Short-lasting atrial fibrillation impaired left ventricular systolic velocity at 1-minute postcardioversion compared to baseline (4.2 vs 5.7 cm/s; P<0.005), which normalized at 1 week.
Observational (n=10)
Does prompt cardioversion by an implantable atrial defibrillator improve ventricular systolic and diastolic function in patients with paroxysmal atrial fibrillation?
Short-lasting atrial fibrillation impairs systolic and diastolic function in both ventricles despite adequate rate control, but early restoration of sinus rhythm by an implantable atrial defibrillator minimizes ventricular dysfunction.
Absolute Event Rate: 4.2% vs 5.7%
p-value: p=< 0.005
AF with a fast ventricular response may cause ventricular mechanical impairment, though whether short-lasting AF with satisfactory rate control may affect ventricular function is unknown. This study investigated if prompt cardioversion by an implantable atrial defibrillator (IAD) may prevent left (LV) and right ventricular (RV) systolic and diastolic dysfunction. Ten patients (mean age 61 +/- 9 years, 8 men) with paroxysmal AF without structural heart disease who received an IAD were studied by echocardiography and tissue Doppler imaging (TDI) for both ventricles. Measurements were made during baseline sinus rhythm and at 1-minute, 20-minute, 4-hour, and 1-week postcardioversion of an episode of spontaneous AF. The occurrence of AF and the ventricular rate were monitored at 2-hour intervals by the device. There were 50 episodes of AF with a mean duration of 8.8 +/- 8.9 days (2 hours to 37 days). There was no difference in M-mode measured LV fractional shortening and ejection fraction between baseline sinus rhythm and after cardioversion. However, the TDI derived myocardial systolic velocity (TDI-S) was significantly lower at 1-minute postcardioversion and was normalized at 1 week in both LVs (baseline: 5.7 +/- 1.8, 1 minute: 4.2 +/- 1.0, 20 minutes: 4.3 +/- 0.9, 4 hours: 4.8 +/- 1.0, 1 week: 5.5 +/- 1.8 cm/s; P 48 hours) resulted in a more depressed TDI-S in LV (> 48 hours: 4.2 +/- 1.0, < or = 48 hours: 5.3 +/- 1.3 cm/s; P < 0.01). Shocks in sinus rhythm did not affect any of the above echocardiographic parameters. Therefore, despite adequate rate control, short-lasting AF impairs systolic and diastolic function in both ventricles, which improves gradually after cardioversion. Early restoration of sinus rhythm by an IAD minimizes ventricular dysfunction. TDI is a sensitive tool to assess early systolic and diastolic dysfunction.
Yu et al. (Fri,) conducted a observational in Paroxysmal atrial fibrillation (n=10). Cardioversion by an implantable atrial defibrillator vs. Baseline sinus rhythm was evaluated on Left ventricular myocardial systolic velocity (TDI-S) at 1-minute postcardioversion (p=< 0.005). Short-lasting atrial fibrillation impaired left ventricular systolic velocity at 1-minute postcardioversion compared to baseline (4.2 vs 5.7 cm/s; P<0.005), which normalized at 1 week.