Left ventricular systolic and diastolic function in patients with atrioventricular nodal re-entrant tachycardia treated by radiofrequency current ablation.

Background: The impact of radiofrequency current ablation (RFCA) on left ventricular (LV) systolic and diastolic function in patients with atrioventricular nodal re-entrant tachycardia (AVNRT) is not well established yet.
Methods: The study group consisted of 25 patients (18 W, mean age 43 +/- 11) with recurrent episodes of AVRT without any concomitant diseases. The control group was formed of 25 healthy volunteers. In both study and control groups, transthorasic echocardiography (TTE) and Doppler were performed in order to assess LV systolic and diastolic function. In AVNRT syndrome patients, TTE was followed by electrophysiology study and RFCA. TTE was repeated after six months in the study group.
Results: Significant differences were found between the study and control groups with regard to LV systolic (FS--fractional shortening: 37 +/- 4 vs. 42 +/- 6%, p = 0.001; ESV--end-systolic volume: 19 +/- 4 vs. 17 +/- 4 ml/m(2), p = 0.03; EF--ejection fraction: 55 +/- 5 vs. 62 +/- 4%, p = 0.001) and diastolic function (E wave: 69 +/- 17 vs. 84 +/- 15 cm/s, p = 0.002; E/A: 1.09 +/- +/- 0.42 vs. 1.38 +/- 0.27, p = 0.005; DT--duration difference between A and AR waves: 7 +/- 29 vs. -28 +/- 13 ms, p = 0.001; DT--deceleration time of E wave: 223 +/- 34 vs. 177 +/- 27 ms, p = 0.001; IVRT--isovolumic relaxation time: 105 +/- 15 vs. 86 +/- 11 ms, p = 0.001; E/A while Valsalva manoeuvre: 0.93 +/- 0.35 vs. 1.25 +/- 0.16, p = 0.001; AR--atrial reversal velocity: 27 +/- 7 vs. 14 +/- 11 cm/s, p = 0.001) variables. In 6-month follow-up decrease in LVESV (19 +/- 4 vs. 17 +/- 4 ml, p < 0.03) and increase in EF (55 +/- 5 vs. 62 +/- 4%, p < 0.001) was noted. Doppler analysis showed an increase in E wave (69 +/- 17 vs. 79 +/- 20 cm/s, p < 0.02), E/A ratio (1.09 +/- 0.42 vs. 1.30 +/- 0.27, p < 0.006) and decrease in A wave (68 +/- 13 vs. 63 +/- 10 cm/s, p < 0.02), DT (223 +/- 34 vs. 179 +/- 22 ms, p < 0.001), IVRT (105 +/- 15 vs. 89 +/- 11 ms, p < 0.001) and DT (7 +/- 29 vs. -13 +/- 28 ms, p < 0.001).
Conclusions: Successful RFCA of slow atrioventricular conduction pathway in patients with AVNRT and AVRT results in improvement of LV systolic and diastolic function.