Abstract
In a previous paper (Mounsey, 1966) the genesis of praecordial pulsations in health and disease was examined. The normal, short, outward impulse at the apex reflected underlying early systolic outward movement of the underlying ventricle as visualized in the lateral angiocardiogram. The sustained impulse of left ventricular hypertrophy was seen in the angiocardiogram to be due to failure of retraction of the antero-apical portion of the left ventricle in late systole. In cardiac aneurysm where a sustained impulse is also met, paradoxical pulsation of the aneurysm with failure of late systolic retraction accounted for the abnormal impulse. Marked systolic retraction of the cardiac impulse was met in two important conditions, tricuspid incompetence and constrictive pericarditis. The high stroke-output of the dilated right ventricle in tricuspid incompetence with both forward and backward ejection of blood accounted for systolic retraction at the apex in this condition. In constrictive pericarditis, on the other hand, in cases where the process involves predominantly the atrioventricular groove and outflow tract regions, the relatively free surface of the anterior wall of the right ventricle may show compensatory increased movement with marked systolic retraction and diastolic expansion, themselves in turn transmitted to the praecordium. The giant atrial beat of hypertrophic obstructive cardiomyopathy reflected increased atrioventricular transport function as was shown in the timed cineangiocardiogram. In the present paper, details of the form of the cardiac impulse in health and disease are described. These have been recorded with an instrument measuring absolute displacement, the impulse cardiograph (Beilin & Mounsey, 1962). The impulse cardiogram aims at being a graphic record of what the physician's hand and fingers feel.