Background: In patients with left ventricular (LV) dysfunction the mitral leaflet coaptation point (CPMA) is displaced towards the LV apex. The aim of our study was to estimate the value of CPMA measurement as a simple index regarding the acute effects of cardiac resynchronization therapy (CRT), which is coming to be an established method of treatment for congestive heart failure (CHF).
Methods: We studied 20 patients with CHF (NYHA III-IV) and LV ejection fraction (LVEF) 22 +/- 4%. All patients received CRT and an echocardiogram was performed within 24-48 hours. The echocardiographic indices LV end-diastolic diameter (LVEDD) and end-systolic diameter (LVESD), LVEF, mitral annulus diameter (MAD), and the degree of intraventricular desynchronization, were measured at CRT off and CRT on. The CPMA, the distance between the coaptation point of the mitral leaflets and the mitral annulus, was measured from the apical 4-chamber view in end-systole at both CRT on and CRT off.
Results: CRT improved both the contractility and dimensional indices in CHF patients. CPMA decreased from 11.3 +/- 2 mm at CRT off to 9.1 +/- 1.8 mm after CRT on (p < 0.001) and MAD from 38.9 +/- 3.9 mm at CRT off to 37.5 +/- 3.7 mm at CRT on (p < 0.002). LVEF improved from 24.5 +/- 5.7% at CRT off to 29.5 +/- 5.1% at CRT on (p < 0.001). There was an improvement in LV synchronization from 88 +/- 7 ms at CRT off to 48 +/- 3 ms at CRT on (p < .001). CPMA was correlated with MAD (r = 0.52, p < 0.05 and r = 0.59, p < 0.05 at CRT off and CRT on, respectively). Moreover, the absolute change in CPMA was correlated with LVESD (r = 0.68) and LVEDD (r = 0.65), both p < 0.05, with the time difference of the basal segments of the septal and lateral wall at CRT on (r = 0.68, p < 0.01), and inversely correlated with LVEF (r = -0.55, p < 0.05).
Conclusion: In patients with severe LV systolic dysfunction and dilatation CRT was associated with an improvement in both CPMA and MAD.