In some patients with heart failure with reduced ejection fraction (HFREF), their ECG may detect a bundle branch block (a delay or blockage along the specialized pathway through which the electrical impulses travel at fast speed at the level of the bottom chambers (ventricles) to make your heart beat). 

The delay or blockage may occur on the right or left side of your heart: right bundle branch block (RBBB) or left bundle branch block (LBBB.) This results in a slow propagation of electrical impulse in the ventricles (the pumping chambers of the heart), which leads to a dyssynchronous and inefficient contraction of the heart. 

Patients with these type of conduction abnormalities, especially those who have left bundle branch block, will benefit from cardiac resynchronization therapy, or CRT-D therapy, in addition to an implantable cardiac defibrillator (ICD).

This additional therapy will be a special ICD device (biventricular ICD or BIV-ICD) comprising three leads (wires in the heart) which will provide simultaneous electrical impulses to the ventricles and restore the synchronous contraction. More than two-thirds of these patients will have a significant improvement in their symptoms and heart function with the use of this state-of-the-art-technology. 

For the individuals who do not improve, our team at Valley will carefully troubleshoot all potential reasons for the lack of response and consider the most appropriate strategy to optimize the response. These options might involve different medication or technology or cardiac ablation.