Symptomatic myocardial bridges: overview of ischemic mechanisms and current diagnostic and treatment strategies
Martial G. Bourassa, MD, FACC*,*,
Ady Butnaru, MD*,
Jacques Lespérance, MD* and
Jean-Claude Tardif, MD, FACC*
* Department of Medicine and Research Center, Montreal Heart Institute, Montreal, Quebec, Canada
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Figure 1 Coronary angiogram of a patient with myocardial bridging of the left anterior descending coronary artery in the right anterior oblique position. (A) An absence of constriction during diastole is shown. (B) This depicts the "milking effect" during systole (arrow).
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Figure 2 Intracoronary Doppler blood flow velocity profile showing the characteristic "finger-tip"-like flow velocity acceleration during early diastole (single arrow) followed by a plateau phase at mid-to-late diastole (arrows in A and B). During systole, there is almost no flow within the bridged segment, but a retrograde flow phenomenon occurs at the entry site of the myocardial bridge (arrows in A). During rapid atrial pacing, absolute diastolic flow velocities are increased, and the duration of the plateau phase is reduced owing to shortened diastole (C). Reproduced from Schwarz et al. (13), with permission.
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Figure 3 Intravascular ultrasound imaging of the myocardial bridging in diastole (A) and in systole (B). A typical half-moon-shaped echolucent area surrounds the bridge during the entire cardiac cycle (arrows). Note the catheter artifact in diastole (A) at seven o’clock.
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