Prediction of Transition to Chronic Atrial Fibrillation in Elderly Patients with Nonvalvular Paroxysmal Atrial Fibrillation by Transthoracic Doppler Echocardiography

Abstract

It is well known that paroxysmal atrial fibrillation (PAF) often precedes the development of chronic atrial fibrillation (CAF). The purpose of this study was to determine prospectively whether transthoracic echocardiography is useful for the prediction of the transition to CAF in elderly patients with nonvalvular PAF. Forty-two consecutive elderly patients (> or =65 years) with nonvalvular PAF were prospectively evaluated after undergoing transthoracic echocardiography. The study endpoint was the transition to CAF (AF; > or = 6 mo). During a follow-up period of 32 +/- 24 mo, 12 patients developed CAF. Patients with CAF had a significantly lower peak A velocity (A) and a higher E/A ratio of the transmitral inflow (TMF) such as a pseudonormalization pattern, and a lower peak atrial reversal wave velocity, higher peak diastolic wave velocity (D), and lower peak systolic/diastolic wave velocity ratio (S/D ratio) of the pulmonary venous flow (PVF). Kaplan-Meier analysis revealed that the transition to CAF was observed more often when A was < or = 70 cm/sec and E/A ratio was > or = 1.07 of TMF, and D was > or = 44 cm/sec and the S/D ratio was < or = 1.34 of PVF. All patients developed CAF when the E/A ratio was > or = 1.15 or the S/D ratio was < or = 0.75. This prospective study suggests that elderly patients at high risk for transition to CAF have a pseudonormalization pattern of TMF and a diastolic dominant pattern of PVF, and that transthoracic Doppler estimation of TMF and PVF may be useful in identifying elderly patients at high risk for the transition from nonvalvular PAF to CAF.