Beneficial effects of direct call to emergency medical services in acute myocardial infarction.

Objectives: We investigated the impact of an emergency medical services call on the management of acute myocardial infarction, considering time intervals for intervention and revascularization procedures.

Methods: Data were prospectively collected from January 2001 to October 2002 from 531 patients hospitalized for myocardial infarction with ST segment elevation and a pre-hospital delay of less than 24 h.

Results: Only 26% of patients called the emergency medical services at the onset of symptoms (n=140).

Effect of in vivo heart irradiation on coronary reactivity in the rat.

The frequent exposure of the heart to radiation during thoracic tumor radiotherapy often results in chronic impairment of myocardial function. The aim of the present investigation was to evaluate the effect of irradiation on coronary vascular tone in rat hearts exposed in vivo to a single dose of 20 Gy gamma rays. The ability of rat hearts to respond to changes in coronary reactivity was analyzed 1, 15, 30 and 60 days following cardiac irradiation, using the Langendorff model, after perfusion of either L-nitro-arginine (LNA), an inhibitor of nitric oxide synthetase or SIN 1, a nitric oxide donor drug.

Analysis of myosin heavy chain functionality in the heart.

Comparison of mammalian cardiac alpha- and beta-myosin heavy chain isoforms reveals 93% identity. To date, genetic methodologies have effected only minor switches in the mammalian cardiac myosin isoforms. Using cardiac-specific transgenesis, we have now obtained major myosin isoform shifts and/or replacements.