Development of a pro-arrhythmic ex vivo intact human and porcine model: cardiac electrophysiological changes associated with cellular uncoupling
| Autor: | Min-Young Kim, Charles Houston, Nicholas S. Peters, Fu Siong Ng, Joseph Brook, Suofeiya Ma, Konstantinos N. Tzortzis, Richard J. Jabbour, Simos Koutsoftidis, Chris D. Cantwell, Annam Sufi, David S. Pitcher, Balvinder S. Handa, Ji-Jian Chow, Xinyang Li, Rasheda A. Chowdhury, Danya Agha-Jaffar, Catherine Jenkins, Anil A. Bharath, Anand Jothidasan, Poppy Bristow, Sian E. Harding, Justin Perkins |
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| Přispěvatelé: | British Heart Foundation, Rosetrees Trust, Imperial College Healthcare NHS Trust- BRC Funding |
| Rok vydání: | 2020 |
| Předmět: |
Adult
Male Swine Physiology Clinical Biochemistry Carbenoxolone 1106 Human Movement and Sports Sciences Pharmacology Electrocardiography Gap junction uncoupling Physiology (medical) medicine Animals Humans Receptor Excitation Contraction Coupling Chemistry Myocardium Contact electrogram Isolated heart Gap junction Langendorff Heart Isolated Heart Preparation 0606 Physiology Molecular medicine Electrophysiology medicine.anatomical_structure Ventricle 1116 Medical Physiology Female Ex vivo model Ex vivo Large animal medicine.drug |
| ISSN: | 0031-6768 |
| Popis: | We describe a human and large animal Langendorff experimental apparatus for live electrophysiological studies and measure the electrophysiological changes due to gap junction uncoupling in human and porcine hearts. The resultant ex vivo intact human and porcine model can bridge the translational gap between smaller simple laboratory models and clinical research. In particular, electrophysiological models would benefit from the greater myocardial mass of a large heart due to its effects on far-field signal, electrode contact issues and motion artefacts, consequently more closely mimicking the clinical setting. Porcine (n = 9) and human (n = 4) donor hearts were perfused on a custom-designed Langendorff apparatus. Epicardial electrograms were collected at 16 sites across the left atrium and left ventricle. A total of 1 mM of carbenoxolone was administered at 5 ml/min to induce cellular uncoupling, and then recordings were repeated at the same sites. Changes in electrogram characteristics were analysed. We demonstrate the viability of a controlled ex vivo model of intact porcine and human hearts for electrophysiology with pharmacological modulation. Carbenoxolone reduces cellular coupling and changes contact electrogram features. The time from stimulus artefact to (-dV/dt)max increased between baseline and carbenoxolone (47.9 ± 4.1–67.2 ± 2.7 ms) indicating conduction slowing. The features with the largest percentage change between baseline and carbenoxolone were fractionation + 185.3%, endpoint amplitude − 106.9%, S-endpoint gradient + 54.9%, S point − 39.4%, RS ratio + 38.6% and (-dV/dt)max − 20.9%. The physiological relevance of this methodological tool is that it provides a model to further investigate pharmacologically induced pro-arrhythmic substrates. |
| Databáze: | OpenAIRE |
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