biventricular versus right ventricular pacing in heart failure patients with atrioventricular block (block hf)

Conditions: Atrioventricular Block; Heart Diseases

Summary: heart failure is a progressive disease that decreases the pumping action of the heart. this may cause a backup of fluid in the heart and may result in heart beat changes. when there are changes in the heartbeat, sometimes a pacemaker is used to control the rate and rhythm of the heartbeat. in this trial, the researchers will test if pacing both the left and right lower half of the heart (ventricles) will: * decrease the number of hospital and clinic visits due to heart failure symptoms * extend life * delay heart failure symptoms as compared to those who are paced in only one ventricle (the right ventricle)


Eligibility criteria:
inclusion criteria: * subject has standard class i or class iia indication for pacemaker implantation in accordance with acc/aha/hrs guidelines * subjects diagnosed with atrioventricular (av) block. an av block is a disturbance when the heart's natural pacemaker sends a message from the atrium (top part of heart) to the ventricle (bottom part of heart) and the message is partially or totally blocked * subject is receiving first time implant * subjects with heart failure but no symptoms of it (new york heart association \[nyha\] class i), or subjects with mild heart failure that only sometimes interferes with their daily activities (nyha class ii), or subjects with heart failure that severely limits daily activities (nyha class iii) * subjects with documented reduced heart pumping function (left ventricular ejection fraction ≤ 50%) within past 90 days * subject is at least 18 years old * subject or authorized legal guardian or representative has signed and dated the informed consent * subject is able to receive a pectoral implant * subject is expected to remain available for follow-up visits at the study center * subject is willing and able to comply with the protocol exclusion criteria: * subject has ever had a previous or has an existing device implant * subjects with some forms of chest pain or myocardial infarction (heart attack) within the past 30 days * subjects with coronary bypass within the past 30 days * subjects with stent within the past 30 days * subjects with valve repair or replacement within the past 6 months or is indicated for repair or replacement * subjects with a mechanical right heart valve * subject is indicated for a biventricular pacing device (crt-p or crt-d devices) * subject is enrolled in a concurrent study which may confound the results of this study (co-enrollment in any concurrent clinical study requires approval of the study manager) * subject is pregnant, or of child bearing potential and not on a reliable form of birth control * subjects with a previous heart transplant * subjects has been classified as nhya functional class iv within prior 90 days (subjects with severe heart failure and should always be resting) * subject, legal guardian or authorized representative is unable or unwilling to cooperate or give written informed consent

Keywords: atrioventricular block cardiac resynchronization therapy pacemaker defibrillator nyha class i, ii or iii heart failure