Indices of electrical and contractile remodeling during atrial fibrillation in man

Background: Atrial electrical and contractile remodeling have been demonstrated to coincide during atrial fibrillation (AF) in experimental studies. We explored whether electrical and contractile remodeling correlate in man and explored its clinical implications. Methods: Forty-nine patients with persistent AF were studied. Electrical remodeling was assessed noninvasively using spectral analysis to estimate the average fibrillatory rate (AFR). Atrial contractility was assessed by transesophageal echocardiography (TEE) measurement of left atrial appendage outflow velocity (LAAOV). Results: The AFR was 403 +/- 43 fibrillations per minute (fpm) and the LAAOV was 0.27 +/- 0.14 m/s. A significant correlation was found between AFR and LAAOV (r =-0.47, P = 0.001). In patients with a LAAOV >= 0.25 m/s, the AFR was 387 +/- 48 fpm compared to 419 +/- 31 fpm among patients with LAAOV < 0.25 m/s (P < 0.01). Conclusions: This study demonstrates that indices of electrical and contractile remodeling are strongly correlated in persistent AF in man. The interindividual overlap, however, is too large to allow predictions of LAAOV based on fibrillatory frequency alone.