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Ozturk O, Ozturk U, Nergiz S, Karahan MZ. The Relationship between Angiotensin-II Type 1 Receptor Gene Polymorphism and Repolarization Parameters after a First Anterior Acute Myocardial Infarction. Korean Circ J 2016; 46:791-797. [PMID: 27826337 PMCID: PMC5099334 DOI: 10.4070/kcj.2016.46.6.791] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 05/19/2016] [Accepted: 06/13/2016] [Indexed: 12/01/2022] Open
Abstract
Background and Objectives Genetic influence on T-wave peak to End (Tpe) time in patients with a first anterior acute myocardial infarction (AMI) is uncertain. A polymorphism in the angiotensin-II type 1 receptor (AT1R) gene was discovered recently. The polymorphism consists of an A or C variant, given three different possible genotypes: AA, AC, CC. The purpose of this study was to determine the effects of polymorphism of the AT1R gene polymorphism on Tpe after a first anterior AMI. Subjects and Methods The subjects were 142 patients (110 men, 32 women, 58±13 years) with a first anterior AMI; ten patients were excluded from this study. Based on the polymorphism of the AT1R gene, they were classified into two groups: Group 1 (AA genotype) of 91 patients and group 2 (AC and CC genotype) of 41 patients. A 12-lead resting ECG was recorded at admission to the coronary care unit in patients with anterior AMI and were manually measured with a ruler. QTc, QTd, QTcd, Tpe, Tpe/QT parameters were measured. Results There was no significant difference in the baseline characteristics of patients (p>0.05). We found significant reduction in QTc, QTd, QTcd, Tpe, Tpe/QT indices Group 1 (AA genotype) (mean 66±28 ms) than group 2 (AC and CC genotype) (mean 95±34 ms) (p<0.05). Conclusion In patients with a first anterior AMI, AT1R gene polymorphisms may influence on repolarization parameters. Although further studies are required.
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Affiliation(s)
- Onder Ozturk
- Department of Cardiology, Diyarbakır Gazi Yasargil Education and Research Hospital, Diyarbakir, Turkey
| | - Unal Ozturk
- Department of Public Health and Neurology, Dicle University Medical Faculty, Diyarbakir, Turkey
| | - Sebnem Nergiz
- Department of Microbiology, Dicle University Medical Faculty, Diyarbakir, Turkey
| | - M Zulkif Karahan
- Department of Cardiology, Diyarbakır Gazi Yasargil Education and Research Hospital, Diyarbakir, Turkey
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Use of echocardiography reveals reestablishment of ventricular pumping efficiency and partial ventricular wall motion recovery upon ventricular cryoinjury in the zebrafish. PLoS One 2014; 9:e115604. [PMID: 25532015 PMCID: PMC4274112 DOI: 10.1371/journal.pone.0115604] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 11/28/2014] [Indexed: 11/27/2022] Open
Abstract
Aims While zebrafish embryos are amenable to in vivo imaging, allowing the study of morphogenetic processes during development, intravital imaging of adults is hampered by their small size and loss of transparency. The use of adult zebrafish as a vertebrate model of cardiac disease and regeneration is increasing at high speed. It is therefore of great importance to establish appropriate and robust methods to measure cardiac function parameters. Methods and Results Here we describe the use of 2D-echocardiography to study the fractional volume shortening and segmental wall motion of the ventricle. Our data show that 2D-echocardiography can be used to evaluate cardiac injury and also to study recovery of cardiac function. Interestingly, our results show that while global systolic function recovered following cardiac cryoinjury, ventricular wall motion was only partially restored. Conclusion Cryoinjury leads to long-lasting impairment of cardiac contraction, partially mimicking the consequences of myocardial infarction in humans. Functional assessment of heart regeneration by echocardiography allows a deeper understanding of the mechanisms of cardiac regeneration and has the advantage of being easily transferable to other cardiovascular zebrafish disease models.
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Sun X, Cai J, Fan X, Han P, Xie Y, Chen J, Xiao Y, Kang YJ. Decreases in electrocardiographic R-wave amplitude and QT interval predict myocardial ischemic infarction in Rhesus monkeys with left anterior descending artery ligation. PLoS One 2013; 8:e71876. [PMID: 23967258 PMCID: PMC3742514 DOI: 10.1371/journal.pone.0071876] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 07/10/2013] [Indexed: 02/05/2023] Open
Abstract
Clinical studies have demonstrated the predictive values of changes in electrocardiographic (ECG) parameters for the preexisting myocardial ischemic infarction. However, a simple and early predictor for the subsequent development of myocardial infarction during the ischemic phase is of significant value for the identification of ischemic patients at high risk. The present study was undertaken by using non-human primate model of myocardial ischemic infarction to fulfill this gap. Twenty male Rhesus monkeys at age of 2–3 years old were subjected to left anterior descending artery ligation. This ligation was performed at varying position along the artery so that it produced varying sizes of myocardial infarction at the late stage. The ECG recording was undertaken before the surgical procedure, at 2 h after the ligation, and 8 weeks after the surgery for each animal. The correlation of the changes in the ECG waves in the early or the late stage with the myocardial infarction size was analyzed. The R wave depression and the QT shortening in the early ischemic stage were found to have an inverse correlation with the myocardial infarction size. At the late stage, the R wave depression, the QT prolongation, the QRS score, and the ST segment elevation were all closely correlated with the developed infarction size. The poor R wave progression was identified at both the early ischemic and the late infarction stages. Therefore, the present study using non-human primate model of myocardial ischemic infarction identified the decreases in the R wave and the QT interval as early predictors of myocardial infarction. Validation of these parameters in clinical studies would greatly help identifying patients with myocardial ischemia at high risk for the subsequent development of myocardial infarction.
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Affiliation(s)
- Xiaorong Sun
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jindan Cai
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xin Fan
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Pengfei Han
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yuping Xie
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Jianmin Chen
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Ying Xiao
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Y. James Kang
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
- * E-mail:
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Laparoscopic surgery: does it increase the probability of atrial and ventricular arrhythmias in children? Surg Laparosc Endosc Percutan Tech 2008; 18:173-7. [PMID: 18427337 DOI: 10.1097/sle.0b013e3181654470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Despite the minor physiologic changes those occur during laparoscopic procedures, pneumoperitoneum with CO2 insufflation may induce alterations in electrocardiographic (ECG) variables, which may predict severe atrial and ventricular arrhythmias. This study aims to assess QT dispersion (QTD) and P wave dispersion (PWD) changes in children who have undergone laparoscopic appendectomy. PATIENTS AND METHODS Sixteen patients (12 males and 4 females) who had preoperative diagnosis of appendicitis were included in the study. As laparoscopic exploration revealed appendicitis in all patients, laparoscopic appendectomy was performed. Preinsufflation (ECG1), postinsufflation (ECG2), predesufflation (ECG3), and postdesufflation (ECG4) ECGs were achieved at a speed of 25 mm/s for QTD and PWD analyses. RESULTS Although mean corrected QTD and PWD at ECG2 and ECG3 were significantly greater than ECG1 and ECG4, those changes induced by insufflation of CO2 were reversible. CONCLUSIONS The clinical significance of pneumoperitoneum, which causes an increase in corrected QTD and PWD in children, remains to be determined with further studies.
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Abstract
Among patients with cardiac disease, the identification of those who are at low risk and those who are at high risk for major cardiac events is crucial for a rational clinical management of individual patients. A correct noninvasive risk stratification of cardiac patients, in particular, has relevant clinical implications because it would avoid unnecessary exposure to potentially risky invasive diagnostic or interventional procedures in low-risk patients, whereas it would allow an appropriate aggressive diagnostic and therapeutic approach in high-risk patients. Furthermore, the appropriate identification of low- and high-risk patients would also have social and economic implications by favoring optimization of resource distribution and costs. A large number of studies in previous decades provided evidence that several methods and variables derived from the analysis of the electrocardiogram (ECG) are powerful predictors of major cardiac events in several clinical conditions. Despite that, there has been limited attention about how several of these findings can be used in clinical practice. Furthermore, in recent years, most studies about risk stratification of cardiac patients have mainly been focused on the use of a number of serum/plasma biomarkers with reduced attention to ECG variables. Surprisingly, however, there have been few attempts to establish whether the various proposed risk markers add any significant information to that obtainable from ECG methods. In this article, the evidence for the prognostic value of variables derived from the assessment of the ECG signal by several methods and techniques will be briefly reviewed. Because of the largeness of the topic, this review will be necessarily incomplete. Because most of the clinical research in this field concerned risk stratification of patients with coronary artery disease, the article will be largely focused on this population of patients. The role of ECG methods in specific cardiac diseases and, in particular, in the general population of asymptomatic subjects will be briefly discussed when believed appropriate and helpful. Furthermore, only major clinical events (ie, cardiac death, arrhythmic events, acute myocardial infarction) will be taken into account as end points in this article. Minor clinical events (eg, coronary revascularization procedures, coronary artery restenosis, recurrences of symptoms) are indeed less robust as end points because they are widely biased by subjective judgments.
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Vassilikos VP, Karagounis LA, Psichogios A, Maounis T, Iakovou J, Manolis AS, Cokkinos DV. Correction for heart rate is not necessary for QT dispersion in individuals without structural heart disease and patients with ventricular tachycardia. Ann Noninvasive Electrocardiol 2006; 7:47-52. [PMID: 11844291 PMCID: PMC7027774 DOI: 10.1111/j.1542-474x.2001.tb00138.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND It remains controversial whether QT dispersion should be corrected for heart rate, especially when the limitations of rate correction formulae are considered. We investigated whether incremental atrial pacing affects QT dispersion and the rate-corrected values according to Bazett's formula in individuals without structural heart disease and in patients with history of sustained ventricular tachycardia. METHODS We studied 32 individuals without structural heart disease (group A), and 16 patients with a history of sustained ventricular tachycardia (group B). QT dispersion and corrected for heart rate QT dispersion using Bazett's formula (QTc dispersion) were calculated in sinus rhythm, and during continuous right atrial pacing for one minute at 100 and 120 beats/min. RESULTS Interobserver variability was not significant (P > or = 0.10). QT dispersion did not differ at rest between groups A and B and did not change significantly from baseline at any heart rate in both groups. However, QTc dispersion increased significantly with atrial pacing in a similar manner in group A and group B (42 +/- 19 ms at rest vs 53 +/- 23 ms at 120 beats/min, P < 0.001 for group A, 39 +/- 16 ms at rest vs 60 +/- 19 ms at 120 beats/min, P < 0.001 for group B). CONCLUSIONS We conclude that QT dispersion remains unchanged during atrial pacing at heart rates up to 120 beats/min in both individuals without structural heart disease and in patients with a history of sustained ventricular tachycardia. Correction by Bazett's formula results in prolongation of QTc dispersion, yielding values which may be misleading.
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Papadopoulos CE, Zaglavara T, Karvounis HI, Haaverstad R, Parharidis GE, Louridas GE, Kenny A. QT dispersion is determined by the relative extent of normal, hibernating, and scarred myocardium in patients with chronic ischemic cardiomyopathy. A dobutamine stress echocardiography study before and after surgical revascularization. J Electrocardiol 2005; 39:103-9. [PMID: 16387061 DOI: 10.1016/j.jelectrocard.2005.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Indexed: 12/14/2022]
Abstract
INTRODUCTION The aim of the present study was to evaluate a possible association between QT dispersion (QTd) and the amount of viable and scarred myocardial tissue after revascularization in patients with coronary artery disease and impaired left ventricular (LV) function. METHODS Twenty-two patients with ischemic LV dysfunction underwent dobutamine stress echocardiography (DSE) before and 6 months after surgical revascularization. Mean corrected QT-interval value and QTd were calculated at baseline and follow-up. Segments consisting of transmural scar were determined as the segments that remained akinetic in all stages of DSE despite reperfusion. Patients were divided into 2 groups according to the number of definitive segments consisting of transmural scar (minor scar group, < or =2 scarred segments; major scar group, >2 scarred segments). RESULTS QTd was significantly lower in the minor compared with the major scar group at baseline and follow-up (mean [SD], 61 [22] vs 98 [33] milliseconds, P = .008, and 45 [18] vs 68 [21] milliseconds, P = .01, respectively). Segments consisting of transmural scar positively correlated to QTd at baseline (r = 0.53, P = .01) and follow-up (r = 0.62, P = .002). CONCLUSIONS QTd is positively correlated with the extent of scarred myocardial tissue assessed by DSE. Surgical revascularization results in reduction of QTd in all patients with hibernating myocardium and LV dysfunction.
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Li CY, Jia LZ, Wang L. Value of QT dispersion in evaluating spatial dispersion of ventricular repolarization during acute myocardial ischemia. Exp Clin Cardiol 2001; 6:179-182. [PMID: 20428255 PMCID: PMC2858996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
OBJECTIVES To study the value of epicardial QT interval dispersion in predicting ischemia-induced heterogeneity of ventricular repolarization. ANIMALS AND METHODS Ischemia was produced by total occlusion of the obtuse branch of the circumflex coronary artery in seven open-chest sheep. A 64-channel electrocardiogram (ECG) was acquired from the epicardium before and after coronary artery occlusion. Wavelet transformation was used to determine the characteristic points of the epicardial ECGs, and to measure the QT interval and activation-recovery interval (ARI) and their dispersions. RESULTS The average QT interval and ARI from the epicardial ECG were not changed by acute myocardial ischemia (P=0.07 and P=0.13, respectively). QT dispersion remained unchanged during ischemia (P=0.17), whereas ARI dispersion was significantly increased by acute ischemia (59.9+/-24.0 ms versus 126.3+/-32.1 ms, P<0.001). CONCLUSIONS These findings indicate that epicardial QT dispersion is less sensitive than ARI dispersion in estimating repolarization heterogeneity induced by acute myocardial ischemia.
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Affiliation(s)
- Chuan Yong Li
- Department of Biophysics, School of Physics, Nankai University, Tianjin, People’s Republic of China, and
| | - Lin Zhuang Jia
- Department of Biophysics, School of Physics, Nankai University, Tianjin, People’s Republic of China, and
| | - Lexin Wang
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, New South Wales, Australia
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Abstract
QT dispersion was originally proposed to measure spatial dispersion of ventricular recovery times. Later, it was shown that QT dispersion does not directly reflect the dispersion of recovery times and that it results mainly from variations in the T loop morphology and the error of QT measurement. The reliability of both automatic and manual measurement of QT dispersion is low and significantly lower than that of the QT interval. The measurement error is of the order of the differences between different patient groups. The agreement between automatic and manual measurement is poor. There is little to choose between various QT dispersion indices, as well as between different lead systems for their measurement. Reported values of QT dispersion vary widely, e.g., normal values from 10 to 71 ms. Although QT dispersion is increased in cardiac patients compared with healthy subjects and prognostic value of QT dispersion has been reported, values are largely overlapping, both between healthy subjects and cardiac patients and between patients with and without adverse outcome. In reality, QT dispersion is a crude and approximate measure of abnormality of the complete course of repolarization. Probably only grossly abnormal values (e.g. > or =100 ms), outside the range of measurement error may potentially have practical value by pointing to a grossly abnormal repolarization. Efforts should be directed toward established as well as new methods for assessment and quantification of repolarization abnormalities, such as principal component analysis of the T wave, T loop descriptors, and T wave morphology and wavefront direction descriptors.
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Affiliation(s)
- M Malik
- Department of Cardiological Sciences, St. George's Hospital Medical School, London, United Kingdom.
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De Sutter J, Tavernier R, De Buyzere M, Jordaens L, De Backer G. Lipid lowering drugs and recurrences of life-threatening ventricular arrhythmias in high-risk patients. J Am Coll Cardiol 2000; 36:766-72. [PMID: 10987597 DOI: 10.1016/s0735-1097(00)00787-7] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES To evaluate a possible effect of lipid lowering drugs on recurrences of ventricular arrhythmias (VA) after implantable cardioverter defibrillator (ICD) implantation. BACKGROUND In patients with coronary artery disease (CAD), lipid lowering drugs reduce total and sudden cardiac death. Because the mechanism is not completely understood, we studied whether these drugs have a favorable influence on the occurrence of life-threatening VA in patients with CAD and ICD implants. METHODS We conducted an observational study in 78 patients with CAD and life-threatening VA, treated with an ICD. After ICD implantation, 27 patients were on treatment with lipid lowering drugs (group I) and 51 were not (group II). Patients were studied for the following end points: recurrences of VA requiring ICD intervention, cardiac death and hospitalization. RESULTS After a mean follow-up of 490 +/- 319 days, 35 patients (45%) had recurrences of VA requiring ICD intervention. In multivariate analysis, the use of lipid lowering drugs (chi-square 6.33, p = 0.012) and poorly tolerated sustained monomorphic ventricular tachycardia as initial presentation (chi-square 4.84, p = 0.028) remained as independent predictors of recurrences of VA. Patients in groups I and II had similar baseline clinical characteristics, but patients in group I had a lower incidence of recurrences of VA (6/27 or 22% vs. 29/51 or 57%, p = 0.004) and of the combined end points of cardiac death and hospitalization (4/27 or 15% vs. 23/51 or 45%, p = 0.015) compared with patients in group II. CONCLUSIONS This is the first observation that the use of lipid lowering drugs is associated with a reduction of recurrences of VA in patients with CAD and ICD implants. These data require confirmation in a prospective randomized trial.
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Affiliation(s)
- J De Sutter
- Department of Cardiology, University Hospital Ghent, Belgium.
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Anderson KP, Shusterman V, Brode S, Gottipaty V, Schwartzman D, Weiss R. Noninvasive Testing for Selection of Patients for Electrophysiological Study. Ann Noninvasive Electrocardiol 1999. [DOI: 10.1111/j.1542-474x.1999.tb00234.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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