14th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 2000

Jan. 29 - Feb. 5, 2000
Marilleva, Trento, Italy

RT-89

Early recurrences of atrial fibrillation: role of left ventricular relaxation impairment

Giuseppina Belotti, Antonella Fedele, Cinzia Gatti, Claudio Poluzzi, Giuseppe Penati, Alessandro Locatelli, Antonino Piti.
Cardiology Department, Ospedale Treviglio-Caravaggio, Treviglio, Italy

Abstract

BACKGROUND AND AIM. Early recurrences of atrial fibrillation (AF) are related to electrical atrial remodeling due to increase of intracellular calcium and previous studies showed relapse reduction by calcium antagonists.

Intracellular calcium plays a crucial role also in ventricular relaxation, evaluable with doppler-echocardiography.

Whether LV relaxation impairment, that shares pathophysiological mechanism with atrial electrical remodeling, is associated to AF recurrences, is not still known.

METHODS AND RESULTS. We studied 42 patients (pts, 28 males, mean age 64±18 yrs) underwent successful electrical cardioversion (EC) for persistent AF. Doppler-echo was performed before EC, to evaluate LV diastolic parameters as isovolumic relaxation time, acceleration, deceleration, peak velocity, duration and velocity integral of E wave on transmitral flow. AF recurrence occurred in 24 pts (57%, all-REC) within 30 days from EC: in 8 pts immediately (imm-REC) and in 16 pts after discharge (>disch-REC). The pts without recurrences showed a significantly higher acceleration rate (1600±662 cm/sec²) than pts with imm-REC (988±342, p=0.02), pts with >disch-REC (1002±287, p=0.001) and all pts with recurrence (1024±304, p<0.001); the absence of AF relapse was also associated to a shorter acceleration time (55±10 msec), than imm-REC (74±16, p=0.001), >disch-REC (76±10, p<0.001) and all-REC (74±15, p<0.001). The isovolumic relaxation time in pts without relapse was significantly shorter (70±9 msec) than in pts with relapse (imm-REC 94±20 msec, p=0.001, > disch-REC 94±18, p<0.001, all-REC 93±18, p<0.001).

CONCLUSIONS. Early AF recurrences, either immediately after EC or after 30 days from EC, are related to diastolic pattern of LV relaxation impairment. Intracellular calcium might play a role in AF relapse not only for atrial electrical remodeling, but also through its effect on LV relaxation; relapse reduction by calcium antagonists observed in previous studies might be also due to LV relaxation improvement.

Key Words