Acta med. scand. Vol. 197, pp. 249-254, 1975
IDIOPATHIC HYPERTROPHIC SUBAORTIC STENOSIS Jsrgen Fischer Hansen, Ole Pedersen-Bjergaard, Poul Stage and Fritz Efsen From Medical Department B and Radiologic Department X , Rigshospitalet, University Hospital, Copenhagen, Denmark
Abstracr. The clinical and laboratory findings in 29 patients with idiopathic hypertrophic subaortic stenosis are pre-
sented. Dyspnoea during exercise, angina pectoris, syncope combined with left ventricular hypertrophy on ECG and chest X-ray and a systolic ejection murmur at the apex and the left sternal border are the most important findings. The findings were different in patients below and above 30 years of age. Most of the patients below 30 were in function group I, had a normal heart volume on chest X-ray, and syncope was related to exercise. All patients above 30 had symptoms, nearly all were in function groups 11-IV and often complained of palpitations, had increased heart volume on chest X-ray, sign of enlarged left atrium or atrial fibrillation on ECG. Syncope was not related to exercise, but always associated with palpitation in patients above 35 years of age. Pathologic Q waves were found more often in the younger age group. The differential diagnosis is discussed in relation to fixed aortic stenosis, mitral valve disease, ventricular septa1 defect, coronary artery disease, and hypertrophic cardiomyopathy without outflow tract obstruction. Idiopathic hypertrophic subaortic stenosis (IHSS) has attracted increasing attention in the recent years mainly for two reasons, firstly o n account of the peculiar pathophysiology and secondly as an explanation of sudden death in apparently healthy young people (3, 12, 15). The haemodynamic findings at rest and after administration of inotropic agents o r P-adrenergic blockers have been appropriately defined (2, 6). However, the diagnosis based on history, clinical findings, ECG and chest X-ray is considered t o be difficult to establish (7, 17). A correct diagnosis is important because IHSS may be treated with P-adrenergic blockers and/or operation (1, 3, 9, 21, 22, 28) and advice against heavy exercise may be important in the younger age groups. IHSS is a rare disease and can easily b e overlooked. For these reasons it was decided to
make a retrospective study of simple clinical parameters as mentioned above to evaluate which findings are important for the diagnosis of IHSS. PATIENTS A N D METHODS Among 498 patients with aortic stenosis IHSS was diagnosed in 29. They were examined in the Cardiac Laboratory, Medical Department B, Rigshospitalet, Copenhagen, and studied for the first time in the years 1952-72. In two patients the diagnosis was based on autopsy findings and in 27 on haemodynamic findings as described by Braunwald et al. (2). The diagnosis was subsequently verified at autopsy in three (26) and at operation in one of the latter 27 patients. A pressure gradient between the left ventricle and aorta at rest, varying between 10 and 165 mmHg, was found in the 27 patients by left heart catheterization. In addition to these findings I 1 patients had pressure differences of 10-40 mmHg over the right ventricular outflow tract. All records were revised with respect to family history, symptoms and signs, ECG and PCG findings, chest X-ray and diagnosis on the first admission to the Department. The $-test was used for statistical evaluation.
RESULTS Sex and age. Seven patients were females (mean age
37 years, range 9-60} and 22 were males (mean age 31 years, range 6-56). Twelve patients were below and 17 above 30 years of age. Symptoms (Table I). Seven patients had no complaints when seen for the first time in the Department. They were admitted because of the accidental finding of an abnormal ECG or a heart murmur. When relating symptoms t o age, a significantly @
IDIOPATHIC HYPERTROPHIC SUBAORTIC STENOSIS Jsrgen Fischer Hansen, Ole Pedersen-Bjergaard, Poul Stage and Fritz Efsen From Medical Department B and Radiologic Department X , Rigshospitalet, University Hospital, Copenhagen, Denmark
Abstracr. The clinical and laboratory findings in 29 patients with idiopathic hypertrophic subaortic stenosis are pre-
sented. Dyspnoea during exercise, angina pectoris, syncope combined with left ventricular hypertrophy on ECG and chest X-ray and a systolic ejection murmur at the apex and the left sternal border are the most important findings. The findings were different in patients below and above 30 years of age. Most of the patients below 30 were in function group I, had a normal heart volume on chest X-ray, and syncope was related to exercise. All patients above 30 had symptoms, nearly all were in function groups 11-IV and often complained of palpitations, had increased heart volume on chest X-ray, sign of enlarged left atrium or atrial fibrillation on ECG. Syncope was not related to exercise, but always associated with palpitation in patients above 35 years of age. Pathologic Q waves were found more often in the younger age group. The differential diagnosis is discussed in relation to fixed aortic stenosis, mitral valve disease, ventricular septa1 defect, coronary artery disease, and hypertrophic cardiomyopathy without outflow tract obstruction. Idiopathic hypertrophic subaortic stenosis (IHSS) has attracted increasing attention in the recent years mainly for two reasons, firstly o n account of the peculiar pathophysiology and secondly as an explanation of sudden death in apparently healthy young people (3, 12, 15). The haemodynamic findings at rest and after administration of inotropic agents o r P-adrenergic blockers have been appropriately defined (2, 6). However, the diagnosis based on history, clinical findings, ECG and chest X-ray is considered t o be difficult to establish (7, 17). A correct diagnosis is important because IHSS may be treated with P-adrenergic blockers and/or operation (1, 3, 9, 21, 22, 28) and advice against heavy exercise may be important in the younger age groups. IHSS is a rare disease and can easily b e overlooked. For these reasons it was decided to
make a retrospective study of simple clinical parameters as mentioned above to evaluate which findings are important for the diagnosis of IHSS. PATIENTS A N D METHODS Among 498 patients with aortic stenosis IHSS was diagnosed in 29. They were examined in the Cardiac Laboratory, Medical Department B, Rigshospitalet, Copenhagen, and studied for the first time in the years 1952-72. In two patients the diagnosis was based on autopsy findings and in 27 on haemodynamic findings as described by Braunwald et al. (2). The diagnosis was subsequently verified at autopsy in three (26) and at operation in one of the latter 27 patients. A pressure gradient between the left ventricle and aorta at rest, varying between 10 and 165 mmHg, was found in the 27 patients by left heart catheterization. In addition to these findings I 1 patients had pressure differences of 10-40 mmHg over the right ventricular outflow tract. All records were revised with respect to family history, symptoms and signs, ECG and PCG findings, chest X-ray and diagnosis on the first admission to the Department. The $-test was used for statistical evaluation.
RESULTS Sex and age. Seven patients were females (mean age
37 years, range 9-60} and 22 were males (mean age 31 years, range 6-56). Twelve patients were below and 17 above 30 years of age. Symptoms (Table I). Seven patients had no complaints when seen for the first time in the Department. They were admitted because of the accidental finding of an abnormal ECG or a heart murmur. When relating symptoms t o age, a significantly @
