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Real time myocardial contrast echocardiography (RTMCE) is a cost-effective and simple method to quantify coronary flow reserve ( CFR). We aimed to determine the value of RTMCE to predict cardiac events after percutaneous coronary intervention ( PCI). We have studied myocardial blood volume (A), velocity ( β), flow indexes ( MBF, A × β), and vasodilator reserve (stress-to-rest ratios) in 36 patients with acute coronary syndrome ( ACS) who underwent PCI. CFR ( MBF at stress/ MBF at rest) was calculated for each patient. Perfusion scores were used for visual interpretation by MCE and correlation with TIMI flow grade. In qualitative RTMCE assessment, post- PCI visual perfusion scores were higher than pre- PCI (Z = −7.26, P < 0.01). Among 271 arteries with TIMI flow grade 3 post- PCI, 72 (36%) did not reach visual perfusion score 1. The β- and A × β-reserve of the abnormal segments supplied by obstructed arteries increased after PCI comparing to pre- PCI values (P < 0.01). Patients with adverse cardiac events had significantly lower β- and lower A × β-reserve than patients without adverse cardiac events. In the former group, the CFR was ≥ 1.5 both pre- and post- PCI. CFR estimation by RTMCE can quantify myocardial perfusion in patients with ACS who underwent PCI. The parameters β-reserve and CFR combined might predict cardiac events on the follow-up. [ABSTRACT FROM AUTHOR]

Abstract: Aims: To investigate the cardiovascular regulatory mechanism of adenosine A2A receptor (A2AR) in the rostral ventrolateral medulla (RVLM) in acute myocardial ischemic (AMI) rats. Main methods: The animal model of AMI was established by ligating the left anterior descending coronary artery (LAD). The A2AR expression was examined by immunohistochemistry, western blot and real-time PCR. CGS21680 and SCH58261 (an agonist and antagonist of A2AR) were respectively microinjected into the RVLM. In a subgroup of rats, PD98059 (an antagonist of extracellular signal-regulated kinase (ERK1/2)) was microinjected prior to CGS21680 administration. Phosphorylation of ERK1/2 was examined by western blot. Key findings: Our results demonstrated that A2AR immunoreactive positive neurons, the expressions of protein and mRNA of A2AR in the RVLM of AMI group were increased compared with the sham group. Microinjection CGS21680 into the RVLM inhibited mean arterial pressure (MAP) and heart rate (HR) in both AMI and sham groups. The inhibition was significantly greater in AMI group than in sham group. The cardiovascular effects of CGS21680 mentioned above were almost abolished by prior administration of PD98059. The increase of ERK1/2 in the RVLM with the cardiovascular responses was induced by CGS21680 in AMI rats; this effect was also blocked by SCH58261. Significance: This study reveals that the activated A2AR in the RVLM underlies the depressor and bradycardiac responses in AMI rats via phosphorylation of ERK1/2 increasing. [Copyright &y& Elsevier]