Efficacy of calcium channel blockers in the treatment of the myocardial bridging: a pilot study.

BACKGROUND

Myocardial Bridging (MB) is defined as a segment of a major epicardial coronary artery, the "tunnelled artery", that goes intramurally through the myocardium beneath the muscle bridge.

MATERIALS AND METHODS

A 69-year-old male patient with a story of arterial hypertension and dyslipidemia in treatment with converting enzyme inhibitors (ACE-I), antiplatelet therapy and HMG-CoA reductase inhibitors and calcium channel blockers, presented with anginal-like chest pain and dyspnea. The coronary angiography showed a myocardial bridging and no hemodynamically significant coronary artery disease.

RESULTS

On admission in our Department, the exercise cyclo ergometer test was significant for > 3 mm ST segment depression in the anterior and lateral leads (V3, V4, V5, V6) associated with chest pain. The coronary angiography revealed a 40% stenosis of the distal tract of the right coronary artery (RCA), a 30% stenosis of the proximal tract of the left anterior descending artery (LAD) and 40% of the proximal tract of the first diagonal branch. A 30% stenosis in the middle tract of the left circumflex coronary artery (LCX) was then detected. A marked systolic localized narrowing (90%) on the middle tract of the LAD, after the second diagonal branch (a myocardial bridge) was also detected. After eight months, the exercise cyclo ergometer test using a standard Bruce protocol was normal and, after sixteen months, no significant coronary artery disease (< 50%) and no myocardial bridging were detected by the coronary 64-multislice spiral computed tomography. Two years later, the patient was readmitted to our Department because of angina-like chest pain during light exertion in the last two months. The coronary angiography of the right system revealed a 30% stenosis of the proximal tract and a 50% stenosis of the distal tract of the RCA. The coronary angiography of the left system showed a 30% stenosis of the proximal tract of the LAD and 85% of the middle tract of the first diagonal branch. A 40% stenosis in the middle tract of the left circumflex coronary artery (LCX) was then detected. No MB of the middle tract of the LAD was detected, and a bare metal stent (Presillion 2.5 x 12 mm) was deployed in the middle tract of the first diagonal branch.

CONCLUSIONS

After 2 years, the administration of the calcium channel blockers has been effective in the treatment of the MB but no effect on the atherosclerotic plaque growth has been demonstrated.