Cardiac resynchronization therapy when no lateral pacing option exists: vectorcardiographic guided non-lateral left ventricular lead placement predicts acute hemodynamic response

Aims A difficult cardiac resynchronization therapy (CRT) implantation scenario emerges when no lateral pacing option exists. The aim of this study was to explore the effect of biventricular pacing (BIVP) on vectorcardiographic parameters in patients with a non-lateral left ventricular (LV) lead position. We hypothesized that perimeter and area reduction for both the QRS complex and T-wave would predict acute CRT response. Methods and results Twenty-six patients (14 ischaemic) with a mean age of 63 ± 10 years and standard CRT indication underwent device implantation with continuous LV pressure registration. The LV lead was placed in either an anterior or apical position. Biventricular pacing was performed at a rate 10% above intrinsic rhythm with acute CRT response defined as LV ΔdP/dtmax >10%. Using this criterion 12 patients were identified as acute CRT responders (responders: 16.7 ± 4.8% vs. non-responders: 1.9 ± 5.3%, P