A 59‐year‐old man with history of hypertension and heavy smoking presented with recurrent dizziness, palpitation and chest pain during exertion. At admittance, an ECG recording showed rapidly conducting atrial fibrillation (mean heart rate 140 bpm) and otherwise normal findings. Blood pressure and a laboratory examination were normal. Within a few minutes after admission, atrial fibrillation spontaneously converted to sinus rhythm. To exclude coronary artery disease, the patient underwent 64‐slice electronic beam computed tomography (EBCT). No calcification or coronary plaque was detected. However, a myocardial bridge of the mid‐segment of the left anterior descending coronary artery (LAD) was found (panels). Selection of different phases of the scanning cycle showed systo‐diastolic diameter change of the vessel.
(A) Curved multiplanar reconstruction showing the mid‐portion of the left anterior descending coronary artery (LAD). Note the course of the vessel within the myocardium. Arrows indicate entry and exit point of the vessel. (B) Volume rendering modality taken in diastole (60% of the R–R cycle), showing the uncompressed portion of the LAD. (C) Same as in B but taken in systole (40% of the R–R cycle), showing full compression of the LAD.
A myocardial bridge occurs when the myocardium covers a discrete portion of an epicardial coronary artery. A myocardial bridge is most commonly localised in the middle segment of the LAD. Systolic vessel compression and delayed diastolic relaxation may impair coronary blood flow, resulting in angina‐like chest pain. Usually, myocardial bridging is a benign, congenital condition with a favourable long‐term outcome; infrequently, it may be associated with myocardial infarction, conduction disturbances and even sudden death.
When a diastolic “cuff‐like” picture is noticed at EBCT, analysis of both diastolic and systolic images helps to confirm the systolic compression of the artery. This “dynamic” imaging such as provided by EBCT may be particularly helpful in linking clinical history to the anatomical finding.