ISOTOPIC VENTRICULAR TOMOGRAPHY IN 36 CAS ES OF MITRAL-VALVE PROLAPSUS

Left and right ventricular wall motion was studied in mitral valve pro lapse with or without ventricular arrhythmias. Regional and global ven tricular wall motion was evaluated by isotopic methods, based in eject ion fraction and Fourier phase analysis representing the progression o f wall contraction. The synchronisation of the ventricles was characte rized by the difference of the mean phase of each ventricle. The heter ogeneity of contraction of each ventricle was defined by the dispersio n around the mean (standard deviations of the phases). Fifteen of the 36 patients had complex ventricular arrhythmias (Lown grade greater th an or equal to 111), 12 had LVP and 16 had mitral regurgitation. In mi tral valve prolapse, the RV EF was decreased compared with normal cont rols (30 +/- 9 % vs 40 +/- 10 %; p < 0.001), especially in patients wi th mitral regurgitation (26 +/- 7% vs 30 +/- 10 %; p = NS) and complex ventricular arrhythmias (26 +/- 7 % vs 32 +/- 10 %; p < 0.01). The SD P of the LV was greater than those of controls (18 +/- 11 degrees vs 1 1 +/- 5 degrees;p = NS) whereas the SDP of the RV was greater (27 +/- 17 degrees vs 12 +/- 5 degrees; p < 0.05) especially in those with com plex ventricular arrhythmias (36 +/- 21 degrees vs 21 +/- 10 degrees; p < 0.01). The SDP of LV and RV were greater in patients with mitral r egurgitation: 20 +/- 11 degrees versus 17 +/- 10 degrees (NS) and 35 /- 21 degrees versus 20 +/- 8 degrees (p < 0.01). Heterogenous ventric ular contraction, more marked in the right ventricle in mitral valve p rolapse suggests severe myocardial disruption in this valvular disease , reflected by the high incidence of LVP and complex ventricular arrhy thmias.