Propagation of Mitral Valve Closure Flow to the Pulmonary Vein: Its Clinical Relevance to Left Atrial Compliance in Patients With Atrial Fibrillation

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OBJECTIVES: Mitral valve closure produces a flow which propagates through the left atrium (LA) to the pulmonary vein (PV) and forms a small flow reversal (C wave) on the PV flow pattern. We examined whether propagation of mitral closure flow into LA might reflect LA compliance in patients with atrial fibrillation (AF).
METHODS: We recorded PV flow velocity pattern using transesophageal echocardiography in 73 patients with AF. They were divided into 3 groups according to the estimated severity of LA damage; almost normal (Group I, 16 patients with lone AF), mildly damaged (Group II, 23 patients), and severely damaged LA function (Group III, 34 patients). C wave peak velocity (CV), the time from Q wave on ECG to the C wave peak (QC) and QC divided by LA long-axis diameter (QC/LAD) were obtained. Of the study population, in 18 patients with mitral stenosis who underwent percutaneous mitral valvotomy, mean LA compliance was calculated by dividing cardiac stroke volume by systolic rise in LA pressure.
RESULTS: QC and QC/LAD proportionally prolonged as the disease severity increased (QC; 84±23 vs. 93±21 vs. 107±27 ms, p<0.01, QC/LAD; 1.44±0.32 vs. 1.47±0.32 vs. 1.79±0.55ms/mm, p<0.05 for Group I, II and III, respectively). QC and QC/LAD showed significant negative correlations with mean LA compliance (p<0.05).
CONCLUSION: Propagation of a flow into LA produced by mitral closure may provide new noninvasive indexes to assess LA compliance in patients with AF.