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Background: Ischemic cardiomyopathy (ICM) is associated with electrical and structural remodelling, leading to arrhythmias. Caveolin-1 (Cav1) is a membrane protein involved in the pathogenesis of ischemic injury. Cav1 deficiency has been associated with arrhythmogenicity. The current study aimed to determine how Cav1 overexpression inhibits arrhythmias and cardiac remodelling in ICM.
Methods: ICM was modelled using left anterior descending (LAD) artery ligation for 4 weeks. Cardiac-specific Cav1 overexpression in ICM on arrhythmias, excitation-contraction coupling, and cardiac remodelling were investigated using the intramyocardial injection of an adeno-associated virus serotype 9 (AAV-9) system, carrying a specific sequence expressing Cav1 (AAV) under the cardiac troponin T (cTnT) promoter.
Results: Cav1 overexpression decreased susceptibility to arrhythmias by upregulating gap junction connexin 43 (CX43) and reducing spontaneous irregular proarrhythmogenic Ca waves in ventricular cardiomyocytes. It also alleviated ischemic injury-induced contractility weakness by improving Ca cycling through normalizing Ca-handling protein levels and improving Ca homeostasis. Masson stain and immunoblotting revealed that the deposition of excessive fibrosis was attenuated by Cav1 overexpression, inhibiting the transforming growth factor-β (TGF-β)/Smad2 signalling pathway. Coimmunoprecipitation assays demonstrated that the interaction between Cav1 and cSrc modulated CX43 expression and Ca-handling protein levels.
Conclusions: Cardiac-specific overexpression of Cav1 attenuated ventricular arrhythmia, improved Ca cycling, and attenuated cardiac remodelling. These effects were attributed to modulation of CX43, normalized Ca-handling protein levels, improved Ca homeostasis, and attenuated cardiac fibrosis.
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http://dx.doi.org/10.1016/j.cjca.2022.10.005 | DOI Listing |
Heart Rhythm
September 2025
Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, United States. Electronic address:
Background: Electronic nicotine delivery systems (ENDS) utilize "E-liquids" in order to generate "E-vapor", an inhalable aerosolized mixture containing nicotine and flavors. Flavored ENDS are very popular among teens who vape, however, the possible cardiac electrophysiological harm of inhalation exposure to flavored ENDS are not fully understood.
Objective: To test if inhalation exposure to flavoring carbonyls in e-liquids compromises mitochondrial integrity, increases oxidative stress, and leads to cardiac electrophysiological toxicity.
Am Heart J
September 2025
Institute of Sports Medicine and Science, National Italian Olympic Committee, Largo Piero Gabrielli, 1 - 00197 Rome, Italy.
Background: Athlete's heart, characterized by cardiac chambers adaptations to exercise has some diagnostic overlaps with dilated cardiomyopathy (DCM). In the setting of differential diagnosis, myocardial work indexes (MWI), afterload-independent tool, could be helpful to identify early subclinical alterations. The aim of our study was to assess the utility of MWI in athletes with mildly reduced left ventricular ejection fraction (LVEF).
View Article and Find Full Text PDFJACC Case Rep
September 2025
Cardiovascular Division, Department of Medicine, Froedtert and Medical College of Wisconsin, Milwaukee, Wisconsin, USA. Electronic address:
Baroreflex activation therapy (BAT) improves functional status, quality of life, and exercise capacity in patients with heart failure with reduced ejection fraction; however, its direct effects on reversing adverse cardiac remodeling as assessed by improvements in cardiac structure, function, and coupling with the arterial system remain unclear. We present 2 cases of patients who initially presented with decompensated heart failure, and despite initial medical therapy and continued outpatient follow-up, were unable to tolerate full escalation of guideline-directed medical therapy. The patients remained symptomatic, with high biomarker levels, poor functional capacity, severe heart failure symptoms, and objectively had decreased stroke volume, low left ventricular ejection fraction, and high left ventricular mass.
View Article and Find Full Text PDFESC Heart Fail
September 2025
Institute of Cardiology, ASST Spedali Civili, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, Brescia, Italy.
Atrial functional mitral regurgitation (AFMR) is an increasingly recognized subtype of mitral regurgitation, characterized by left atrial remodelling and mitral annular dilation in the absence of primary mitral valve disease or left ventricular dysfunction. Closely linked to chronic atrial fibrillation and heart failure with preserved ejection fraction, AFMR is associated with poor clinical outcomes and represents a growing therapeutic challenge. This expert opinion paper summarizes current evidence on the epidemiology, pathophysiology, diagnosis and management strategies, including medical therapy and emerging data supporting surgical and transcatheter interventions in selected patients.
View Article and Find Full Text PDFRev Cardiovasc Med
August 2025
Department of Cardiology, Istinye University School of Medicine, 34396 Istanbul, Turkey.
Coronary artery aneurysms (CAAs) are frequent entities that are encountered in up to 8% of patients undergoing coronary imaging. The most frequent cause of CAAs is atherosclerotic "positive remodeling" of coronary arteries, while congenital, inflammatory, and traumatic etiologies could also be seen. Aneurysms serve as foci for thrombus formation, which may occlude the aneurysmatic segment or embolize distally.
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