Effect of Short-term Cardiac Memory on Ventricular Electrical Restitution and QT Intervals in Humans
Cardiac memory (CM) can alter the configuration of action potentials and the transmural repolarization gradient in ventricular tissue. This study evaluated the effects of CM on ventricular arrhythmogenicity. A total of 20 patients (12 females, 8 males; mean age, 46 ± 13 years) were enrolled. The fol...
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doaj-9be89fba89a445d9b87294a00f0831532020-11-25T01:18:05ZengWileyKaohsiung Journal of Medical Sciences1607-551X2009-02-01252536110.1016/S1607-551X(09)70041-5Effect of Short-term Cardiac Memory on Ventricular Electrical Restitution and QT Intervals in HumansKun-Tai Lee0Chih-Sheng Chu1Kai-Hung Cheng2Ye-Hsu Lu3Chih-Hsin Huang4Tsung-Hsien Lin5Ming-Chuan Lee6Sheng-Hsiung Sheu7Wen-Ter Lai8Department of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, TaiwanDepartment of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, TaiwanDivision of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, TaiwanDivision of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, TaiwanDivision of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, TaiwanDepartment of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, TaiwanDivision of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung, TaiwanDepartment of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, TaiwanDepartment of Internal Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, TaiwanCardiac memory (CM) can alter the configuration of action potentials and the transmural repolarization gradient in ventricular tissue. This study evaluated the effects of CM on ventricular arrhythmogenicity. A total of 20 patients (12 females, 8 males; mean age, 46 ± 13 years) were enrolled. The following indicators were measured to evaluate ventricular arrhythmogenicity: (1) the action potential duration at 90% repolarization (APD 90) recorded from the right ventricular apex (RVA); (2) the maximal slope of the action potential duration restitution curve (APDR) constructed by programmed extra stimuli from RVA; and (3) the maximal corrected QT interval (QTc) and QT interval dispersion (QTd). The short-term CM was induced by constant pacing from the RVA at a pacing cycle length (PCL) of 400 ms for 20 minutes. After induction of CM, the mean APD 90 were significantly shortened at both PCLs of 600 ms and 400 ms (252.9 ± 6.4 ms vs. 235.6 ± 6.4 ms and 231.2 ± 6.4 ms vs. 214.4 ± 7.3 ms, respectively; p = 0.001). No significant change regarding the maximal slopes of APDR were found at both PCLs of 600 ms and 400 ms (1.05 ± 0.09 vs. 0.96 ± 0.11 and 0.85 ± 0.08 vs. 0.84 ± 0.09, respectively). QTc (417.3 ± 9.1 ms vs. 454.7 ± 8.3 ms; p = 0.001), but not QTd (63.4 ± 5.4 ms vs. 65.7 ± 6.1 ms), was significantly shortened. Short-term CM significantly decreased ventricular APD 90 and QTc, but did not significantly change the maximal slope of APDR or QTd. These results suggest that CM might not have a significant effect on ventricular arrhythmogenicity.http://www.sciencedirect.com/science/article/pii/S1607551X09700415cardiac memoryQT intervalventricular arrhythmiasventricular electrical restitution |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Kun-Tai Lee Chih-Sheng Chu Kai-Hung Cheng Ye-Hsu Lu Chih-Hsin Huang Tsung-Hsien Lin Ming-Chuan Lee Sheng-Hsiung Sheu Wen-Ter Lai |
spellingShingle |
Kun-Tai Lee Chih-Sheng Chu Kai-Hung Cheng Ye-Hsu Lu Chih-Hsin Huang Tsung-Hsien Lin Ming-Chuan Lee Sheng-Hsiung Sheu Wen-Ter Lai Effect of Short-term Cardiac Memory on Ventricular Electrical Restitution and QT Intervals in Humans Kaohsiung Journal of Medical Sciences cardiac memory QT interval ventricular arrhythmias ventricular electrical restitution |
author_facet |
Kun-Tai Lee Chih-Sheng Chu Kai-Hung Cheng Ye-Hsu Lu Chih-Hsin Huang Tsung-Hsien Lin Ming-Chuan Lee Sheng-Hsiung Sheu Wen-Ter Lai |
author_sort |
Kun-Tai Lee |
title |
Effect of Short-term Cardiac Memory on Ventricular Electrical Restitution and QT Intervals in Humans |
title_short |
Effect of Short-term Cardiac Memory on Ventricular Electrical Restitution and QT Intervals in Humans |
title_full |
Effect of Short-term Cardiac Memory on Ventricular Electrical Restitution and QT Intervals in Humans |
title_fullStr |
Effect of Short-term Cardiac Memory on Ventricular Electrical Restitution and QT Intervals in Humans |
title_full_unstemmed |
Effect of Short-term Cardiac Memory on Ventricular Electrical Restitution and QT Intervals in Humans |
title_sort |
effect of short-term cardiac memory on ventricular electrical restitution and qt intervals in humans |
publisher |
Wiley |
series |
Kaohsiung Journal of Medical Sciences |
issn |
1607-551X |
publishDate |
2009-02-01 |
description |
Cardiac memory (CM) can alter the configuration of action potentials and the transmural repolarization gradient in ventricular tissue. This study evaluated the effects of CM on ventricular arrhythmogenicity. A total of 20 patients (12 females, 8 males; mean age, 46 ± 13 years) were enrolled. The following indicators were measured to evaluate ventricular arrhythmogenicity: (1) the action potential duration at 90% repolarization (APD 90) recorded from the right ventricular apex (RVA); (2) the maximal slope of the action potential duration restitution curve (APDR) constructed by programmed extra stimuli from RVA; and (3) the maximal corrected QT interval (QTc) and QT interval dispersion (QTd). The short-term CM was induced by constant pacing from the RVA at a pacing cycle length (PCL) of 400 ms for 20 minutes. After induction of CM, the mean APD 90 were significantly shortened at both PCLs of 600 ms and 400 ms (252.9 ± 6.4 ms vs. 235.6 ± 6.4 ms and 231.2 ± 6.4 ms vs. 214.4 ± 7.3 ms, respectively; p = 0.001). No significant change regarding the maximal slopes of APDR were found at both PCLs of 600 ms and 400 ms (1.05 ± 0.09 vs. 0.96 ± 0.11 and 0.85 ± 0.08 vs. 0.84 ± 0.09, respectively). QTc (417.3 ± 9.1 ms vs. 454.7 ± 8.3 ms; p = 0.001), but not QTd (63.4 ± 5.4 ms vs. 65.7 ± 6.1 ms), was significantly shortened. Short-term CM significantly decreased ventricular APD 90 and QTc, but did not significantly change the maximal slope of APDR or QTd. These results suggest that CM might not have a significant effect on ventricular arrhythmogenicity. |
topic |
cardiac memory QT interval ventricular arrhythmias ventricular electrical restitution |
url |
http://www.sciencedirect.com/science/article/pii/S1607551X09700415 |
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