Abstract 3066: Left Atrial Asynchrony Before And After Electrical Cardioversion: Mechanical Resynchronization And Improvement Of Atrial Function After One Month Of Synus Rhythm
Background: Dispersed conduction due to atrial fibrillation (AF) is linked to cavity remodelling and loss of filling and emptying properties. Cardioversion (CV) should remodulate function through recovery of atrial mechanical synchronism (AMS). Purpose: To assess if conversion of AF to sinus rhythm (SR) is associated with improvement of AMS, 101 patients (pts) with AF, age 70±8 yrs, with or without (n=5) structural heart disease were echoed 1 week before electrical CV (all pts) and 1 month later only in case of SR maintenance (n=53).
Methods: Atrial volume was calculated from anteroposterior diameter and area according to the formula: 4.2*diameter/ 2*area/2. 2D strain (speckle tracking technique) was used to estimate peak and standard deviation (SD) of the time-to-peak (% of R-R’ interval) of the deformation of 6 segments arbitrarily identified along the septum, the roof and the lateral wall of the atrial cavity, as imaged in a 4-chamber view. BNP was also measured 1 week before in all pts and 1 month after CV, if SR was maintained.
Results: There was a significant decrement in atrial volume after SR was restored (from 59.6 ±20.4 ml/m2 [59.5±19.7 ml/m2 for all pts] to 52.8±21.3 ml/m2; p=0.002) together with an increase in mean peak strain (from 9.6±4.9% [9.7±4.8% for all pts] to 15.9±7.0%, p<0.001). There was no change in time-to-peak of individual strains before and after CV (from 52.3±12.7% [52.2±12.0% for all pts] to 50.4±11.3%; p=NS), but SD significantly decreased (from 19.1±7.6% [20.2±8.1% for all pts] to 15.6±7.4%; p=0.015) suggesting improved AMS. Also BNP decreased significantly (from 128±99 pg/ml [118±87 pg/ml for all pts] to 87±90 pg/m; p<0.001) and its change corresponded to the reduction in atrial volume (P=0.016). A logistic regression analysis identified SD as the only predictor of maintenance of SR post CV (p=0.076), with a 1.5 increment, per 10 SD reduction, in the chance of maintaining SR at 1 month. Duration of AF, atrial volume, peak strain, BNP and ventricular EF did not exert any effect on SR persistence.
Conclusion: In AF patients that maintain SR 1 month after CV
AMS is significantly decreased and this improvement favourably modulates atrial strain, volume and dismission of BNP,
the extent of AMS pre-CV can predict maintenance of SR at 1 month.