Abnormalities of the QRS Complex

Abstract

Abnormalities of the QRS axis and the QRS interval have been discussed in earlier chapters and will be noted in this chapter only as they relate to other problems. As a general rule, the QRS complex reflects primarily left ventricular activity and to a much lesser extent right ventricular activity, since the mass of the left ventricle is so much greater. Thus, when hypertrophy, conduction abnormalities, and infarction occur in the left ventricle, they have a much greater effect on the electrocardiogram (ECG) than when they occur in the right ventricle. Abnormalities of the right ventricle may be entirely obscured.