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

Not Applicable

Terminated

Interventions: Device: RV DDD(R)-60 with AV optimization
Device: RV DDD(R)-60

Brief Summary: 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.

Detailed Description: 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.

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
RV pacing optimization on/off	RV DDD(R)-60 with AV optimization	RBBB pacing Arm 1 is RV pacing optimization on/off
RV pacing optimization off/on	RV DDD(R)-60	Standard demand pacing Arm 2 is RV pacing optimization off/on

Primary Outcome Measures

Name	Time	Method
Change of LV Ejection Fraction Compared to Baseline	Baseline to 3 months	LV Ejection Fraction is defined as \[(end diastolic volume minus end systolic volume) / (end diastolic volume\] as measured by echocardiography. Comparison of LV Ejection Fraction with RV pacing optimization on vs. RV pacing optimization off. Arm 1 is RV pacing optimization on then off Arm 2 is RV pacing optimization off then on

Secondary Outcome Measures

Name	Time	Method
Electrocardiographic: QRS Duration	Baseline to 3 months	Comparing baseline to intervention on Comparing intervention off to intervention off Expect statistically significant decrease with intervention on