Effect of lead at high right interventricular septum and ventricular apex on cardiac functions and tricuspid regurgitation in patients implanted with VVI permanent pacemakers

AIM:To determine the effect of lead at high right interventricular septum (HRVS) and right ventricular apex (RVA) on cardiac functions and tricuspid regurgitation (TR). METHODS: A 2year followup was conducted in 52 cases implanted with VVI permanent pacemakers, including 27 cases of lead at HRVS and 25 cases of lead at RVA. Cardiac function and tricuspid regurgitation were measured with the same pacing frequency (65 1/min) at 1 week, 6 months, 1 year and 2 years postimplantation. Left ventricular ejection fraction (LVEF), fractional shortening (LVFS) and tricuspid regurgitation (TR) were measured with echocardiogram and brain natriuretic peptide (BNP) was monitored. RESULTS: Lead at HRVS did not significantly affect LVEF, BNP and tricuspid regurgitation. Lead at RVA deteriorated cardiac functions and increased tricuspid regurgitation. CONCLUSION: Pacing at HRVS is superior to pacing at RVA, indicating the importance of physiological pacing of high right interventricular septum.