ABC | Volume 112, Nº4, April 2019

Original Article Philbois et al Isolated left ventricular pacing in bradyarrhythmias Arq Bras Cardiol. 2019; 112(4):410-421 Table 2 – Operation data of study participants Characteristics Total (n = 71) LV Group (n = 35) RV Group (n= 36) p Pacemaker type, n (%) Single-chamber 3 (4.2) 2 (5.7) 1 (2.8) 0.614 (3) Dual-chamber 68 (95.8) 33 (94.3) 35 (97.2) Lead implant access Subclavian vein puncture 44 (62.0) 16 (45.7) 28 (77.8) Cephalic vein dissection 6 (8.5) 2 (5.7) 4 (11.1) 0.002 (3) Both 21 (29.6) 17 (48.6) 4 (11.1) Duration of ventricular lead positioning Average ± SD (minutes) 22.2 ± 21.4 38.5 ± 19.8 6.4 ± 3.6 < 0.001 (2) Variation (minutes) 2 - 119 8 - 119 2 - 15 Total procedure duration Average ± SD (minutes) 84.8 ± 29.9 103.3 ± 27.9 66.9 ± 19.0 < 0.001 (2) Variation (minutes) 34 - 167 45 - 167 34 - 113 RV pacing site, n (%) Apex - - 4 (11.1) Septum - - 32 (88.9) NA LV pacing site, n (%) Anterolateral - 6 (17.1) - Lateral - 26 (74.3) - NA Posterolateral - 3 (8.6) - LV: left ventricle; NA: not applicable; RV: right ventricle; SD: standard deviation. (2) Unpaired Student’s t-test; (3) Fisher’s exact test. Table 3 – Echocardiographic outcomes, derived from the comparison between the baseline echocardiogram and the echocardiogram performed at the 24-month follow-up visit Echocardiographic outcomes LV Group (n = 34) RV Group (n = 34) p LVEF 10% reduction 7 (20.6%) 8 (23.5%) 0.767 (1) Without 10% reduction 27 (79.4%) 26 (76.5%) FSVLV 15% increase 10 (29.4%) 9 (27.3%) 0.846 (1) Without 15% increase 24 (70.6%) 24 (72.7%) Alteration of LVEF and/or FSVLV Present 12 (35.3%) 11 (32.3%) 0.798 (1) Absent 22 (64.7%) 23 (67.7%) Intraventricular dyssynchrony Delay ≥ 65 ms 14 (43.7%) 19 (55.9%) 0.324 (1) Delay < 65 ms 18 (56.3%) 15 (44.1%) Interventricular dyssynchrony Delay ≥ 100 ms 22 (68.7%) 31 (91.2%) 0.022 (1) Delay < 100 ms 10 (31.3%) 3 (8.8%) LVESV: left ventricular end-systolic volume; LV: left ventricle; LVEF: left ventricle ejection fraction; RV: right ventricle. (1) Chi-squared test. 416