Remodeling of sinus node function in patients with congestive heart failure: reduction in sinus node reserve

Area of Science:

• Cardiology
• Electrophysiology
• Heart Failure Research

Background:

• Atrial remodeling is common in congestive heart failure (CHF).
• Sinus node function derangement is hypothesized in CHF patients.

Purpose of the Study:

• To investigate sinus node function in patients with symptomatic CHF.
• To evaluate anatomic and electrophysiologic changes in the sinus node complex and surrounding atrial tissue.

Main Methods:

• Studied 18 CHF patients and 18 controls under autonomic blockade.
• Assessed intrinsic sinus cycle length, corrected sinus node recovery time (CSNRT), and sinoatrial conduction time.
• Utilized electroanatomic mapping to analyze sinus node complex, sinoatrial propagation, and crista terminalis characteristics.

Main Results:

• CHF patients exhibited prolonged intrinsic sinus cycle length and CSNRT.
• Abnormalities included caudal sinus activity localization and prolonged sinoatrial conduction time.
• Fractionated electrograms, double potentials, and reduced voltage amplitude were observed along the crista terminalis in CHF patients.

Conclusions:

• CHF patients present significant sinus node remodeling with structural changes.
• A reduced functional sinus node reserve was identified in CHF.
• Findings suggest implications for bradycardia, chronotropic agent use, and pacing in CHF.