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Long-term safety and efficacy of right ventricular outflow tract compared with apical pacing
Abstracts / Journal of Electrocardiology 40 (2007) S1 – S77 PAC-15 Angiographic anatomy of the coronary veins acceptable for transvenous biventricular or left ventricular pacing Harun Kilic, Kudret Aytemir Diskapi YB EA Hospital, Ankara, Turkey Hacettepe University, Ankara, Turkey Introduction: Permanent left ventricular or biventricular pacing has been shown to improve the hemodynamic and clinical status of patients with severe heart failure. The left ventricular pacing via the lateral or posterior cardiac veins improves systolic function. The present study investigated the structure of the coronary veins in patients admitted for coronary angiography, and the acceptability of the veins’ diameter for the insertion of commercially available leads was assessed. Methods: In a total of 374 patients admitted for coronary angiography, a simultaneous coronary venography had been performed after injection of 8 to 10 mL of contrast material into the left coronary artery. The presence and diameter of veins as visualized by venous phase of coronary angiography determine their acceptability for the placement of a lead. For defining permanent vein, left ventricular lead distal end size (N1.5 mm) must fit the size of the vein halfway of the heart from base to apex. Results: Detailed x-ray image analysis was performed in 360 patients. The posterior vessel diameter for lead introduction was acceptable in 84.4%. The lateral vessel diameter for lead introduction was acceptable in 35%. The lateral or posterior vessel diameter for lead introduction was acceptable in 89.4%. In this study, we find left posterior vein that is acceptable for biventricular or left ventricular pacing was present in 93.1% of patients, whereas left marginal vein was present in 58% of patients. Conclusions: We show that in our population, left marginal vein acceptability ratio is much less than that in previous studies. Therefore, for biventricular or left ventricular pacing, using left posterior vein will increase the intervention success. doi:10.1016/j.jelectrocard.2007.03.031
PAC-16 Long-term safety and efficacy of right ventricular outflow tract compared with apical pacing Okan Erdogˇan, Meryem Aktoz, Armagˇan Altun Department of Cardiology, School of Medicine, Trakya University, Edirne, Turkey
Introduction: Right ventricular apex (RVA) for pacing lead position has been traditionally used for many years because of its established safety, stability, and easy accessibility. However, recent studies revealed that RVA pacing is associated with asynchronous activation of the left ventricle and resulted in impaired hemodynamic function related to myocardial perfusion defects, especially when pacing duration increased. Right ventricular outflow tract (RVOT) pacing has been proposed as an alternative pacing site and resulted in hemodynamic benefits as well as improved myocardial perfusion by enabling synchronous activation of the left ventricle. Although previous work related to RVOT pacing reported its short-term safety and hemodynamic benefit, long-term safety and efficacy of RVOT compared with RVA pacing remain to be confirmed given the paucity of long-term follow-up data. The aim of the present study was to compare the safety and change in pacing parameters of RVOT vs RVA pacing sites during a longterm follow-up period. Methods: Patients in group 1 (n = 16) and group 2 (n = 16) who were paced in RVOT and RVA, respectively, were retrospectively selected from patients with pacemakers (n = 200) who were routinely followed at our pacemaker clinic. Commercially available active fixation leads were used in all patients. Pacing parameters were compared at implant and long-term follow-up visits. Results: The mean duration of follow-up was 38.25 F 18 months for RVOT and 30.43 F 20 months for RVA (P = .255). Impedance values, pacing thresholds, and R wave amplitudes measured at implant and last pacemaker check did not significantly change both within RVOT and
S73
between RVOT vs RVA pacing groups. However, pacing threshold at implant significantly increased in RVA during long-term follow-up (0.63 F 0.19 V vs 1 F 0.82 V, P = .007). There was no lead dislodgment or any other procedure-related complication at implant or during follow-up. Conclusions: The mean duration of follow-up was 38.25 F 18 months for RVOT and 30.43 F 20 months for RVA (P = .255). Impedance values, pacing thresholds, and R wave amplitudes measured at implant and last pacemaker check did not significantly change both within RVOT and between RVOT vs RVA pacing groups. However, pacing threshold at implant significantly increased in RVA during long-term follow-up (0.63 F 0.19 V vs 1 F 0.82 V, P = .007). There was no lead dislodgment or any other procedure-related complication at implant or during follow-up.
doi:10.1016/j.jelectrocard.2007.03.032
Oral Presentation PAC-17 Acute effect of pacing mode on endothelial function in patients with cardiac pacemakers Ali Serdar Fak, Beste O¨zben, Ahmet Toprak, M. Azra Tanrikulu, Nurdan Papila, A. Altug Cincin, Mutlu Su¨merkan, A. Oytun Baykan, Ahmet Oktay Marmara University Medical School, Istanbul, Turkey
Introduction: Compared with atrial-based pacing, ventricular pacing is suggested to have somewhat more deleterious hemodynamic effects, which most probably arise from inappropriate baroreceptor activation. Brachial artery flow-mediated dilation (FMD) is a well-studied measure of endothelial function that has been used to noninvasively assess conduit artery and microvascular endothelial function. Endothelial function is known to be affected by various local and systemic factors including baroreceptor activity. The aim of the study was to explore whether the cardiac pacing mode has any effect on endothelial functions. Methods: Twelve patients (mean age 75.08 F 8.53 years) with previously implanted DDD or VDD cardiac pacemakers were included into the study. All patients had stable atrial rhythms during the study. Patients were randomized to either atrial-based pacing mode (VDD or DDD) or VVI pacing mode first, and then crossover was performed with the other pacing mode. During VVI pacing, ventricular rhythm was set at least 10 beats per minute greater than the intrinsic atrial rhythm. Blood pressure and heart rhythm were monitored during the entire study. Endothelial function was assessed by brachial artery ultrasonography. Basal diameter of the brachial artery and both FMD and endothelium-independent vasodilation with nitroglycerin (NTG) were measured 1 hour after each pacing mode. Results: The FMD values both as absolute change and percentage change were found to be significantly lower in the VVI pacing mode compared with those in the atrial-based pacing mode (VDD or DDD). On the other hand, NTG-mediated vasodilation values both as absolute change and percentage change did not differ significantly with the pacing mode (Table 1). Conclusions: The VVI pacing mode leads to lower FMD values compared with atrial-based pacing mode. This might be one of the mechanisms leading to deleterious hemodynamic effects and pacemaker syndrome in patients with VVI pacing. Table 1 Endothelial measures during pacing VVI pacing Mean baseline diameter (mm) 3.58 F 0.70 FMD absolute (mm) 0.17 F 0.09 FMD percentage (%) 4.84 F 2.37 NTG absolute (mm) 0.47 F 0.22 NTG percentage (%) 13.51 F 6.36
doi:10.1016/j.jelectrocard.2007.03.033
Atrial-based pacing P 3.68 F 0.62 0.27 F 0.12 6.64 F 3.04 0.54 F 0.18 14.75 F 4.98
.75 .015 .028 .155 .308
PAC-16 Long-term safety and efficacy of right ventricular outflow tract compared with apical pacing Okan Erdogˇan, Meryem Aktoz, Armagˇan Altun Department of Cardiology, School of Medicine, Trakya University, Edirne, Turkey
Introduction: Right ventricular apex (RVA) for pacing lead position has been traditionally used for many years because of its established safety, stability, and easy accessibility. However, recent studies revealed that RVA pacing is associated with asynchronous activation of the left ventricle and resulted in impaired hemodynamic function related to myocardial perfusion defects, especially when pacing duration increased. Right ventricular outflow tract (RVOT) pacing has been proposed as an alternative pacing site and resulted in hemodynamic benefits as well as improved myocardial perfusion by enabling synchronous activation of the left ventricle. Although previous work related to RVOT pacing reported its short-term safety and hemodynamic benefit, long-term safety and efficacy of RVOT compared with RVA pacing remain to be confirmed given the paucity of long-term follow-up data. The aim of the present study was to compare the safety and change in pacing parameters of RVOT vs RVA pacing sites during a longterm follow-up period. Methods: Patients in group 1 (n = 16) and group 2 (n = 16) who were paced in RVOT and RVA, respectively, were retrospectively selected from patients with pacemakers (n = 200) who were routinely followed at our pacemaker clinic. Commercially available active fixation leads were used in all patients. Pacing parameters were compared at implant and long-term follow-up visits. Results: The mean duration of follow-up was 38.25 F 18 months for RVOT and 30.43 F 20 months for RVA (P = .255). Impedance values, pacing thresholds, and R wave amplitudes measured at implant and last pacemaker check did not significantly change both within RVOT and
S73
between RVOT vs RVA pacing groups. However, pacing threshold at implant significantly increased in RVA during long-term follow-up (0.63 F 0.19 V vs 1 F 0.82 V, P = .007). There was no lead dislodgment or any other procedure-related complication at implant or during follow-up. Conclusions: The mean duration of follow-up was 38.25 F 18 months for RVOT and 30.43 F 20 months for RVA (P = .255). Impedance values, pacing thresholds, and R wave amplitudes measured at implant and last pacemaker check did not significantly change both within RVOT and between RVOT vs RVA pacing groups. However, pacing threshold at implant significantly increased in RVA during long-term follow-up (0.63 F 0.19 V vs 1 F 0.82 V, P = .007). There was no lead dislodgment or any other procedure-related complication at implant or during follow-up.
doi:10.1016/j.jelectrocard.2007.03.032
Oral Presentation PAC-17 Acute effect of pacing mode on endothelial function in patients with cardiac pacemakers Ali Serdar Fak, Beste O¨zben, Ahmet Toprak, M. Azra Tanrikulu, Nurdan Papila, A. Altug Cincin, Mutlu Su¨merkan, A. Oytun Baykan, Ahmet Oktay Marmara University Medical School, Istanbul, Turkey
Introduction: Compared with atrial-based pacing, ventricular pacing is suggested to have somewhat more deleterious hemodynamic effects, which most probably arise from inappropriate baroreceptor activation. Brachial artery flow-mediated dilation (FMD) is a well-studied measure of endothelial function that has been used to noninvasively assess conduit artery and microvascular endothelial function. Endothelial function is known to be affected by various local and systemic factors including baroreceptor activity. The aim of the study was to explore whether the cardiac pacing mode has any effect on endothelial functions. Methods: Twelve patients (mean age 75.08 F 8.53 years) with previously implanted DDD or VDD cardiac pacemakers were included into the study. All patients had stable atrial rhythms during the study. Patients were randomized to either atrial-based pacing mode (VDD or DDD) or VVI pacing mode first, and then crossover was performed with the other pacing mode. During VVI pacing, ventricular rhythm was set at least 10 beats per minute greater than the intrinsic atrial rhythm. Blood pressure and heart rhythm were monitored during the entire study. Endothelial function was assessed by brachial artery ultrasonography. Basal diameter of the brachial artery and both FMD and endothelium-independent vasodilation with nitroglycerin (NTG) were measured 1 hour after each pacing mode. Results: The FMD values both as absolute change and percentage change were found to be significantly lower in the VVI pacing mode compared with those in the atrial-based pacing mode (VDD or DDD). On the other hand, NTG-mediated vasodilation values both as absolute change and percentage change did not differ significantly with the pacing mode (Table 1). Conclusions: The VVI pacing mode leads to lower FMD values compared with atrial-based pacing mode. This might be one of the mechanisms leading to deleterious hemodynamic effects and pacemaker syndrome in patients with VVI pacing. Table 1 Endothelial measures during pacing VVI pacing Mean baseline diameter (mm) 3.58 F 0.70 FMD absolute (mm) 0.17 F 0.09 FMD percentage (%) 4.84 F 2.37 NTG absolute (mm) 0.47 F 0.22 NTG percentage (%) 13.51 F 6.36
doi:10.1016/j.jelectrocard.2007.03.033
Atrial-based pacing P 3.68 F 0.62 0.27 F 0.12 6.64 F 3.04 0.54 F 0.18 14.75 F 4.98
.75 .015 .028 .155 .308