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Atrial fibrillation is the commonest form of arrhythmia affecting millions of people. Early detection of patients with paroxysmal atrial fibri- llation (PxAF) and rapid restoration of sinus rhythm (SR) not only ensures better quality of life but also minimizes the risk of chronicity, stroke, and fatality. We sought to study whether advanced echocardiographic imaging, using 2D speckle tracking (2DSTE), of the right atrium (RA) & right ventricle (RV) could predict recurrence of AF 1- year post successful cardioversion, since right sided heart has not been studied non-invasively in AF.
30 patients with PxAF were studied pre cardioversion and 1- year post cardioversion. 2D STE was used to compute RV basal, mid, and apical strain (S%), as well as RA reservoir& booster strain. The data were obtained during index beat (beat preceding 2 RR intervals of near equal duration of < 60 ms) at base line as well as 1-year post cardioversion. Left ventricular ejection fraction (LVEF %) and filling pressure (E/E') were also registered during the same index beat.
Of the 30 patients 25 were available for follow up 2DSTE. 15 patients were in SR and 10 continued to have AF. Patients with SR had significantly greater RV basal (28±6 vs. 22± 5), mid (26± 6 vs. 20± 5), apical S% (24± 4 vs. 17 ± 5) (all p=0.01). RA reservoir & RA booster S% were also greater in SR compared with AF (28±9 vs.16± 4 and 10 ±3 vs. 2± 0.8 respectively; all p <0.0001). Multiple regression revealed that RA booster S% was the strongest predictor for maintenance of SR (β= −0.73; Adjusted R2 = 0.89). Not only that baseline RA booster S% had the greatest odds of predicting AF recurrence 1-year post cardioversion (OR=4.5; p= 0.02). Though baseline LVEF % was higher in SR (62± 5 vs. 51 ±4; P <0.05) it had a marginal impact on AF recurrence (OR= 1.2; p = 0.05). E/E’ did not have any impact (OR=0.7; p = 0.8).
Use of index beat to quantify RA, RV mechanics in PxAF is feasible. RV S% was significantly lower in AF but the RA booster S% remained the strongest predictor of maintenance of SR 1 -year post cardioversion. Whether altered RA mechanics detetcted by 2DSTE could act as a substrate responsible for perpetuation of AF remains to be studied.
Poster Sessions, Expo North
Sunday, March 10, 2013, 9:45 a.m.-10:30 a.m.
Session Title: Imaging: Echo: Atrial Imaging
Abstract Category: 18. Imaging: Echo
Presentation Number: 1226-336
- 2013 American College of Cardiology Foundation