Mitral valve echocardiograms recorded in 57 patients revealed spontaneous ventricular premature contractions in 46 and supraventricular premature contractions in 11. The latter patients had normal mitral valve motion. Five patterns of mitral valve movement were observed in patients with premature ventricular contractions: (1) normal movement (18 patients); (2) valve prolapse (20 patients); (3) absent valve opening (3 patients); (4) no valve closure (1 patient); and (5) normal motion with long coupling intervals and mitral valve prolapse with short coupling intervals (4 patients). The velocity of valve closure during the premature ventricular contraction was greater than that of the regular beat in 28 patients. The presence of normal mitral valve movement during premature beats in all seven patients with severe cardiomegaly and the occurrence of valve prolapse only with short coupling intervals in the four patients with parasystole indicate that a small ventricular volume is an important factor in valve prolapse. The normal mitral valve motion observed in the 11 patients with supraventricular extra-systoles suggests that a small ventricular volume alone is not sufficient to produce valve prolapse; abnormal papillary muscle and ventricular activation are probably also required. Mitral valve prolapse may be an important cause of mitral regurgitation induced during ventricular premature contractions.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine