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 accept-

ability 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 Erdogan, Meryem Aktoz, Armagan 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 long-

term 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

between RVOT vs RVA pacing groups. However, pacing threshold at

implant significantly increased in RVA during long-term follow-up (0.63 F0.19 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 F0.19 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 Ozben, Ahmet Toprak, M. Azra Tanrikulu,

Nurdan Papila, A. Altug Cincin, Mutlu Sumerkan,

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.

doi:10.1016/j.jelectrocard.2007.03.033

Table 1

Endothelial measures during pacing

VVI pacing Atrial-based pacing P

Mean baseline diameter (mm) 3.58 F 0.70 3.68 F 0.62 .75

FMD absolute (mm) 0.17 F 0.09 0.27 F 0.12 .015

FMD percentage (%) 4.84 F 2.37 6.64 F 3.04 .028

NTG absolute (mm) 0.47 F 0.22 0.54 F 0.18 .155

NTG percentage (%) 13.51 F 6.36 14.75 F 4.98 .308

Abstracts / Journal of Electrocardiology 40 (2007) S1–S77 S73