Infarto agudo al miocardio secundario a disección coronaria espontánea biarterial: reporte de un caso y revisión de literatura / Acute myocardial infarction due to spontaneous two vessel coronary artery dissection

Resumen: La disección coronaria espontánea ha surgido como una causa interesante y poco reconocida de síndrome coronario agudo no aterosclerótico. Ocurre más frecuentemente en mujeres jóvenes, donde de forma importante puede asociarse a anomalías arteriales no coronarias. La clave para un tratamiento oportuno es el diagnóstico precoz que impida su evolución a cuadros más severos. Se presenta el caso de una mujer de 36 años con un síndrome coronario agudo secundario a una disección coronaria espontánea bi-arterial que evolucionó de forma grave a una insuficiencia cardíaca aguda. El objetivo es informar un cuadro poco usual y proporcionar evidencia que respalde el cómo debe enfrentarse.

Abstract: Spontaneous coronary dissection is an important cause of acute non-atherosclerotic coronary syndrome. It occurs more frequently in young women, often without significantly associated coronary arterial anomalies. Early diagnosis is a key to prompt treatment, in order to prevent severe complications. We report the case of a 36-year-old woman with an acute coronary syndrome secondary to spontaneous bi-arterial coronary dissection progressing to severe acute heart failure. A discussion of the management of this condition is included.

Exercise induces early and late myocardial preconditioning in dogs.

OBJECTIVE: We tested the hypothesis that exercise induces myocardial preconditioning in dogs. METHODS: We instrumented dogs with a snare on the anterior descending coronary artery and catheters in the root of the aorta, left ventricular cavity and coronary sinus. After recovering from surgery the dogs were trained to stay in the laboratory and run on a treadmill. Subsequently, they were randomly allocated to five groups: (1) non-preconditioned dogs: under anesthesia, the anterior descending coronary artery was occluded during 1 h and then reperfused during 4.5 h. (2) Early preconditioned dogs: procedure similar to group 1 but the dogs performed exercise on a treadmill for five periods of 5 min each before the coronary occlusion. (3) Late preconditioned dogs: procedure similar to group 2 but 24 h were allowed to elapse between the preconditioning exercise and the coronary occlusion. (4) Early preconditioned dogs plus 5-hydroxydecanoate: procedure similar to group 2 but 5-hydroxydecanoate was administered prior to exercise. (5) Non-preconditioned dogs with 5-hydroxydecanoate: procedure similar to group 1 but 5-hydroxydecanoate was administered at a time equivalent to that in group 4. RESULTS: Exercise did not induce myocardial ischemia and the hemodynamics during the experiments did not differ between groups. Exercise immediately before the coronary occlusion decreased the infarct size (percent of the risk region) by 78% (P<0.05), an effect that was abolished with 5-hydroxydecanoate. Exercise 24 h prior to coronary occlusion decreased infarct size by 46% (P<0.05 vs. non-preconditioned dogs, P<0.05 vs. early preconditioned dogs). 5-Hydroxydecanoate by itself did not modify infarct size. These effects could not be explained by changes in collateral flow to the ischemic region. CONCLUSIONS: Exercise prior to a coronary occlusion induces early and late preconditioning of the infarct size. The early effect is mediated through mitochondrial ATP-sensitive potassium channels.