HV interval in calcific aortic stenosis. Relation to left ventricular function and effect of valve replacement

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Surgery

Background:

• Calcific aortic stenosis (AS) is a significant valvular heart disease.
• Syncope is a concerning symptom in patients with AS.
• The electrophysiological underpinnings of syncope in AS require further elucidation.

Purpose of the Study:

• To investigate the role of bradycardia and tachycardia in syncope pathogenesis in AS.
• To correlate hemodynamic data with electrophysiological abnormalities.
• To assess the impact of aortic valve replacement on electrophysiological parameters.

Main Methods:

• Intracardiac electrography and 24-hour ambulatory electrocardiographic monitoring in 20 AS patients.
• Assessment of sinus node function and HV interval.
• Correlation analysis with hemodynamic data (pressure gradient, ejection fraction).
• Re-evaluation after aortic valve replacement.

Main Results:

• Impaired sinus node function in 5/20 patients; prolonged HV interval (≥50 ms) in 11/20.
• No significant difference in electrophysiological findings between patients with and without syncope.
• HV interval correlated inversely with left ventricular ejection fraction (LVEF).
• No correlation between HV interval and pressure gradient.
• Post-aortic valve replacement, sinus node function remained unchanged, but HV interval increased by 7.8 ms.

Conclusions:

• Bradycardia and tachycardia are infrequent causes of syncope in calcific AS.
• A prolonged HV interval is a common electrophysiological abnormality in AS.
• Aortic valve replacement does not correct, and may worsen, HV interval prolongation.
• Cardiac contractility and electrical conductivity appear to deteriorate in parallel in AS.