Incidence of T Wave Alternation After Acute Myocardial Infarction and Correlation with Other Prognostic Parameters: Results of a Prospective Study

Abstract

Tachycardia induced alternation of the T wave (TWA) has been associated with arrhythmia morbidity in mixed patient populations. However, less is known concerning the general incidence of TWA and its usefulness in risk stratification early after acute myocardial infarction (MI). TWA was prospectively and systematically assessed in 140 consecutive patients 15 +/- 6 days after acute MI and prior to discharge. Results of TWA measurements were compared to other noninvasive risk markers, LV function, and coronary angiography. Sustained TWA was present at rest or inducible during exercise in 27% of patients. The patient-specific heart rate for the onset of TWA was 98 +/- 9 beats/min. After multivariate analysis, TWA correlated with age (P = 0.02) and LV function (P = 0.002) and occurred more often in patients after nonanterior MI (P = 0.03). Acute results of Holter monitoring, late potentials by signal-averaged ECG, and heart rate variability were unrelated to the TWA status. During follow-up (451 +/- 210 days) two major arrhythmic events occurred. The incidence of TWA early after MI is about 25%. TWA is related to age and LV function but not to other common arrhythmia markers. Although TWA does not appear to be related to excessive cardiac morbidity, evaluation of the prognostic significance of TWA requires further study.

T-Wave Alternans and the Susceptibility to Ventricular Arrhythmias

“…However, when TWA was measured earlier (eight days) after MI by Tapanainen et al (77), it failed to predict mortality. A similar result was reported by Schwab et al (79) for TWA measured 15 Ϯ 6 days after MI. The Alternans Cardiac Electrical Stability Study (80) examined 448 patients with LVEF 48 Ϯ 11% after MI, and reported that TWA evolves from early (5 to 21 days) to later (28 to 56 days) measurements, with 67% concordance.…”

Is Microvolt T-Wave Alternans the Answer to Risk Stratification in Heart Failure?

“…In 1 study, 140 consecutive patients were investigated in the first 30 days after MI. Only 3 end points (death/VTE) accrued over 15 months of follow-up 19 and MTWA did not predict events. The second study examined the predictive value of MTWA for all-cause death in 323 consecutive patients early after MI (mean, 8 days post-MI).…”

Microvolt T-Wave Alternans for the Risk Stratification of Ventricular Tachyarrhythmic Events

“…After reviewing and eliminating clearly ineligible studies by review of titles and abstracts, 27 articles were identified for full review (5,. A search of the literature of each author and a review of the bibliographies of these articles identified an additional four articles for review (37)(38)(39)(40). From these 31 articles, 14 were eliminated…”