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The Cardiovascular Effects of a Meal: J-Tpeak and Tpeak -Tend Assessment and Further Insights Into the Physiological Effects.

Täubel, J; Ferber, G; Van Langenhoven, L; Del Bianco, T; Fernandes, S; Djumanov, D; Kanters, JK; Graff, C; Camm, AJ (2019) The Cardiovascular Effects of a Meal: J-Tpeak and Tpeak -Tend Assessment and Further Insights Into the Physiological Effects. J Clin Pharmacol, 59 (6). pp. 799-810. ISSN 1552-4604 https://doi.org/10.1002/jcph.1374
SGUL Authors: Camm, Alan John

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Abstract

Meal intake leads to a significant and prolonged increase in cardiac output to supply the splanchnic vasculature. A meal is associated with sympathetic activation of the cardiovascular system, and food ingestion is correlated with an increase in heart rate, an increase in cardiac stroke volume, and QTc interval shortening for up to 7 hours. Given the complexity of the system, one or several of many mechanisms could explain this observation. The shortening of the QTc interval was correlated with a rise of C-peptide following food ingestion, but the mechanisms by which C-peptide may be involved in the modulation of cardiac repolarization are still unknown. This shortening of the myocardial action potential caused by the ingestion of food was further investigated in the present study by measuring the QRS, J-Tpeak , and Tpeak -Tend intervals in search of further clues to better understand the underlying mechanisms. A retrospective analysis was conducted based on data collected in a formal thorough QT/QTc study in which 32 subjects received a carbohydrate-rich "continental" breakfast, moxifloxacin without food, and moxifloxacin with food. We assessed the effect of food on T-wave morphology using validated algorithms for measurement of J-Tpeak and Tpeak -Tend intervals. Our findings demonstrate that a standardized meal significantly shortened J-Tpeak for 4 hours after a meal and to a much lesser extent and shorter duration (up to 1 hour) prolonged the Tpeak -Tend and QRS intervals. This suggests that the QTc shortening occurs mainly during phase 2 of the cardiac action potential. As there was no corresponding effect on Tpeak -Tend beyond the first hour, we conclude that a meal does not interfere with the outward correcting potassium channels but possibly with Ca2+ currents. An effect on mainly Ca2+ aligns well with our understanding of physiology whereby an increase in stroke volume, as observed after a meal, is associated with changes in Ca2+ cycling in and out of the sarcoplasmic reticulum during cardiac myocyte contraction.

Item Type: Article
Additional Information: © 2019, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial (http://creativecommons.org/licenses/by-nc/4.0/) License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Keywords: IKr, IKs, J-Tpeak, Tpeak-Tend, calcium cycling, cardiac electrophysiology, cardiac repolarization, electrocardiogram after food, ion channel effects, IKr, IKs, J-Tpeak, Tpeak-Tend, calcium cycling, cardiac electrophysiology, cardiac repolarization, electrocardiogram after food, ion channel effects, 1115 Pharmacology And Pharmaceutical Sciences, Pharmacology & Pharmacy
SGUL Research Institute / Research Centre: Academic Structure > Molecular and Clinical Sciences Research Institute (MCS)
Journal or Publication Title: J Clin Pharmacol
ISSN: 1552-4604
Language: eng
Dates:
DateEvent
June 2019Published
11 January 2019Published Online
14 December 2018Accepted
Publisher License: Creative Commons: Attribution-Noncommercial 4.0
PubMed ID: 30633366
Go to PubMed abstract
URI: https://openaccess.sgul.ac.uk/id/eprint/110741
Publisher's version: https://doi.org/10.1002/jcph.1374

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