Importance of regional specificity of T-wave alternans in assessing risk for cardiovascular mortality and sudden cardiac death during routine exercise testing

Leino, Johanna; Verrier, Richard L.; Minkkinen, Mikko; Lehtimäki, Terho; Viik, Jari; Lehtinen, Rami; Nikus, Kjell; Kööbi, Tiit; Turjanmaa, Väinö; Kähönen, Mika; Nieminen, Tuomo

doi:10.1016/j.hrthm.2010.11.004

Cited by 30 publications

(25 citation statements)

References 31 publications

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“…[13] However, we have computed TWA value across the entire T wave, which might introduce a dilution effect and might explain the small TWA values observed in this study. Moreover, previous studies have shown that TWA shows regional distribution among different precordial leads, with the maximum TWA monitored from the anterolateral precordial lead V5 [19]. In this study, we found that the maximum TWA was most frequently observed in the anterolateral precordial lead V4.…”

Section: Discussionsupporting

confidence: 60%

Evaluation of beat-to-beat ventricular repolarization lability from standard 12‐lead ECG during acute myocardial ischemia

Al‐Zaiti

Alrawashdeh

Martin‐Gill

et al. 2017

Journal of Electrocardiology

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Background Acute myocardial ischemia is a common cause of ventricular arrhythmias, yet recent ECG methods predicting susceptibility to ventricular tachyarrhythmia have not been fully evaluated during spontaneous ischemia. We sought to evaluate the clinical utility of alternans and non-alternans components of repolarization variability from the standard 10-second 12-lead ECG signals to risk stratify patients with acute chest pain. Methods We enrolled consecutive, non-traumatic, chest pain patients transported through Emergency Medical Services (EMS) to three tertiary care hospitals with cardiac catheterization lab capabilities in Pittsburgh, PA. ECG signals were manually annotated by an electrophysiologist, then automatically processed using a custom-written software. Both T wave alternans (TWA) and non-alternans repolarization variability (NARV) were calculated using the absolute RMS differences over the repolarization window between odd/even averaged beats and between consecutive averaged pairs, respectively. The primary study outcome was the presence of acute myocardial infarction (AMI) documented by cardiac angiography. Results After excluding patients with secondary repolarization changes (n=123) and those with excessive noise (n=90), our final sample included 537 patients (age 57±16 years, 56% males). Patients with AMI (n=47, 9%) had higher TWA and NARV values (p<0.01). Mean RR correlated with TWA, and noise measures correlated with TWA and NARV, after adjusting for potential confounders. There was a high collinearity between TWA and NARV, and each was separately predictive of AMI after controlling for number of analyzed beats, noise measures, and other clinical variables. Conclusions Despite limitations imposed by signal quality, TWA and NARV are higher in patients with AMI, even after correction for potential confounders. The clinical value of TWA and NARV derived from standard ECG using our time-domain RMS method is questionable due to small number of beats and significant noise.

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Section: Discussionsupporting

confidence: 60%

Evaluation of beat-to-beat ventricular repolarization lability from standard 12‐lead ECG during acute myocardial ischemia

Al‐Zaiti

Alrawashdeh

Martin‐Gill

et al. 2017

Journal of Electrocardiology

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“…Predictivity of TWA analysis by the MMA method has been demonstrated in >4,800 patients, including those with coronary artery disease, recent or old myocardial infarction, congestive heart failure, or cardiomyopathy (23). In FINCAVAS (Finnish Cardiovascular Study), the largest investigation of TWA to date, TWA predicted sudden cardiac death and cardiovascular and total mortality in a general population of >3.500 low-risk patients referred for routine, symptom-limited exercise testing (23)(24)(25). REFINE study done by Exner et al (26) demonstrated that MMA TWA may predict adverse events in post-MI patiets with moderately depressed left ventricular functions.…”

Section: Discussionmentioning

confidence: 99%

No association between scar size and characteristics on T-wave alternans in post-myocardial infarction patients with relatively preserved ventricular function presented with nonsustained ventricular tachycardia

Yalın

Gölcük²,

Teker³

et al. 2014

Anadolu Kardiyol Derg

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Objective: Microvolt T-wave Alternans (TWA) is associated with abnormal repolarization and predicts arrhythmic mortality in patients with previous myocardial infarction (MI). Infarct tissue size and heterogeneity characterized by cardiac magnetic resonance (CMR) has been shown to be associated with arrhythmogenic substrates and sudden cardiac death. Although both delayed enhancement-CMR (de-CMR) and TWA are useful in risk stratification of post-MI patients with preserved left ventricular function, the relationship between scar size and TWA has not studied yet. In this study, we aimed to study the relation between TWA and scar size and characteristics assessed with CMR in post-MI patients (pts) with relatively preserved systolic function presented with nonsustained VT. Methods: This observational cross-sectional study was enrolled 36 post-MI patients with mild-systolic dysfunction and non-sustained ventricular tachycardia. Eight pts were excluded. Both TWA and contrast enhanced CMR were performed. Left ventricular ejection fraction (LVEF), dense scar, peri-infarct zone and total scar masses were assessed and these values to left ventricular (LV) mass ratios were calculated. Infarct ratios and characteristics were determined and compared among patients with negative TWA and those with positive TWA. Results: For the positive (n=12) vs. negative (n=16) TWA patients there were no significant difference between LVEF (44.9±5.4% vs. 44.0±3.2%, p=NS) and LV masses (121.89±26.56 g vs. 106.14±21.16 g, p=NS). The ratio of scar core to LV mass (3.37±0.68% vs. 3.31±1.01%, p=NS), peri-infarct zone to LV mass (23.61±7.93% vs. 21.64±9.08%, p=NS), total scar to LV mass (26.98±7.86% vs. 24.96±9.62%, p=NS) were all similar. Conclusion: There were no association between scar size and infarct heterogeneity and prevelance of TWA in post-MI patients with relatively preserved LVEF with non-sustained VT. Our data suggest that these two modalities may reflect different arrhythmogenic mechanisms in this cohort. (Anadolu Kardiyol Derg 2014; 14: 442-7)

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“…In patients during the early post-MI phase with or without heart failure, a cutpoint of ≥47 μ V also predicted sudden cardiac death (69,70,74). Leino et al (66) demonstrated a 55% and 58% increase in risk of cardiovascular and sudden cardiac death, respectively, per 20 μ V of TWA.…”

Section: Methodology For Twa Assessmentmentioning

confidence: 99%

“…The MMA allows microvolt TWA analysis during routine, symptom-limited exercise stress testing (64 – 66,68) and during post-exercise recovery (54,67,68) as well as during ambulatory ECG monitoring (69–74) in the flow of clinical evaluation (Table 2). Risk stratification is based on the peak TWA value throughout the 24-h ambulatory ECG recording or the symptom-limited exercise test.…”

Section: Methodology For Twa Assessmentmentioning

confidence: 99%

Microvolt T-Wave Alternans

Verrier

Klingenheben

Malík

et al. 2011

Journal of the American College of Cardiology

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386

141

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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.

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Importance of regional specificity of T-wave alternans in assessing risk for cardiovascular mortality and sudden cardiac death during routine exercise testing

Cited by 30 publications

References 31 publications

Evaluation of beat-to-beat ventricular repolarization lability from standard 12‐lead ECG during acute myocardial ischemia

Evaluation of beat-to-beat ventricular repolarization lability from standard 12‐lead ECG during acute myocardial ischemia

No association between scar size and characteristics on T-wave alternans in post-myocardial infarction patients with relatively preserved ventricular function presented with nonsustained ventricular tachycardia

Microvolt T-Wave Alternans

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