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ECG-Based Identification of Sudden Cardiac Death through Sparse Representations. SENSORS 2021; 21:s21227666. [PMID: 34833740 PMCID: PMC8622957 DOI: 10.3390/s21227666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 02/01/2023]
Abstract
Sudden Cardiac Death (SCD) is an unexpected sudden death due to a loss of heart function and represents more than 50% of the deaths from cardiovascular diseases. Since cardiovascular problems change the features in the electrical signal of the heart, if significant changes are found with respect to a reference signal (healthy), then it is possible to indicate in advance a possible SCD occurrence. This work proposes SCD identification using Electrocardiogram (ECG) signals and a sparse representation technique. Moreover, the use of fixed feature ranking is avoided by considering a dictionary as a flexible set of features where each sparse representation could be seen as a dynamic feature extraction process. In this way, the involved features may differ within the dictionary's margin of similarity, which is better-suited to the large number of variations that an ECG signal contains. The experiments were carried out using the ECG signals from the MIT/BIH-SCDH and the MIT/BIH-NSR databases. The results show that it is possible to achieve a detection 30 min before the SCD event occurs, reaching an an accuracy of 95.3% under the common scheme, and 80.5% under the proposed multi-class scheme, thus being suitable for detecting a SCD episode in advance.
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Blesius V, Schölzel C, Ernst G, Dominik A. HRT assessment reviewed: a systematic review of heart rate turbulence methodology. Physiol Meas 2020; 41:08TR01. [PMID: 32485688 DOI: 10.1088/1361-6579/ab98b3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Heart rate turbulence (HRT) is a biphasic reaction to a ventricular premature contraction (VPC) mainly mediated by the baroreflex. It can be used for risk stratification in different disease patterns. Despite existing standards there is a lot of variation in terms of measuring and calculating HRT, which complicates research and application. OBJECTIVE This systematic review outlines and evaluates the methodological spectrum of HRT research, especially filtering criteria, parameter calculation and thresholds. APPROACH The analysis includes all research papers written in English that have been published before 12.10.2018, are listed on PubMed and involve calculation of HRT parameter values. MAIN RESULTS HRT assessment is still being performed in various ways and important specifications of the methodology are not given in many articles. Nevertheless, some suggestions regarding HRT methodology can be made: a normalised turbulence slope should be used to uncouple the parameter from heart rate and frequency of extrasystoles. Filtering criteria as formerly reviewed in the guidelines should be met and mentioned. The minimal number of VPC snippets (VPCSs) as well as new cut-off values for different risks need to be further evaluated. Most importantly, the exact and complete methodology must be described to ensure reproducibility and comparability. SIGNIFICANCE Methodical variation hinders comparability of research and medical application. Our continuing questions help to further standardise the measurement and calculation of HRT and increase its value for medical risk stratification.
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Disertori M, Masè M, Rigoni M, Nollo G, Ravelli F. Heart Rate Turbulence Is a Powerful Predictor of Cardiac Death and Ventricular Arrhythmias in Postmyocardial Infarction and Heart Failure Patients: A Systematic Review and Meta-Analysis. Circ Arrhythm Electrophysiol 2016; 9:e004610. [PMID: 27879279 DOI: 10.1161/circep.116.004610] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 11/01/2016] [Indexed: 11/16/2022]
Abstract
BACKGROUND Heart rate turbulence (HRT) has been proposed as a candidate marker of altered autonomic tone, and some studies showed its prognostic value for both cardiac death (CD) and sudden death. Nevertheless, HRT is not currently used in the clinical practice. METHODS AND RESULTS We performed a systematic review and meta-analysis of the predictive value of HRT for the end points of total mortality, CD, and fatal and nonfatal ventricular arrhythmias in postacute myocardial infarction and heart failure patients. MEDLINE and The Cochrane Library databases were systematically searched to identify studies, which analyzed the predictive value of abnormal HRT for the defined end points. Twenty studies (25 cohorts: 12 832 patients) were identified by the systematic review, and 15 studies (20 cohorts: 11 499 patients) were included in the meta-analyses. Abnormal HRT was a predictive marker for all the end points in heart failure patients and more markedly in postacute myocardial infarction patients, where 9 out of the 10 cohorts had an ejection fraction >30%. In postacute myocardial infarction patients, HRT had pooled risk ratios of 3.53 (95% confidence interval [CI], 2.54-4.90), 4.82 (95% CI, 3.12-7.45), and 4.48 (95% CI, 3.04-6.60), and positive likelihood ratios of 3.5 (95% CI, 2.6-4.8), 4.1 (95% CI, 3.0-5.7), and 2.7 (95% CI, 2.2-3.3) for total mortality, CD, and arrhythmic events, respectively. The combination of abnormal HRT and T-wave alternans (5 cohorts: 1516 patients) increased the predictive power for CD and arrhythmic events. CONCLUSIONS HRT is a powerful predictor of both CD and arrhythmic events, particularly in postacute myocardial infarction patients with ejection fraction >30%. HRT power increases in combination with T-wave alternans analysis.
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Affiliation(s)
- Marcello Disertori
- From the Healthcare Research and Innovation Program, PAT-FBK, Trento, Italy (M.D., M.R., G.N.); Department of Cardiology, Santa Chiara Hospital, Trento, Italy (M.D.); and Department of Physics, University of Trento, Italy (M.M., F.R.).
| | - Michela Masè
- From the Healthcare Research and Innovation Program, PAT-FBK, Trento, Italy (M.D., M.R., G.N.); Department of Cardiology, Santa Chiara Hospital, Trento, Italy (M.D.); and Department of Physics, University of Trento, Italy (M.M., F.R.)
| | - Marta Rigoni
- From the Healthcare Research and Innovation Program, PAT-FBK, Trento, Italy (M.D., M.R., G.N.); Department of Cardiology, Santa Chiara Hospital, Trento, Italy (M.D.); and Department of Physics, University of Trento, Italy (M.M., F.R.)
| | - Giandomenico Nollo
- From the Healthcare Research and Innovation Program, PAT-FBK, Trento, Italy (M.D., M.R., G.N.); Department of Cardiology, Santa Chiara Hospital, Trento, Italy (M.D.); and Department of Physics, University of Trento, Italy (M.M., F.R.)
| | - Flavia Ravelli
- From the Healthcare Research and Innovation Program, PAT-FBK, Trento, Italy (M.D., M.R., G.N.); Department of Cardiology, Santa Chiara Hospital, Trento, Italy (M.D.); and Department of Physics, University of Trento, Italy (M.M., F.R.)
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Sassi R, Cerutti S, Lombardi F, Malik M, Huikuri HV, Peng CK, Schmidt G, Yamamoto Y. Advances in heart rate variability signal analysis: joint position statement by the e-Cardiology ESC Working Group and the European Heart Rhythm Association co-endorsed by the Asia Pacific Heart Rhythm Society. Europace 2015; 17:1341-53. [PMID: 26177817 DOI: 10.1093/europace/euv015] [Citation(s) in RCA: 379] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 01/13/2015] [Indexed: 12/18/2022] Open
Abstract
Following the publication of the Task Force document on heart rate variability (HRV) in 1996, a number of articles have been published to describe new HRV methodologies and their application in different physiological and clinical studies. This document presents a critical review of the new methods. A particular attention has been paid to methodologies that have not been reported in the 1996 standardization document but have been more recently tested in sufficiently sized populations. The following methods were considered: Long-range correlation and fractal analysis; Short-term complexity; Entropy and regularity; and Nonlinear dynamical systems and chaotic behaviour. For each of these methods, technical aspects, clinical achievements, and suggestions for clinical application were reviewed. While the novel approaches have contributed in the technical understanding of the signal character of HRV, their success in developing new clinical tools, such as those for the identification of high-risk patients, has been rather limited. Available results obtained in selected populations of patients by specialized laboratories are nevertheless of interest but new prospective studies are needed. The investigation of new parameters, descriptive of the complex regulation mechanisms of heart rate, has to be encouraged because not all information in the HRV signal is captured by traditional methods. The new technologies thus could provide after proper validation, additional physiological, and clinical meaning. Multidisciplinary dialogue and specialized courses in the combination of clinical cardiology and complex signal processing methods seem warranted for further advances in studies of cardiac oscillations and in the understanding normal and abnormal cardiac control processes.
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Acharya UR, Fujita H, Sudarshan VK, Sree VS, Eugene LWJ, Ghista DN, Tan RS. An integrated index for detection of Sudden Cardiac Death using Discrete Wavelet Transform and nonlinear features. Knowl Based Syst 2015. [DOI: 10.1016/j.knosys.2015.03.015] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Heart rate turbulence (HRT) is a baroreflex-mediated biphasic reaction of heart rate in response to premature ventricular beats. Heart rate turbulence is quantified by: turbulence onset (TO) reflecting the initial acceleration of heart rate following premature beat and turbulence slope (TS) describing subsequent deceleration of heart rate. Abnormal HRT identifies patients with autonomic dysfunction or impaired baroreflex sensitivity due to variety of disorders, but also may reflect changes in autonomic nervous system induced by different therapeutic modalities such as drugs, revascularization, or cardiac resynchronization therapy. More importantly, impaired HRT has been shown to identify patients at high risk of all-cause mortality and sudden death, particularly in postinfarction and congestive heart failure patients. It should be emphasized that abnormal HRT has a well-established role in stratification of postinfarction and heart failure patients with relatively preserved left ventricular ejection fraction. The ongoing clinical trials will document whether HRT can be used to guide implantation of cardioverter-defibrillators in this subset of patients, not covered yet by ICD guidelines. This review focuses on the current state-of-the-art knowledge regarding clinical significance of HRT in detection of autonomic dysfunction and regarding the prognostic significance of this parameter in predicting all-cause mortality and sudden death.
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Affiliation(s)
- Iwona Cygankiewicz
- Department of Electrocardiology, Medical University of Lodz, Sterling Regional Center for Heart Diseases, 91-425 Lodz, Poland.
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ALBARWANI S, AL-SIYABI S, TANIRA MO. Lisinopril Indifferently Improves Heart Rate Variability During Day and Night Periods in Spontaneously Hypertensive Rats. Physiol Res 2013; 62:237-45. [DOI: 10.33549/physiolres.932425] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The aim of this work was to investigate the effect of 10 weeks of lisinopril treatment to spontaneously hypertensive rats (SHRs) on day/night variations of blood pressure, heart rate and autonomic cardio-regulation parameters. Male SHR with surgically implanted radio-telemetry implant that provided direct measurements of arterial pressure and electrocardiogram wave were used. Animals were allocated to two groups (n=5 each). The first group was treated with lisinopril (20 mg/kg by gavage) daily for 10 weeks (treated group); whereas the second was gavaged daily with tap water (untreated group). Arterial blood pressure, ECG and other telemetry parameters were recorded at the start and at the end of 10-week treatment. Collected data were analyzed using specialized software and were statistically tested. In addition to the expected lowering of blood pressure, spectral analysis of R-R intervals revealed that lisinopril treatment for 10 weeks significantly caused 2-3 fold increase in heart rate variability (HRV) during both active and inactive periods. However, R-R interval durations demonstrated variable distribution patterns during those periods. The cause of observed distribution pattern of R-R intervals during active and inactive periods may be of significance to better understand HRV changes and warrants further investigations.
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Affiliation(s)
- S. ALBARWANI
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman
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VOSS ANDREAS, GOERNIG MATTHIAS, SCHROEDER RICO, TRUEBNER SANDRA, SCHIRDEWAN ALEXANDER, FIGULLA HANSR. Blood Pressure Variability as Sign of Autonomic Imbalance in Patients with Idiopathic Dilated Cardiomyopathy. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2012; 35:471-9. [DOI: 10.1111/j.1540-8159.2011.03312.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zuern CS, Barthel P, Bauer A. Heart rate turbulence as risk-predictor after myocardial infarction. Front Physiol 2011; 2:99. [PMID: 22180744 PMCID: PMC3238051 DOI: 10.3389/fphys.2011.00099] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 11/24/2011] [Indexed: 01/16/2023] Open
Abstract
Heart rate turbulence (HRT) is the baroreflex-mediated short-term oscillation of cardiac cycle lengths after spontaneous ventricular premature complexes. HRT is composed of a brief heart rate acceleration followed by a gradual heart rate deceleration. In high risk patients after myocardial infarction (MI) HRT is blunted or diminished. Since its first description in 1999 HRT emerged as one of the most potent risk factors after MI. Predictive power of HRT has been studied in more than 10,000 post-infarction patients. This review is intended to provide an overview of HRT as risk-predictor after MI.
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Affiliation(s)
- Christine S. Zuern
- Innere Medizin III (Kardiologie), Eberhard-Karls-Universität TübingenTübingen, Germany
| | - Petra Barthel
- Medizinische Klinik, Technische Universität München UniversityMünchen, Germany
| | - Axel Bauer
- Innere Medizin III (Kardiologie), Eberhard-Karls-Universität TübingenTübingen, Germany
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Poliwczak AR, Białkowska J, Broncel M, Koziróg M, Dworniak K, Kotecka K, Jabłkowski M. Heart rhythm turbulence and NT-proBNP in decompensated liver cirrhosis--a pilot study. Med Sci Monit 2011; 17:PR5-11. [PMID: 21629202 PMCID: PMC3539552 DOI: 10.12659/msm.881788] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 02/23/2011] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Heart rhythm turbulence (HRT) is a novel tool for evaluation of cardiovascular mortality. Liver cirrhosis is associated with hemodynamic and myocardial disturbances termed cirrhotic cardiomyopathy. In the stable stage of liver cirrhosis, systolic and myocardial dysfunction is correlated with brain natriuretic peptide (BNP). The aim was to evaluate HRT and its correlation with NT-proBNP, echocardiographic and biochemical parameters in patients with decompensation of liver cirrhosis. MATERIAL/METHODS The study included 18 patients with decompensated liver cirrhosis and 18 healthy volunteers. Participants underwent echocardiography and 24-hour ECG monitoring. Serum NT-proBNP and other biochemical parameters were measured. Turbulence onset (TO) and turbulence slope (TS) were used to indicate HRT. RESULTS Mean HR (87/min vs. 75/min), TO (-0.385% vs. -0.92%), NT-proBNP (304.85 pg/ml vs. 83.2 pg/ml), LAd (42.5 mm vs. 34.5 mm), RVdd (29.5 mm vs. 25 mm), SPAP (36.5 mmHg vs. 22.5 mmHg) were significantly (p<0.05) higher in patients with liver cirrhosis. Patients with normal TO and TS had better stage in Child-Pugh classification (P=0.04) than patients with abnormal values. Significant negative correlation was found between creatinine and TO, and between mean HR and TS, and significant positive correlation was found between LAd and TS. LV diastolic dysfunction was noted in a majority of cirrhotic patients (n=16). CONCLUSIONS Patients with decompensated cirrhosis had elevated levels of NT-proBNP and LV diastolic dysfunction. TO values in cirrhotic patients differed significantly from the control group. These findings can indicate risk of symptomatic heart failure development and may be a marker of cirrhotic cardiomyopathy. HRT parameters seem not to be appropriate death predicators.
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Affiliation(s)
- Adam Rafał Poliwczak
- Department of Internal Diseases and Clinical Pharmacology, Medical University of Lodz, Lodz, Poland.
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Bauer A, Zürn CS, Schmidt G. Heart Rate Turbulence to Guide Treatment for Prevention of Sudden Death. J Cardiovasc Pharmacol 2010; 55:531-8. [DOI: 10.1097/fjc.0b013e3181d4c973] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Bauer A, Malik M, Schmidt G, Barthel P, Bonnemeier H, Cygankiewicz I, Guzik P, Lombardi F, Müller A, Oto A, Schneider R, Watanabe M, Wichterle D, Zareba W. Heart rate turbulence: standards of measurement, physiological interpretation, and clinical use: International Society for Holter and Noninvasive Electrophysiology Consensus. J Am Coll Cardiol 2008; 52:1353-65. [PMID: 18940523 DOI: 10.1016/j.jacc.2008.07.041] [Citation(s) in RCA: 260] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 06/18/2008] [Accepted: 07/10/2008] [Indexed: 01/09/2023]
Abstract
This consensus statement has been compiled on behalf of the International Society for Holter and Noninvasive Electrophysiology. It reviews the topic of heart rate turbulence (HRT) and concentrates on technologies for measurement, physiologic background and interpretation, and clinical use of HRT. It also lists suggestions for future research. The phenomenon of HRT refers to sinus rhythm cycle-length perturbations after isolated premature ventricular complexes. The physiologic pattern of HRT consists of brief heart rate acceleration (quantified by the so-called turbulence onset) followed by more gradual heart rate deceleration (quantified by the so-called turbulence slope) before the rate returns to a pre-ectopic level. Available physiologic investigations confirm that the initial heart rate acceleration is triggered by transient vagal inhibition in response to the missed baroreflex afferent input caused by hemodynamically inefficient ventricular contraction. A sympathetically mediated overshoot of arterial pressure is responsible for the subsequent heart rate deceleration through vagal recruitment. Hence, the HRT pattern is blunted in patients with reduced baroreflex. The HRT pattern is influenced by a number of factors, provocations, treatments, and pathologies reviewed in this consensus. As HRT measurement provides an indirect assessment of baroreflex, it is useful in those clinical situations that benefit from baroreflex evaluation. The HRT evaluation has thus been found appropriate in risk stratification after acute myocardial infarction, risk prediction, and monitoring of disease progression in heart failure, as well as in several other pathologies.
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Affiliation(s)
- Axel Bauer
- Deutsches Herzzentrum, Medizinische Klinik der Technischen Universität München, Munich, Germany
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Rojo-Alvarez JL, Barquero-Pérez O, Mora-Jiménez I, Everss E, Rodríguez-González AB, García-Alberola A. Heart rate turbulence denoising using support vector machines. IEEE Trans Biomed Eng 2008; 56:310-9. [PMID: 19272942 DOI: 10.1109/tbme.2008.2003146] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Heart rate turbulence (HRT) is a transient acceleration and subsequent deceleration of the heart rate after a premature ventricular complex (PVC), and it has been shown to be a strong risk stratification criterion in patients with cardiac disease. In order to reduce the noise level of the HRT signal, conventional measurements of HRT use a patient-averaged template of post-PVC tachogram (PPT), hence providing with long-term HRT indexes. We hypothesize that the reduction of the noise level at each isolated PPT, using signal processing techniques, will allow us to estimate short-term HRT indexes. Accordingly, its application could be extended to patients with reduced number of available PPT. In this paper, several HRT denoising procedures are proposed and tested, with special attention to support vector machine (SVM) estimation, as this is a robust algorithm that allows us to deal with few available time samples in the PPT. Pacing-stimulated HRT during electrophysiological study are used as a low-noise gold standard. Measurements in a 24-h Holter patient database reveal a significant reduction in the bias and the variance of HRT measurements. We conclude that SVM denoising yields short-term HRT measurements and improves the signal-to-noise level of long-term HRT measurements.
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Affiliation(s)
- José Luis Rojo-Alvarez
- Department of Signal Theory and Communications, University Rey Juan Carlos, 28943 Madrid, Spain.
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Watanabe MA, Alford M, Schneider R, Bauer A, Barthel P, Stein PK, Schmidt G. Demonstration of circadian rhythm in heart rate turbulence using novel application of correlator functions. Heart Rhythm 2007; 4:292-300. [PMID: 17341391 DOI: 10.1016/j.hrthm.2006.11.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 11/09/2006] [Indexed: 10/23/2022]
Abstract
BACKGROUND Demonstration of a circadian rhythm in two parameters of heart rate turbulence--turbulence onset (TO) and turbulence slope (TS)--has been difficult. OBJECTIVE The aim of this study was to devise a new method for detecting circadian rhythm in noisy data and to apply it to selected Holter recordings from two postmyocardial infarction databases: Cardiac Arrhythmia Suppression Trial (CAST, n = 684) and Innovative Stratification of Arrhythmic Risk (ISAR, n = 327). METHODS For each patient, TS and TO were calculated for each hour with >4 ventricular premature contractions (VPCs). An autocorrelation function Corr(Deltat) = <TS(t) TS(t + Deltat)> then was calculated and averaged over all patients. Positive Corr(Deltat) indicates that TS at a given hour and Deltat hours later are similar. TO was treated likewise. Simulations and mathematical analysis showed that a circadian rhythm required Corr(Deltat) to have a U-shape consisting of positive values near Deltat = 0 and 23 and negative values for intermediate Deltat. Significant deviation of Corr(Deltat) from the correlator function of pure noise was evaluated as a Chi-square value. RESULTS Circadian patterns were not apparent in hourly averages of TS and TO plotted against clock time, which had large error bars. However, their correlator functions produced Chi-square values of approximately 10 in CAST (both P <.0001) and approximately 3 in ISAR (both P <.0001), indicating the presence of circadian rhythmicity. CONCLUSION Correlator functions may be a powerful tool for detecting the presence of circadian rhythms in noisy data, even with recordings limited to 24 hours.
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Affiliation(s)
- Mari A Watanabe
- Department of Internal Medicine, St. Louis University, St. Louis, Missouri 63110, USA.
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Truebner S, Cygankiewicz I, Schroeder R, Baumert M, Vallverdú M, Caminal P, Vazquez R, Bayés de Luna A, Voss A. Compression entropy contributes to risk stratification in patients with cardiomyopathy / Kompressionsentropie zur verbesserten Risikostratifizierung bei Patienten mit DCM. BIOMED ENG-BIOMED TE 2006; 51:77-82. [PMID: 16915769 DOI: 10.1515/bmt.2006.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Sudden cardiac death (SCD) is a leading cause of mortality with an incidence of 3 million cases per year worldwide. Therapies for patients who have survived an SCD episode or have a high risk of developing lethal ventricular arrhythmia are well established and depend mainly on risk stratification. In this study we investigated the suitability of the non-linear measure compression entropy (Hc) for improved risk prediction in cardiac patients. We recorded 24-h Holter ECG for 300 patients with congestive heart failure (CHF). During a mean follow-up period of 12 months, 32 patients died due to a cardiac event. Hc depends on the compression parameters window length w and buffer length b, which were optimised by analysing a subgroup of patients. Compression entropies based on the beat-to-beat interval (BBI) were subsequently calculated and compared with standard heartrate variability parameters. Statistical analysis revealed significant differences between high- and low-risk CHF patients in standard HRV measures, as well as compression entropy based on the BBI (cardiac death, p = 0.005; SCD, p = 0.02). In conclusion, the implementation of non-linear compression entropy analysis in multivariate analysis seems to be useful for enhanced risk stratification of cardiac death, especially SCD, in ischaemic cardiomyopathy patients.
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Affiliation(s)
- Sandra Truebner
- Department of Medical Engineering, University of Applied Sciences Jena, Jena, Germany
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Palatini P, Benetos A, Grassi G, Julius S, Kjeldsen SE, Mancia G, Narkiewicz K, Parati G, Pessina AC, Ruilope LM, Zanchetti A. Identification and management of the hypertensive patient with elevated heart rate: statement of a European Society of Hypertension Consensus Meeting. J Hypertens 2006; 24:603-10. [PMID: 16531784 DOI: 10.1097/01.hjh.0000217838.49842.1e] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Paolo Palatini
- Department of Clinical and Experimental Medicine, University of Padova, Padua, Italy.
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Francis J, Watanabe MA, Schmidt G. Heart rate turbulence: a new predictor for risk of sudden cardiac death. Ann Noninvasive Electrocardiol 2005; 10:102-9. [PMID: 15649245 PMCID: PMC6932040 DOI: 10.1111/j.1542-474x.2005.10102.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Initial acceleration and a subsequent deceleration of sinus rhythm following a ventricular ectopic beat with a compensatory pause has been termed heart rate turbulence (HRT). The changes in sinus rhythm are thought to be mediated by a baroreflex response to the lower stroke volume of the ectopic beat. HRT is vagally mediated and abolished by atropine, whereas beta-blockers have no effect. HRT has been shown to be an independent and powerful predictor of mortality after myocardial infarction. In patients on beta-blockers, it scores better than left ventricular ejection fraction (LVEF) in its predictive value. Two common measures of HRT are turbulence onset and turbulence slope. When both these measures are abnormal, it is as powerful a predictor of mortality as LVEF. HRT correlates with other indices of cardiac autonomic functions like baroreflex sensitivity and heart rate variability. A composite autonomic index including all these three has been shown to be a powerful predictor of mortality. In patients undergoing direct percutaneous intervention for myocardial infarction, HRT improves in those attaining successful reperfusion. Abnormal values for HRT have been noted in patients with dilated cardiomyopathy and Chagas disease. Diabetic and elderly individuals are more likely to have blunted HRT. HRT cannot be measured in patients lacking ventricular ectopic beats and in patients presenting with atrial fibrillation.
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Affiliation(s)
| | - Mari A. Watanabe
- Department of Pharmacological and Physiological Science, St. Louis University, St. Louis, MO
| | - Georg Schmidt
- 1. Medizinische Klinik der Technischen Universität München, München, Germany
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