Left atrial appendage flow in nonrheumatic atrial fibrillation - Relationship with pulmonary venous flow and ECG fibrillatory wave amplitude

Objective: This study was conducted (1) to examine the relationship between left atrial appendage (LAA) flow velocity and pulmonary venous flow (PVF) variables during nonrheumatic atrial fibrillation (AF), and (2) to determin e whether a reduction in LAA flow is reflected by the fibrillatory wave amp litude on the surface EGG. Background: Although LAA Doppler echocardiographic signals provide informat ion regarding the velocity and direction of flow only for a localized narro w sample, systolic PVF represents in part the global left atrial function, mainly relaxation. Controversy exists about whether the amplitude of fibril latory waves recorded on the surface ECG correlates with LAA flow velocity during AF. Measurements and results: Thirty-three patients (20 men, 13 women; mean [+/ - SD] age, 61 +/- 11 years) with nonrheumatic AF undergoing transthoracic a nd transesophageal echocardiography were studied. A correlation between LAA flow velocity and systolic PVF variables (peak systolic velocity, R = 0.45 0, p = 0.009; velocity-time integral of systolic flow, R = 0.491, p = 0.004 ; systolic fraction of PVF, R = 0.627, p < 0.0001) was observed. Patients w ith a low LAA flow profile (< 25 cm/s) had a reduced systolic PVF. Longer A F duration and the occurrence of moderate mitral regurgitation were related to reduced LAA flow. AF was subdivided into coarse (peak-to-peak fibrillat ory amplitude greater than or equal to 1 mm) or fine (< 1 mm) in standard E CG lead V1. There was no association between the coarseness of AF and the L AA flow profile. Conclusion: In patients with nonrheumatic AF, a reduction in LAA flow veloc ity correlates with a reduction in systolic PVF. These hemodynamic changes are not reflected by the ECG fibrillatory wave amplitude.