Background: The clinical and echocardiographic parameters associated with the risk of developing new onset atrial fibrillation (AF) in congestive heart failure (CHF) have not been studied comprehensively. We determined if dyssynchronous left atrial (LA) lengthening and contraction predicted future development of new onset AF in patients with CHF.
Methods: One hundred fifty-eight patients who were admitted for CHF without past or current AF were evaluated. We measured the time to peak velocity and time to peak strain with reference to the QRS complex during ventricular systole (reservoir) and late diastole (atrial contraction) in mid-portion of 4 LA walls. Dyssynchronous atrial lengthening and contraction (atrial dyssynchrony) was defined as the standard deviation of each parameter.
Results: New onset AF developed in 21 patients (13.3%) after a mean follow-up of 43+/-15 months. Based on univariate Cox analysis, older age, larger LA dimension and volume index, lower LA fractional shortening, and the presence of atrial dyssynchrony were associated with new onset AF. In multivariate Cox analysis, atrial dyssynchrony based on strain (>39 ms, HR 10.0, p=0.003) and LA size (> or =45 mm, HR 4.3, p=0.016) were independent predictors of new onset AF in CHF.
Conclusions: We demonstrated that atrial dyssynchrony based on strain is the strongest univariate and multivariate predictor for new onset AF in hospitalized patients with CHF.