IJCS | Volume 31, Nº5, September / October 2018

553 Sousa et al. Ventricular tachycardia and anomalous coronary Int J Cardiovasc Sci. 2018;31(5)551-555 Case Report rhythm (Image 1C) after 24 hours and the etiological investigation was initiated with a transthoracic echocardiogram, which disclosed only mild and diffuse left ventricular impairment. The exercise testing and magnetic resonance imaging of the heart showed no alterations, and serologic tests for Chagas’ disease and cardiac markers were negative. Acute myocarditis was suspected, which would have lead to the VT and a tachycardiomyopathy caused by the time he remained on sustained VT. The patient received amiodarone, carvedilol, captopril and spironolactone, remaining asymptomatic and being followed at the outpatient clinic in the following months, without complications. Ventricular function was normal at the transthoracic echocardiography and exercise testing at 3 and 6 months after the event, without arrhythmias or myocardial ischemia. As there was no symptom recurrence, even after the patient returned to his work routine, amiodarone was withdrawn. However, without the antiarrhythmic drug, a new event was triggered in December 2014, which led the patient to once again seek the emergency care unit with palpitations and cold sweats. The VT was reverted again with electrical cardioversion, and the patient returned to the cardiology outpatient clinic for assessment. An angiotomography was then requested, which disclosed the anomalous origin of one of the coronary arteries (Figure 2). The diagnosis was confirmed after a coronary angiography, which concluded that the left coronary artery originated from the right coronary artery, coursing between the pulmonary artery and the aorta (interarterial course). With the anatomical definition of the condition, the surgical correction was chosen, using an internal mammary artery graft to the anterior descending and circumflex arteries, with the left main coronary artery ligation being successfully performed. The patient has been followed for 2 years, with no new episodes of VT and no medication. Discussion Ventricular arrhythmias comprehend a spectrum that range from ventricular extrasystoles, VT, to ventricular fibrillation. Ventricular fibrillation is the one most frequently associated with acute coronary syndrome. On the other hand, the SMVT has as its electrophysiological mechanism of re-entry related to scarring due to structural heart disease (e.g., previous infarction and Chagas’ disease). In the younger population - children, adolescents, and young adults - with sustained episodes of VT, the condition is usually due to diseases that manifest early in life, including genetically-determined arrhythmias, acute myocarditis, and congenital heart disease – among the latter, coronary artery anomalies. 5 Congenital anomalies of the coronary arteries may result in benign or malignant clinical consequences depending on their course and origin. 2 They are usually classified into four groups: according to the coronary origin and course (absent left main coronary artery, anomalous location of the coronary ostium inside or outside the appropriate Valsalva sinus, anomalous location of the coronary ostium in the inappropriate Valsalva sinus and single coronary artery); intrinsic to the coronary anatomy (stenosis or atresia of coronary ostia, coronary aneurysm, coronary hypoplasia and myocardial bridge); anomalies of terminal coronary circulation (fistulas into cardiac chambers, inferior vena cava or pulmonary arteries and veins); and anomalous anastomotic vessels. 2 The anomaly described in this case is that of the left coronary artery originating from the right coronary sinus, a rare congenital abnormality, with a prevalence of 0.15% in the overall population. 6 This anomalous coronary artery is most commonly related to sudden death (59% of cases), usually preceded by physical activity (in 81% of these cases). The cases in which the coronary artery courses between the aorta and pulmonary (interarterial) arteries, as described in the reported patient, are the ones most often associated with severe outcomes. 6 One of the potential mechanisms that explains this fact is the coronary artery compression by the aorta and the pulmonary trunk during exercise, leading to myocardial ischemia. 2,7,8 When only the origin is anomalous, but the coronary artery does not follow this course, there is no risk of sudden death. 4 In general, the pre-pulmonary, subpulmonary or retroaortic courses are considered benign. 3,4 In general, most patients remain asymptomatic or exhibit symptoms only after strenuous physical exercise, which may have a fatal outcome in these cases. Clinical presentation ranges from palpitations, dyspnea, chest pain and syncope to sudden death, 4,6,7 being the second leading cause of sudden death in young individuals. 2,6 Basso et al. 8 reported that only ten (36%) of the 27 cases with sudden death (23 anomalous left coronary arteries and four right coronary artery anomalies from the