Effect of age and sex on the incidence of ventricular arrhythmia in a rat model of acute ischemia - 18/09/21
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Abstract |
Background |
The impact of sex and age on the arrhythmic susceptibility within the setting of acute ischemia is masked by the fact that acute coronary events result from coronary artery disease appearing with age much earlier among men than among women.
Methods and results |
LAD ligation or sham operations were performed in rats of both sexes at the age 3 and 24 months. An ECG was recorded continuously for 6 h after the operation. The number of early and late premature ventricular beats (PVBs), episodes of ventricular tachycardia (VT) and fibrillation (VF), heart rate, QRS, QT and Tpeak-Tend duration were analysed. Epicardial action potentials were recorded in vivo, Ca2+ signaling was evaluated in isolated cardiomyocytes, fibrosis and connexin-43 expression and localization were measured in the septum. PVBs, VT and VF episodes are much more common in older males than in young males and females independently from their age. Fibrosis with varying intensity in different muscle layers, hypertrophy of cardiomyocytes, reduced number of gap junctions and their appearance on the lateral myocyte membrane, QT prolongation, increase transmural dispersion of repolarisation and a decreased function of SERCA2a may increase the propensity to arrhythmia within the setting of acute ischemia.
Conclusion |
We show that the male sex, especially in case of older individuals is a strong predictor of increased arrhythmic susceptibility within the acute ischemia setting regardless of its impact on the occurrence of cardiovascular diseases. A personalized sex-dependent prevention treatment is needed to reduce the mortality in acute phases of myocardial infarction.
Le texte complet de cet article est disponible en PDF.Graphical Abstract |
Highlights |
• | Older age and male sex predispose to arrhythmias in acute myocardial ischemia. |
• | Age and sex influence arrhythmia risk regardless of cardiovascular comorbidities. |
• | QT and Tpeak-Tend prolongation and low SERCA2a function increase arrhythmia risk. |
• | Non-heterogeneous fibrosis and decreased Cx43 expression are pro-arrhythmic. |
• | Personalized prevention strategies may reduce mortality in acute myocardial ischemia. |
Keywords : Arrhythmia, Acute ischemia, Ageing, Sex
Plan
Vol 142
Article 111983- octobre 2021 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
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