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

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.

Findings on 3D speckle tracking echocardiography in asymptomatic methamphetamine abusers.

To detect potential cardiac abnormalities in asymptomatic methamphetamine abusers using three-dimensional speckle tracking echocardiography (3D STE). Fifty-three male methamphetamine abusers, free of cardiac symptoms/signs, were enrolled in this study. A control group of 53 age-matched male normal subjects was studied for comparison. Standard 3D, flow and tissue Doppler echo with measurements of left ventricular end-diastolic volume (LVEDV), end-systolic volume (LVESV), ejection fraction (LVEF), the ratio of the early to late diastolic transmitral filling velocity (E/A), the ratio of the early diastolic transmitral filling velocity to the early diastolic septal tissue velocity (E/E') and 3D STE with measurements of global area strain (GAS), global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) were performed, respectively. These echocardiographic parameters were compared between methamphetamine abusers and normal subjects, and receiver operating characteristic curve (ROC) analysis was done to differentiating methamphetamine abusers from normal subjects. LVESV, LVEDV, LVEF, E/A, E/E' ratios and GRS were not significantly different between methamphetamine abusers and normal subjects (p > 0.05). However, GAS, GLS and GCS were significantly less in methamphetamine abusers than in normal subjects (p < 0.05). The areas under ROC (AUC) for GAS were greatest among all the 3D STE derived LV global strains (GAS vs. GLS, GCS and GRS, 0.95 vs. 0.76, 0.69 and 0.61, respectively). The cutoff value with - 30.3% of GAS had sensitivity of 91.8%, specificity of 91.6% and accuracy of 91.3% for differentiating methamphetamine abusers from normal subjects. The potential myocardial function abnormalities can be detected by 3D STE in asymptomatic methamphetamine abusers, and GAS is a good indicator for indentifying methamphetamine abusers from normal population, which can be used to screening and monitor methamphetamine abuse, detect subclinical LV dysfunction, predict potential methamphetamine-related cardiotoxicity, and to initiate early cardioprotective therapy before the onset of overt heart failure in time.