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 st andard 12-lead electrocardiograms were recorded before, during, and af ter ultrasonography. Ischemia was defined as new-onset ST segment devi ation of greater than or equal to 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 p atients had ischemia during intracoronary ultrasonography. The electro cardiogram resembled the characteristic pattern observed with occlusio n of the vessel under study, involving ST segment elevation in contigu ous leads in 89% of patients. A higher proportion of women (88%) had i schemia than men (58%), and women had smaller arterial lumenal areas c ompared with men (6.3 vs 9.1 mm(2); p < 0.05). Individuals with ischem ia were smaller than those without ischemia (body surface area = 1.99 vs 1.79 m(2); P = 0.01). The mean duration of ischemia was 4 minutes a nd the mean 12-lead ST segment deviation score was 8.5 mm (maximum 20. 5 mm). No patient with ischemia during ultrasonography had complicatio ns. Ischemia is common during intracoronary ultrasonography, particula rly in women and individuals with smaller vessels; however, no adverse outcomes occur as a result.