[Ischemic preconditioning. Is it always a beneficial phenomenon?]. / Precondicionamiento isquémico. Es siempre un fenómeno beneficioso?

INTRODUCTION AND OBJECTIVES: Hearts exposed to reversible ischemia stand a subsequent prolonged episode of coronary artery occlusion (ischemic preconditioning) better. The reduction of infarct size by means of preconditioning has been amply demonstrated, but the relationship between preconditioning and contractile function remains less well defined. In this study we assess the effect of a later ischemia on the regional contractility in a stunned-preconditioned myocardium. METHODS: We analyze the shortening fraction in the ischemic (dependent on the left anterior descending coronary artery), periischemic and control zone (dependent on the left circumflex coronary artery), using chronic implants of ultrasonic crystals in 17 adult mongrel dogs. In the control series, we quantified the effects of partial (30-60% reduction of coronary flow from the basal) and transitory (15 minutes) ischemic episode in the regional myocardial function in a "virgin" myocardium. In two other series, the myocardium was previously stunned-preconditioned through brief and repeated ischemias. Afterwards, at 5th day (series B) and at 15th day (series C), the dogs were subjected to ischemic episode similar to control ones. RESULTS: After comparing the results with the control series, we observed that the shortening fraction of the ischemic zone was decreased by 107% (p < 0.01) during partial ischemic episode when it was induced on the 5th day of the stunning-preconditioning (series B). CONCLUSIONS: In dogs, the brief and repeated episodes of ischemia could condition the contractile function so that a later partial and transitory reduction of coronary flow could induce a severe affectation of contractility expressed as a diskinetic area.

[Aneurysm of the left main coronary artery caused by thoracic trauma]. / Aneurisma del tronco común de la arteria coronaria izquierda secundario a traumatismo torácico.

A 30 years-old female patient, presented with a clinical picture of acute pulmonary edema associated with anterior myocardial necrosis following a car accident with mild blunt chest injury. The coronary angiogram showed the existence of an aneurysm in the left main coronary artery (LMCA) causing extrinsic compression of the artery. Subsequent angiograms showed a complete disappearance of the aneurysm. The patient remains symptom-free three years after the accident. Blunt chest injury is a potential cause of heart damage. Although the coronary arteries may be damaged, the development of an aneurysm has been reported on very few occasions and always in connection with the anterior descending coronary artery. Our case is the first case described with the location of the aneurysm in the left main artery.

[Emboligenic mitral papillary fibroelastoma and positive antiphospholipid antibodies]. / Fibroelastoma papilar mitral embolígeno y anticuerpos antifosfolípidos positivos.

Cardiac papillary fibroelastoma has been associated to high levels of antiphospholipid antibodies, either primary or in the context of systemic lupus erythematosus. We present the case of a young female with several episodes of peripheral emboli. Two-dimensional echocardiography demonstrated a tumor on the anterior mitral leaflet. The mass was resected and histologically showed a papillary architecture covered by hyperplasic endocardial cells on a layer of connective tissue and a central core of collagen and elastic fibers. The immunologic study demonstrated high titers of anticardiolipin antibodies, complement consumption and positive antinuclear antibodies. The patient keep high anticardiolipin antibodies titers at follow-up but embolization has not recurred and has no symptoms.