Value and limitations of intravascular ultrasound imaging in characterizing coronary atherosclerotic plaque

Acute myocardial infarction caused by a myocardial bridge treated with intracoronary stenting

The clinical significance of myocardial bridges (MBs) is variable, and most patients are asymptomatic. However, angina, myocardial infarction, and sudden death have been reported in association with MBs. Here we describe the use of intracoronary stenting for the treatment of a patient with an anterior myocardial infarction due to an MB.

Frequency, duration, magnitude, and consequences of myocardial ischemia during intracoronary ultrasonography

To determine the frequency, duration, magnitude, and possible adverse effects of ischemia during intracoronary ultrasonography, real-time standard 12-lead electrocardiograms were recorded before, during, and after ultrasonography. Ischemia was defined as new-onset ST segment deviation of > or = 1 mm in one or more leads, measured at J + 80 msec. The magnitude of ischemia was expressed as the sum of absolute ST segment deviations across 12 leads. Eighteen (67%) of 27 patients had ischemia during intracoronary ultrasonography. The electrocardiogram resembled the characteristic pattern observed with occlusion of the vessel under study, involving ST segment elevation in contiguous leads in 89% of patients. A higher proportion of women (88%) had ischemia than men (58%), and women had smaller arterial lumenal areas compared with men (6.3 vs 9.1 mm2; p < 0.05). Individuals with ischemia were smaller than those without ischemia (body surface area = 1.99 vs 1.79 m2; p = 0.01). The mean duration of ischemia was 4 minutes and the mean 12-lead ST segment deviation score was 8.5 mm (maximum 20.5 mm). No patient with ischemia during ultrasonography had complications. Ischemia is common during intracoronary ultrasonography, particularly in women and individuals with smaller vessels; however, no adverse outcomes occur as a result.