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Spontaneous coronary artery dissection (SCD) is an uncommon clinical condition. It usually appears in healthy young women during peripartum period. Here, we present a case of SCD that occurred during treadmill exercise testing and disappeared spontaneously one day after.

Introduction
Spontaneous coronary artery dissection (SCD) is an extremely rare condition. It is usually documented during peripartum period in young pregnant women having a history of oral contraceptive use.¹ It may also be observed in elderly patients with atherosclerotic disorder.^2,3 Spontaneous rupture of vulnerable plaque plays a pivotal role in the pathogenesis of SCD that occurs in these patients. Therapeutic approaches include pharmaceutical, percutaneous coronary interventions or surgery (CABG), although optimal treatment strategy has not been well defined. Here, we describe a case of SCD that disappeared spontaneously.

Case Report
A 72-year old man with prostate cancer was referred to our clinic for preoperative evaluation. He had a history of hypertension and was taking indapamid but had no history of smoking. He was suffering from exertional dyspnea, which was thought to be angina pectoris equivalent. His heart rate was 74 beats/min and blood pressure was 130/75 mmHg. The physical examination was normal. The ECG revealed sinus rhythm and left ventricular hypertrophy voltage criteria. He underwent treadmill exercise testing on Bruce protocol but it was ended at 5 minutes because of typical angina pectoris and 2 mm down-sloping ST segment depression on V4-6 derivations. The patient was hospitalized and therapy with low-molecular weight heparin, aspirin, beta-blocker and a statin was started. One day later, the patient underwent cardiac catheterization with suspected coronary artery disease. Coronary angiography was performed with 6 Fr Judkins left and right catheters via femoral access and revealed spontaneous dissection line at the proximal left anterior descending artery and a plaque causing 40% narrowing just after the distal part of dissection (Figures 1 and 2). No guidewire or any other device was used during coronary angiography. We had no access to intravascular ultrasonography, angioscopy or multislice coronary angiography for more detailed examination of the coronary dissection. Elective coronary stent implantation was planned and clopidogrel was added to the drug regimen (300 mg loading dose and 75 mg/day thereafter). On the following day, the patient was taken to catheterization laboratory for percutaneous coronary intervention (PCI). However, the dissection line could not be visualized and it had disappeared totally (Figure 3). He was discharged from the hospital with clopidogrel 75 mg/day, acetylsalicylic acid 300 mg/day, metoprolol 50 mg/day and atorvastatin 20 mg/day therapy. Neither chest pain nor ST-segment depression was documented on treadmill exercise testing performed one month later.

Discussion
SCD is most commonly observed in peripartum women, however, may also be associated with atherosclerosis, particularly in elderly patients.^1–3 Clinically, it either manifests with sudden death or is frequently detected at post-mortem autopsy studies.⁴ The exact mechanism is not known, but oral contraceptives, systolic hypertension, rigorous physical exercise and cocaine use have been implicated.^5–8 In this case, a history of hypertension and exercise testing might have triggered development of SCD. Although there is no optimal therapeutic approach, clinical and angiographic regression has been reported with beta-blockers, nitrates and antiplatelet agents.^7–9 Also, we planned PCI because it has been found to be useful.¹⁰

To our knowledge, this is the first report of spontaneous closure of SCD at the left anterior descending coronary artery one day after diagnosis. Dissection healed in a very short time, possibly due to retrograde filling nature of dissection. The patient was asymptomatic at 6-month clinical follow-up with negative exercise testing.

This case showed that SCD could, although rare, regress spontaneously without intervention.