Right ventricular pacing at the low right ventricular outflow tract (143 ± 17 ms) and mid-septum (151 ± 20 ms) resulted in shorter QRS durations compared to apical pacing (167 ± 18 ms).
Does the site of right ventricular pacing affect QRS duration in patients with bradycardia or tachycardia?
Right ventricular pacing at the low outflow tract or mid-septum results in a narrower QRS complex compared to apical pacing, though 32% of patients show no significant difference.
To assess the effect of various right ventricular pacing sites on QRS duration, we enrolled 50 patients (mean age, 64 ± 13 years; 36 men); 16 had bradycardia and 34 had tachycardia. The right ventricle was arbitrarily divided into 5 sections: high and low right ventricular outflow tract, mid septum, low septum, and apex. Right ventricular pacing was performed using an electrode catheter at each of the 5 sites. QRS duration was 162 ± 20 ms during high right ventricular outflow tract pacing, 143 ± 17 ms during low right ventricular outflow tract pacing, 151 ± 20 ms during mid-septal pacing, 163 ± 16 ms during low-septal pacing, and 167 ± 18 ms during apical pacing. Paced QRS duration was shorter during low right ventricular outflow tract and mid-septal pacing compared to apical pacing in 34 patients. There was a difference of 10 ms or less in the paced QRS duration between these pacing sites in the other 16 patients. QRS duration was shortest when the septum was paced in the right ventricle. However, QRS duration was similar during pacing in the septum and the apex in 32% of patients.
Nakamura et al. (Sat,) conducted a other in Bradycardia or tachycardia (n=50). Right ventricular pacing at various sites vs. Apical pacing was evaluated on QRS duration. Right ventricular pacing at the low right ventricular outflow tract (143 ± 17 ms) and mid-septum (151 ± 20 ms) resulted in shorter QRS durations compared to apical pacing (167 ± 18 ms).
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