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Introduction: Contemporary non-ST-elevation myocardial infarction-acute coronary syndrome guidelines emphasize early-risk stratification and optimizing therapy including an invasive strategy in high-risk patients. To assess the feasibility of initiating this strategy in the prehospital environment, we examined how such patients are transported to hospital, their risk profile, and the proportion potentially eligible for such a strategy., Methods: Consecutive patients with ST-segment elevation myocardial infarction admitted in Edmonton were studied between September and November 2008 and divided according to their mode of transport to hospital: emergency medical services (EMS) versus self-presenting. Baseline characteristics, GRACE Risk Score, blinded core laboratory electrocardiogram analysis, cardiac biomarkers, in-hospital procedures, and outcomes were analyzed., Results: Thirty-five percent (93/263) of patients presented via EMS and often to percutaneous coronary intervention hospitals, that is, 64.5% versus 44.1% (P = .0016). They were older (75 vs 62 years, P < .001), more often female (43% vs 28.1%, P < .001), diabetic (34.4% vs 22.9%, P = .045), and hypertensive (72.0% vs 57.1%, P = .017) and had higher GRACE Risk Scores (median 166 vs 130, P < .001). Electrocardiogram analysis revealed more baseline Q waves (38.8% vs 25.5%, P = .031) and ST depression ≥2 mm (P = .027) in EMS-transported patients. Fewer EMS patients underwent cardiac catheterization (60.2% vs 88.2%, P < .001), and a paradoxical relationship existed between catheterization rates and GRACE Risk Score in the total cohort (low-risk: 93.4% vs high-risk: 59.3%, P < .001). The composite of death/re-myocardial infarction/congestive heart failure/shock was greater in EMS patients (unadjusted odds ratio 3.96, 95% CI 1.80-8.69, P = .001); these differences were attenuated after GRACE Risk Score adjustment., Conclusion: Regional strategies using risk-based triage, early medical therapy, and timely triage to percutaneous coronary intervention centers represents an unrealized opportunity to enhance ST-segment elevation myocardial infarction care., (Copyright © 2011 Mosby, Inc. All rights reserved.)

Objectives: This study sought to determine whether combined assessment of autonomic tone plus cardiac electrical substrate identifies most patients at risk of serious events after myocardial infarction (MI) and to compare assessment at 2 to 4 weeks versus 10 to 14 weeks after MI., Background: Methods to identify most patients at risk of serious events after MI are required., Methods: Patients (n = 322) with an ejection fraction (EF) <0.50 in the initial week after MI were followed up for a median of 47 months. Serial assessment of autonomic tone, including heart rate turbulence (HRT), electrical substrate, including T-wave alternans (TWA), and EF was performed, interpreted blinded, and categorized using pre-specified cut-points where available. The primary outcome was cardiac death or resuscitated cardiac arrest. All-cause mortality and fatal or nonfatal cardiac arrest were secondary outcomes., Results: Mean EF significantly increased over the initial 8 weeks after MI. Testing 2 to 4 weeks after MI did not reliably identify patients at risk, whereas testing at 10 to 14 weeks did. The 20% of patients with impaired HRT, abnormal exercise TWA, and an EF <0.50 beyond 8 weeks post-MI had a 5.2 (95% confidence interval [CI] 2.4 to 11.3, p < 0.001) higher adjusted risk of the primary outcome. This combination identified 52% of those at risk, with good positive (23%; 95% CI 17% to 26%) and negative (95%; 95% CI 93% to 97%) accuracy. Similar results were observed for the secondary outcomes., Conclusions: Impaired HRT, abnormal TWA, and an EF <0.50 beyond 8 weeks after MI reliably identify patients at risk of serious events. (Assessment of Noninvasive Methods to Identify Patients at Risk of Serious Arrhythmias After a Heart Attack; http://www.clinicaltrials.gov/ct/show/NCT00399503?order=1; NCT00399503).

A 39-year-old man presented to a university hospital emergency department with anginal chest pain, ventricular tachycardia and ST elevation in the anterolateral leads (V3 to V6, I and aVL). Due to discrepancies in the history and physical examination, thrombolysis was withheld until a past electrocardiogram could be obtained, which was unchanged. Subsequent investigations revealed no evidence of myocardial necrosis, and the patient was diagnosed with hypertrophic cardiomyopathy. This is the first reported case of hypertrophic cardiomyopathy with ST elevation as the predominant electrocardiographic abnormality. In patients with discrepancies in the clinical presentation, it is essential to obtain past elecrocardiograms to ensure appropriate utility of thrombolysis.

Objective: To correlate angiocardiographic and electrocardiographic (ECG) measures of risk in coronary artery disease (CAD) patients., Setting: Baseline substudy of the Simvastatin/Enalapril Coronary Atherosclerosis Trial (SCAT), a 2 x 2 factorial, randomized, controlled trial of CAD regression., Patients: One hundred and twenty-three CAD patients, 113 males and 10 females; average age, 59 years., Methods: Bivariate correlations of multiple quantitative measures of epicardial coronary angiographic luminal narrowing (quantitative coronary angiography [QCA]) and body surface ECG maps of the sum of the decrease in the potential time integral of the ST segment (SST decrease) between rest and symptom-limited exercise and between rest and 1 and 5 mins postexercise recovery., Results: The average number of epicardial coronary segments analyzed per patient was 12. The mean diameter averaged 2.78 mm; the minimal diameter, 2.01 mm. The mean percentage coronary stenosis averaged 29.6% and the most severe averaged 62.9%. sigma ST decrease averaged -5323 microV.s between rest and peak exercise and recovered slowly, averaging -5117 microV.s at 1 min postexercise and -4562 microV.s at 5 mins. No QCA measure correlated with any ECG variable (range of r, 0.002 to -0.179; not significant)., Conclusions: Among CAD patients there are no close, or causal, relations between angiographic measures of anatomic epicardial coronary atherosclerosis and ECG functional measures of exercise-induced myocardial ischemia. These data suggest that demonstrated values of stress ECG and coronary angiography for the prediction of clinical risk in CAD patients are largely independent of each other.

The present study was planned to investigate whether the sum of ST segment depression in 12-lead electrocardiogram (sigma STD) in relation to change in heart rate (delta HR) during exercise, sigma STD/delta HR index, could be utilized to predict the extent of underlying coronary artery disease. Two hundred and twenty-six consecutive patients were included in this study, 191 men and 35 women, aged 28-74 years (mean 56). Patients were classified into two groups. Group I consisted of 165 patients with either no coronary disease, single or double vessel disease. Group II included 61 patients with triple vessel or left main stem stenosis. It was found that the sigma STD/delta HR index at 25 mm. beat-1 X min. 10(2) provided the best separation between Groups I and II patients. All but 3 of the 61 patients in Group II had a sigma STD/delta HR index greater than 25. In contrast, all but 4 of the 165 patients in Group I had an index less than 25. The sensitivity, specificity and positive predictive value in the identification of Group II patients by using the index were 95%, 98% and 94% respectively. Utilization of ST segment depression of greater than or equal to 2 mm in a VF alone as a test criterion for the recognition of Group II patients had a low sensitivity (41%), specificity (88%) and positive predictive value (56%).(ABSTRACT TRUNCATED AT 250 WORDS)