Pressure-volume loop analysis during implantation of biventricular pacemaker/cardiac resynchronization therapy device to optimize right and left ventricular pacing sites.

AIMS

To evaluate the clinical utility of pressure-volume loop analyses during pacemaker/implantable cardioverter defibrillator (ICD) implantations to assess the optimal right ventricular (RV) and/or left ventricular (LV) lead position.

METHODS AND RESULTS

29 patients with heart failure and chronic RV apical pacing were studied. Stroke work (SW), LV ejection fraction (LVEF), cardiac output (CO), and LV dP/dt(max) were assessed using a conductance catheter in the LV during RV apical, RV outflow tract, single-site LV, and biventricular pacing at different left-sided pacing locations. Left ventricular ejection fraction was 34.3 +/- 9.8%. Compared with baseline, RV outflow tract pacing showed a small increase of 4.0 +/- 6.4% in LV dP/dt(max) and no improvement in SW, LVEF, or CO. In the optimal biventricular configuration, SW increased 39 +/- 41%, LVEF increased 22 +/- 13%, CO increased 16 +/- 16%, and LV dP/dt(max) increased 10 +/- 11% (all P < 0.05). In 45% of the patients, the optimal LV lead position was found at a different location as the 'first choice' postero-lateral or lateral target vein.

CONCLUSION

Pressure-volume loop analysis during pacemaker/ICD implantations facilitates to determine the optimal LV pacing site. Patients with chronic RV pacing showed a significant acute improvement in LV function when LV pacing or biventricular pacing is applied.