The RSR' pattern in right chest leads in hypertrophic cardiomyopathy: vectorcardiographic analysis.

Vectorcardiogram (VCG) was studied in four patients with hypertrophic cardiomyopathy (HCM) with RSR' pattern in right chest leads. In these patients there ws an anterior QRS loop with a slow inscription in the initial part of the QRS loop, the pathognomonic initial pig-tail curl pattern was also observed in two patients. Though mid-terminal conduction delay was also observed in two patients, the slowly inscribed terminal QRS vector oriented anteriorly and to the right, thus characteristic of right, thus characteristic of right bundle branch block (RBBB), was not observed.

ECG pattern of left ventricular hypertrophy in nonobstructive hypertrophic cardiomyopathy: the significance of the mid-precordial changes.

A review of electrocardiograms from 33 patients with nonobstructive hypertrophic cardiomyopathy was made. In 22 patients there was noted a high QRS voltage, depression of the ST segment, and inversion of the T wave, satisfying the diagnostic criteria of left ventricular hypertrophy with the abnormal changes not only extending to the midprecordial leads but showing the most striking abnormal changes in Lead V4 in 20 patients. The frontal plane electrical axis was normal (around 60 degrees), with the most remarkable changes in Lead II.