Correlations between electrocardiographic findings and echocardiographic patterns in 116 patients with hypertrophic cardiomyopathy

: To evaluate the correlation between electrocardiographic and echocardiographic m-mode (E-TM) and two-dimensional (E-2D) patterns, 116 patients with hypertrophic cardiomyopathy (HCM) were studied by these two methods. Patients were classified into four types, according to Maron et al's E-2D classification of HCM. In addition a subgroup (IIIb) of 15 patients in types III, had typical left ventricular concentric hypertrophy. Twelve per cent of the study patients had a normal ECG, and most often those patients showed types I-II and IIIb. Left ventricular hypertrophy by ECG was most frequent (46%) and was found mostly in type III (P less than 0.02). Abnormal Q waves, suggestive but not diagnostic of HCM, were found in 22 of 116 (18%) patients, and were present in equal proportion in each morphologic type. Isolated ST-T changes were found in the same percentage of patients. Six of 7 patients with giant negative T waves had apical left ventricular hypertrophy, but 4 other patients with apical hypertrophy had no such ECG findings. Mean left atrial dimensions at E-TM, although larger in patients with atrial fibrillation, with statistical significance (P less than 0.001), were not predictive of this arrhythmia. ECG is still useful in the diagnosis of HCM, although there is no abnormal pattern specific for the disease, and even a normal ECG can be found in these patients.