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Spontaneous coronary artery dissection (SCAD) accounts approximately for 0.2% of cases of acute coronary syndrome. It is defined "spontaneous" in absence of any coronary wall damage. This disease affects primarily young women in good health, with no risk factors for coronary artery disease, especially during the postpartum period. Since the clinical presentation varies widely from no symptoms to typical angina and sudden cardiac death, SCAD incidence is underestimated.A 40-year-old woman, in the 8th week after delivery, was admitted to our emergency department because of acute chest pain, and a diagnosis of inferior and posterior non-ST-elevation myocardial infarction was made. Emergency coronary angiography showed a small SCAD of the distal segment of a little marginal branch. Because of the small dimension of the dissection, optimal medical therapy was started. However, two days later, symptoms recurred and the ECG showed an anterior ST-elevation myocardial infarction. The patient was therefore transferred to the cath lab and coronary angiography showed extensive dissection of the left anterior descending coronary artery with good angiographic result. Percutaneous coronary intervention was performed and three drug-eluting stents were implanted.No retrospective studies or randomized clinical trials are available to guide the best treatment option in patients with SCAD, because of the wide variety of clinical presentation and the rarity of the pathology. Early and correct diagnosis of SCAD is key for adequate management. First, the site and precise quantification of lesion severity should be assessed with multiple angiographic projections. Intravascular ultrasound and optical coherence tomography can provide additional information about the entry point of the lesion. Hemodynamic status and extension of the myocardium at risk should be also evaluated to determine the best therapeutic strategy. Since the presence of SCAD may be associated with aneurysm formation and dissections of other arteries, screening of the arterial tree may be useful, especially of the supra-aortic trunks and splanchnic circulation.

Despite the therapeutic success of percutaneous transluminal coronary angioplasty (PTCA), the mechanisms by which PTCA increase vessel luminal size remain uncertain. To better understand the transmural morphologic changes associated with PTCA of stenosed coronary arteries, we studied with a high-frequency intravascular ultrasound catheter 18 coronary artery segments in 18 patients following balloon angioplasty. High-quality cross-sectional images were obtained from 15 coronary sites without complications in all patients. Two distinctive morphologic features following balloon angioplasty were appreciated by intravascular ultrasound imaging. The first pattern, observed in 10 cases (67%), consisted of a stretched plaque without any evidence of dissection. The second pattern, found in 5 cases (33%), demonstrated a dissection of the plaque ranging from a radial tear with separation of the 2 ends of the plaque to an extensive dissection which, in 1 case, encompassed the entire circumference of the artery. Although angiography showed a good post-angioplasty result in all cases, intravascular ultrasound evidenced a large amount of residual atheroma occupying the artery cross-sectional area. In addition, this imaging modality revealed more often than angiography the presence of calcification and dissection. These data demonstrate that PTCA creates different morphologic patterns which are related to the mechanisms of lumen enlargement and that the coronary artery anatomy after dilatation is much more complex than that observed with angiography. This study confirms that intravascular ultrasound is a feasible and safe imaging modality which provides new valuable insight into the mechanisms by which angioplasty improves vessel patency.

In effort angina the exercise test can shift the ST-segment during the active phase and/or recovery. To investigate whether coronary vasomotility has some part in these electrocardiographic patterns, in 15 patients with stable effort angina we performed a quantitative angiographic evaluation of single, significant coronary stenoses (greater than 50%) during: spontaneous rhythm, graded atrial pacing (max 160 b/min) and at 1-3-5 min of recovery, both without drugs and after Ca-blockade (nifedipine, 10 mg sl). The greatest ST changes were at peak of the pacing in 9 patients (Group 1) and at recovery in 6 (Group 2). In each patient the stenotic lumen was reduced by atrial pacing (-9%, p less than 0.03); in Group 1 the lumen recovered soon after the end of the pacing, whereas in Group 2 narrowings became greater (-17%, p less than 0.02) at about 3 min of the recovery phase. In both groups nifedipine did not prevent the enhancement of the stenosis during pacing, but avoided constriction and ST changes during recovery in Group 2. Thus, in effort angina a superimposed active vasoconstriction contributes to the increase of the ST changes during the recovery phase of the exercise.

Calcium antagonists and beta-blockers may retard or inhibit atherogenesis. We tested whether nifedipine or propranolol may retard or induce regression of coronary atherosclerosis in man. In selected population of 113 patients with effort angina and proven coronary artery disease, the coronary cineangiographic pattern after 2 year therapy with nifedipine (Group 1, 39 patients), propranolol (Group 2, 36 patients), or isosorbide dinitrate (control group, 38 patients) was compared to the pre-treatment pattern. After 2 years the disease evolved to a different extent in the 3 groups. The number of lesions with evidence of progression was significantly smaller after nifedipine (14), and larger after propranolol (39) as compared with controls (24). Patients with evidence of progression of old lesions, and appearance of new lesions were significantly fewer in Group 1 than in Group 2 and in control patients. Thus, nifedipine seemed more protective than either of the other drugs against coronary atherosclerosis. The coronary risk factors were within normal limits in the nifedipine treated group and remained so with treatment supporting that they were likely dissociated from influences on atherosclerosis. The evolution, at least as judged by the number of lesions with progression, appeared significantly (p less than 0.01) worse with propranolol than with isosorbide dinitrate. This may prospect that nitrate contrasted the evolution of the disease, or that propranolol made it worse, possibly through unfavourable modifications of serum lipids (28% rise of total triglyceride and 25% decrease of HDL cholesterol were already detectable at 12 months in Group 2).