly, and 250 mg amoxicillin i.v. 6 hourly). Her temperature, pulse, and respiration and ECG were monitored continuously, with a special nurse constantly in attendance. Despite medication, her tachycardia persisted at the same rate, she became increasingly breathless, and died 24 hs after admission. Permission for an autopsy was refused.
Fig. 1. C h e s t x-ray s h o w i n g grossly enlarged cardiomediastinal s h a d o w C / T ratio 150/185 m m s (81%) due to thyrotoxic heart disease.
230
Comment
Hyperthyroid heart disease is rare under the age of 40 years; the main circulatory problems are tachycardia, high cardiac output, and vasodilatation leading to decreased peripheral vascular resistance, and may lead to arrhythmias, such as atrial fibrillation (AF), although this is rare in children. This case is presented because of its rarity and fatal outcome, despite apparent appropriate therapy for thyroid storm, instead of the usual benign course of steady recovery. CCF, due to thyrotoxic heart disease, is the one form of "heart failure" that does not respond to diuretics and digoxin alone; although Keith [5] states that this must be treated in the usual way with digitalis, digoxin has no effect on the sinus tachycardia in this condition, as myocardial contractility is actually enhanced already [3, 4, 6, 7]. Treatment with an antithyroid drug is required together with a beta blocker, such as propranolol, to control the heart rate, and to give symptomatic relief from palpitations. For the former carbimazole would be the choice in Britain, while in North America propyl thiouracil is preferred. Forfar et al. [2] suggested the occurrence of thyroid-induced cardiomyopathy in all patients with hyperthyroidism. Significant cardiac enlargement has been reported in about 50% of hyperthyroid children [l, 8]. In children, ECG abnormalities commonly seen are sinus tachycardia, left atrial hypertrophy, left ventricular hypertrophy (and less often biventricular hypertrophy), right bundle branch block, and less commonly AF [8]. Pilapil and Watson [8] observed that ECG changes are reversible after, but not necessarily soon after, becoming euthyroid. Cavallo et al. [ 1] found that mitral regurgitation, cardiac enlargement, and CCF represent serious complications of juvenile hyperthyroidism and are related to prolonged duration of the disease and poor treatment compliance. Why did this girl die despite what appears to have been appropriate therapy? This question is difficult to answer, since no postmortem studies were done, and it was impossible to undertake detailed cardiac studies in so brief a stay. There was no
Pediatric Cardiology Vol. 11, No. 4, 1990
history of previous or recent rheumatic carditis or clinical evidence of valvular regurgitation, and pericarditis was thought to be excluded by the absence of a pericardial friction rub, muffled heart sounds, and the typical ECG changes of generalized ST segment elevation followed by inversion or flattening of the T waves (although the latter alone was present). It is likely that her CCF due to thyrotoxic cardiomyopathy was aggravated by pneumonia. There was some clinical evidence of thyrotoxic myopathy, shown particularly by extreme weakness of the arms, perhaps associated with a duration of thyrotoxicosis of 2 years or more.
References I. Cavallo A, Joseph C J, Casta A (1984) Cardiac comt~lications in juvenile hyperthyroidism. Am J Dis Child 138:479-482 2. Forfar JC, Muir AL, Sawers SA, Toft TD (1982) Abnormal left ventricular function in hyperthyroidism. Evidence for a possible reversible cardiomyopathy. N Engl J Med 307:11651170 3. Gibson JD II, Harris AW (1939) Clinical studies of the blood volume V. Hyperthyroidism and myxoedema. J Clin Invest 18:59-65 4. Grossman W, Robin MI, Johnson LW, Brooks HL, Selenkow HA, Dexter L (1971) The enhanced myocardial contractility of thyrotoxicosis: Role of the beta adrenergic receptor. Ann Intern Med 74:869-874 5. Keith JD (1977) The heart in hyperthyroidism and hypothyroidism. In: Keith JD, Rowe RD, Vlad P (eds) Heart disease in infancy and childhood, 3rd edn. Collier-Macmillan, New York, London, pp 987-990 6. Lester LA, Sodt PC, Rich BH, Lucky AW, Hutcheon N, Arcilla RA (1982) Cardiac abnormalities in children with hyperthyrodism. Pediatr Cardiol 2:215-223 7. Merillon JP, Passa PH, Chastre J, Wolf A, Gourgon R (1981) Left ventricular function in hyperthyroidism. Br Heart J 46:137-143 8. Pilapil VR, Watson DG (1979) Electrocardiogram in hyperthyroid children. Am J Dis Child 119:245-248
E.S. Mucklow Department o f Pediatrics St. Mao"s Ho.spital Newport, Isle ~]" Wight, UK P030 5TG. UK
Pediatric Cardiology 9 Springer-VerlagNew York Inc. 1990
Fatal Thyrotoxic Heart Disease in a 7-Year-Old Girl
Case History A 7-year-old Arab girl presented with complaints of tiredness, palpitations, shortness of breath, sweating, and steady weight loss for more than a year. She had no recent fever or cough, and all five siblings were well. She had no history of rheumatic fever, and there was no family history of thyroidrelated disease, or of myasthenia gravis, pernicious anemia, diabetes mellitus, ulcerative colitis, or collagen disorders. On examination, she was emaciated with a weight of 17.5 kg (10th percentile) and a height of 117 cm (75th percentile) with very prominent ribs, sternum and iliac crests, and marked exophthalmos with proptosis. Her temperature was 38~ (oral), she had a waterhammer pulse of 180/min and blood pressure of 130/50 with the heart apex beat (HAB) in the anterior axillary line in the left 6th intercostal space. There was no gallop rhythm, murmur, or pericardial friction rub. The jugular venous pressure was raised 2 cm above the suprasternal notch; there were numerous crepitations at both lung bases, arid the liver was palpable 3 cm below the right costal margin. The thyroid gland was smooth and diffusely and symmetrically enlarged, and a moderate bruit was audible. The palms of her hands were warm and moist, and there was a fine tremor of the outstretched hands. There was generalized weakness of the limb muscles, particularly of the arms and trunk. A provisional diagnosis of thyrotoxicosis with congestive cardiac failure (CCF) was made and confirmed by a chest x-ray, which showed a grossly enlarged cardiomediastinal shadow and C/T ratio of 150/185 mm (81%) (Fig. 1). There was also an area of radiodensity in the right mid-zone; pneumonic consolidation was considered most likely, but there was no cough and only mild fever, and crepitations were heard only at the bases, consistent with CCF. Other investigations showed a hemoglobin level of
10.3 g/dl, film normochromic, total white blood cell count 6.6 • 109 (neutrophils 43%. Lymphocytes 46%, monocytes 9% and eosinophils 2%), PBI 13.6 p~g/100 ml (normal, 4-8), and an electrocardiogram (ECG) showed a sinus tachycardia and a left ventricular hypertrophy pattern (voltage criteria) and nonspecific flattening of T waves. She was admitted urgently to the ward, and treatment started with oral 5 mg carbimazole t.d.s., 20 mg propranolol t.d.s., 40 mg furosemide o.d., and antibiotics (250 mg flucloxacillin i.v. 6 hourly, and 250 mg amoxicillin i.v. 6 hourly). Her temperature, pulse, and respiration and ECG were monitored continuously, with a special nurse constantly in attendance. Despite medication, her tachycardia persisted at the same rate, she became increasingly breathless, and died 24 hs after admission. Permission for an autopsy was refused.
Fig. 1. C h e s t x-ray s h o w i n g grossly enlarged cardiomediastinal s h a d o w C / T ratio 150/185 m m s (81%) due to thyrotoxic heart disease.
230
Comment
Hyperthyroid heart disease is rare under the age of 40 years; the main circulatory problems are tachycardia, high cardiac output, and vasodilatation leading to decreased peripheral vascular resistance, and may lead to arrhythmias, such as atrial fibrillation (AF), although this is rare in children. This case is presented because of its rarity and fatal outcome, despite apparent appropriate therapy for thyroid storm, instead of the usual benign course of steady recovery. CCF, due to thyrotoxic heart disease, is the one form of "heart failure" that does not respond to diuretics and digoxin alone; although Keith [5] states that this must be treated in the usual way with digitalis, digoxin has no effect on the sinus tachycardia in this condition, as myocardial contractility is actually enhanced already [3, 4, 6, 7]. Treatment with an antithyroid drug is required together with a beta blocker, such as propranolol, to control the heart rate, and to give symptomatic relief from palpitations. For the former carbimazole would be the choice in Britain, while in North America propyl thiouracil is preferred. Forfar et al. [2] suggested the occurrence of thyroid-induced cardiomyopathy in all patients with hyperthyroidism. Significant cardiac enlargement has been reported in about 50% of hyperthyroid children [l, 8]. In children, ECG abnormalities commonly seen are sinus tachycardia, left atrial hypertrophy, left ventricular hypertrophy (and less often biventricular hypertrophy), right bundle branch block, and less commonly AF [8]. Pilapil and Watson [8] observed that ECG changes are reversible after, but not necessarily soon after, becoming euthyroid. Cavallo et al. [ 1] found that mitral regurgitation, cardiac enlargement, and CCF represent serious complications of juvenile hyperthyroidism and are related to prolonged duration of the disease and poor treatment compliance. Why did this girl die despite what appears to have been appropriate therapy? This question is difficult to answer, since no postmortem studies were done, and it was impossible to undertake detailed cardiac studies in so brief a stay. There was no
Pediatric Cardiology Vol. 11, No. 4, 1990
history of previous or recent rheumatic carditis or clinical evidence of valvular regurgitation, and pericarditis was thought to be excluded by the absence of a pericardial friction rub, muffled heart sounds, and the typical ECG changes of generalized ST segment elevation followed by inversion or flattening of the T waves (although the latter alone was present). It is likely that her CCF due to thyrotoxic cardiomyopathy was aggravated by pneumonia. There was some clinical evidence of thyrotoxic myopathy, shown particularly by extreme weakness of the arms, perhaps associated with a duration of thyrotoxicosis of 2 years or more.
References I. Cavallo A, Joseph C J, Casta A (1984) Cardiac comt~lications in juvenile hyperthyroidism. Am J Dis Child 138:479-482 2. Forfar JC, Muir AL, Sawers SA, Toft TD (1982) Abnormal left ventricular function in hyperthyroidism. Evidence for a possible reversible cardiomyopathy. N Engl J Med 307:11651170 3. Gibson JD II, Harris AW (1939) Clinical studies of the blood volume V. Hyperthyroidism and myxoedema. J Clin Invest 18:59-65 4. Grossman W, Robin MI, Johnson LW, Brooks HL, Selenkow HA, Dexter L (1971) The enhanced myocardial contractility of thyrotoxicosis: Role of the beta adrenergic receptor. Ann Intern Med 74:869-874 5. Keith JD (1977) The heart in hyperthyroidism and hypothyroidism. In: Keith JD, Rowe RD, Vlad P (eds) Heart disease in infancy and childhood, 3rd edn. Collier-Macmillan, New York, London, pp 987-990 6. Lester LA, Sodt PC, Rich BH, Lucky AW, Hutcheon N, Arcilla RA (1982) Cardiac abnormalities in children with hyperthyrodism. Pediatr Cardiol 2:215-223 7. Merillon JP, Passa PH, Chastre J, Wolf A, Gourgon R (1981) Left ventricular function in hyperthyroidism. Br Heart J 46:137-143 8. Pilapil VR, Watson DG (1979) Electrocardiogram in hyperthyroid children. Am J Dis Child 119:245-248
E.S. Mucklow Department o f Pediatrics St. Mao"s Ho.spital Newport, Isle ~]" Wight, UK P030 5TG. UK
