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Gonçalves MA, Pedro JM, Silva C, Magalhães P, Brito M. Influence of cigarette smoking on the Index of Cardiac Electrophysiological Balance in apparently healthy Angolans. Glob Cardiol Sci Pract 2024; 2024:e202405. [PMID: 38404660 PMCID: PMC10886906 DOI: 10.21542/gcsp.2024.5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/11/2023] [Indexed: 02/27/2024] Open
Abstract
Background: Tobacco use accelerates atherosclerosis and is one of the predictors of death from ischemic heart disease, arrhythmias, heart failure, and sudden death. A new non-invasive parameter, the Index of Cardiac Electrophysiological Balance (iCEB) between depolarization and repolarization of the action potential, was considered a new biomarker for the identification of patients at increased arrhythmic risk. Objectives: We aimed to evaluate the iCEB in apparently healthy Angolans with habitual cigarette smoking compared to non-smokers. Subjects and methods: Data were obtained from the CardioBengo study, a cross-sectional community-based study in which a random sample of individuals aged between 15 and 84 years was selected. In total, 214 apparently healthy subjects, 102 smokers, and 112 non-smokers in the same age group were included in the final analysis. Results: The average age of the participants was 42.17 ± 13.04 years old and 26.6% of the sample was female. Smoking subjects had higher iCEB and corrected Index of Cardiac Electrophysiological Balance (iCEBc) values compared with non-smoking controls (4.39 vs. 4.25; p = 0.024, respectively), and (4.74 vs. 4.57; p = 0.030, respectively). Conclusions: In summary, iCEB and iCEBc were significantly higher in habitual smokers than in nonsmokers, which represents an increased risk of ventricular arrhythmogenesis in healthy habitual smokers. To the best of our knowledge, this is the first study performed in Africa to evaluate iCEB in smokers, making this type of study very important in low- and middle-income countries in the context of epidemiological transition.
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Affiliation(s)
- Mauer A.A. Gonçalves
- Centro de Estudos Avançados em Educação e Formação Médica (CEDUMED), Faculty of Medicine, Agostinho Neto University, Luanda, Angola
- Department of Physiological Sciences, Faculty of Medicine, Agostinho Neto University, Luanda, Angola
- Centro de Investigação em Saúde de Angola (CISA), Angola
| | | | - Carina Silva
- Health and Technology Research Center (H&TRC), Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Portugal
- CEAUL - Centro de Estatística e Aplicações, Faculdade de Ciências, Universidade de Lisboa, Portugal
| | - Pedro Magalhães
- Department of Physiological Sciences, Faculty of Medicine, Agostinho Neto University, Luanda, Angola
| | - Miguel Brito
- Centro de Investigação em Saúde de Angola (CISA), Angola
- Health and Technology Research Center (H&TRC), Escola Superior de Tecnologia da Saúde de Lisboa, Instituto Politécnico de Lisboa, Portugal
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Bohny P, Boettger S, Jenewein J. Dose-dependent QTc interval prolongation under haloperidol and pipamperone in the management of delirium in a naturalistic setting. Front Psychiatry 2023; 14:1257755. [PMID: 37854439 PMCID: PMC10579563 DOI: 10.3389/fpsyt.2023.1257755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/20/2023] [Indexed: 10/20/2023] Open
Abstract
Objective Delirium is an acute, life-threatening neuropsychiatric disorder frequently occurring among hospitalized patients. Antipsychotic medications are often recommended for delirium management but are associated with cardiovascular risks. This study aimed to investigate the frequency and magnitude of QTc interval prolongation and clinically relevant side effects occurring in delirium patients managed with haloperidol and/or pipamperone. Methods This descriptive retrospective cohort study evaluated 102 elderly (mean age: 73.2 years) inpatients with delirium treated with either haloperidol, pipamperone, a combination of both, or neither in a naturalistic setting over the course of up to 20 days or until the end of delirium. Results A total of 86.3% of patients were treated with haloperidol and/or pipamperone at a mean daily haloperidol-equipotent dose of 1.2 ± 1 mg. Non-cardiovascular side effects were registered in 2.9% of all patients and correlated with higher scores on the Delirium Observation Screening Scale. They did not occur more frequently under antipsychotic treatment. The frequency of QTc interval prolongation was comparably common among all groups, but prolongation magnitude was higher under antipsychotic treatment. It was positively correlated with antipsychotic dosage and the total number of QTc interval-prolonging substances administered. Critical QTc interval prolongation was registered in 21.6% (n = 19) of patients in the group treated with antipsychotics compared to 14.3% (n = 2) of patients in the unmedicated group; however, the difference was not statistically significant. Polypharmacy was associated with a higher risk of critical QTc interval prolongation and increased mortality during delirium. Conclusion Delirium treatment with haloperidol and/or pipamperone was not associated with a higher risk of QTc-interval prolongation in this naturalistic patient sample but was greater in magnitude and correlated with equipotent dosage and the number of QT interval-prolonging substances used. Polypharmacy was associated with higher mortality and increased risk of critical QTc prolongation.
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Affiliation(s)
- Philipp Bohny
- Center for Psychiatry and Psychotherapy, Triaplus Clinic Zugersee, Zug, Switzerland
- Department of Consultation-Liaison-Psychiatry and Psychosomatic Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Soenke Boettger
- Faculty of Medicine, University of Zurich, Zurich, Switzerland
| | - Josef Jenewein
- Faculty of Medicine, University of Zurich, Zurich, Switzerland
- Privatklinik Hohenegg, Meilen, Switzerland
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Precise T-wave endpoint detection using polynomial fitting and natural geometric approach algorithm. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2022.104254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Khalilian MR, Ghasemi A, Khazaei N, Khoshkhou S, Mahmoudi E. Repolarization disparity as a predictor of response to Head up Tilt-table Test in pediatric syncope. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2021; 44:1397-1403. [PMID: 34181271 DOI: 10.1111/pace.14305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 06/01/2021] [Accepted: 06/21/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND Head up Tilt-table Test (HUTT) is a practical examination of the most common type of pediatrics syncope. The electrocardiographic (ECG) changes during this test, show the autonomic defects that cause neuraly-mediated syncope in response to tilting process. METHODS All pediatric syncope patients referred to our center in a 1-year period, were included in the study. HUTT was performed and patients were classified into two groups of Negative and Positive HUTT results, and the latter group was subclassified as three subgroups of "vasodepressor", "cardioinhibitory" and "mixed type" responses to HUTT. QT and corrected QT (QTc) dispersion was measured by the baseline standard 12-lead ECG obtained before HUTT. RESULTS Eighty-six patients with a mean age of 12.19 ± 5.34 were included. Patients with positive HUTT were significantly younger and male gender was more prevalent in this group. Mean QT dispersion was significantly higher in patients with positive HUTT result and also in patients with mixed response to HUTT compared to isolated vasodepressor response. Duration of QTc interval did not change between different study groups. Reciever-Operating-Characteristic (ROC) analysis showed that QT dispersion higher than 32 ms is a significant predictor of positive HUTT result (with 92% sensitivity and 98% specificity) and values higher than 40 ms can predict the mixed type of response to HUTT (with 84% sensitivity and 63% specificity). CONCLUSIONS Baseline myocardial repolarization disparity significantly correlates with susceptibility to symptomatic vasovagal syncope. This pathology seems to play its role mainly via excessive vagotonic response to sympathetic activation during HUTT process (known as cardioinhibitory response).
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Affiliation(s)
- Mohammad Reza Khalilian
- Department of Pediatrics, School of Medicine, Shahid Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abdolrahim Ghasemi
- Department of Pediatrics, School of Medicine, Shahid Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Narges Khazaei
- Department of Pediatrics, School of Medicine, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sara Khoshkhou
- Department of Pediatrics, School of Medicine, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Elham Mahmoudi
- Department of Pediatrics, School of Medicine, Shahid Modarres Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Bodén R, Lindström L, Rautaharju P, Sundström J. Electrocardiographic signs of autonomic imbalance in medicated patients with first-episode schizophrenia spectrum disorders – relations to first treatment discontinuation and five-year remission status. Eur Psychiatry 2020; 27:213-8. [DOI: 10.1016/j.eurpsy.2010.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/16/2010] [Accepted: 12/08/2010] [Indexed: 10/18/2022] Open
Abstract
AbstractPurposeTo explore measures in electrocardiograms (ECG) influenced by autonomic balance in early schizophrenia spectrum disorders and to examine their relation to subsequent first antipsychotic pharmacotherapy discontinuation and five-year remission status.Subjects and methodsTwelve-lead ECGs were recorded at baseline in 58 patients with first-episode schizophrenia spectrum disorders and in 47 healthy controls of similar age. Selected ECG variables included heart rate and measures of repolarization. Pharmacotherapy data were extracted from medical records. At a five-year follow-up the patients were interviewed and assessed with the Positive and Negative Syndrome Scale.ResultsPatients had higher heart rate and a different ST-T pattern than the controls. High T-wave amplitudes in the leads aVF and V5 and ST-elevations in V5 were associated both with higher risk of an earlier discontinuation of first antipsychotic pharmacotherapy and with non-remission five years later.Discussion and conclusionIn this longitudinal cohort study, simple ECG measures influenced by autonomic balance in the early phase of schizophrenia spectrum disorders contained prognostic information. As this is the first report of this association and is based on a relatively small sample, the results should be interpreted with caution.
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Liu Y, Fu X, Gao H, Ren Y, Li H, He Y, Wang G. Effects of different concentrations of desflurane on the index of cardiac electrophysiological balance in gynecologic surgery patients. Can J Physiol Pharmacol 2019; 98:332-335. [PMID: 31770012 DOI: 10.1139/cjpp-2019-0290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The objectives were to observe the effects of different concentrations of desflurane on QT, QTc, Tp-e, Tp-e/QT, and the index of cardiac electrophysiological balance (iCEB). Sixty patients were randomly divided into group D1, group D2, and group D3 by using a random number table, 20 in each group. After entering the operating room, patients received 10 mL/kg hydroxyethyl starch, 0.1 mg/kg midazolam, 0.1 mg/kg vecuronium, 3 μg/kg fentanyl, and 0.3 mg/kg etomidate intravenously and then accepted intubation and mechanical ventilation. The desflurane evaporator was opened. The concentrations of desflurane in the D1, D2, and D3 groups were maintained at 0.6, 1.3, and 2.0 minimum alveolar concentration (MAC), respectively. Twelve-lead ECGs were recorded at time before induction (T1) and at 20 min after desflurane reached the required concentration (T2). HR and MAP were recorded measure and the QT interval, QTc interval, Tp-e interval, Tp-e/QT ratio, and iCEB were calculated. Compared with before inhalation (T1), the QTc interval was prolonged in the D1, D2, and D3 groups after inhalation of different concentrations of desflurane for 20 min (T2) (P < 0.05) and the Tp-e/QT ratio decreased in the D1 and D2 groups at T2 (P < 0.05). Compared with the D1 and D2 groups, the Tp-e/QT ratio of the D3 group increased at T2 (P < 0.05). There was no significant difference in Tp-e interval and iCEB at any time (P > 0.05). The study suggested that inhalation of desflurane at a normal concentration cannot cause arrhythmogenic characteristics and affect the cardiac electrophysiological stability.
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Affiliation(s)
- Yanqiu Liu
- Department of Anesthesiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, P.R. China
| | - Xiaokui Fu
- Department of Anesthesiology, Guizhou Medical University, Guiyang, Guizhou, P.R. China
| | - Hong Gao
- The Third Affiliated Hospital of Guizhou Medical University, Duyun, Guizhou, P.R. China
| | - Yimin Ren
- Department of Anesthesiology, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, P.R. China
| | - Huayu Li
- Department of Anesthesiology, Guizhou Medical University, Guiyang, Guizhou, P.R. China
| | - Youqin He
- Department of Anesthesiology, Guizhou Medical University, Guiyang, Guizhou, P.R. China
| | - Guilong Wang
- Department of Anesthesiology, Guizhou Medical University, Guiyang, Guizhou, P.R. China
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Guizhi Decoction () Inhibits Cholinergic Transdifferentiation by Regulating Imbalance of NGF and LIF in Salt-Sensitive Hypertensive Heart Failure Rats. Chin J Integr Med 2019; 26:188-196. [PMID: 31111424 DOI: 10.1007/s11655-019-2706-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/08/2019] [Indexed: 12/23/2022]
Abstract
OBJECTIVE To observe the imbalance of anatomical and functional innervation factors of sympathetic nerves, nerve growth factor (NGF) and leukemia inhibitory factor (LIF), in salt-sensitive hypertensive heart failure rats and to explore the effects of treatment with Guizhi Decoction () on sympathetic remodeling by inhibiting cholinergic transdifferentiation. METHODS SS-13BN and Dahl salt-sensitive (DS) rats were divided into 3 groups: SS-13BN group (control group, n=9), DS group (model group, n=9) and GS group (Guizhi Decoction, n=9). After 10 weeks of a high-salt diet, the GS group rats were given Guizhi Decoction and other two groups were given saline at an equal volume as a vehicle. After 4 weeks' intragastric administration, rats were executed to detect the relevant indicators. Echocardiography and plasma n-terminal pro-B type natriuretic peptide (NT-proBNP) levels were used to assess cardiac function. Noradrenaline (NA) levels in the plasma and myocardium were detected to evaluate the sympathetic function. NGF and LIF expression were detected in the myocardium by Western blot or quantitative real-time PCR. Double immunofluorescence or Western blot was used to detect tyrosine hydroxylase (TH), choline acetyltransferase (CHAT) and growth associated protein 43 (GAP43) in order to reflect anatomical and functional changes of sympathetic nerves. RESULTS DS group had anatomical and functional deterioration of sympathetic nerves in the decompensation period of heart failure compared with SS-13BN group. Compared with the DS group, Guizhi Decoction significantly decreased the expression of LIF mRNA/protein (P<0.01), increased the expression of NGF (P<0.05 or P<0.01), enhanced the levels of TH+/GAP43+ and TH+/CHAT+ positive nerve fibers (P<0.01), and improved the protein expression of TH and GAP43 in left ventricle, but had no effect on CHAT (P>0.05). Guizhi Decoction inhibited inflammatory infiltration and collagen deposition of myocardial injury, increased the content of myocardial NA (P<0.05), reduced the plasma NA level (P<0.01), improved cardiac function (P<0.01), and improved weight and blood pressure to some extent (P<0.05), compared with DS group. CONCLUSIONS Guizhi Decoction could inhibit cholinergic transdifferentiation of sympathetic nerves, improve the anatomical and functional denervation of sympathetic nerves, and delay the progression of decompensated heart failure. The mechanism may be associated with the correction of the imbalance of NGF and LIF.
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Ozturk S, Gurbuz AS, Efe SC, Iliaz R, Banzragch M, Demir K. QTc ınterval is prolonged in Wilson's disease with neurologic ınvolvement. Acta Clin Belg 2018; 73:328-332. [PMID: 29493400 DOI: 10.1080/17843286.2018.1443001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Background Neurologic and liver involvement in Wilson's disease (WD) is well-documented, however, few reports demonstrated cardiac involvement. Tpe and Tpe/QT are new measures of ventricular repolarization which were recently suggested as predictor of arrythmogenesis. We aimed to evaluate ventricular depolarization and repolarization parameters including QT, QTc, Tpe intervals, Tpe/QT, Tpe/QTc ratios, and QT dispersion (QTd) in patients with WD. Materials and methods Thirty-five patients with WD and 30 healthy controls were included in the study. Patients were evaluated by a neurologist in addition to MR imaging. Twenty-one of 35 patients were diagnosed as neuroWilson (NW), whereas 14 patients as non-NW. ECG recordings were obtained using a 12-lead commercial device (Cardiac Science, Burdick s500,USA). All patients underwent standard echocardiographic evaluation. These two groups of patients and healthy controls were compared. Results There were no difference between patients with WD and healthy controls in terms of age sex, BMI, liver, and kidney functions where as patients with WD were anemic and thrombocytopenic. Left atrial, ventricular dimensions, left ventricular systolic, and diastolic functions were similar between patients and healthy control. QT interval was prolonged in patient group, however, QTc, Tpe intervals, Tpe/QT, and Tpe/QTc ratios and QTd did not differ between groups. When patients with NW and non-NW were compared, both QT and QTc intervals were significantly longer in patients with NW, however, Tpe interval, Tpe/QT and Tpe/QTc ratios, and QTd did not differ. Conclusion QT and QTc intervals are prolonged in patients with Wilson's disease and neurologic involvement.
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Affiliation(s)
- Semi Ozturk
- Department of Cardiology, Haseki Training and Research Hospital, Istanbul, Turkey
| | - Ahmet Seyfeddin Gurbuz
- Meram Faculty of Medicine, Department of Cardiology, Necmettin Erbakan University, Konya, Turkey
| | - Suleyman Cagan Efe
- Department of Cardiology, Istanbul Training and Research Hospital, Istanbul, Turkey
| | - Raim Iliaz
- Department of Gastroenterology, Medicine Hospital, Istanbul, Turkey
| | - Mutse Banzragch
- Department of Gastroenterology, Acıbadem University Faculty of Medicine, Kocaeli Hospital, Kocaeli, Turkey
| | - Kadir Demir
- İstanbul Faculty of Medicine, Department of Gastroenterology, Istanbul University, Istanbul, Turkey
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Padfield GJ, Escudero CA, DeSouza AM, Steinberg C, Gibbs K, Puyat JH, Lam PY, Sanatani S, Sherwin E, Potts JE, Sandor G, Krahn AD. Characterization of Myocardial Repolarization Reserve in Adolescent Females With Anorexia Nervosa. Circulation 2016; 133:557-65. [PMID: 26769740 DOI: 10.1161/circulationaha.115.016697] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 12/29/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND Patients with anorexia nervosa exhibit abnormal myocardial repolarization and are susceptible to sudden cardiac death. Exercise testing is useful in unmasking QT prolongation in disorders associated with abnormal repolarization. We characterized QT adaptation during exercise in anorexia. METHODS AND RESULTS Sixty-one adolescent female patients with anorexia nervosa and 45 age- and sex-matched healthy volunteers performed symptom-limited cycle ergometry during 12-lead ECG monitoring. Changes in the QT interval during exercise were measured, and QT/RR-interval slopes were determined by using mixed-effects regression modeling. Patients had significantly lower body mass index than controls; however, resting heart rates and QT/QTc intervals were similar at baseline. Patients had shorter exercise times (13.7±4.5 versus 20.6±4.5 minutes; P<0.001) and lower peak heart rates (159±20 versus 184±9 beats/min; P<0.001). The mean QTc intervals were longer at peak exercise in patients (442±29 versus 422±19 ms; P<0.001). During submaximal exertion at comparable heart rates (114±6 versus 115±11 beats/min; P=0.54), the QTc interval had prolonged significantly more in patients than controls (37±28 versus 24±25 ms; P<0.016). The RR/QT slope, best described by a curvilinear relationship, was more gradual in patients than in controls (13.4; 95% confidence interval, 12.8-13.9 versus 15.8; 95% confidence interval, 15.3-16.4 ms QT change per 10% change in RR interval; P<0.001) and steepest in patients within the highest body mass index tertile versus the lowest (13.9; 95% confidence interval, 12.9-14.9 versus 12.3; 95% confidence interval, 11.3-13.3; P=0.026). CONCLUSIONS Despite the absence of manifest QT prolongation, adolescent anorexic females have impaired repolarization reserve in comparison with healthy controls. Further study may identify impaired QT dynamics as a risk factor for arrhythmias in anorexia nervosa.
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Affiliation(s)
- Gareth J Padfield
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Carolina A Escudero
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Astrid M DeSouza
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Christian Steinberg
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Karen Gibbs
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Joseph H Puyat
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Pei Yoong Lam
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Shubhayan Sanatani
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Elizabeth Sherwin
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - James E Potts
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - George Sandor
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.)
| | - Andrew D Krahn
- From Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, Canada (G.J.P., C.S., K.G., A.D.K.); British Columbia Children's Hospital, Vancouver, Canada (C.A.E., A.M.D., P.Y.L., S.S., E.S., J.E.P., G.S.); and Centre for Health Evaluation and Outcome Sciences, University of British Columbia, Vancouver, Canada (J.H.P.).
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Kim JB, Hong S, Park JW, Cho DH, Park KJ, Kim BJ. Utility of corrected QT interval in orthostatic intolerance. PLoS One 2014; 9:e106417. [PMID: 25180969 PMCID: PMC4152255 DOI: 10.1371/journal.pone.0106417] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Accepted: 08/06/2014] [Indexed: 12/20/2022] Open
Abstract
We performed this study to determine whether electrocardiographic corrected QT (QTc) interval predicts alterations in sympathovagal balance during orthostatic intolerance (OI). We reviewed 1,368 patients presenting with symptoms suggestive of OI who underwent electrocardiography and composite autonomic function tests (AFTs). Patients with a positive response to the head-up tilt test were classified into orthostatic hypotension (OH), neurocardiogenic syncope (NCS), or postural orthostatic tachycardia syndrome (POTS) groups. A total of 275 patients (159 OH, 54 NCS, and 62 POTS) were included in the final analysis. Between-group comparisons of OI symptom grade, QTc interval, QTc dispersion, and each AFT measure were performed. QTc interval and dispersion were correlated with AFT measures. OH Patients had the most severe OI symptom grade and NCS patients the mildest. Patients with OH showed the longest QTc interval (448.8±33.6 msec), QTc dispersion (59.5±30.3 msec) and the lowest values in heart rate response to deep breathing (HRDB) (10.3±6.0 beats/min) and Valsalva ratio (1.3±0.2). Patients with POTS showed the shortest QTc interval (421.7±28.6 msec), the highest HRDB values (24.5±9.2 beats/min), Valsalva ratio (1.8±0.3), and proximal and distal leg sweat volumes in the quantitative sudomotor axon reflex test. QTc interval correlated negatively with HRDB (r = −0.443, p<0.001) and Valsalva ratio (r = −0.425, p<0.001). We found negative correlations between QTc interval and AFT values representing cardiovagal function in patients with OI. Our findings suggest that prolonged QTc interval may be considered to be a biomarker for detecting alterations in sympathovagal balance, especially cardiovagal dysfunction in OH.
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Affiliation(s)
- Jung Bin Kim
- Department of Neurology, Korea University Medical Center, Korea University College of Medicine, Seoul, Korea
| | - Soonwoong Hong
- Department of Neurology, Korea University Medical Center, Korea University College of Medicine, Seoul, Korea
| | - Jin-Woo Park
- Department of Neurology, Korea University Medical Center, Korea University College of Medicine, Seoul, Korea
| | - Dong-Hyuk Cho
- Department of Cardiology, Korea University Medical Center, Korea University College of Medicine, Seoul, Korea
| | - Ki-Jong Park
- Department of Neurology, Kyungsang University Medical Center, Jinjoo, Korea
| | - Byung-Jo Kim
- Department of Neurology, Korea University Medical Center, Korea University College of Medicine, Seoul, Korea
- * E-mail:
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11
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Park KM, Shin KJ, Kim SE, Park J, Ha SY, Kim BJ. Prolonged Corrected QT Interval in Patients with Myotonic Dystrophy Type 1. J Clin Neurol 2013; 9:186-91. [PMID: 23894242 PMCID: PMC3722470 DOI: 10.3988/jcn.2013.9.3.186] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 04/30/2013] [Accepted: 04/30/2013] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND AND PURPOSE Sudden cardiac death is one of the leading causes of death in patients with myotonic dystrophy type 1 (DM1). It has been proposed that a prolonged QT interval is associated with sudden cardiac death in several neurological diseases, including multiple system atrophy, idiopathic Parkinson's disease, and diabetic autonomic neuropathy. However, analyses of the corrected QT (QTc) interval in DM1 patients are rare in the literature. The purposes of this study were to determine the association between the QT interval and DM1, and the affecting factors. METHODS Thirty-nine patients diagnosed with DM1 through genetic testing were enrolled. The QTc interval (calculated using Bazett's formula: QTc=QT/√RR) was compared between these patients and 39 normal healthy controls. The clinical and laboratory factors affecting QTc interval in the patient group were investigated. RESULTS The QTc interval was significantly longer in the DM1 group (411.2±44.7 msec, mean±SD) than in the normal control group (355.6±20.6 msec). Intragroup analysis revealed that a prolonged QTc interval in DM1 patients was associated with being female and older, having a longer disease duration, and exhibiting abnormal electrocardiography findings. CONCLUSIONS The higher incidence of sudden cardiac death in the DM1 population is associated with the observed prolonged QTc interval in those patients.
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Affiliation(s)
- Kang Min Park
- Department of Neurology, Haeundae Paik Hospital, Inje University, Busan, Korea
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12
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Iodice V, Low DA, Vichayanrat E, Mathias CJ. Cardiovascular autonomic dysfunction in MSA and Parkinson's disease: Similarities and differences. J Neurol Sci 2011; 310:133-8. [DOI: 10.1016/j.jns.2011.07.014] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 06/27/2011] [Accepted: 07/11/2011] [Indexed: 02/02/2023]
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13
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Andrássy G, Szabo A, Ferencz G, Trummer Z, Simon E, Tahy A. Mental stress may induce QT-interval prolongation and T-wave notching. Ann Noninvasive Electrocardiol 2007; 12:251-9. [PMID: 17617071 PMCID: PMC6932412 DOI: 10.1111/j.1542-474x.2007.00169.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND The effects of active and passive mental stress (PMS) on the QT interval were studied by using an intraindividual regression method of QT-interval correction for heart rate. METHODS Thirty healthy males (age 21.2 +/- 1.8 years) performed a mental arithmetic for 1 minute, which was considered as active mental stress (AMS) because of the performance requirement. A 1-minute unpleasant video clip was used for PMS. Two baseline and two (an early and a late) ECGs were prepared in both mental stress periods. The individual QT-RR relationship was assessed by linear regression analysis of 7-15 (11.0 +/- 1.9) controlled QT-RR data pairs, also obtained from ECGs gained during a successive set of 9 isometric stretching exercises. RESULTS Heart rate has increased significantly at both measurements in response to AMS (P < 0.0001), but not in response to passive stress. QTc significantly prolonged early in AMS (P = 0.0004), then normalized by the end of the period. During PMS, no significant QTc changes were observed. The evolution of bifid T waves was noted in 14 subjects: 8 presented bifid T waves during both AMS and exercise, and 6 during only exercise. CONCLUSIONS AMS and PMS elicit different cardiovascular reactions. Our results indicate that changes in the autonomic tone, probably abrupt sympathetic predominance, may cause QTc prolongation and bifid T waves. This suggests that besides stress quality and intensity, the dynamics of stress application and perception also influence repolarization.
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Affiliation(s)
- Gábor Andrássy
- Department of Cardiology, Saint Francis Hospital, Budapest, Hungary.
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14
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Sezgin AT, Barutcu I, Ozdemir R, Gullu H, Topal E, Esen AM, Tandogan I, Acikgoz N. Effect of slow coronary flow on electrocardiographic parameters reflecting ventricular heterogeneity. Angiology 2007; 58:289-94. [PMID: 17626982 DOI: 10.1177/0003319707302486] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
QT interval dispersion reflects regional variations in ventricular repolarization and cardiac electrical instability. Previous studies have showed that QT interval dispersion changes during episodes of myocardial ischemia. Slow coronary flow (SCF) in epicardial coronary arteries is a rare and unique angiographic finding. Whether this pattern of flow is associated with electrocardiographic abnormalities is unknown. Therefore, this study was designed to investigate whether SCF results in electrocardiographic (ECG) changes compared to normal coronary flow. For this aim 24 patients with angiographically proven SCF who had no obstructive coronary lesion (group I) and 25 patients without coronary artery disease (group II) were included in the study. Both groups underwent a routine standard 12-lead surface electrocardiogram recorded at 50 mm/s during rest. QT dispersion (QTd), corrected QT (QTc), and corrected QT dispersion (QTcd) were calculated. Distributions of sex, age, body mass index (BMI), and cardiac risk factors were similar in the 2 groups. Mean heart rate was similar in the 2 groups (74 +/-8 vs 77 +/- 7 p > 0.05). Mean QRS interval durations were similar in the groups (92 +/-7 vs 90 +/-6 ms p > 0.005). In group I, QTd, QTcd, and QTc, were significantly higher than in group II (QTd: 73 +/-14 vs 40 +/-14; QTcd: 71 +/-15 vs 42 +/-9; QTc: 414 +/-14 vs 388 +/-13, respectively p <0.05). In conclusion, SCF was found to be associated with prolonged QT interval and increased QT dispersion. Ischemia in microvascular level and/or altered autonomic regulation of the heart may be responsible mechanisms.
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Affiliation(s)
- Alpay Turan Sezgin
- Department of Cardiology, Baskent University, Practice and Research Hospital, Adana, Turkey
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15
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Abstract
INTRODUCTION The QT interval is a predictor of sudden death. Many drugs prolong the QT, primarily through I(Kr) block. Autonomic tone directly affects heart rate and ventricular repolarization, but its effects in the setting of I(Kr) block are unknown. OBJECTIVE Determine the effects of autonomic tone on heart rate and QT interval after I(Kr) block. METHODS AND RESULTS Healthy adults (n = 9) were administered ibutilide with ECGs obtained at regular intervals. On a separate day, subjects were administered intravenous propranolol and atropine to induce autonomic block, resulting in intrinsic heart rate and QT interval; ibutilide was administered again, with serial ECGs obtained at regular intervals. No differences in baseline RR, QT, or QTc intervals were seen between the two study days. Ibutilide in the setting of intact autonomic tone prolonged QTc by 43 +/- 8 msec (P = 0.001) and prolonged RR interval by 93 +/- 39 msec (P = 0.04). Autonomic block alone on the second day prolonged QTc by 16.7 +/- 9.4 msec (P = 0.02). An additional 68 +/- 5 msec prolongation of QTc was seen with ibutilide in the setting of double autonomic block (P = 0.036). There was no effect of ibutilide on intrinsic heart rate (P = 0.125). CONCLUSION Autonomic block results in an exaggeration of drug-induced QT prolongation by ibutilide. I(Kr) block has no effect on intrinsic heart rate. QT-prolonging drugs may have more deleterious effects in those with underlying autonomic dysfunction, thus increasing the risk for sudden death.
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Affiliation(s)
- Andrew H Smith
- Division of Pediatric Cardiology, Vanderbilt Children's Hospital, Nashville, Tennessee 37232, USA.
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16
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Su HM, Chiu HC, Lin TH, Voon WC, Liu HW, Lai WT. Longitudinal study of the ageing trends in QT interval and dispersion in healthy elderly subjects. Age Ageing 2006; 35:636-8. [PMID: 17047010 DOI: 10.1093/ageing/afl114] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ho-Ming Su
- Division of Cardiology, Department of Internal Medicine, Kaohsiung Medical University Chung-Ho Memorial Hospital, Kaohsiung Medical University, Kaohsiung, 100 Shih-Chuan 1st Road, Kaohsiung 807, Taiwan.
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17
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Esen AM, Barutcu I, Melek M, Kaya D, Onrat E, Batukan Esen O. Comparison of QT interval duration and dispersion in elderly population versus healthy young subjects. Clin Auton Res 2004; 14:408-11. [PMID: 15666071 DOI: 10.1007/s10286-004-0217-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2003] [Revised: 07/12/2004] [Indexed: 10/25/2022]
Abstract
We compared QT dispersion (QTd) in 75 elderly and 36 young subjects and found that those over the age of 75 years had higher QTd than those younger than 75. In addition those older than 75 years had higher QTd values compared to the younger subjects. We concluded that QTd increased especially over the age of 75.
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18
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Diedrich A, Jordan J, Shannon JR, Robertson D, Biaggioni I. Modulation of QT interval during autonomic nervous system blockade in humans. Circulation 2002; 106:2238-43. [PMID: 12390954 DOI: 10.1161/01.cir.0000035241.76918.6c] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND It is thought that the autonomic nervous system modulates QT interval, but traditional autonomic blockade combining propranolol and atropine has produced conflicting results. We used the alternative approach of interrupting neurotransmission at the level of autonomic ganglia to determine its effect on the QT interval. METHODS AND RESULTS We infused trimethaphan at increasing doses (0.5 to 10 mg/min IV) while monitoring heart rate, heart rate variability spectra, QT interval, and blood pressure in 10 normal volunteers, 9 patients with multiple system atrophy (MSA), and 8 patients with pure autonomic failure (PAF). The QT interval was corrected for heart rate using Bazett's formula (QTc). Patients with PAF had very low heart rate variability and a prolonged QTc at baseline (465+/-8 ms) compared with patients with MSA (448+/-6 ms) and normal subjects (432+/-6 ms). In normal subjects, trimethaphan dose-dependently prolonged QTc (to 469+/-7 ms), decreased RR interval (995+/-45 to 670+/-35 ms), and abolished heart rate variability. In MSA patients, trimethaphan also prolonged QTc (to 463+/-7 ms) and reduced heart rate variability but did not significantly change RR interval (from 813+/-38 to 801+/-39). CONCLUSIONS Autonomic blockade prolongs QT interval in normal subjects to a similar duration as in PAF patients. Furthermore, blocking residual autonomic tone in PAF patients is associated with a further increase in QT interval length. Patients with MSA have greater residual sympathetic tone and greater prolongation of the QT interval during ganglionic blockade than PAF patients.
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Affiliation(s)
- André Diedrich
- Autonomic Dysfunction Center, Vanderbilt University, Nashville, Tenn. 37232-2195, USA.
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19
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Deguchi K, Sasaki I, Tsukaguchi M, Kamoda M, Touge T, Takeuchi H, Kuriyama S. Abnormalities of rate-corrected QT intervals in Parkinson's disease-a comparison with multiple system atrophy and progressive supranuclear palsy. J Neurol Sci 2002; 199:31-7. [PMID: 12084439 DOI: 10.1016/s0022-510x(02)00079-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A number of patients with Parkinson's disease (PD) and multiple system atrophy (MSA), in whom sudden death does occur occasionally, have QT or rate-corrected QT (QTc) interval prolongation on electrocardiogram (ECG). Although these QT or QTc interval abnormalities are likely related to autonomic dysfunction, the pathophysiology remains unknown. The aim of this study was to compare the degree of QTc interval prolongation among akinetic-rigid syndromes, namely PD and related disorders, and to evaluate the relationship between QTc prolongation and severity of autonomic dysfunction. Thirty-four patients with PD, 22 with MSA, 11 with progressive supranuclear palsy (PSP) and 30 healthy controls underwent standard autonomic function tests, and electrocardiography variables (RR, QT and QTc intervals) were measured by an ECG recorder with an automated analyzer. The relationship between QTc interval and cardiovascular reflex tests were also analyzed. Orthostatic hypotension and decreased heart rate in response to respiratory stimuli were prominent in MSA, while these were relatively mild in PD. Unlike the RR and QT intervals, the QTc interval significantly differed among all groups (p<0.01). The QTc interval was significantly prolonged in PD (409+/-17 ms; p<0.001) and MSA (404+/-14 ms; p<0.05) compared with healthy controls (394+/-19 ms). Neither autonomic dysfunction nor QTc interval prolongation was evident in PSP. QTc intervals and cardiovascular reflexes did not correlate, except for Valsalva ratio. The QTc interval was obviously prolonged in PD patients to an extent that could not be accounted for simply by autonomic dysfunction levels. MSA patients showed slightly prolonged QTc intervals in spite of marked cardiovascular autonomic dysfunction. Abnormalities of the QTc may reflect the degeneration of cardioselective sympathetic and parasympathetic neurons that cannot be fully captured by cardiovascular autonomic function tests.
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Affiliation(s)
- Kazushi Deguchi
- Third Department of Internal Medicine, Kagawa Medical University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
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20
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Ileri M, Yetkin E, Tandoğan I, Hisar I, Atak R, Senen K, Cehreli S, Demirkan D. Effect of habitual smoking on QT interval duration and dispersion. Am J Cardiol 2001; 88:322-5. [PMID: 11472720 DOI: 10.1016/s0002-9149(01)01653-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- M Ileri
- Department of Cardiology, Türkiye Yüksek Ihtisas Hospital, Ankara, Turkey.
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21
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Güler N, Kati I, Demirel CB, Bilge M, Eryonucu B, Topal C. The effects of volatile anesthetics on the Q-Tc interval. J Cardiothorac Vasc Anesth 2001; 15:188-91. [PMID: 11312477 DOI: 10.1053/jcan.2001.21949] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To examine the effects of halothane, isoflurane, and sevoflurane on Q-Tc interval (corrected for heart rate) during inhalation induction of anesthesia. DESIGN Prospective, double-blind, randomized study. SETTING Departments of Cardiology and Anesthesiology in a university hospital. PARTICIPANTS Patients undergoing noncardiac surgery. INTERVENTIONS A total of 65 American Society of Anesthesiologists physical status I-II patients, aged 16 to 50 years, undergoing general anesthesia, were randomly allocated to receive halothane, isoflurane, or sevoflurane. MEASUREMENTS AND MAIN RESULTS The time to reach the predetermined end-tidal concentrations of 3 minimum alveolar concentration was 6 to 10 minutes. When compared with preinduction values, heart rate decreased after halothane (p < 0.01) and sevoflurane (p < 0.05) administration; in contrast, heart rate increased after induction of anesthesia with isoflurane (p < 0.05). The mean QRS intervals were not significantly changed after halothane, isoflurane, or sevoflurane. The Q-Tc interval was increased with isoflurane compared with baseline (465 +/- 23 v 441 +/- 18 msec, p < 0.01), not changed with sevoflurane (441 +/- 17 v 434 +/- 19 ms, p > 0.05), and shortened with halothane (426 +/- 23 v 445 +/- 21 msec, p < 0.01). CONCLUSION Sevoflurane or halothane may be preferred to isoflurane in patients with conditions that are known to induce a prolonged Q-Tc interval. The effects of Q-Tc interval changes resulting from different anesthetic agents on morbidity and the incidence of arrhythmias during anesthesia warrant further investigation.
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Affiliation(s)
- N Güler
- Department of Cardiology, School of Medicine Yüzüncü Yil University, Van, Turkey.
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22
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Haapalahti P, Mäkijärvi M, Montonen J, Korhonen P, Salorinne Y, Oikarinen L, Viitasalo M, Toivonen L. Effects of cardiovascular autonomic function tests on QT dispersion in the 12-lead electrocardiogram of healthy patients. J Electrocardiol 2000; 33:321-7. [PMID: 11099357 DOI: 10.1054/jelc.2000.18357] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Changes in autonomic tone modulate QT interval duration. How cardiovascular autonomic reflexes affect QT dispersion, a suggested marker of arrhythmia risk, is not well established. We studied 10 healthy young adult volunteer men during quiet and deep breathing, the Valsalva maneuver, sustained handgrip, hyperventilation, the cold pressor test, and mental stress. An automated method was used for measurement of QT-peak and QT-end intervals, and QT dispersion was defined as maximum-minimum of the measured intervals. QT-peak dispersion was greater on deep expiration than deep inspiration (49 +/- 20 ms vs 37 +/- 14 ms, P < .05). QT-end dispersion decreased in the tachycardia phase of the Valsalva maneuver (45 +/- 23 ms vs 35 +/- 21 ms, P < .05), but QT dispersion did not change during the other interventions. Rapid cardiovascular autonomic reflex adjustment does not change QT dispersion in healthy young adult men. However, large intrathoracic volume and intrathoracic pressure changes during forced respiratory movements might confound QT dispersion measurements.
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Affiliation(s)
- P Haapalahti
- Department of Medicine, Helsinki University Central Hospital, Finland
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23
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Davey P. QT interval lengthening in cardiac disease relates more to left ventricular systolic dysfunction than to autonomic function. Eur J Heart Fail 2000; 2:265-71. [PMID: 10938487 DOI: 10.1016/s1388-9842(00)00065-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND There are multiple influences on the QTc interval, including the autonomic nervous system. Which influence is the principal determinant of the variation in QTc interval between different cardiac diseases is not yet clear, though some studies have suggested that the QTc interval primarily reflects sympatho-vagal balance. This study investigated this claim further. AIM To determine if autonomic tone was the prime determinant of variation in the QTc interval between subjects with different cardiac diseases. METHODS Subjects with different cardiac diseases were studied, QTc interval determined and correlated with three different measures of the autonomic nervous system, that of baroreflex sensitivity, catecholamine levels (epinephrine and norepinephrine) and sympatho-vagal balance as determined by power spectrum analysis. RESULTS 47 subjects were studied, comprising 17 subjects with heart failure, 14 subjects with left ventricular hypertrophy and 16 control subjects. For the group as a whole there was no relationship between QTc interval and any measure of the autonomic nervous system function, but there was a reasonable relationship between fractional shortening and QTc interval (r=0.47, P<0.003). For subjects with an echocardiographic fractional shortenings less than 0.35 (which correlates with an ejection fraction of <50%), a strong relationship between fractional shortening and QTc interval remained (r=0.57, P<0.002), but in addition a relationship between QTc interval and catecholamine levels developed (for epinephrine: r=0.67, P<0.002; and for norepinephrine: r=0.62, P<0.005). Multiple regression analysis showed that fractional shortening and epinephrine levels were independently related to QTc interval. CONCLUSION In subjects with a variety of cardiac diseases, the prime determinant of QTc interval is left ventricular systolic performance rather than the autonomic nervous system, though in subjects with low normal and less fractional shortenings catecholamine levels are independently related to QTc interval.
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Affiliation(s)
- P Davey
- Department of Cardiovascular Medicine, John Radcliffe Hospital, OX3 9DU, Oxford, UK.
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Costantini O, Drabek C, Rosenbaum DS. Can sudden cardiac death be predicted from the T wave of the ECG? A critical examination of T wave alternans and QT interval dispersion. Pacing Clin Electrophysiol 2000; 23:1407-16. [PMID: 11025899 DOI: 10.1111/j.1540-8159.2000.tb00971.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- O Costantini
- Heart and Vascular Research Center, Case Western Reserve University, Cleveland, Ohio 44109-1998, USA
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Arildsen H, May O, Christiansen EH, Damsgaard EM. Increased QT dispersion in patients with insulin-dependent diabetes mellitus. Int J Cardiol 1999; 71:235-42. [PMID: 10636529 DOI: 10.1016/s0167-5273(99)00140-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
AIM To compare the QT dispersion in unselected patients with insulin-dependent diabetes mellitus to non-diabetic control subjects and to assess the association between the QT dispersion and cardiac autonomic neuropathy, ischaemic heart disease, blood pressure level and nephropathy. METHODS 42 patients with insulin-dependent diabetes mellitus and 80 control subjects aged 40-57 years participated. The QT interval was measured in a resting 12-lead electrocardiogram (ECG) and the QT dispersion defined as the difference between the maximum and minimum QT interval. Bazett's formula was used to correct for heart rate (QTc). The degree of cardiac autonomic neuropathy was assessed by five function tests and ischaemic heart disease was defined by a previous myocardial infarction, ECG abnormalities or a positive exercise test. RESULTS Compared to control subjects, diabetic patients had a longer QTc interval (433 vs. 416 ms; P=0.002) and a higher QT dispersion (36 vs. 30 ms; P=0.02). In the diabetic group, the QTc interval was prolonged in patients with autonomic neuropathy (449 vs. 420 ms; P=0.007) and the QT dispersion was increased in patients with ischaemic heart disease (51 vs. 33 ms; P=0.004). No association was found to urinary albumin excretion rate or blood pressure. CONCLUSION The QT dispersion as well as the QTc interval is increased in patients with insulin-dependent diabetes mellitus. The association between QT dispersion and ischaemic heart disease indicates that abnormalities in cardiac repolarisation may be caused by complications to diabetes rather than diabetes in itself.
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Affiliation(s)
- H Arildsen
- Department of Cardiology (Research Unit), Skejby University Hospital, Aarhus N, Denmark.
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Ashikaga T, Nishizaki M, Arita M, Yamawake N, Suzuki M, Hashimoto Y, Kishi Y, Numano F, Hiraoka M. Effect of dipyridamole on QT dispersion in vasospastic angina pectoris. Am J Cardiol 1999; 84:807-10. [PMID: 10513778 DOI: 10.1016/s0002-9149(99)00441-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Life-threatening ventricular arrhythmias have frequently been documented in patients with vasospastic angina. Moreover, the incidence of ventricular arrhythmias has been closely associated with increased QT dispersion. However, the underlying mechanism responsible for this arrhythmogenesis has not been clarified. The effects of dipyridamole and subsequent aminophylline administration on QT dispersion were examined in 35 patients with vasospastic angina and 30 patients with atypical chest pain. None of the patients enrolled in this study revealed any significant stenosis in coronary angiography. QT dispersion during dipyridamole followed by aminophylline administration was compared between the 2 groups. The baseline QT dispersion was similar in both groups (vasospastic angina: 27 +/- 8 ms; atypical chest pain: 28 +/- 7 ms). No significant changes in QT dispersion were observed in patients with atypical chest pain by dipyridamole (23 +/- 9 ms) and subsequent aminophylline administration (23 +/- 5 ms). However, the QT dispersion in patients with vasospastic angina increased significantly by dipyridamole administration (53 +/- 14 ms, p <0.0001) and returned to baseline by subsequent aminophylline administration (26 +/- 10 ms). Our data suggest that the disparity of ventricular repolarization in vasospastic angina may be mediated by increased endogenous adenosine.
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Affiliation(s)
- T Ashikaga
- Department of Cardiology, Yokohama Minami Kyosai Hospital, Yokohama-city, Japan
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Abstract
Various methods for automatic electrocardiogram T-wave detection and Q-T interval assessment have been developed. Most of them use threshold level crossing. Comparisons with observer detection were performed due to the lack of objective measurement methods. This study followed the same approach. Observer assessments were performed on 43 various T-wave shapes recorded: (i) with 100 mm s-1 equivalent paper speed and 0.5 mV cm-1 sensitivity; and (ii) with 160 mm s-1 paper speed and vertical scaling ranging from 0.07 to 0.02 mV cm-1, depending on the T-wave amplitude. An automatic detection algorithm was developed by adequate selection of the T-end search interval, improved T-wave peak detection and computation of the angle between two 10 ms long adjacent segments along the search interval. The algorithm avoids the use of baseline crossing and direct signal differentiation. It performs well in cases of biphasic and/or complex T-wave shapes. Mean differences with respect to observer data are 13.5 ms for the higher gain/speed records and 14.7 ms for the lower gain/speed records. The algorithm was tested with 254 various T-wave shapes. Comparisons with two other algorithms are presented. The lack of a 'gold standard' for the T-end detection, especially if small waves occur around it, impeded adequate interobserver assessment and evaluation of automatic methods. It is speculated that a simultaneous presentation of normal and high-gain records might turn more attention to this problem. Automatic detection methods are in fact faced with 'high-gain' data, as high-resolution analogue-to-digital conversion is already widely used.
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Affiliation(s)
- I K Daskalov
- Centre of Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria.
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Glickstein JS, Axelrod FB, Friedman D. Electrocardiographic repolarization abnormalities in familial dysautonomia: an indicator of cardiac autonomic dysfunction. Clin Auton Res 1999; 9:109-12. [PMID: 10225616 DOI: 10.1007/bf02311768] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Electrocardiographic repolarization intervals were evaluated to determine the extent of cardiac autonomic dysfunction in patients with familial dysautonomia (FD) and to determine if any of these intervals could serve as a possible predictor of clinical symptoms. METHODS Thirty-seven electrocardiograms of patients with FD were retrospectively evaluated. QT, JT, rate-corrected QT and JT intervals were calculated as well as QT and QTC dispersion. Results were compared to normative data and electrocardiograms of 20 age-matched control subjects. OBSERVATIONS In the FD group, prolongation of QTC (>450 msec) was noted in 5/37 (13.5%) patients, as compared to 0/20 normal controls (p = NS), and prolongation of JTc (>340 msec) in 16/37 (43.3%) patients, as compared to 0/20 normal controls (p < 0.001). QT and QTC dispersion were abnormal in 3/37 (8.1%) and 5/37 (13.5%), respectively. In the 16 FD patients with prolonged JTc, six had a positive history of syncope, whereas none of the 21 with normal JTc had syncope or symptoms suggesting arrhythmia (p < 0.003). The positive predictive value of having syncope or symptoms suggestive of arrhythmia with an abnormal JTc is 37.5% (95% CI [15%, 65%]). The negative predictive value is 100% (95% CI [87%, 100%]). CONCLUSION In the FD population, the electrocardiographic measure of repolarization that was most frequently abnormal was the JTc interval . Prolongation of the JTc interval was significantly more frequent than prolongation of the QTC interval (p < 0.001) QT and QTC dispersions were less significantly affected in the FD population, indicating uniform ventricular recovery time. These results suggest that a prolonged JTc interval may be a more sensitive indicator of abnormal ventricular repolarization and cardiac autonomic dysfunction. Due to the known sympathetic denervation inherent in patients with FD, they are at risk for unopposed parasympathetic predominance. FD patients, therefore, are more likely to have brady arrhythmias and asystole rather than polymorphic ventricular tachycardia. The increased incidence of syncope in patients with prolonged JTc suggests that this measure may serve as a helpful marker to predict which FD patients are at increased risk of serious clinical sequelae including bradyarrhythmias with asystole or sudden death.
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Affiliation(s)
- J S Glickstein
- Department of Pediatrics, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York 10467, USA
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Choy AM, Lang CC, Roden DM, Robertson D, Wood AJ, Robertson RM, Biaggioni I. Abnormalities of the QT interval in primary disorders of autonomic failure. Am Heart J 1998; 136:664-71. [PMID: 9778070 DOI: 10.1016/s0002-8703(98)70014-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Experimental evidence shows that activation of the autonomic nervous system influences ventricular repolarization and, therefore, the QT interval on the ECG. To test the hypothesis that the QT interval is abnormal in autonomic dysfunction, we examined ECGs in patients with severe primary autonomic failure and in patients with congenital dopamine beta-hydroxylase (DbetaH) deficiency who are unable to synthesize norepinephrine and epinephrine. SUBJECTS AND METHODS Maximal QT and rate-corrected QT (QTc) intervals and adjusted QTc dispersion [(maximal QTc - minimum QTc on 12 lead ECG)/square root of the number of leads measured] were determined in blinded fashion from ECGs of 67 patients with primary autonomic failure (36 patients with multiple system atrophy [MSA], and 31 patients with pure autonomic failure [PAF]) and 17 age- and sex-matched healthy controls. ECGs of 5 patients with congenital DbetaH deficiency and 6 age- and sex-matched controls were also analyzed. RESULTS Patients with MSA and PAF had significantly prolonged maximum QTc intervals (492+/-58 ms(1/2) and 502+/-61 ms(1/2) [mean +/- SD]), respectively, compared with controls (450+/-18 ms(1/2), P < .05 and P < .01, respectively). A similar but not significant trend was observed for QT. QTc dispersion was also increased in MSA (40+/-20 ms(1/2), P < .05 vs controls) and PAF patients (32+/-19 ms(1/2), NS) compared with controls (21+/-5 ms(1/2)). In contrast, patients with congenital DbetaH deficiency did not have significantly different RR, QT, QTc intervals, or QTc dispersion when compared with controls. CONCLUSIONS Patients with primary autonomic failure who have combined parasympathetic and sympathetic failure have abnormally prolonged QT interval and increased QT dispersion. However, QT interval in patients with congenital DbetaH deficiency was not significantly different from controls. It is possible, therefore, that QT abnormalities in patients with primary autonomic failure are not solely caused by lesions of the sympathetic nervous system, and that the parasympathetic nervous system is likely to have a modulatory role in ventricular repolarization.
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Affiliation(s)
- A M Choy
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tenn 37232-2195, USA
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Sarubbi B, Ducceschi V, Briglia N, Mayer MS, Santangelo L, Iacono A. Compared effects of sotalol, flecainide and propafenone on ventricular repolarization in patients free of underlying structural heart disease. Int J Cardiol 1998; 66:157-64. [PMID: 9829329 DOI: 10.1016/s0167-5273(98)00201-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Antiarrhythmic drugs are known to affect the depolarization and repolarization time in a different fashion. The aim of the present study was to compare the effects of Sotalol, Flecainide and Propafenone on some common (QT, QTc, JT, JTc) or uncommon (QTc dispersion, T-peak to T-end interval) electrocardiographic parameters in order to evaluate the effects of these antiarrhythmic drugs on ventricular repolarization time both in terms of absolute values and of dispersion across the myocardium. The analysis of these antiarrhythmic drug effects was performed on the standard 12-lead electrocardiograms of 31 patients (17F and 14M, age 38.1+/-17 years, range 11-67 years) in the free-drug state and at the steady state after oral treatment with Sotalol (160 mg daily), Flecainide (200 mg daily) and Propafenone (450 mg daily). These drugs were prescribed, separately, to all the 31 patients, free of underlying structural heart disease, for the treatment of their atrio-ventricular nodal re-entry tachycardia. Data of the present study show that Sotalol, over the range prescribed, significantly prolongs ventricular repolarization index QT (P=0.001), JT (P=0.0001) and JTc (P=0.0001) values in an homogeneous fashion, as shown by the significant decrease in QTcD (P=0.019) and Tp-Te (P=0.01). On the contrary, Flecainide treatment was associated with an increase in QTcD (P=0.029), Tp-Te (0.0001), QT (P=0.001), QTc (P=0.0001) and QRS (P=0.0001), with no significant changes in JT and JTc. Propafenone, over the range prescribed, did not affect repolarization time, resulting only in a prolongation of depolarization time as expressed by the increase of QRS (P=0.0001).
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Affiliation(s)
- B Sarubbi
- Seconda Università degli Studi di Napoli, Facoltà di Medicina e Chirurgia, Istituto Medico Chirurgico di Cardiologia, Cattedra di Cardiologia, Italy
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Weston PJ, Glancy JM, McNally PG, Thurston H, de Bono DP. Can abnormalities of ventricular repolarisation identify insulin dependent diabetic patients at risk of sudden cardiac death? Heart 1997; 78:56-60. [PMID: 9290403 PMCID: PMC484865 DOI: 10.1136/hrt.78.1.56] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
OBJECTIVE To study the possible association or QT dispersion and mean QTc intervals, as measured from standard 12 lead electrocardiograms, with baroreceptor-cardiac reflex sensitivity (BRS) in insulin dependent diabetic patients. DESIGN Comparative study of non-invasive assessment of BRS, QT interval, and QT dispersion. SETTING Large teaching hospital. SUBJECTS 31 young asymptomatic, normotensive, insulin dependent diabetic patients, aged 20-55 years with normal clinical autonomic function. METHODS QT intervals and QT dispersion were measured by a single observer blinded to other data about the patients. BRS was measured after activating the baroreflex with a Valsalva manoeuvre, and the rate in change of R-R interval to increasing systolic pressure during phase 4 was measured; in addition sequence analysis of resting systolic blood pressure and heart rate was performed during standing. The alpha coefficient--an index of the overall gain of the baroreflex mechanisms--was estimated from spectral analysis data of systolic blood pressure and pulse interval variability. RESULTS Mean (SD) QTc interval was 406 (23) ms, QT dispersion was 44 (13) ms. There was no association between QT dispersion and any measurement of BRS. There was a negative correlation between mean QTc intervals and sequence analysis BRS (r = -0.355, P = 0.049), but no association with Valsalva BRS. The alpha coefficient, showed a significant negative correlation with mean QTc (r = -0.42, P = 0.008). CONCLUSIONS Abnormal BRS may be reflected in the heart by global prolongation of ventricular repolarisation, but not by dispersion of ventricular repolarisation. This may, in part, explain the increase in sudden cardiac death seen in IDDM patients.
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Affiliation(s)
- P J Weston
- Department of Medicine and Therapeutics, University of Leicester, United Kingdom
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