A clinical study on familial heart diseases

Clinical pictures of 107 cases of familial heart diseases belonging to 30 families were studied. 1. Initial manifestations frequently observed were palpitation, chest pain, becoming aware of irregular heart beats, dyspnea and a syncopal attack. The initial manifestation was most frequently observed in the second or the third decade. In familial idiopathic cardiomyopathy a systolic murmur was the most common auscultatory findingd followed by the third and fourth heart sounds. 2. The cardiothoracic ratio was not necessarily increased. 3. In the ECG of familial idiopathic cardiomyopathy, arrythmia was frequently observed. A-V block was rare but a premature ventricular contraction was frequent. During a syncopal attack, the ECG showed ventricular trachycardia. An abnormal Q-wave, ST segment depression and a negative T-wave were also observed but their incidence did not differ from one lead to the other. Some cases of familial heart diseases showed QTc-prolongation but QTc was not over 0.47 seconds and was not as markedly prolonged as in familial QT-prolongation syndrome. 4. A similarity of clinical findings was observed among cases belonging to the same family. There was a striking similarity among the patients belonging to the same family in initial symptoms, characters of a systolic murmur, morphology of the cardiac silhouette, morphology of an abnormal Q-wave or ST segment depression and in the leads which showed these abnormalities. 5. The most frequent mode of death was sudden death. A cardiothoracic ratio of 0.6 or more, an abnormal R-wave in V1 suggesting high dorsal wall damage, left axis deviation, and the low voltage of Sv1 + Rv5 of 1.5 mV or less suggested a poor prognosis.