Clinical variables affecting recovery of left atrial mechanical function after cardioversion from atrial fibrillation.

OBJECTIVES: We sought to evaluate the effect of clinical factors on recovery of atrial function after cardioversion for atrial fibrillation. BACKGROUND: Lack of effective mechanical atrial function (EMAF) after cardioversion of atrial fibrillation predisposes to thromboembolic complications and delays improvement in functional capacity. METHODS: Fifty-two patients underwent cardioversion (group I, electrical cardioversion, n = 40; group II, pharmacologic or spontaneous cardioversion, n = 12) for atrial fibrillation. Serial transmitral inflow Doppler variables were recorded after cardioversion until EMAF (atrial filling velocity > 0.50 m/s) was seen. Clinical variables (age, duration of atrial fibrillation, left ventricular ejection fraction, left atrial diameter, underlying cardiovascular disease, antiarrhythmic drug therapy and mode of cardioversion) were tested for an association with the outcomes of recovery of atrial function by day 3 and day 7. RESULTS: Effective mechanical atrial function recovered in 68% of patients by day 3 and in 76% by day 7 after cardioversion. The mode of cardioversion was significantly associated with recovery of atrial function by day 3 in bivariate and multivariate analyses (odds ratio 0.12, 95% confidence interval 0.01 to 1.0, for electrical cardioversion). None of the variables had an association with recovery of atrial function by day 7. Group I patients took a longer time to recover atrial function than group II patients (p = 0.012). In addition, group I patients had a significantly lower peak atrial filling velocity (mean [+/-SD] 0.39 +/- 0.19 m/s vs. 0.56 +/- 0.16 m/s) and a higher early filling to atrial filling velocity ratio (2.5 +/- 1.2 vs. 1.5 +/- 0.5) after cardioversion. CONCLUSIONS: A high proportion of patients recover EMAF within 1 week after cardioversion. Patients who undergo electrical cardioversion display a greater degree and a longer duration of mechanical atrial dysfunction than those who convert pharmacologically or spontaneously.

Prognostic value of stress echocardiography in the evaluation of atypical chest pain patients without known coronary artery disease.

Patients with atypical chest pain frequently lack significant coronary artery disease (CAD) and are, therefore, at low risk for future adverse cardiovascular events. We hypothesized that in this group of patients, stress echocardiography could identify those at risk for cardiac events. We retrospectively reviewed (mean follow-up 23.0 +/- 7.2 months) the prognostic value of stress echocardiography for major (cardiac death, myocardial infarction, congestive heart failure, and unstable angina) and total (major events plus coronary revascularization) cardiac events in 661 patients with atypical chest pain, normal global left ventricular (LV) systolic function, and no history of CAD. A positive stress echocardiogram was defined as the development of new or worsening wall motion abnormalities with exercise stress (80%) or dobutamine (20%). A total of 41 cardiac and 16 major events were noted. The event-free survival for total cardiac events was 97% for a normal stress echocardiogram and 93% for a normal stress electrocardiogram (ECG) at 30 months. A positive stress ECG predicted an event-free rate of 86% compared with 74% for stress-induced wall motion abnormalities and 42% if stress-induced LV dysfunction accompanied the wall motion abnormalities. A strategy recommending invasive studies based on positive stress echocardiogram results increased the per-patient cost, but led to greater savings per cardiac event predicted and provided incremental prognostic value for future cardiac events beyond clinical and stress electrocardiographic data. Thus, stress echocardiography in low-risk patients for CAD appears to be more cost effective than a stress ECG.