H.S. Vos

Comparison of the haemodynamics of different pacing sites in patients undergoing resynchronisation treatment: need for individualisation of lead localisation

Background: Biventricular pacing is a new therapy for the treatment of heart failure. However, a substantial number of patients do not respond to this therapy. Hypothesis: Individually determined maximal pacing sites will improve the haemodynamic response and increase the number of responders. Methods: In 48 patients with heart failure, the acute haemodynamic effects of nine different pacing configurations were studied, using two right and left ventricular pacing sites and their combinations. Cardiac index was measured using Doppler echocardiography. For further analysis, the combination with the highest cardiac index improvement was compared with baseline. Moreover, the number of responders was calculated using a cut-off value of 10% increase in cardiac index. Results: The mean (SD) increase in cardiac index ranged between 3.8% (6.0%) and 11.1% (8.6%). The pacing site with maximal cardiac index was highly variable between patients, and here the cardiac index increased to 14.8% (7.6%; (p<0.001). The number of responders varied between 15% and 64%, increasing to 75% at the site with maximal increase in cardiac index. In a subset of patients, the haemodynamic improvement after pacemaker implantation correlated well with the acute haemodynamics. Conclusion: Individualisation of pacing configuration for biventricular pacing leads to further haemodynamic improvement in patients with heart failure and reduces the number of patients not responding to this therapy.

Cardiac Resynchronization Therapy: Is There Any Correlation Between Pacing Site and Hemodynamic Improvement?

With the start of the pacing era, the right ventricular apex was used as a pacing site due to the stable position and ease of implantation [1]. With the importance of hemodynamics in the 1980s AV sequential pacing was introduced [2]. With the introduction of active fixation leads, other stimulation sites, such as the right ventricular outflow tract, were studied for hemodynamic results because of the impaired hemodynamic function of stimulating the right ventricular apex [3–5].