Characteristics of the temporal elevation of diastolic tension, produced by ischemia-reperfusion in isolated and paced Langendorff's hearts of guinea pigs, were studied. The elevation of diastolic tension corresponded with an elevation of left ventricular end diastolic pressure after a short ischemic period in the isovolumic heart. These phenomena were thought to be a result of incomplete relaxation. The degree of the elevation of diastolic tension depended upon the duration of ischemic period (3-10 min). This elevation was reproducible in one preparation; nearly the same changes were obtained in a second trial after 35 min of reperfusion when the ischemic period was within 5 min. An increment in the pacing rate to 150% of the first trial value doubled the elevation of diastolic tension by the second 5 min ischemia. Inhibition of glycolytic flux by iode acetic acid augmented the elevation after 3 min of ischemia. In addition, 5 min of ischemia with iode acetic acid caused contracture and recovery was slight. On the other hand, either lowering the Ca2+ concentration in the perfusing solution to a half the normal value, or treatment with Ca2+ antagonists (such as diltiazem), reduced the elevation of diastolic tension significantly. Diltiazem also suppressed the increment in elevation produced by a high pacing rate. It can be concluded that the temporal elevation of diastolic tension during reperfusion reflects the ischemic failure of the heart. This change is presumably due to intracellular Ca2+ overload or accumulation. In addition, since ischemic changes were reproducible in this preparation, it is a useful model for estimating the effects of drugs on the ischemic heart.
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http://dx.doi.org/10.1536/ihj.24.277 | DOI Listing |
Genes Dis
March 2025
Department of Cardiology, Children's Hospital of Chongqing Medical University, National Clinical Research Center for Child Health and Disorders, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing 400014, China.
Aging is an independent risk factor for cardiovascular diseases. Cardiac diastolic dysfunction (CDD), ultimately leading to heart failure with preserved ejection fraction (HFpEF), is prevalent among older individuals. Although therapeutics have made great progress, preventive strategies remain unmet medical needs.
View Article and Find Full Text PDFCurr Probl Cardiol
January 2025
Cardiology, RVM Institute of Medical Sciences and Research Center, Laxmakkapally, India.
Background: Diastolic wall strain (DWS), also referred to as right ventricular (RV) dysfunction, is a significant predictor of pulmonary embolism (PE) and heart failure (HF). Rooted in linear elastic theory, DWS reflects decreased wall thinning during diastole, indicating reduced left ventricular (LV) compliance and increased diastolic stiffness. Elevated diastolic stiffness is associated with worse outcomes, particularly in PE and HF with preserved ejection fraction (HFpEF).
View Article and Find Full Text PDFJ Feline Med Surg
January 2025
Department of Clinical Science, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Objectives: Cardiovascular complications are well known in humans with autosomal dominant polycystic kidney disease (PKD), but limited data exist for cats. This study aimed to assess echocardiographic changes, cardiac troponin I (cTnI) levels and systolic blood pressure (SBP) in Persian cats with PKD to detect early cardiac abnormalities.
Methods: In total, 52 Persian and mixed-Persian cats were enrolled, with 26 cats in the control group and 26 diagnosed with PKD via ultrasound due to the unavailability of genetic testing.
Sci Rep
January 2025
Cardiovascular Institute, Children's Hospital of Philadelphia, Philadelphia, PA, USA.
Heart failure with preserved ejection fraction (HFpEF) is increasingly common but its pathogenesis is poorly understood. The ability to assess genetic and pharmacologic interventions is hampered by the lack of robust preclinical mouse models of HFpEF. We developed a novel "two-hit" model, which combines obesity and insulin resistance with chronic pressure overload to recapitulate clinical features of HFpEF.
View Article and Find Full Text PDFAlcohol Clin Exp Res (Hoboken)
January 2025
Neuromuscular and Occupational Performance Laboratory, Department of Kinesiology & Sport Management, Texas Tech University, Lubbock, Texas, USA.
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