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Biomedical subjects

E Lyons

Publications and source records attributed to E Lyons.

30 records · Page 2Linked to original sources
PubMed1989

Effect of exercise level on the ability of thallium-201 tomographic imaging in detecting coronary artery disease: analysis of 461 patients.

This study examined the effect of the level of exercise on the ability of thallium-201 imaging with single photon emission computed tomography (SPECT) to detect coronary artery disease. Patients in group 1 (n = 164) achieved adequate exercise end points, defined as positive exercise electrocardiograms or greater than or equal to 85% of maximal predicted heart rate. Patients in group 2 (n = 108) had submaximal exercise. The SPECT thallium-201 images showed perfusion defects in 74%, 88%, and 98%, respectively, of patients with one, two and three vessel coronary artery disease in group 1, compared with 52%, 84% and 79%, respectively, of such patients in group 2 (p less than 0.05). Perfusion defects showed partial or complete redistribution consistent with ischemia in 56%, 80% and 88%, respectively, of patients with one, two and three vessel coronary artery disease in group 1 compared with 35%, 58% and 56%, respectively, of such patients in group 2 (p = 0.08, less than 0.03 and less than 0.001, respectively). Of 58 patients with normal coronary angiograms or less than 50% diameter stenosis, 36 (62%) had normal SPECT images. In a separate group of 131 patients with less than 5% pretest probability of coronary artery disease, the specificity was 93%. The sensitivity of exercise SPECT imaging in group 1 was higher than that of ST segment depression (p less than 0.001). Thus, the level of exercise affects the results of SPECT thallium imaging in the localization and evaluation of the extent of coronary artery disease and the detection of ischemia.

Coronary Angiography↗
PubMed1989

Use of technetium-99m isonitrile (RP-30A) in assessing left ventricular perfusion and function at rest and during exercise in coronary artery disease, and comparison with coronary arteriography and exercise thallium-201 SPECT imaging.

This study compared the results of stress and rest single-photon emission computed tomography imaging of myocardial perfusion using technetium-99m isonitrile (RP-30A) with the results of stress and redistribution tomographic thallium imaging and the results of coronary arteriography in 39 patients, 11 without and 28 with coronary artery disease (CAD). Each patient underwent 2 exercise studies at identical workload, heart rate and double product. In a subset of 13 patients, concomitant evaluation of left ventricular (LV) function using first-pass radionuclide angiography with a multi-crystal camera also was performed with bolus injections of isonitrile. Isonitrile had similar sensitivity (82 vs 82%, difference not significant), a slightly--but not significantly--higher specificity (100 vs 82%) and similar predictive accuracy (87 vs 82%) to thallium-201. The tracer uptake was assessed in 20 segments/study. There was concordance between the isonitrile and thallium-201 images in 723 of the 780 segments (93%) (kappa = 0.83 +/- 0.02). In general, the isonitrile images were considered of better quality than the thallium-201 images. All 10 patients with CAD who underwent concomitant first-pass radionuclide angiography had either perfusion abnormalities or an abnormal ejection fraction response to exercise. Thus, technetium-99m isonitrile provides a reliable method of assessment of CAD with a sensitivity, specificity and predictive accuracy comparable to that of exercise thallium-201 imaging. Additional advantages include better image quality and the ability to obtain concomitant assessment of LV function with the use of first-pass radionuclide angiography.

Angiography↗
PubMed1989

Use of oral dipyridamole SPECT thallium-201 imaging in detection of coronary artery disease.

This study examined the merits of oral dipyridamole SPECT thallium-201 imaging in detecting CAD and multivessel CAD. The 65 patients included in this study (aged 62 +/- 11 years) were not candidates for exercise testing (for the usual reasons). Coronary arteriography revealed no significant CAD in 17 patients and greater than or equal to 50% narrowing of one or more vessels in 48 patients; 12 had one-vessel and 36 had multivessel CAD (high-risk group). Thallium-201 was injected intravenously 45 minutes after an oral dose of 375 mg of dipyridamole, and SPECT imaging was performed within 10 minutes and 4 hours after injection. There were no serious side effects; only six patients (8%) had ST segment depression and 18 patients (28%) had chest pain. The heart rate increased from 74 +/- 15 beats/min at rest to 84 +/- 14 beats/min at peak effect (p = 0.001); the systolic blood pressure did not change (130 +/- 18 and 128 +/- 20 mm Hg, respectively, p = NS). The thallium images were abnormal in 6 of 17 patients (35%) with no CAD, in 7 of 12 patients with one-vessel disease (58%), and in 34 of 36 patients with multivessel CAD (94%) (p = 0.001). Twenty-one of 25 patients (84%) with a perfusion abnormality in more than one vascular territory had multivessel CAD assessed by angiography. Thus oral dipyridamole SPECT thallium-201 imaging is a safe and inexpensive method for the detection of CAD in patients who are otherwise not candidates for exercise testing.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1989

Late maternal age and postdate pregnancy.

Charts of 443 postdate pregnancies were reviewed to determine the effect of late maternal age on pregnancy outcome. There were significantly more low 1-minute Apgar scores, intrapartum decelerations, and cesarean sections in the group of women greater than 35 years old. Use of oxytocin percentages and the results were similar with regard to both groups. Five-minute Apgar scores also were similar. Women greater than 35 years of age are less able to be delivered of postdate infants with optimal outcomes, but it is still safe to allow them to exceed 42 weeks' gestation.

Adult↗
PubMed1979

Real-time ultrasound observation of fetal activity in labour.

Fetal activity was observed by realtime ultrasound for one hour in 25 patients in labour. Fetal respiratory movement, although reduced compared to the antenatal period, was observed in 13 patients. In three patients, hiccough-like movements were noted. Fetal body and/or extremity movements were observed in all patients (mean 41/hour) and frequently occurred in episodes. These bursts of movements were significantly correlated with contractions and fetal heart rate (FHR) accelerations. There was a significant association between absent or reduced number of fetal respiratory movements and/or hiccoughs (10 or less/hour) and an abnormal FHR. Absence of any type of fetal activity was also significantly associated with an abnormal FHR. The correlation between fetal activity and conventional methods of fetal assessment is discussed.

Female↗
PubMed1977

Creatine kinase and its isoenzymes in the serum of women during pregnancy and the peripartum period.

In serum obtained from 28 women before, during, and after normal labor and delivery, creatine kinase activity was seen to be distinctly elevated immediately after labor and 24 h later, but had returned to normal six weeks later. In most cases the increase was due to the MM isoenzyme and was attributed to skeletal-muscle damage associated with labor. In 15 cases, the BB isoenzyme was observed, and in three patients the MB isoenzyme. Cord blood, which contains all three isoenzymes, may be the source of the MB and BB isoenzymes. Uterine muscle contains exclusively BB isoenzyme, and therefore uterine muscle damage is a likely source of the serum BB isoenzyme. The relationship among these isoenzymes in serum after delivery must be recognized, to avoid misdiagnosing myocardial infarction at this critical time.

Creatine Kinase↗