PT  - JOURNAL ARTICLE
AU  - Taborsky, Milos
AU  - Fedorco, Marian
AU  - Skala, Tomas
AU  - Kocianova, Eva
AU  - Pastucha, Dalibor
AU  - Richter, David
AU  - Petrkova, Jana
AU  - Di Gregorio, Franco
AU  - Barbetta, Alberto
AU  - Vaclavik, Jan
TI  - Acute effects of right ventricular pacing on cardiac haemodynamics and transvalvular impedance
DP  - 2014 Dec 9
TA  - Biomedical papers
PG  - 569--576
VI  - 158
IP  - 4
AID - 10.5507/bp.2013.009
IS  - 12138118
AB  - Aims: To assess the acute side-effects of right ventricular (RV) stimulation applied in apex and mid-septum, in order to establish the optimal lead location in clinical practice.
Methods: During pacemaker implantation, the ventricular lead was temporarily fixed in the apex and then moved to mid-septum. In both positions, surface and endocardial electrograms and transvalvular impedance (32 cases), left ventricular (LV) pressure (23), and transthoracic echocardiography (10) were acquired with intrinsic activity and VDD pacing.
Results: A larger increase in QRS duration was noticed with apical than septal pacing (65 ± 25 vs. 45 ± 29 ms; P<10<sup>-4</sup>). The proportion of cases where RV stimulation affected the transvalvular impedance waveform was higher with apical lead location (56% vs. 20%; P<0.02). VDD pacing at either site reduced the maximum dP/dt by 6% with respect to intrinsic AV conduction (IAVC; P<0.005). The maximum pressure drop taking place in 100 ms was reduced by 6 and 8%, respectively, with apical and septal pacing (P<0.01 vs. IAVC). Apical VDD decreased mitral annulus velocity in early diastole (E') from 7.5 ± 1.4 to 5.9 ± 0.9 cm/s (P<0.02) and prolonged the E-wave deceleration time (DT) from 156 ± 33 to 199 ± 54 ms (P<0.02), while septal pacing induced non-significant modifications in E' and DT.
Conclusion: Ventricular stimulation acutely impairs LV systolic and diastolic performance, independent of the pacing site. Septal lead location preserves RV contraction mechanics and reduces the electrical interventricular delay.