Associazione indipendente tra la riserva di flusso coronarico e le pressioni di riempimento e il rilasciamento del ventricolo sinistro

Abstract

Background: A cross-talk between coronary flow and left ventricular (LV) function is recognized. This study tested the hypothesis that impairment of coronary flow reserve (CFR) in arterial hypertension is associated with LV systolic and diastolic dysfunction, independently on abnormalities of LV geometry. Methods: We studied 59 newly diagnosed, never treated hypertensive patients, using transthoracic Doppler echocardiography, including pulsed Tissue Doppler of mitral annulus and CFR on left anterior descending artery (low dose dipyridamole). The study population was divided in 2 groups according to age-normalized relative wall thickness (RWTn): 36 with normal LV geometry (RWTn ≤ 0.41) and.23 patients with LV concentric geometry (RWTn > 0.41) Results: Patients with LV concentric geometry (RWTn > 0.41) had significantly lower midwall (but not endocardial) shortening, longer isovolumic relaxation time (IVRT), lower Tissue Doppler derived early diastolic velocity (Em), higher ratio of transmitral E velocity to Em and lower CFR than patients with normal LV geometry (RWTn ≤ 0.41). In the whole population lower CFR was significantly associated with lower midwall shortening and Em, longer IVRT and higher E/Em ratio. After controlling for heart rate, mean blood pressure and RWTn, only the relation of CFR with IVRT, Em and E/Em ratio remained significant. Conclusions: Reduced midwall mechanics is associated to lower CFR, a relation depending on LV concentric geometry. A reduced CFR is associated with both impaired relaxation and increased filling pressure, a relation that is independent on LV geometry and pressure load.