single beat determination of intraventricular systolic dyssynchrony in patients with atrial fibrillation and systolic dysfunction.

results: the average of dyssynchrony in eight cycles showed a positive correlation with dyssynchrony in target beat rr1/rr2 = 1. average of dyssynchrony in target beat was 46.77 msec, and average of 8 cycle was = 47.701, (p value = 0.776, pearson linear correlation 0.769). objectives: we proposed to evaluate intraventricular mechanical dyssynchrony by measuring time-to-peak systolic velocity between basolateral and basoseptal segments (septum to lateral wall delay) using tissue doppler study (tdi) by two different methods. materials and methods: 31 patient (68 ± 10.3 years) with heart failure (ef < 35%) and af rhythm, r-r cycle length more than 500 msec were evaluated. we found a target beat in which preceding r-r (r-r1) to pre-preceding r-r (r-r2) ratio was 1(rr1/rr2 = 1) then measured the intraventricular dyssynchrony in that cycle. intraventricular dyssynchrony was also determined and averaged for 8 consecutive cardiac cycles. the values at rr1/rr2 = 1 were compared with the average of intraventricular dyssynchrony in eight cycles and the relationship between dyssynchrony were evaluated by paired t-test, linear pearson correlation (r2), linear regression analysis. background: atrial fibrillation (af) is the most common clinically significant cardiac arrhythmia. however, diagnosis of intraventricular dyssynchrony in patients with af is difficult due to beat-to-beat variation. additionally, evaluation of mechanical dyssynchrony in the traditional method is based on average of 5 to 10 beats, which is exhausting and time consuming. single-beat evaluation of a beat with equal subsequent cardiac cycles has been proposed as an accurate method in patients with af. conclusions: measurement of intraventricular dyssynchromy in basoseptal and basolateral segments in af and heart failure patients in a single beat with rr1/rr2 = 1 , were very similar to the average value of eight cardiac cycle.