Effect of selective heart rate reduction through sinus node Ifcurrent inhibition on severely impaired left ventricular diastolic dysfunction in patients with chronic heart failure

AimsThe aim of the study was the assessment of heart rate reduction effect through selective If current inhibition on several left ventricular (LV) diastolic function parameters and left atrial (LA) volumetric parameters in patients with systolic heart failure (HF).Methodsand results In total 54 patients with systolic HF and pseudonormal/restrictive type of diastolic dysfunction were randomly allocated to either the ivabradine (27) or control group (27) during a 3-month period. Left atrial volume index (LAVI) and the following diastolic function parameters were determined by transmitral pulsed wave and mitral annulus tissue Doppler study before and after the therapy period: deceleration time (DT), peak early to late mitral inflow wave velocity ratio (E/A) and the ratio of mitral peak velocity of early filling (E) to early diastolic mitral annular velocity (Em) (E/Em). Parametric variables were compared by a two-set analysis of variance with a repeated measurement for the time factor. Ivabradine treatment was accompanied by increase of DT (30.19 ± 30.21 msec in ivabradine, versus 4.07 ± 16.93 msec in controls, 95% CI, P= 0.00001), decrease of E/A ratio (-0.83 ± 1.2, in ivabradine versus –0.05 ± 0.42 in controls, P= 0.0001) and decrease of E/Em ratio (-5.16 ± 3.9 in ivabradine versus 0.99 ± 4.34, P= 0.0002 in controls). Ivabradine also improved LAVI (-6.14 ± 5.17 ml/m² versus 0.65 ± 4.29 ml/m² in controls, P< 0.0001). After 3 months of treatment heart rate was significantly reduced in the ivabradine group (P <0.0001).ConclusionTreatment with ivabradine improves LV diastolic function through reducing E/A ratio, E/Em ratio and increasing DT. These changes may contribute to the improvement of intracardiac haemodynamics with decrease of LAVI and improvement of LV filling.