Myocardial Noncompaction Presenting With Myocardial Bridge

Myocardial noncompaction, namly isolated noncompaction of the left ventricular myocardium (NVM), is a rare congenital disease. It can be either seen in the absence of other cardiac anomalies, or associated with other congenital cardiac defects, mostly stenotic lesions of the left ventricular outflow tract. A myocardial bridge (MB) is thought being associated with coronary heart disease, such as coronary spasm, arrhythmia, and so on. The significance of MB in association with other congenital cardiac conditions is unknown. We report a novel case who was presented NVM and MB. A 34-year-old man complained of chest prickling-like pain and dizzy for 1 year. His blood pressure was 110/70 mm Hg. Echocardiograph revealed increased trabeculations below the level of papillary muscle of left ventricle (LV); deep intertrabecular recesses in the endocardial wall of LV particularly in apex free wall; and LV ejection fraction of 57%. A coronary computerized tomography scan showed that part, 38.9 cm, of left descending artery tunnel was surrounding by cardiac muscles rather than resting on top of the myocardium. The therapeutics interventions included lifestyle cares, agents of anti-ischemia and improvement myocardial cell metabolism. The patient was followed up for 2.6 years, and his general condition was stable. This case indicates that NVM can be developed with MB, and the complete diagnosis of NVM and MB should be made by different image studies. (Medicine 94(36):e1425) Abbreviations: CT = computerized tomography, EF = ejection fraction, LAD = left descending artery, LV = left ventricle, MB = myocardial bridge, NVM = isolated noncompaction of the left ventricular myocardium. INTRODUCTION g Lu, MD, Aiyi Xiao, MD, and Jun Li, MD, PhD loose interwoven meshwork of myocardial fibers during embryogenesis. Clinical manifestations of it are highly variable, from no symptoms to arrhythmias, congestive heart failure, and systemic thromboemboli. It can be either seen in the absence of other cardiac anomalies, or associated with other congenital cardiac defects. A total of 12% of the patients with NVM have associated with other cardiac malformations, including various forms of congenital heart disease, particularly stenotic lesions of the left ventricular outflow tract (46%, mainly bicuspid aortic valve), Ebstein anomaly (25%), tetralogy of Fallot (8%), and double outlet right ventricle (4%). A myocardial bridge (MB) is defined as one of the coronary arteries tunnels through the myocardium rather than resting on top of it. MB was thought benign in the past. Currently, with the increasing studies, it is recognized clinically important mainly because of being associated with coronary heart disease, such as coronary spasm, arrhythmia, ischemia, acute coronary syndromes and sudden death. The significance of MB in association with other congenital cardiac conditions is unknown, although it was reported to accompany hypertrophic cardiomyopathy with significantly more frequent up to 41%. Both NVM and MB are congenital diseases. Currently, the diagnoses of the diseases sometimes are overlooked, missed, or delayed because of lack of the knowledge. Meanwhile, the diseases were discovered more chances than before as the new cardiac imaging technologies developed. Increasing the knowledge about the diseases is necessary. Here we report a parent attention to the diseases, and beware that NVM can be developed with MB. CASE REPORT A 34-year-old man, Han Chinese, self-employed garment worker, complained of chest prickling-like pain and dizzy for 1 year, visited our hospital in September 2012. He was ever diagnosed as low blood pressure and nervous breakdown. He was not smoking. His past medical history was unremarkable, but he was physically weak as he was young. He had no family history of heart diseases. His blood pressure was 110/70 mm Hg; heart rate was 72 beats/min. Physical examination was not remarkable. Electrocardiograph and chest x-ray showed normal. Echocardiograph revealed increased trabeculations below the level of papillary muscle of left ventricle (LV), and deep intertrabecular recesses in the endocardial wall of LV particularly in apex free wall (Figure 1A) where the trabecular thickness was 9 mm and the cardiac muscles became thinner. In addition, the apical impulse was decreased. Regional mitral regurgitation al movement was observed. The funcM-mode, Tiech method) showed LV of 57%. www.md-journal.com | 1