MYOCARDIAL BRIDGING IN A SURVIVOR OF SUDDEN CARDIAC NEAR-DEATH - ROLEOF INTRACORONARY DOPPLER FLOW MEASUREMENTS AND ANGIOGRAPHY DURING DOBUTAMINE STRESS IN THE CLINICAL-EVALUATION

Extensive myocardial bridging in the left anterior descending coronary artery was found in a 46 year old survivor of sudden cardiac near-dea th. Positron emission tomography and dobutamine stress echocardiograph y revealed ischaemia in the myocardium distal to the bridging. Spasm w as excluded as cause of the ischaemia by intracoronary infusion of ace tylcholine. Further evaluation of the haemodynamic importance of the b ridging using intracoronary Doppler flow velocity measurements reveale d an abnormal flow reserve. Dobutamine stress during coronary angiogra phy caused increased mechanical compression during diastole. This was accompanied by multiple premature ventricular contractions. After a de bridging operation the flow velocity reserve was normal. The abnormali ties found during dobutamine stress had disappeared. Unexpectedly, a s pasm was inducible. This may have been due to local oedema or scar for mation after the operation. For the evaluation of the haemodynamic imp ortance of myocardial bridging, intracoronary Doppler flow velocity me asurements and angiography during dobutamine stress may be helpful in clinical decision making.