Selective ergonovine-induced coronary artery spasm and ST-segment alternans after blunt thoracic trauma

Repolarization alternans: techniques, mechanisms, and cardiac vulnerability

Sudden cardiac death continues to be the leading cause of mortality in developed countries. Electrical alternans of the ST segment and the T wave on the surface ECG as a noninvasive marker of patients at risk is a phenomenon that was initially observed early in this century and was seen then to be associated with cardiac rhythm disturbances. Substantial evidence indicates that T wave alternans (TWA) is related to myocardial ischemic as a harbinger of malignant ventricular arrhythmias because it reflects dispersion and heterogeneity of repolarization. Recent data have demonstrated a significant correlation between TWA and vulnerability to ventricular arrhythmias in individuals with or without organic heart disease, it also predicts the results of electrophysiological testing and arrhythmia-free survival in patients with a variety of cardiac diseases. This article reviews the historical background of TWA and discusses the early experimental and recent clinical evidence implying an integral link between TWA and ischemia-induced cardiac vulnerability.

Myocardial infarction in men aged 40 years or less: a prospective clinical-angiographic study

HYPOTHESIS

The study was undertaken to characterize acute myocardial infarction (AMI) in young patients.

METHODS

In all 108 consecutive Mediterranean patients with AMI (102 men and 6 women), aged < or = 40 years, were prospectively included in this study over a period of 6.5 years. Coronary angiography was carried out within the first month and data from these patients with normal or diseased coronary arteries were compared. Clinical features, risk factors, and in-hospital and late morbidity and mortality were evaluated.

RESULTS

Young patients with AMI represent 4.1% of the 2,644 patients admitted because of definite AMI during this period. The most common risk factors were cigarette smoking (94.5%) and hypercholesterolemia (48%). Location of the AMI was anterior in 37%, inferior in 57.5%, and non-Q in 5.5%. A history of previous angina was present in 42.5% of the patients, including all seven patients with previous myocardial infarction (6.5%). However, in 52% of the patients the anginal episodes started in the week prior to the AMI. In-hospital mortality and mortality during a mean follow-up of 41 +/- 23 months were 3.7 and 3.8%, respectively. The Kaplan-Meier actuarial curve assessed on 97 of 104 survivors was 100 and 94% at 1 and 5 years, respectively. Coronary arteries were angiographically normal in 17 (20%) of 87 survivors. Compared with young patients who had obstructive lesions, this subset had a lower age and fewer risk factors, reinfarction (p < 0.05), and late angina (p < 0.01), but development of congestive heart failure and survival were similar in both groups.

CONCLUSION

These data suggest that young patients with AMI are very frequently heavy smokers, have a high incidence of angiographically normal coronary arteries, and that the short- and long-term prognosis is excellent.