The value of left parasternal impulse recordings in the assessment of mitral regurgitation.

Left parasternal cardiograms were recorded at the fifth intercostal space in 30 patients with mitral regurgitation. Early systolic outward movements (E), late systolic outward movements (LOM), and the ratio of the LOM area to the total area occupied by the left parasternal cardiogram (LPC area) were examined. Thirteen patients had pure mitral regurgitation due to ruptured chordae tendineae (ten patients) or "floppy mitral valve" (three patients). In these patients LOM/E correlated significantly with the regurgitation volume determined by the difference between angiographic and Fick stroke volumes, (r = 0.93, P < 0.01), and with the height of the "v" wave in the pulmonary artery wedge pressure tracings (r = 0.79; P <0.01). Simultaneous recordings of left parasternal movements and pulmonary wedge pressures in eight patients in this group showed a close relationship between LOM and "v" waves. Fourteen patients had rheumatic heart disease and mitral regurgitation associated with mitral stenosis of varying degrees of severity. In this group there was no significant correlation between LOM/E or LOM area/LPC area and the regurgitation volume or the height of the "v" wave. Of three patients who had congenital atrial septal defect in addition to mitral regurgitation, none had prominent LOM in the left parasternal cardiogram. This study suggests that if mitral stenosis and atrial septal defect can be excluded on clinical evidence, the left parasternal cardiogram may be used to obtain a noninvasive assessment of the severity of mitral regurgitation, particularly in patients with recent onset of the disease.