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Arrhythmogenic age-related effects of lysophosphatidylcholine in the rat heart
1Istituto di Medicina Interna, Cardiologia e Chirurgia Cardiovascolare, II Facoltà di Medicina e Chirurgia, Napoli.
Insights
Lysophosphatidylcholine and epinephrine increase age-related ventricular arrhythmias in aging rat hearts. Combined treatment showed higher incidence than individual substances, highlighting age
Area of Science:
- Cardiology
- Cardiac Electrophysiology
- Gerontology
Background:
- Ventricular arrhythmias are a leading cause of death in coronary artery disease patients, particularly the elderly.
- Age-related cardiac electrophysiology changes and severe coronary artery disease exacerbate this risk.
- Lysophosphoglycerides in ischemic myocardium may cause arrhythmias via oscillatory after-potentials.
Purpose of the Study:
- To investigate the arrhythmogenic effects of lysophosphatidylcholine (LPC) and epinephrine in aging rat hearts.
- To determine if age influences the cardiac response to LPC and epinephrine.
- To assess the combined impact of LPC and epinephrine on ventricular arrhythmias.
Main Methods:
- Isolated, perfused hearts from adult (6-12 months) and senescent (24 months) rats were used.
- Hearts were divided into four groups: control, epinephrine, LPC, and combined epinephrine + LPC.
- Arrhythmia incidence was analyzed across age groups and treatment conditions.
Main Results:
- A linear correlation was observed between age and the incidence of LPC- and epinephrine-induced ventricular arrhythmias.
- Combined treatment with epinephrine and LPC resulted in a significantly higher incidence of arrhythmias (p < 0.01) compared to individual treatments.
- Senescent rat hearts exhibited a greater susceptibility to these arrhythmogenic agents.
Conclusions:
- Age significantly influences the arrhythmogenic potential of lysophosphatidylcholine.
- Epinephrine exacerbates the arrhythmogenic effects of lysophosphatidylcholine, particularly in aged hearts.
- These findings suggest a critical role for age in the development of drug-induced ventricular arrhythmias in cardiovascular disease.
Abstract:
Ventricular arrhythmias are the most common cause of death among patients with coronary artery disease; this is more evident in the elderly, who tend to have more severe coronary artery disease and age-dependent modifications of cardiac electrophysiology. Lysophosphoglycerides, which accumulate in the ischemic myocardium, are responsible for oscillatory after-potentials and may contribute to the development of ventricular arrhythmias. The aim of this study was to examine the effects of lysophosphatidylcholine (5 x 10(-5) M) in the absence or presence of epinephrine (10(-6) M) in isolated, perfused hearts from adult (6-12 months old) and senescent (24 months old) rats. Rat hearts (30/group) were randomly divided into four groups each of which included hearts of 6, 12 and 24-month old rats. The groups comprised a control group, a group treated with epinephrine, a group treated with lysophosphatidylcholine and a group treated with both epinephrine and lysophosphatidylcholine. Analysis of arrhythmias indicated a linear correlation between epinephrine- and lysophosphatidylcholine-induced ventricular arrhythmias and age. The incidence of arrhythmias was higher in the hearts treated with epinephrine and lysophosphatidylcholine together than in those treated with either substance separately (p less than 0.01). The results indicate that age influences the arrhythmogenic action of lysophosphatidylcholine, and that epinephrine contributes to this effect.