Temporal Variations in Microvolt T-Wave Alternans Testing after Acute Myocardial Infarction
- 1 April 2007
- journal article
- Published by Wiley in Annals of Noninvasive Electrocardiology
- Vol. 12 (2), 98-103
- https://doi.org/10.1111/j.1542-474x.2007.00147.x
Abstract
Microvolt T-wave alternans (TWA) have been accepted as a tool for assessing vulnerability to ventricular tachyarrhythmias. There is lack of data concerning prospective temporal variations in TWA measurements after acute myocardial infarction (AMI). We analysed the temporal patterns of TWA in post-AMI patients. TWA tests were performed <1 month (TWA_early) and 6 months (TWA_late) after AMI in 51 consecutive patients treated with successful percutaneous coronary intervention (PCI). Twenty seven patients (53%) had anterior wall infarctions and 24 (47%) had inferior/lateral wall infarctions. TWA was measured during a treadmill manual exercise protocol and defined as positive, negative and indeterminate. Group A included patients with TWA negative in both tests and Group B included those with TWA abnormal (positive or indeterminate) at first or second determinations. TWA_early was negative, positive and indeterminate in 38 (74.6%), 8 (15.6%) and 5 (9.8%) patients, respectively, whereas TWA_late was negative, positive and indeterminate in 30 (58.9%), 14 (27.4%) and 7 (13.7%) patients, respectively. TWA_early was classified as normal in 74.6% and abnormal in 25.4% of the cases, and TWA_late was normal in 58.9% and abnormal in 41.1%. TWA tests were concordant in 36 patients (70.6%) and discordant 15 patients (29.4%). At TWA_late, 10 patients (19.6%) changed from TWA negative to TWA abnormal and 4 patients (7.8%) from TWA abnormal to TWA negative. After TWA_early+TWA_late, 45% of the patients had 1 test classified as abnormal. Left ventricular ejection fraction was <50% in 22% of Group A and 52% of Group B (P = 0.037). In the era of primary PCI, temporal changes in TWA measurements may occur frequently during the first 6 months post-AMI. These findings should be considered in risk stratification strategies following AMI.Keywords
This publication has 31 references indexed in Scilit:
- Temporal trends on the risk of arrhythmic vs. non-arrhythmic deaths in high-risk patients after myocardial infarction: a combined analysis from multicentre trialsEuropean Heart Journal, 2005
- Microvolt T-Wave Alternans Distinguishes Between Patients Likely and Patients Not Likely to Benefit From Implanted Cardiac Defibrillator TherapyCirculation, 2004
- Ischemic “memory image” in acute myocardial infarctio of123I-BMIPP after reperfusion therapy: A comparison with99mTc-pyrophosphate and201Tl dual-isotope SPECTAnnals of Nuclear Medicine, 2002
- Short-Term Reproducibility of T Wave Alternans MeasurementJournal of Cardiovascular Electrophysiology, 2002
- Incidence of T Wave Alternation After Acute Myocardial Infarction and Correlation with Other Prognostic Parameters: Results of a Prospective StudyPacing and Clinical Electrophysiology, 2001
- Optimal Target Heart Rate for Exercise‐Induced T‐Wave AlternansAnnals of Noninvasive Electrocardiology, 2001
- Combined assessment of T-wave alternans and late potentials used to predict arrhythmic events after myocardial infarctionJournal of the American College of Cardiology, 2000
- Prevalence, characteristics and prognostic value during long-term follow-up of nonsustained ventricular tachycardia after myocardial infarction in the thrombolytic eraJournal of the American College of Cardiology, 1999
- Evaluation and treatment strategies in patients at high risk of sudden death post myocardial infarctionClinical Cardiology, 1997
- Electrical Alternans and Vulnerability to Ventricular ArrhythmiasNew England Journal of Medicine, 1994