Mechanisms and significance of QRS macrovoltage in the absence of cardiac hypertrophy.

The electric stimulation of the lateral ventricular walls carried out in experiments on dog heart (open-thorax), as well as the analysis of the clinical, radiological and electrocardiographic data recorded in 462 cases with QRS macrovoltage led to the following conclusions: a) in 22% of the cases (hospital cardiologic examinations) this anomaly cannot be accounted for either by age, blood pressure or cardiac hypertrophy; b) a temporarily perturbed development of the ventricular depolarization, i.e. a "jerky" depolarization, not stagnant enough to produce an intraventricular block, may generate great negativity and positivity myocardial masses responsible for the appearance of large dipoles, namely of the increased QRS voltage; c) the coincident ischemia and macrovoltage of the QRS major wave, as well as the subsequent evolution of incipient CHD in a series of patients point to the hypothesis according to which the regional myocardial ischemia may induce a QRS macrovoltage by means of the above mechanism.