Familial hypertrophic cardiomyopathy associated with prolongation of the QT interval.

In a 61 year old female patient who suffered from atypical chest pain we diagnosed long QT syndrome by QTc duration of 467 ms, macroscopic T wave alternans and notched T waves in three leads and hypertrophic cardiomyopathy with asymmetric thickening of basal parts of the septum (2.0 cm) without relevant outflow tract obstruction by echocardiography. Coronary angiography could exclude coronary artery disease. In a systematic family screening two sons of the patient could also be diagnosed as having long QT syndrome with QTc durations of 472 and 496 ms and asymmetric septal thickening (1.8 and 2.1 cm, respectively). One of these two sons suffered from pre-syncope, the other was asymptomatic despite maximum sports activity. In the third son, LQTS and hypertrophic cardiomyopathy could be excluded.