Vascular Endothelial Function and Cardiac Resynchronization Response in Patients With Heart Failure

Vascular Endothelial Function and Cardiac Resynchronization Response in Patients With Heart Failure

The purpose of this research study is to determine the role of blood vessel endothelial function in heart failure and the effect of Cardiac Resynchronization Therapy (CRT) on heart and endothelial function.

Inclusion Criteria:

• CRT Group: Patients recommended for CRT-P or CRT-D for heart failure (HF) according to current American Heart Association (AHA)/American College of Cardiology (ACC)/Heart Rhythm Society (HRS) guidelines of Left Ventricle Ejection Fraction (LVEF)<35%, Left Bundle Branch Block (LBBB)>120 ms, New York Heart Association (NYHA) Class II-III).
• Control Group: Patients who undergo device (pacemaker or ICD) implantation or a pack change for sinus node dysfunction or AV blocks

Exclusion Criteria:

• Patients who are unwilling or unable to return for follow up visits 3 months after device implantation.