Heart Failure
Conditions
Keywords
Heart Failure, resynchronisation, ICD
Brief summary
Heart failure is a major health problem in Canada. Recent advances in medical and device therapy have helped to reduce the morbidity and mortality of patients with this problem. Among these treatments, cardiac resynchronization therapy (CRT) has very recently been shown to be effective to improve functional class, quality of life and exercise tolerance of the patients with the most severe symptoms of heart failure and a prolonged duration of the QRS on the 12-lead Electrocardiography (ECG).
Detailed description
Resynchronization of the failing ventricle is currently achieved by pacing the left and right ventricles simultaneously with specialized electrodes and a cardiac stimulator. However, controversy persists concerning the optimal configuration for cardiac pacing in these patients. Right ventricular pacing alone has been shown to be deleterious in some patient populations. The benefits of biventricular pacing in heart failure patients may be due primarily to left ventricular stimulation and may, in some patients, be decreased by the presence of simultaneous RV stimulation. Preliminary data from our own animal work suggest that in the majority of cases, LV stimulation alone is better than RV stimulation, and that BiV stimulation represents an intermediary situation between LV and RV stimulation.
Interventions
DEVICEDevice programming
6-month period
Sponsors
Abbott Medical Devices
Canadian Institutes of Health Research (CIHR)
Montreal Heart Institute
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
(for Greater and Lesser EARTH): Patient must answer yes 1. Does the patient require an ICD or an ICD replacement? 2. Does the patient have a documented LVEF less than or equal to 35% measured in the previous 6 months (without major concomitant clinical event)? 3. Does the patient have a QRS duration \< 120 ms? 4. Is the patient in sinus rhythm? 5. Was the six-minute walk test distance less than 400 meters and limited by heart failure symptoms?
Exclusion criteria
Patient must have answered NO to all of the
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The primary endpoint is total exercise duration at a constant submaximal load (ETT submaximal load is defined as 75% of peak exercise during the baseline metabolic evaluation) | one year |
Secondary
| Measure | Time frame |
|---|---|
| Clinical, electrical, echocardiographic, MUGA scan endpoints, Neuro-hormones | one year |
Countries
Canada
Outcome results
None listed