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Background: Clinical improvement after transmyocardial laser revascularization (TMR) is typically delayed, and patients therefore remain at risk for ischemic events after the procedure. The purpose of this study was to define the range of creatine phosphokinase (CPK) and CPK-MB enzyme elevation after TMR and to assess the incidence of early postoperative ischemic events., Methods: Twenty-one patients undergoing isolated TMR were evaluated for 48 hours after surgery with serial CPK and CPK-MB enzymes and 12-lead electrocardiograms for evidence of myocardial ischemia or injury. Clinically evident postoperative ischemic events including angina pectoris, myocardial infarction (MI), and cardiac death were recorded as well., Results: Eleven patients (52.4%) had ischemic electrocardiographic changes in the first 48 hours after TMR. Ischemia was clinically silent in 7 (63.6%) of these 11 patients. Cardiac death occurred in 1 patient (4.8%) as a result of acute MI. Nonfatal MI occurred in an additional 4 patients (19.0%). Of the 5 patients with MI, 4 had angina pectoris versus no angina in the 16 patients without MI (P =.02). All patients had elevated CPK and CPK-MB levels after TMR: however, peak CPK (P =.02) and CPK-MB (P =. 005) levels were significantly higher for patients suffering postoperative MI compared with those without MI., Conclusions: Transient ischemia occurs frequently after TMR and is clinically silent in the majority of patients. Patients with postoperative MI are more likely to have symptomatic ischemia as well as significant cardiac enzyme elevation. The combination of 12-lead electrocardiogram and cardiac enzymes appears to have significant merit for the diagnosis of myocardial ischemia and infarction after TMR. These studies should be obtained in all patients undergoing TMR for the first 48 hours after surgery.

Doppler tissue imaging (DTI) is a new noninvasive imaging modality that directly interrogates myocardial velocity with high temporal and spatial resolution. This study was designed to test the hypothesis that quantitative DTI provides unique information regarding regional myocardial systolic and diastolic function during acute ischemic events. Myocardial velocities were quantified during the acute ischemic and reperfusion phases of 13 elective percutaneous coronary angioplasty procedures in 12 patients. In myocardium subtended by angioplasty vessels, peak velocities decreased during occlusive balloon inflation (from 21.2 +/- 9.8 to -0.6 +/- 4.0 mm/sec in systole [p < 0.001] and from 21.7 +/- 9.2 to -0.6 +/- 3.9 mm/sec in diastole [p < 0.001]). During early reperfusion, velocities exceeded those observed at baseline (p = 0.003). In regions remote from the treated artery, peak myocardial velocities increased in the absence of significant stenosis but remained unchanged or decreased in the presence of significant stenosis of the associated vessel. We conclude that (1) myocardial velocities rapidly decrease during acute ischemia and show a rebound increase after reperfusion, and (2) in regions remote from ischemia, velocities display distinct patterns on the basis of the presence or absence of obstructive coronary disease in the associated vessel. Quantitative DTI is a useful tool for the assessment of myocardial velocity and may provide new insights into myocardial systolic and diastolic function.

Doppler tissue imaging (DTI) is a new echocardiographic imaging technique from which quantitative data regarding myocardial velocity can be extracted. The purpose of this study was to compare endocardial velocities determined from DTI with those determined from M-mode echocardiography and to assess the range of myocardial velocities in normal subjects. Nineteen subjects were evaluated by M-mode echocardiography and quantitative DTI for maximal systolic velocities of the anteroseptal and inferoposterior walls. Mid-myocardial and epicardial velocities were also measured by DTI for each wall. Maximal systolic velocities of the anteroseptal and inferoposterior endocardium determined by DTI correlated significantly with those derived from M-mode echocardiography (r = 0.87). The velocity of the inferoposterior wall by DTI (27.3 +/- 4.8 mm/sec) was greater than that of the anteroseptum (20.8 +/- 4.1 mm/sec) by a mean difference of 7.0 +/- 5.7 mm/sec (p < 0.001). A peak velocity gradient of 5.9 +/- 3.5 mm/sec (p < 0.001) between the epicardium to endocardium was detected. These data confirm that (1) regional myocardial velocities may be quantified with DTI in human beings; (2) the high resolution of DTI allows velocities to be determined at different levels within the myocardium; and (3) heterogeneity of myocardial velocities may be demonstrated in normal subjects.