Congestive Heart Failure, Atrial Fibrillation Clinical Trial
Official title:
Congestive Heart Failure Atrial Arrhythmia Monitoring and Pacing (CHAMP)
The purpose of the study is to characterize atrial arrhythmias in patients indicated for Cardiac Resynchronization Therapy (CRT) and to monitor changes in atrial arrhythmias while CRT is provided.
The combination of congestive heart failure and atrial fibrillation is a common co
morbidity, although the exact prevalence of AF in the heart failure population is still
unclear. Recent studies show a prevalence of AF ranging from about 10% to 50%, although the
type of AF observed and investigated in these studies is not always clearly described.
A number of mechanisms attributed to congestive heart failure may contribute to the
development of AF Experimental congestive heart failure promotes sustained AF by ionic
remodeling and increased interstitial fibrosis. In contrast to tachycardia-mediated AF, in
congestive heart failure no shortening of atrial refractoriness occurs. Atrial tissue stress
caused by congestive heart failure may also contribute to promotion of AF by inducing
triggered activity, affecting atrial refractoriness properties or resulting in increased
tissue mass supporting re-entry [31]. Existence of these mechanisms suggests that treatment
of congestive heart failure may also influence the development and progression of AF in
these patients. Conversion of chronic AF has been observed in patients with congestive heart
failure treated with biventricular pacing Ventricular ionic remodeling likely underlies the
increased risk for proarrhythmia in heart failure patients exposed to antiarrhythmic drugs,
prolonging the action potential duration , which therefore should be avoided in patients
with congestive heart failure.
The independent prognostic significance of AF in heart failure patients is still not
completely clear. Results from some recent studies suggest no independent prognostic
significance of AF in heart failure patients Result from other large studies on congestive
heart failure suggest an independent prognostic effect of AF in patients with AF and
congestive heart failure, associated with an increased risk for pump failure death and
all-cause mortality a significantly reduced 1-year survival and a higher mortality among
heart failure patients who developed AF A recent review with regard to the mortality in
studies on congestive heart failure suggests that concomitant AF does not have an additional
effect on the mortality in patients with severe heart failure, but does increase the
mortality in the setting of mild-to-moderate heart failure This observation may be
attributed to the fact that the atrial contribution to left ventricular filling is limited
in patients with severe diastolic dysfunction, whereas the atrial contribution may still be
of hemodynamic importance in mild-to-moderate heart failure
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Allocation: Non-Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Diagnostic