Chronic converting enzyme inhibition normalizes QT interval in aging rats

Area of Science:

• Cardiology
• Pharmacology
• Gerontology

Background:

• Aging is associated with significant cardiovascular changes, including altered cardiac structure and function.
• Angiotensin converting enzyme (ACE) inhibitors are widely used to manage cardiovascular diseases.
• The long-term effects of ACE inhibition on cardiac parameters during aging require further investigation.

Purpose of the Study:

• To investigate the effects of captopril, an ACE inhibitor, on electrocardiographic (ECG) parameters in aged rats.
• To assess the impact of long-term captopril treatment on cardiac hypertrophy in aging rats.
• To evaluate the protective role of ACE inhibition in the aging heart.

Main Methods:

• Male rats were treated with captopril (0.5 mg/l) or tap water for 2 or 20 months.
• ECG parameters (RR, PR, P wave, QRS, QT, corrected QT intervals) were measured under anesthesia.
• Chronic ECG recordings were performed to quantify premature beats (SVPB, VPB).
• Cardiac hypertrophy was assessed by heart weight to body weight ratio after sacrifice.

Main Results:

• Captopril significantly increased the RR interval and reduced the corrected QT interval in aged rats.
• Ventricular premature beats (VPB) were significantly reduced by captopril treatment in old rats.
• Captopril prevented cardiac hypertrophy in untreated aged rats.
• While PR interval was longer in aged rats, it was not affected by captopril.

Conclusions:

• Captopril demonstrates remarkable beneficial effects on the aging rat heart.
• ACE inhibition by captopril improves cardiac electrical stability and prevents age-related cardiac hypertrophy.
• Long-term captopril treatment offers significant cardioprotection during the aging process.