labelling all these patients as having heart disease with all the consequences attendant thereto ?

To the Editor: Dr. Greenwald raises an important question and one to which we would like to respond. Our study was initially prompted by the observation of pansystolic posterior bowing of the mitral valve echogram in the presence of marked mitral prolapse on cineangiogram in two consecutive patients during a one week period. We then catalogued the abnormalities described in our report by both retrospective and prospective analysis of the echograms of all patients with mitral prolapse documented by catheterization in our laboratory. The validity of these observations has been substantiated by other investigators. ' Subsequently, we, like many others, have observed an increasing number of echograms which manifest this pansystolic hammock-like posterior motion and collapse in patients both with and without other clinical evidence of mitral prolapse syndromes. Thus, it is clear that a need exists for further clarification of the exact significance of this echographic phenomenon. It is important to emphasize from the start that the ultrasound findings which we reported typically occurred in combination. Thus pansystolic bowing reached its nadir in midsystole, and characteristically there occurred an increased diastolic excursion of the anterior mitral leaflet (usually abutting the septum), increased motion of the left atrial posterior wall, and multiple systolic echoes. The absence of more than one of these ancillary findings should therefore cast suspicion on the diagnosis of mitral prolapse syndrome. Analyzing echograms in this fashion, we have only infrequently encountered patients without other clinical evidence of mitral prolapse. Echocardiography would appear to offer certain advantages over cineangiography in the evaluation of mitral valve motion. Nevertheless, left ventricular angiography remains the gold standard for the evaluation of mitral prolapse and it is likely that the recently described echographic findings will be found to be -falsely positive" in relation to this standard in some patients, and we have documented this finding in one patient. However, rigid adherence to the requirement for midsystolic buckling has yielded falsely negative results in the past. It thus appears that, as with so many tests in medicine, the various echocardiographic manifestations of mitral prolapse will have a sensitivity and specificity. Although the exact sensitivity and specificity remain to be established, and will undoubtedly vary for each echographic manifestation, ultrasound-angiographic correlations thus far available to us have demonstrated all the echographic findings described to be highly specific. The natural history of the mitral prolapse syndromes remains uncertain. Nevertheless, the relatively benign course thus far exhibited by most patients with mitral prolapse diagnosed in recent years by cineangiogram or echocardiogram, coupled with the similarly innocuous effects of "old healed pericarditis," manifested by a midsystolic click and late systolic murmur diagnosed in earlier years, lends support to an optimistic prognosis for this entity. Since these patients exhibited the most overt manifestations of the syndrome, it would be expected that