Endothelin is a novel endothelium-derived vasoactive peptide with potent vasoconstrictor action in the coronary bed; however, its possible contribution to myocardial ischemia and infarction is not known. Plasma endothelin-1 concentration was measured with use of a radioimmunoassay in serial venous samples from 22 patients over a 72 h period after acute myocardial infarction (14 patients with uncomplicated infarction [group I] and 8 patients with hemodynamic or ischemic sequelae [group II]). Twenty-two normal subjects and seven patients with stable angina served as the control subjects. Endothelin-1 levels in patients with stable coronary disease were not different from those of normal subjects (0.62 +/- 0.56 and 0.76 +/- 0.38 pg/ml, respectively). In group I, plasma levels of endothelin-1 rose sharply after myocardial infarction, reaching a peak of 4.95 +/- 0.78 pg/ml at 6 h after the onset of chest pain (p less than 0.05 compared with values in control subjects) and returning rapidly toward the normal range by 24 h. Patients with complicated infarction (group II) demonstrated a similar rapid increase in plasma endothelin-1 to a peak value of 8.29 +/- 1.95 pg/ml; however, plasma endothelin-1 remained elevated in these patients, becoming significantly different from values in group I at 48 and 72 h. There was no correlation between peak increases in creatine kinase and peak endothelin-1 in either group, suggesting that the stimulus for elevation of endothelin-1 was not myocardial necrosis itself. Furthermore, left ventricular ejection fraction did not correlate with the increase in endothelin-1 in group I patients, whereas there was a significant inverse relation between ventricular function and plasma endothelin-1 in group II.(ABSTRACT TRUNCATED AT 250 WORDS)

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Fifty-two patients were randomized into two groups of 26 to the use of either 5 or 7/8F catheters for their first left heart cardiac catheterization. Clinical characteristics for the two groups were similar. 5F catheters were significantly inferior to 7/8F catheters in terms of torque control (P less than .001), ease of engaging coronary ostia (P less than .001), and quality of angiograms (P less than .05). Nine patients in the 5F group required a change to 7/8F catheters for completion of the procedure. There was no difference in procedure time or fluoroscopy time between the groups. Time to haemostasis was significantly shorter in the 5F group (P less than .01), but there was no difference between groups with respect to haematoma formation or rebleed after haemostasis. We conclude the slight advantage of 5F catheters in terms of haemostasis is outweighed by many disadvantages. Their routine use in cardiac catheterization, at least at this time, cannot be recommended.

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