This study compared the effects of ATP-regulated potassium channel (K(ATP)) openers, diazoxide and pinacidil, on diseased and normal human atria and ventricles. We optically mapped the endocardium of coronary-perfused right (n=11) or left (n=2) posterior atrial-ventricular free wall preparations from human hearts with congestive heart failure (CHF, n=8) and non-failing human hearts without (NF, n=3) or with (INF, n=2) infarction. We also analyzed the mRNA expression of the K(ATP) targets K(ir)6.1, K(ir)6.2, SUR1, and SUR2 in the left atria and ventricles of NF (n=8) and CHF (n=4) hearts. In both CHF and INF hearts, diazoxide significantly decreased action potential durations (APDs) in atria (by -21±3% and -27±13%, p<0.01) and ventricles (by -28±7% and -28±4%, p<0.01). Diazoxide did not change APD (0±5%) in NF atria. Pinacidil significantly decreased APDs in both atria (-46 to -80%, p<0.01) and ventricles (-65 to -93%, p<0.01) in all hearts studied. The effect of pinacidil on APD was significantly higher than that of diazoxide in both atria and ventricles of all groups (p<0.05). During pinacidil perfusion, burst pacing induced flutter/fibrillation in all atrial and ventricular preparations with dominant frequencies of 14.4±6.1 Hz and 17.5±5.1 Hz, respectively. Glibenclamide (10 μM) terminated these arrhythmias and restored APDs to control values. Relative mRNA expression levels of K(ATP) targets were correlated to functional observations. Remodeling in response to CHF and/or previous infarct potentiated diazoxide-induced APD shortening. The activation of atrial and ventricular K(ATP) channels enhances arrhythmogenicity, suggesting that such activation may contribute to reentrant arrhythmias in ischemic hearts.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3124600 | PMC |
| http://dx.doi.org/10.1016/j.yjmcc.2011.04.016 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The Effect of Training Experience on Cardiac Morphology in Resistance Exercise Practitioners: A Study on Left Ventricular Systolic and Diastolic Parameters and Left Atrium Mechanical Functions.
Medicina (Kaunas)
December 2024
Department of Rehabilitation Sciences, College of Health and Rehabilitation Sciences, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
: Resistance exercises (REs) are a type of physical activity that individuals from many age groups have been doing recreationally, both as amateurs and professionally, in their daily lives in recent years. It is crucial to understand the effects of such sports on cardiac morphology in order to maximize the benefit of training and to tailor the training content accordingly. The aim of this study was to investigate the relationship between training experience (TE) and left ventricular (LV) systolic and diastolic parameters and left atrial (LA) mechanical function in healthy subjects who regularly performed RE for different durations.
View Article and Find Full Text PDFUnmasking the Epicardial Adipose Tissue-Left Atrial Strain Nexus in HFpEF: A Potential Echocardiographic Signature of Cardiac Adaptation.
Echocardiography
January 2025
Ultrasound Medicine Center, Lanzhou University Second Hospital, Lanzhou, Gansu Province, China.
Purpose: This study aims to investigate the relationship between epicardial adipose tissue (EAT) and left atrial function in patients with preserved ejection fraction heart failure (HFpEF).
Methods: We conducted a cross-sectional study involving 113 patients diagnosed with HFpEF and 48 control subjects without heart failure. Echocardiography was performed to assess EAT thickness and left atrial function was quantified using Autostrain left atrium (LA), including left atrial strain during reservoir phase (LASr), left atrial strain during conduit phase (LAScd), and left atrial strain during contraction phase (LASct).
High volume-rate echocardiography for simultaneous imaging of electromechanical activation and cardiac strain of the whole heart in a single heartbeat in humans.
PLoS One
December 2024
Department of Radiology, Columbia University, New York, NY, United States of America.
Background: Imaging both electrical and mechanical cardiac function can better characterize cardiac disease and improve patient care. Currently, there is no noninvasive technique that can simultaneously image both electrical and mechanical function of the whole heart at the point of care. Here, our aim is to demonstrate that high volume-rate echocardiography can simultaneously map cardiac electromechanical activation and end-systolic cardiac strain of the whole heart in a single heartbeat.
View Article and Find Full Text PDFMid-Term Impact of Conduction System Pacing on Overall Cardiac Performance: A Non-Randomized, Prospective, Single-Center Echocardiographic Study.
Diseases
December 2024
5th Department of Internal Medicine, Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania.
Recently published data suggested significantly lower pacing-induced cardiomyopathy (PICM) incidence with conduction system pacing (CSP). Because most data evaluated only the impact on the left ventricle, this study aimed to assess changes in echocardiographic parameters of morphology and function for all heart chambers in patients with baseline preserved and mid-range LVEF over a medium-term follow-up period after CSP. A total of 128 consecutive patients with LVEF > 40% and successful CSP for bradyarrhythmic indication were prospectively enrolled.
View Article and Find Full Text PDFA Case Report Describing the Surgical Removal of Venous and Intracardiac Cement Leakage after Percutaneous Vertebroplasty in a Hybrid Operating Room.
Ann Ital Chir
December 2024
Department of Cardiovascular Surgery, Centro Cardiologico Monzino IRCCS, 20138 Milan, Italy; Department of Biomedical, Surgical, and Dental Sciences, University of Milan, 20122 Milan, Italy.
Aim: Percutaneous vertebroplasty is generally considered a safe procedure, however, cases of cardioembolism and cardiac perforation have been reported.
Case Presentation: A 69-year-old woman was referred to our emergency department after an outpatient echocardiogram revealed a "thrombus-like" formation involving the right heart. Two weeks before she had undergone percutaneous vertebroplasty of the third to fifth lumbar vertebrae due to osteoporotic fractures.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!