Optimal Target Heart Rate for Exercise‐Induced T‐Wave Alternans

Turitto, Gioia; Caref, Edward B.; El-Attar, Gamal; Helal, Magda; Mohamed, Amina; Pedalino, Ronald; El‐Sherif, Nabil

doi:10.1111/j.1542-474x.2001.tb00096.x

Cited by 34 publications

(20 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because the Spectral Method involves a graded increase in heart rate, the TWA test is usually conducted during bicycle or treadmill exercise to an optimum heart rate (79). Some investigators infused chronotropic agents (21,24) or employed atrial pacing to elevate and stabilize heart rate (23,56,80–82).…”

Section: Methodology For Twa Assessmentmentioning

confidence: 99%

Microvolt T-Wave Alternans

Verrier

Klingenheben

Malík

et al. 2011

Journal of the American College of Cardiology

Self Cite

377

141

View full text Add to dashboard Cite

This consensus guideline was prepared on behalf of the International Society for Holter and Noninvasive Electrocardiology and is cosponsored by the Japanese Circulation Society, the Computers in Cardiology Working Group on e-Cardiology of the European Society of Cardiology, and the European Cardiac Arrhythmia Society. It discusses the electrocardiographic phenomenon of T-wave alternans (TWA) (i.e., a beat-to-beat alternation in the morphology and amplitude of the ST- segment or T-wave). This statement focuses on its physiological basis and measurement technologies and its clinical utility in stratifying risk for life-threatening ventricular arrhythmias. Signal processing techniques including the frequency-domain Spectral Method and the time-domain Modified Moving Average method have demonstrated the utility of TWA in arrhythmia risk stratification in prospective studies in >12,000 patients. The majority of exercise-based studies using both methods have reported high relative risks for cardiovascular mortality and for sudden cardiac death in patients with preserved as well as depressed left ventricular ejection fraction. Studies with ambulatory electrocardiogram-based TWA analysis with Modified Moving Average method have yielded significant predictive capacity. However, negative studies with the Spectral Method have also appeared, including 2 interventional studies in patients with implantable defibrillators. Meta-analyses have been performed to gain insights into this issue. Frontiers of TWA research include use in arrhythmia risk stratification of individuals with preserved ejection fraction, improvements in predictivity with quantitative analysis, and utility in guiding medical as well as device-based therapy. Overall, although TWA appears to be a useful marker of risk for arrhythmic and cardiovascular death, there is as yet no definitive evidence that it can guide therapy.

show abstract

Section: Methodology For Twa Assessmentmentioning

confidence: 99%

Microvolt T-Wave Alternans

Verrier

Klingenheben

Malík

et al. 2011

Journal of the American College of Cardiology

Self Cite

377

141

View full text Add to dashboard Cite

show abstract

“…The TWA phenomenon is partially related to heart rate, and can appear in healthy subjects at fast heart rates. 7,27 Therefore, only the initial fragment in which the heart rhythm was <100 bpm was selected from each record. These fragments were then divided into segments of 32 consecutive beats, resulting in a total of 1744 ECG segments.…”

Section: Real Signals With Added Twamentioning

confidence: 99%

A Multilead Scheme Based on Periodic Component Analysis for T-Wave Alternans Analysis in the ECG

et al. 2010

View full text Add to dashboard Cite

Abstract-T-wave alternans (TWA) is a cardiac phenomenon that appears in the electrocardiogram (ECG) and is associated with the mechanisms leading to sudden cardiac death (SCD). In this study, we propose the use of a multilead TWA analysis scheme that combines the Laplacian likelihood ratio (LLR) method and periodic component analysis (pCA), an eigenvalue decomposition technique whose aim is to extract the most periodic sources of the signal. The proposed scheme is evaluated in different scenarios-from synthetic signals to stress test ECGs-and is compared to other reported schemes based on the LLR method. Results demonstrate that the pCA-based scheme provides a superior ability to detect TWA than previously reported schemes, and has the potential to improve the prognostic value of testing for TWA.

show abstract

“…More specifically, RA has been associated with an increased risk for malignant ventricular arrhythmias and sudden cardiac death (SCD) across a wide range of pathophysiological conditions including both ischemic and non-ischemic congestive heart failure with impaired left ventricle ejection fraction (LVEF) and recent myocardial infarction (MI) 2, 3 . Cardiac alternans can also be produced in structurally normal hearts under conditions of chronotropic stimulation 4, 5 or significant metabolic stress 6 .…”

Section: Introductionmentioning

confidence: 99%