Case Report: Myocardial Bypass in Left Descending Artery - A Rare Congenital Anomaly

Abstract Myocardial bypass (MB) is known to have scientific relevance and is present in several studies with great statistical significance regarding its clinical manifestations and complications. There are still questions about MB in its relationship with heart disease and repercussion in life-threatening conditions. We present a case report of a MB in the left anterior descending coronary artery, whose objective is to identify this rare congenital anomaly and to highlight the patient's clinical outcome in order to elicit greater contributions about the presence of this variant in the emergency room, its diagnosis by angiography and therapeutic management.

High Prevalence and Clinical Implication of Myocardial Bridging in Patients with Early Repolarization

PURPOSE: Recent evidence suggests that early repolarization (ER) is related with myocardial ischemia. Compression of coronary artery by a myocardial bridging (MB) can be associated with clinical manifestations of myocardial ischemia. This study aimed to evaluate the associations of MB in patients with ER. MATERIALS AND METHODS: In consecutive patients (n=1303, age, 61±12 years) who had undergone coronary angiography, we assessed the prevalence and prognostic implication of MB in those with ER (n=142) and those without ER (n=1161). RESULTS: MB was observed in 54 (38%) and 196 (17%) patients in ER and no-ER groups (p<0.001). In multivariate analysis, MB was independently associated with ER (odd ratio: 2.9, 95% confidence interval: 1.98–4.24, p<0.001). Notched type ER was more frequently observed in MB involving the mid portion of left anterior descending coronary artery (LAD) (69.8% vs. 30.2%, p=0.03). Cardiac event was observed in nine (6.3%) and 22 (1.9%) subjects with and without ER, respectively. MB was more frequently observed in sudden death patients with ER (2 out of 9, 22%) than in those without ER (0 out of 22). CONCLUSION: MB was independently associated with ER in patients without out structural heart disease who underwent coronary angiography. Notched type ER was closely related with MB involving the mid portion of the LAD. Among patients who had experienced cardiac events, a higher prevalence of MB was observed in patients with ER than those without ER. Further prospective studies on the prognosis of MB in ER patients are required.

Avaliação da ponte miocárdica pela angiotomografia das coronárias / Evaluation of myocardial bridging by coronary computed tomography

Introdução: A ponte miocárdica (PM) é definida como um segmento de uma artéria coronária epicárdica e que apresenta um curso intramural no miocárdio. Embora a PM seja clinicamente silenciosa, na maioria dos casos, tem sido associada com isquemia do miocárdio, arritmias e morte súbita. A angiografia coronarina convencional é o padrão ouro para a detecção da PM, mas é invasivo e pode não ser suficientemente sensível, comparativamente, aos estudos de autópsia. Recentemente, a tomografia computadorizada multislice das coronárias (angioTC) tornou possível a detecção do curso das artérias coronárias, incluindo a PM. Objetivos: Avaliar a prevalência de PM, em pacientes com suspeita de doença arterial coronariana, submetidos à angioTC e avaliar o valor preditivo desse método no médio prazo. Métodos: Durante o período de 2008 a 2011, 498 pacientes consecutivos foram examinados por angioTC para o diagnóstico de doença coronária, sendo realizada avaliação para presença de PM e foram acompanhados por um seguimento médio de 23 meses, para a ocorrência de eventos cardiovasculares (morte, hospitalização e/ou revascularização do miocárdio). Resultados: A idade média dos pacientes foi de 55,3 ± 14,2 anos, com sexo masculino de 71,1 por cento. Entre os pacientes, 7,6 por cento (38 pacientes) mostraram PM. As principais indicações foram angina pectoris em 40 por cento e teste de estresse positivo em 34 por cento . 34,2 por cento apresentaram doença aterosclerótica, sendo que apenas um paciente apresentou estenose coronariana significativa. Durante o seguimento, nenhum paciente mostrou eventos adversos. Conclusão: A TMC representa uma técnica não invasiva com elevada acurácia na avaliação anatômica das artérias coronárias, podendo ser particularmente útil para avaliar a incidência, localização e morfologia da ponte miocárdica in vivo.

Introduction: The myocardial bridge (MB) is defined as a segment of an epicardial coronary artery that has an intramural course in the myocardium. Although MB is clinically silent in most cases, has been associated with myocardial ischemia, arrhythmias and sudden death. Coronary conventional angiography is the gold standard for detection of MB, but is invasive and cannot be sufficiently sensitive compared to autopsy studies. Recently, multislice computed tomography of coronary arteries (MCTCA) has allowed the detection of coronary artery course, including PM. Objectives: To evaluate MB prevalence in patients with suspected coronary artery disease undergoing MCTCA and to evaluate the predictive value of this method at medium term. Methods: During the period 2008 to 2011, 498 consecutive patients were examined by TMC for the diagnosis of coronary artery disease, being conducted to evaluate the presence of BM and followed for a mean follow-up of 23 months for the occurrence of cardiovascular hard events (death, hospitalization or revascularization). Results: Patients mean age was 55.3 ± 14.2, being male 71.1 percent. Among the patients, 7.6 percent (38 patients) showed MB. Main findings included angina pectoris in 40 percent and a positive stress test in 34 percent. 34.2 percent had atherosclerotic disease, and one patient had significant coronary stenosis. During follow-up, no patients showed adverse events. Conclusion: MCTCA is a noninvasive technique with high accuracy in anatomical evaluation of the coronary arteries and may be particularly useful to assess the incidence, location and morphology of myocardial bridging in vivo.

Infarto agudo do miocárdio associado a ponte miocárdica / Acute myocardial infarction associated to myocardial bridging

Paciente do sexo masculino, 73 anos, hipertenso, dislipidêmico e ex-tabagista, internado com quadro de infarto agudo do miocárdio sem supradesnivelamento do segmento ST. Cineangiocoronariografia demonstrou ponte miocárdica em artéria descendente anterior, sem lesões obstrutivas em outros territórios da circulação coronária. Em decorrência da elevação de marcadores de necrose miocárdica e do surgimento de supradesnivelamento transitório do segmento ST em parede anterior, na vigência de tratamento clínico otimizado, realizou-se ultrassom intracoronário, que evidenciou lesão ulcerada no território da ponte miocárdica, seguido de angioplastia com implante de stent, com sucesso. A evolução foi satisfatória após o procedimento e o paciente recebeu alta hospitalar.

We report the case of a 73-year-old man, with a history of hypertension, dyslipidemia, and previous smoking, admitted with a non-ST segment elevation myocardial infarction. Coronary angiography showed a myocardial bridge in the left anterior descending artery, with no obstructive lesions in other coronary arteries. Because of the raise in serum markers of myocardial necrosis and the development of transient ST segment elevation in the anterior wall, despite optimized medical treatment, we performed intravascular ultrasound, which showed an ulcerated lesion in the myocardial bridge territory, which was followed by a successful coronary angioplasty with stent implantation. The patient had a favorable course and was discharged from the hospital.