Abnormalities of left atrial function after cardioversion: an atrial strain rate study.

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Physiology

Background:

• Atrial myocardial dysfunction post-cardioversion for chronic atrial fibrillation (CAF) requires further elucidation.
• The utility of Doppler-derived atrial strain rate (A-sr) in assessing global left atrial function after cardioversion is not well-defined.

Purpose of the Study:

• To evaluate Doppler-derived atrial strain rate (A-sr) as a measure of global left atrial function.
• To compare A-sr in patients with CAF post-cardioversion against healthy controls.
• To assess changes in A-sr over a 6-month follow-up period.

Main Methods:

• Measured A-sr from four atrial walls using Doppler tissue imaging in 37 cardioverted CAF patients and 37 controls.
• Assessed conventional atrial function parameters and atrial contraction velocity (A' velocity).
• Measured time to peak A-sr from aortic valve closure.

Main Results:

• Immediately post-cardioversion, A-sr was significantly lower in the CAF group compared to controls (p<0.001).
• A-sr correlated with A' velocity (r = 0.63; p<0.001) in patients.
• Atrial function improved within 4 weeks, but the time to peak A-sr remained prolonged compared to controls.

Conclusions:

• Doppler-derived atrial strain rate (A-sr) effectively quantifies global left atrial function.
• Atrial function, assessed by A-sr, is impaired after cardioversion from CAF but demonstrates recovery.
• While overall function improves, prolonged time to peak A-sr suggests persistent subtle dysfunction.