American Journal of Physiology. Heart and Circulatory Physiology This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

A novel method for the percutaneous induction of myocardial infarction by occlusion of small coronary arteries in the rabbit
Am J Physiol Heart Circ Physiol. 2024 Jan 5. doi: 10.1152/ajpheart.00657.2023. Online ahead of print.ABSTRACTArrhythmic sudden cardiac death (SCD) is an important cause of mortality following myocardial infarction (MI). The rabbit has similar cardiac electrophysiology to humans and is therefore an important small animal model to study post-MI arrhythmias. The established approach of surgical coronary ligation results in thoracic adhesions which impede epicardial electrophysiological studies. Adhesions are absent following a percutaneously induced MI, which is also associated with reduced surgical morbidity and so represent...
Source: American Journal of Physiology. Heart and Circulatory Physiology - January 5, 2024 Category: Physiology Authors: Michael Freeman Eline Huethorst Erin Boland Michael Dunne Francis Burton Chris Denning Rachel Myles Godfrey Smith Source Type: research

Impact of ovary-intact menopause in a mouse model of heart failure with preserved ejection fraction
In this study, we report the first investigation into the impact of ovary-intact menopause in the context of HFpEF. To replicate the human condition as faithfully as possible, vinylcyclohexene dioxide (VCD) was used to accelerate ovarian failure (AOF) in female mice while leaving the ovaries intact. HFpEF was established with a mouse model that involves two stressors typical in humans: a high-fat diet and hypertension induced from the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME). In young female mice, AOF or HFpEF-associated stressors independently induced abnormal myocardial strain indicative ...
Source: American Journal of Physiology. Heart and Circulatory Physiology - January 5, 2024 Category: Physiology Authors: Aaron M Troy Diyora Normukhamedova Daniela Grothe Abdul Momen Yu-Qing Zhou Meghan McFadden Mansoor Hussain Filio Billia Hai-Ling Margaret Cheng Source Type: research

NADPH oxidase overexpression and mitochondrial OxPhos impairment are more profound in human hearts donated after circulatory death than brain death
This study investigated cardiac stress and mitochondrial oxidative phosphorylation (OxPhos) in human donation after circulatory death (DCD) hearts regarding warm ischemic time (WIT) and subsequent cold storage and compared them with that of human brain death donor (DBD) hearts. A total of 24 human hearts were procured for the research study-6 in the DBD group and 18 in the DCD group. DCD group was divided into three groups (n = 6) based on different WITs (20, 40, and 60 min). All hearts received del Nido cardioplegia before being placed in normal saline cold storage for 6 h. Left ventricular biopsies were performed at hour...
Source: American Journal of Physiology. Heart and Circulatory Physiology - January 5, 2024 Category: Physiology Authors: Nandan K Mondal Shiyi Li Abdussalam E Elsenousi Aladdein Mattar Katherine V Nordick Harveen K Lamba Camila Hochman-Mendez Todd K Rosengart Kenneth K Liao Source Type: research

Interpretation of field and LEAP potentials recorded from cardiomyocyte monolayers
Am J Physiol Heart Circ Physiol. 2024 Jan 5. doi: 10.1152/ajpheart.00463.2023. Online ahead of print.ABSTRACTMulti-electrode arrays (MEA) are the method of choice for electrophysiological characterization of cardiomyocyte monolayers. The field potentials recorded using a MEA are like extracellular electrograms recorded from myocardium using conventional electrodes. Nevertheless, different criteria are used to interpret field potential and extracellular electrogram, which hampers correct interpretation and translation to the patient. To validate criteria for interpretation of field potentials, we used neonatal rat cardiomyo...
Source: American Journal of Physiology. Heart and Circulatory Physiology - January 5, 2024 Category: Physiology Authors: Auriane C Ernault Rushd F M Al-Shama Jiuru Li Harsha H Devalla Joris R de Groot Ruben Coronel Edward Vigmond Bastiaan J Boukens Source Type: research

Noninvasive analysis of contractility during identical maturations revealed two phenotypes in ventricular but not in atrial iPSC-CM
Am J Physiol Heart Circ Physiol. 2024 Mar 1;326(3):H599-H611. doi: 10.1152/ajpheart.00527.2023. Epub 2024 Jan 5.ABSTRACTPatient-derived induced pluripotent stem cells (iPSCs) can be differentiated into atrial and ventricular cardiomyocytes to allow for personalized drug screening. A hallmark of differentiation is the manifestation of spontaneous beating in a two-dimensional (2-D) cell culture. However, an outstanding observation is the high variability in this maturation process. We valued that contractile parameters change during differentiation serving as an indicator of maturation. Consequently, we recorded noninvasivel...
Source: American Journal of Physiology. Heart and Circulatory Physiology - January 5, 2024 Category: Physiology Authors: Marcel Rap öhn Lukas Cyganek Niels Voigt Gerd Hasenfu ß Stephan E Lehnart J örg W Wegener Source Type: research

The cardiomyocyte origins of diastolic dysfunction: cellular components of myocardial stiffness
Am J Physiol Heart Circ Physiol. 2024 Jan 5. doi: 10.1152/ajpheart.00334.2023. Online ahead of print.ABSTRACTThe impaired ability of the heart to relax and to stretch to accommodate venous return is generally understood to represent a state of 'diastolic dysfunction' and often described using the all-purpose noun 'stiffness'. Despite the now common qualitative usage of this term in fields of cardiac patho/physiology, the specific quantitative concept of stiffness as a molecular and biophysical entity with real practical interpretation in healthy and diseased hearts is sometimes obscure. The focus of this review is to chara...
Source: American Journal of Physiology. Heart and Circulatory Physiology - January 5, 2024 Category: Physiology Authors: Johannes V Janssens Antonia J A Raaijmakers Kate L Weeks James R Bell Kimberley M Mellor Claire L Curl Lea M D Delbridge Source Type: research

Impact of ovary-intact menopause in a mouse model of heart failure with preserved ejection fraction
In this study, we report the first investigation into the impact of ovary-intact menopause in the context of HFpEF. To replicate the human condition as faithfully as possible, vinyl cyclohexene dioxide (VCD) was used to accelerate ovarian failure (AOF) in female mice while leaving the ovaries intact. HFpEF was established using a mouse model that involves two stressors typical in humans: a high-fat diet and hypertension induced from the nitric oxide synthase inhibitor, Nω-nitro- l-arginine methyl ester (L-NAME). In young and middle-aged "old" female mice, AOF alone induced abnormal myocardial strain indicative of early su...
Source: American Journal of Physiology. Heart and Circulatory Physiology - January 5, 2024 Category: Physiology Authors: Aaron M Troy Diyora Normukhamedova Daniela Grothe Abdul Momen Yu-Qing Zhou Meghan McFadden Mansoor Husain Filio Billia Hai-Ling Margaret Cheng Source Type: research

NADPH Oxidase Overexpression and Mitochondrial OxPhos Impairment are More Profound in Human Hearts Donated after Circulatory Death Than Brain Death
This study investigated cardiac stress and mitochondrial oxidative phosphorylation in human DCD (donation after circulatory death) hearts regarding warm ischemic time (WIT) and subsequent cold storage and compared them to that of human DBD (brain death donor) hearts. A total of 24 human hearts were procured for the research study-six in the DBD group and eighteen in the DCD group. DCD group was divided into three groups (n=6) based on different WITs (20, 40, and 60 minutes). All hearts received del Nido cardioplegia before being placed in normal saline cold storage for 6 hours. Left ventricular biopsies were performed at h...
Source: American Journal of Physiology. Heart and Circulatory Physiology - January 5, 2024 Category: Physiology Authors: Nandan K Mondal Shiyi Li Abdussalam E Elsenousi Aladdein Mattar Katherine V Nordick Harveen K Lamba Camila Hochman-Mendez Todd K Rosengart Kenneth K Liao Source Type: research

Non-invasive analysis of contractility during identical maturations revealed two phenotypes in ventricular but not in atrial iPSC-CM
Am J Physiol Heart Circ Physiol. 2024 Jan 5. doi: 10.1152/ajpheart.00527.2023. Online ahead of print.ABSTRACTPatient-derived induced pluripotent stem cells (iPSC) can be differentiated into atrial and ventricular cardiomyocytes to allow for personalized drug screening. A hallmark of differentiation is the manifestation of spontaneous beating in a 2D cell culture. However, an outstanding observation is the high variability in this maturation process. We valued that contractile parameters change during differentiation serving as an indicator of maturation. Consequently, we recorded non-invasively spontaneous motion activity ...
Source: American Journal of Physiology. Heart and Circulatory Physiology - January 5, 2024 Category: Physiology Authors: Marcel Rap öhn Lukas Cyganek Niels Voigt Gerd Hasenfu ß Stephan E Lehnart J örg W Wegener Source Type: research

Impact of ovary-intact menopause in a mouse model of heart failure with preserved ejection fraction
In this study, we report the first investigation into the impact of ovary-intact menopause in the context of HFpEF. To replicate the human condition as faithfully as possible, vinyl cyclohexene dioxide (VCD) was used to accelerate ovarian failure (AOF) in female mice while leaving the ovaries intact. HFpEF was established using a mouse model that involves two stressors typical in humans: a high-fat diet and hypertension induced from the nitric oxide synthase inhibitor, Nω-nitro- l-arginine methyl ester (L-NAME). In young and middle-aged "old" female mice, AOF alone induced abnormal myocardial strain indicative of early su...
Source: American Journal of Physiology. Heart and Circulatory Physiology - January 5, 2024 Category: Physiology Authors: Aaron M Troy Diyora Normukhamedova Daniela Grothe Abdul Momen Yu-Qing Zhou Meghan McFadden Mansoor Husain Filio Billia Hai-Ling Margaret Cheng Source Type: research