Evaluation of regional myocardial perfusion in methamphetamine abusers using real-time myocardial contrast echocardiography.

Abstract

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.Materialand methods: Twenty-two male methamphetamine abusers (11 without chest pain, 11 with chest pain), free of ascertainedcoronary artery disease, were enrolled in this study. A control group of 22 age-matched male healthy participants was studiedfor 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. Compared to healthyparticipants, methamphetamine abusers had higher blood pressure, greater left ventricular mass index and more impaireddiastolic function, with preserved cardiac sizes and systolic function. Methamphetamine abusers with chest pain had a fasterheart rate than those without chest pain and healthy participants. MCE in methamphetamine abusers, especially with chestpain, had significant longer contrast agent arrival times, less functional capillary blood volumes, slower microvascular flowvelocities and less myocardial perfusion than healthy participants (p<0.05). Moreover, along with the increases of dosage andduration 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, >5years) the reductions in the myocardial perfusion indices were more significant (p<0.01). The cutoff value with 5.1 dB2/s ofthe myocardial perfusion at the left ventricular apex had a sensitivity of 87.5%, specificity of 75.2% and accuracy of 81.9% fordifferentiating methamphetamine abusers from normal subjects. Real-time MCE can effectively detect coronarymicrocirculation abnormalities in methamphetamine abusers at rest and myocardial perfusion is significantly reduced in methamphetamineabusers. This finding may be involved in the occurrence and development of cardiac damage.