Aims: To evaluate the feasibility of assessing regional myocardial perfusion using real-time myocardial contrast echocardiography (MCE) at rest for detecting coronary microcirculation abnormalities in methamphetamine abusers.Material and methods: Twenty-two male methamphetamine abusers (11 without chest pain, 11 with chest pain), free of ascertained coronary artery disease, were enrolled in this study. A control group of 22 age-matched male healthy participants was studied for comparison. Standard 2D, flow and tissue Doppler echo with measurements of cardiac morphologic and functional indicators,MCE with measurements of regional myocardial perfusion were performed, respectively.Results: Compared to healthy participants, methamphetamine abusers had higher blood pressure, greater left ventricular mass index and more impaired diastolic function, with preserved cardiac sizes and systolic function. Methamphetamine abusers with chest pain had a faster heart rate than those without chest pain and healthy participants. MCE in methamphetamine abusers, especially with chest pain, had significant longer contrast agent arrival times, less functional capillary blood volumes, slower microvascular flow velocities and less myocardial perfusion than healthy participants (p<0.05). Moreover, along with the increases of dosage and duration of use (from group A to group C, group A: 1-2 g/day, <2 years; group B: 2-3 g/day, 2-5 years; group C: >3 g/day, >5 years) the reductions in the myocardial perfusion indices were more significant (p<0.01). The cutoff value with 5.1 dB2/s of the myocardial perfusion at the left ventricular apex had a sensitivity of 87.5%, specificity of 75.2% and accuracy of 81.9% for differentiating methamphetamine abusers from normal subjects.Conclusions: Real-time MCE can effectively detect coronary microcirculation abnormalities in methamphetamine abusers at rest and myocardial perfusion is significantly reduced in methamphetamine abusers. This finding may be involved in the occurrence and development of cardiac damage.
752-3 Evaluation of Regional Myocardial Perfusion in Early Pacing-induced Left Ventricular Dysfunction Using Myocardial Contrast Echocardiography
