Augmentation of Pulmonary Vein Backflow Velocity during Left Atrial Contraction: A Novel Phenomenon Responsible for Progression of Atrial Fibrillation in Hypertensive Patients

BACKGROUND: Atrial fibrillation (AF) is a common arrhythmia showing disease progression. However, echocardiographic prediction of such progression remains incomplete. This study aimed to identify echocardiographic predictors of AF progression in hypertensive patients. METHODS: Hypertensive patients with paroxysmal AF were divided into two groups: patients with AF which became permanent (group A; n = 13) and those with AF which remained paroxysmal (group B; n = 46) during the same follow-up period (8.0 +/- 2.4 years). Clinical baselines showed no significant differences except for age. Transthoracic echocardiography was recorded 1-2 weeks after termination of the first-detected paroxysms of AF. RESULTS: Echocardiography showed greater left atrial (LA) dimension (p = 0.023) and late diastolic pulmonary vein (PV) backflow velocity (p < 0.001), and a lower LA fractional shortening (p = 0.008) in group A than in group B. Multilogistic regression analysis demonstrated that augmented PV backflow (p = 0.007) and reduced LA fractional shortening (p = 0.032) were independent predictors of the progression of AF. The receiver-operating characteristic curve demonstrated that PV backflow augmentation is the best predictor of future AF perpetuation. CONCLUSION: PV backflow leading to cyclic stretching of PV musculature contributes to AF progression.