Controlled coronary sinus occlusion was shown to retard necrosis of ischemic myocardium. To elucidate this mechanism, regional myocardial blood flow measurement was performed with and without coronary sinus pressure elevation to 30 mmHg (CS30). Colored microspheres were injected into left and right coronary arteries after coronary perfusion of the left anterior descending (LAD) coronary artery was stopped in seven isolated canine hearts with induced atrioventricular block, either paced at 120 beats/min by direct right ventricular stimulation [beating heart (B)] or during asystole induced by stopping pacing [nonbeating heart (NB)]. Regional myocardial blood flow in the LAD perfused area in the control state in the NB with normal coronary sinus pressure (NB-CScont; 0.27 +/- 0.13 ml.min-1.g-1, means +/- SE) was significantly greater than those in B-CScont (0.19 +/- 0.09 ml.min-1.g-1; P < 0.05) and in NB with CS30 (NB-CS30; 0.19 +/- 0.09 ml.min-1.g-1; P < 0.05). Regional myocardial blood flow of the LAD area in B with CS30 (B-CS30; 0.23 +/- 0.10 ml.min-1.g-1) was significantly greater in comparison with that at B-CScont and NB-CS30 (P < 0.05). The augmentative effect of the LAD area regional myocardial blood flow was observed only in the periphery of the ischemic region but not in its center. Cardiac contraction and CS30 impede regional myocardial blood flow in the ischemic bed independently. The coexistence of these two factors enhances regional myocardial blood flow. In conclusion, coronary sinus pressure elevation in B may participate in augmenting collateral flow.
SummaryPaget-Schroetter syndrome (PSS) is thrombosis of the deep veins draining the upper extremity due to anatomic abnormalities of the thoracic outlet that cause subclavian compression and subsequent thrombosis, leading to thrombus formation in the subclavian vein. Vigorous arm activity in sports is a known risk factor. Here, we report a case of PagetSchroetter syndrome in a 31-year-old male non-professional baseball pitcher. (Int Heart J 2017; 58: 637-640)
Inhibitors of cyclic nucleotide phosphodiesterase hydrolysis of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate are known to inhibit platelet aggregation, which plays an important role in acute reocclusion after thrombolysis in acute myocardial infarction. In the present study of a canine preparation of coronary artery thrombosis superimposed on high-grade stenosis, we tested whether the antithrombotic agent cilostazol, an inhibitor of cAMP phosphodiesterase, could prevent acute reocclusion or sustain coronary blood flow after thrombolysis when used with recombinant tissue-type plasminogen activator (rt-PAJ and heparin. Intravenous infusion of rt-PA (0.5 mg/kg body wt for 30 minutes) and heparin (a 150 11)/kg body wt i.v. bolus and then 25 IU/kg body wt per hour i.v.) was combined with cilostazol (0.6 or 1.8 mg/kg body wt for 60 minutes). Without cilostazol, reperfusion was observed in seven of eight dogs, but reocclusion occurred in six of these seven dogs after 9±2 minutes. After administration of 1.8 mg/kg body wt cilostazol (group B-2; a 120-minute observation after the start of rt-PA infusion), reperfusion occurred in all seven dogs (p<0.05 versus control group), and brief cyclic reocclusion was observed in only one dog 63 minutes after reperfusion. At the same dose of cilostazol (group B-2L; a 240-minute observation after the start of rt-PA infusion), reperfusion occurred in all five dogs (p<0.05 versus control group), and coronary blood flow was well maintained except for one short reocclusion in one dog. Cilostazol inhibited cyclic flow reduction in a dose-dependent fashion. We conclude that cilostazol is a new potent antiplatelet agent for preventing reocclusion after coronary thrombolysis, when used in combination with rt-PA and heparin. (
SUMMARYIt remains to be determined whether adding an angiotensin-converting enzyme inhibitor (ACEI) or an angiotensin II receptor blocker (ARB) to antiplatelet therapy has a therapeutic benefit on in-stent restenosis.After successful coronary stenting, 165 patients (167 lesions) were randomly assigned to a basal (aspirin 162 mg + cilostazol 200 mg/day), ACEI (basal treatment + quinapril 10 mg or perindopril 4 mg/day), or ARB (basal treatment + losartan 50 mg/day) treatment group. Quantitative coronary angiography was performed before, immediately following, and 6 months after stenting. Follow-up coronary angiography was completed in 126 patients (128 lesions). Restenosis rates tended to be higher (12, 26, and 12% for the basal, ACEI, and ARB groups, respectively), and target lesion revascularization rates were higher in the ACEI group than in the other groups (9, 23,* and 5%, respectively, *P < 0.05 versus basal group). Moreover, late lumen loss was higher in the ACEI group than in the basal group (0.60 ± 0.55, 0.98 ± 0.61* and 0.73 ± 0.64 mm in the basal, ACEI, and ARB groups, respectively).The combinations of an ACEI or ARB with aspirin and cilostazol are ineffective for the prevention of in-stent restenosis, and an ACEI may even promote intimal proliferation after stent implantation. (Int Heart J 2006; 47: 173-184)
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