T-Wave Abnormality as Electrocardiographic Signature of Myocardial Edema in Non-ST-Elevation Acute Coronary Syndromes.

BACKGROUND: T-wave abnormalities are common during the acute phase of non-ST-segment elevation acute coronary syndromes, but mechanisms underlying their occurrence are unclear. We hypothesized that T-wave abnormalities in the presentation of non-ST-segment elevation acute coronary syndromes correspond to the presence of myocardial edema. METHODS AND RESULTS: Secondary analysis of a previously enrolled prospective cohort of patients presenting with non-ST-segment elevation acute coronary syndromes was conducted. Twelve-lead electrocardiography (ECG) and cardiac magnetic resonance with T2-weighted imaging were acquired before invasive coronary angiography. ECGs were classified dichotomously (ie, ischemic versus normal/nonischemic) and nominally according to patterns of presentation: no ST- or T-wave abnormalities, isolated T-wave abnormality, isolated ST depression, ST depression+T-wave abnormality. Myocardial edema was determined by expert review of T2-weighted images. Of 86 subjects (65% male, 59.4 years), 36 showed normal/nonischemic ECG, 25 isolated T-wave abnormalities, 11 isolated ST depression, and 14 ST depression+T-wave abnormality. Of 30 edema-negative subjects, 24 (80%) had normal/nonischemic ECGs. Isolated T-wave abnormality was significantly more prevalent in edema-positive versus edema-negative subjects (41.1% versus 6.7%, P=0.001). By multivariate analysis, an ischemic ECG showed a strong association with myocardial edema (odds ratio 12.23, 95% confidence interval 3.65-40.94, P<0.0001). Among individual ECG profiles, isolated T-wave abnormality was the single strongest predictor of myocardial edema (odds ratio 23.84, 95% confidence interval 4.30-132, P<0.0001). Isolated T-wave abnormality was highly specific (93%) but insensitive (43%) for detecting myocardial edema. CONCLUSIONS: T-wave abnormalities in the setting of non-ST-segment elevation acute coronary syndromes are related to the presence of myocardial edema. High specificity of this ECG alteration identifies a change in ischemic myocardium associated with worse outcomes that is potentially reversible.

Methods of teaching and evaluating electrocardiogram interpretation skills among cardiology fellowship programs in the United States.

BACKGROUND: This study examines the methods used by cardiology training programs within the United States to teach electrocardiogram (ECG) interpretation and prepare fellows for the American Board of Internal Medicine board examination. METHODS: A link to an 18-question Web-based survey was electronically mailed to 198 fellowship directors in the United States. RESULTS: The response rate was 45%. Most participating programs were university hospitals or affiliates (77%) and of moderate size (at least 11 total fellows [72%]). Programs were coordinated by senior (68%) general (60%) cardiologists. Only 42% of the programs performed formal testing. The American Board of Internal Medicine answer sheet was used by most faculty (92%) when teaching ECG interpretation. CONCLUSIONS: Teaching of ECG interpretation varies among US fellowship programs. Coordination of curricula is performed by senior faculty, likely reflecting a trend toward subspecialization and dilution of ECG expertise among younger faculty. Future endeavors should focus on curriculum standardization with regular competency assessment.

The association between moderate drinking and heart rate variability in healthy community-dwelling older women.

The relationships among moderate alcohol use, autonomic tone, and arrhythmogenesis in older adults have not been adequately studied. Knowledge about these relationships is of increasing importance in light of population aging and recent epidemiological findings that associate moderate alcohol use with decreased rates of coronary artery disease. The purpose of this study was to assess the association between moderate drinking and autonomic tone in older women. Fifty-two Caucasian female participants (age 69 +/- 5.2) were enrolled in the study. Autonomic tone was estimated by time-domain and frequency-domain measures of heart rate variability. Multivariate analysis revealed that alcohol consumption rate in the sample accounted for approximately one third of the 24-h variability in the SDNN and the SDANN, measures of variability cycle lengths of 24-h and more than 5-min, respectively. Significant contributions of alcohol consumption rate to the shorter-term time-domain measures rMSSD and ASDNN, all frequency-domain measures, and HR were not confirmed. However, repeated measures ANOVA revealed that, between the hours of 0000 and 0600, women who drank approximately 0.5 to 3 standard drinks per day had significantly lower [log] HF and [log] LF power compared to abstainers and a tendency toward sympathetic predominance during the evening and nighttime hours. The authors discuss the implications of these findings.