Right Ventricular Septal Pacing in Patients With Right Bundle Branch Block and Heart Failure (The SPARK Trial)

Right Ventricular Septal Pacing in Patients With Right Bundle Branch Block and Heart Failure, a Pilot Clinical Trial (The SPARK Trial)

This clinical study has been designed to test whether a new pacing therapy would lead to improvement in heart function, symptoms and quality of life in a specific group of heart failure patients. This group has a unique electrical conduction problem (Right Bundle Branch Block) that did not respond well to the current available pacing therapy.

This pilot clinical trial will be a randomized single blinded cross over trial. Each subject will undergo three study stages. Subject will be randomized initially to either of the two arms; experimental or placebo, and then will be followed up for 3 months for the first stage to assess outcomes. In the second stage, both arms transition to a two months, intervention free, wash out period. Finally, at the third stage both arms will cross over and subject will be followed up for an additional 3 months for outcomes assessment.

Inclusion Criteria:

• Cardiomyopathy; ischemic or non-ischemic on optimal medical therapy per current heart failure treatment guidelines for at least 3 months.

• LVEF < 35% by trans-thoracic echocardiogram assessment

• Prior implantation of pacemaker/defibrillator with at least an atrial and RV mid septal lead. Atrial lead can be waived if RV lead has atrial sensing capabilities*

• Normal sinus rhythm at enrollment

• RBBB with QRS duration >120 msec on 12 lead surface EKG.

• PR interval <250 msec on 12 lead surface EKG

  • Subjects with biventricular pacemaker/ICD will be eligible for enrollment if their LV lead pacing function has been turned off by the subject's primary cardiologist prior to study enrollment for at least 3 months (this could be due to lead malfunction or the decision to deactivate the LV pacing therapy for any reason per primary cardiologist discretion)

Exclusion Criteria:

• Age younger than 18 years old
• Pregnancy
• Acute Myocardial infarction within 6 months of entry into the study
• Inotrope dependent heart failure condition
• Left ventricular assist device or heart transplantation
• Any other known conditions other than heart failure that could limit survival to < 6 months.
• Atrial fibrillation or flutter burden >10% of the time within the last 6 months
• Atrioventricular node disease that requires ventricular pacemaker support >10% of the time