USEFULNESS OF THE RIGHT PARASTERNAL APPROACH FOR THE EVALUATION OF PROSTHETIC MITRAL-VALVE REGURGITATION BY DOPPLER COLOR-FLOW IMAGING

Since it is difficult to assess prosthetic mitral valve regurgitation by Doppler color flow imaging through the conventional left parasterna l or apical approaches, a semi-invasive transesophageal approach has b een used for its diagnosis. To evaluate the usefulness of the 'right' parasternal approach as a new method to assess prosthetic mitral regur gitation, we studied 21 patients with mitral regurgitation proved by t he transesophageal approach. The types of regurgitation were paravalvu lar leaks (4 patients), physiological leaks of mechanical valves (14 p atients) and transvalvular leaks of bioprostheses (3 patients). Althou gh mitral regurgitation was detected only in 6 patients (29%) by the c onventional approach, the regurgitant jet could be detected in 14 pati ents (67%) by the right parasternal approach (p < 0.05). The types of regurgitation could be determined in 13 patients (62%) by the right pa rasternal approach. Hemodynamically significant mitral regurgitation ( jet area determined by the transesophageal technique greater-than-or-e qual-to 4 cm2) Was correctly assessed in all 5 patients using the righ t parasternal approach, but it was undetectable or markedly underestim ated in 3 patients by the conventional approach. The length and the ar ea of the regurgitant signal found by the right parasternal approach w ere closely correlated with those determined by the transesophageal ap proach (r = 0. 90 for the length and r = 0. 95 for the area, respectiv ely, both p < 0.00 1), but there was no significant correlation betwee n the conventional and the transesophageal approach. Thus, the right p arasternal approach is more useful than the conventional approach in t he qualitative and quantitative diagnosis of prosthetic mitral regurgi tation by Doppler color flow imaging.