Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ten elderly patients each had a ventricular rate responsive pulse generator (Activitrax) placed in them to help correct severe conduction abnormalities; none had suspected ischemic heart disease. The pulse generator was programmed to a maximal pacing rate of 125 ppm, a medium activity threshold, and a rate response of 6. Six weeks after implantation of the pulse generator, the patients were evaluated before exercising and again when the pacing rate reached 125 ppm. The evaluation protocol included an M-mode echocardiogram from which the following measurements were taken: the left ventricular end-diastolic volume (EDV), the end-systolic volume (ESV), the ejection fraction (EF), and the peak systolic pressure/end-systolic volume (PSP/ESV). The numerical values were recorded, calculated, and compared statically with the following results: the EDV increased from 91 +/- 10 to 125 +/- 20 cc (p less than .05); the ESV decreased from 64 +/- 10 to 24 +/- 6 cc (p less than .005); the EF increased from 41 +/- 5 to 61 +/- 10% (p less than .05); and the PSP/ESV ratio increased from 1.70 +/- 1 to 4.10 +/- 2 mm Hg/cc (p = 10). Also, during the maximal pacing rate, the septum of all patients showed paradoxical septal motion. All patients in our study have been asymptomatic and have shown an increase in their exercise capacity. We conclude that during exercise the left ventricular function ins influenced more by heart rate than by AV synchrony, as indicated by an elevated EDV in most patients.
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PMID:The use of biosensors in pacemaker technology: experience with a ventricular rate responsive pacemaker. 187 75

Unstable coronary artery disease (CAD) might be related to obstructions of coronary blood flow by platelet aggregates. In 121 men and 43 women admitted to the coronary care unit with suspected unstable CAD, blood samples for tests of platelet function were obtained within 24 hours after admission. Platelet reactivity was tested in vitro in platelet rich plasma as the aggregability towards ADP 1 microM and collagen 1 mg/ml and as the sensitivity to prostacyclin (PSP). The levels of beta-thromboglobulin and platelet factor 4 were determined ex vivo in platelet poor plasma. Patients who developed a nontransmural myocardial infarction (n = 39) or had signs of myocardial ischemia at an exercise test performed within a week (n = 39) were considered to have unstable CAD while patients without signs of ischemia constituted the control group. In the acute phase the PSP was reduced in patients with unstable CAD without any difference between genders. The aggregability towards ADP was higher in women than men but otherwise there were no differences between groups or sexes in any other test in the acute phase. After 12 months there were no differences in PSP between the groups but women had a lower PSP than men. Thus, in the acute phase of unstable CAD, the platelet sensitivity to the inhibitory effects of prostacyclin was reduced which might contribute to the risk for further platelet aggregation, coronary occlusion and myocardial infarction.
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PMID:Platelet reactivity in unstable coronary artery disease. 295 54