Optimizing Left Ventricular Lead To Improve Cardiac Output

The hypothesis of this study determines if response to CRT therapy could be improved by optimizing LV lead position at the time of the left ventricular pacing lead implantation. This optimization (using a Doppler wire) would alter the left ventricular activation pattern and contraction mechanics. This increase in contractility may improve the likelihood of mid/long term response to therapy. This study will compare 6-month response to CRT (left ventricular ejection fraction, decrease in left ventricular end systolic and end diastolic dimensions and volumes) in heart failure patients. The secondary objective will be to: 1. To determine if optimal lead placement, guided by the largest improvement in stroke volume, results in a greater 6-month improvement in clinical QOL and NYHA class. 2. Acutely compare and/or correlate intra-operative A-V and V-V timing optimization via invasive pressure volume data to post-operative echo optimization of these same parameters. 3. Acutely contrast changes in stroke volume during pacing from several different left ventricular lead locations.