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T Tajimi

Publications and source records attributed to T Tajimi.

At least 37 records · Page 2Linked to original sources
PubMed1984

Effects of beta-blockade on regional myocardial flow and function during exercise.

We examined the effects of a cardioselective beta-blocking drug on exercise-induced regional myocardial ischemia in 10 conscious dogs with chronic coronary artery stenosis. An ameroid constrictor, Doppler flowprobe, and hydraulic cuff were placed around the left circumflex coronary artery, and left ventricular pressure (LVP), systolic wall thickening (% delta WT; by sonomicrometry), and myocardial blood flow (MBF; microspheres) were measured during control standing, control treadmill exercise, and identical exercise after atenolol (1 mg/kg po). Prior to study, in every dog % delta WT and MBF in the ischemic area were normal at rest, indicating collateral development. During control exercise, % delta WT in the ischemic region markedly decreased from 27 to 4%, and transmural ischemia was evident in that region. Heart rate, systolic LVP, and LV (+)dP/dt were significantly lower during exercise after atenolol than during control exercise. % delta WT in the normal area was only 81% of that during control exercise, but dysfunction in the ischemic area was improved (77% increase compared with control exercise). Accompanying the improved function was a significant increase of MBF/beat and relative MBF in the ischemic zone; the endocardial-to-epicardial ratio increased from 0.27 to 0.47. Thus atenolol improved regional MBF distribution, thereby diminishing exercise-induced regional myocardial dysfunction and accelerating its recovery.

Adrenergic beta-Antagonists↗
PubMed1984

Effects of a calcium-entry blocker (diltiazem) on regional myocardial flow and function during exercise in conscious dogs.

We examined the effects of diltiazem, a calcium-entry blocker, on exercise-induced myocardial ischemia in nine conscious dogs with chronic coronary stenoses. An ameroid constrictor, Doppler flow probe, and hydraulic occluder were placed around the left circumflex coronary artery, and left ventricular pressure was measured (Konigsberg micromanometer). Pairs of ultrasonic crystals were implanted for measuring left ventricular systolic wall thickening (% delta WTh) in control (left ventricular anterior wall) and ischemic (left ventricular posterior wall) regions, and regional myocardial blood flow was measured with the microsphere method. Eighteen days (average) after surgery mean coronary blood flow velocity had decreased and reactive hyperemic flow velocity after 10 sec of coronary occlusion was markedly reduced, but % delta WTh at rest remained normal, indicating collateral development. Control treadmill exercise was performed for 3.7 min (average), and 2 hr later administration of 0.3 mg/kg diltiazem was followed by an identical exercise bout. Control exercise increased % delta WTh in the normal region, while in the ischemic region % delta WTh decreased markedly and ischemia was evident (subendocardial flow, 0.29 +/- 0.12[SD] ml/min/g). After diltiazem hemodynamic and % delta WTh values at rest were not changed; during exercise the heart rate was significantly lower (204 +/- 24 vs 227 +/- 33 beats/min, p less than .01), but values for other hemodynamic measures were similar to those during the control run. % delta WTh in the control region was not changed during exercise after diltiazem, but compared with control exercise in the ischemic zone there was less dysfunction and subendocardial flow was greater. Recovery from exercise-induced dysfunction in the ischemic region occurred within 5 min, compared with over 30 min after control exercise. Thus, in a preparation of chronic coronary stenosis, the calcium-entry blocker improved the relationship between regional myocardial flow and function during exercise and led to more rapid recovery of regional myocardial dysfunction.

Animals↗
PubMed1983

Evaluation of pulse contour methods in calculating stroke volume from pulmonary artery pressure curve (comparison with aortic pressure curve).

The reliability of five equations in assessing stroke volume from pulmonary artery pressure curves were critically evaluated in six dogs and in six patients. To alter stroke volume, isoproterenol, dobutamine, propranolol, lactate Ringer solution and artificial pacing were employed in the animal study and diltiazem (a calcium blocker) in the human study. A good correlation was found between the calculated and measured stroke volume (r = 0.80-0.86 in the animal study and r = 0.94-0.96 in the human study). The assessment of stroke volume from the pulmonary arterial pressure curves using equations was as good as that from the aortic pressure curves calculated simultaneously. These results suggest that the five equations may be clinically applicable for assessing stroke volume in critically ill patients. The employment of pulmonary arterial pressure curves in assessing stroke volume may be more useful clinically since its recording can be carried out more safely than recordings of aortic pressure curves.

Animals↗
PubMed1982

Multiple atherosclerotic coronary aneurysms in association with acute myocardial infarction.

A 60-year-old woman with multiple coronary aneurysms, complicated with acute infero-posterior myocardial infarction is presented. The cine-coronary arteriogram disclosed a diffuse dilatation of epicardial coronary arteries associated with multiple aneurysms, fusiform ones in the right coronary and the left circumflex coronary arteries and saccular ones in the left anterior descending coronary artery. Distal run-off was poor. Ventriculography revealed a decrease in the ejection fraction (36%) and segmental abnormal wall motion at the apical and infero-posterior regions. The cause of the aneurysms appeared to be atherosclerotic. We suggested that coronary embolization was the cause of acute myocardial infarction in this case.

Aneurysm↗
PubMed1981

Coronary arterial spasm in single coronary artery.

A 48-year-old man developed severe chest pain and became unconscious. Coronary cineangiography revealed single coronary artery of the type L2b by Sharbaugh and White. Ergonovine, 0.2 mg i.v., produced coronary arterial spasm in the right coronary artery. This case suggests that coronary arterial spasm might be a cause of sudden death in patients with single coronary artery. However, an association of single coronary artery and coronary arterial spasm might be coincidental.

Coronary Angiography↗
PubMed1977

Long-lasting effect of oral molsydomine on exercise performance: a new antianginal agent.

This study examines whether the beneficial effects of molsydomine, a recently introduced antianginal agent, on exercise performance of patients with angina pectoris are long lasting. The hemodynamic effects are known to persist for several hours. The effects of molsydomine on the duration of exercise and the time to the onset of ST depression were compared to those of placebo during two hours after oral administration. Molsydomine prolonged the duration of exercise in all eight patients (average 2.8 min, P less than 0.001) and delayed the onset of ST depression (average 2.2 min, P less than 0.001), while the placebo failed to alter these measurements. The increment of the duration of exercise produced by 2 mg of molsydomine in two hours following oral administration was comparable to the increment produced in a few minutes after 0.3 mg of nitroglycerin given sublingually. The results indicate that molsydomine offers prophylasis for angina pectoris that lasts at least two hours after oral administration.

Administration, Oral↗
PubMed1975

Skin potential activity in rats, cats, and primates (including man): a phylogenetic point of view.

With rats, cats, nonhuman primates, and humans serving as subjects, skin potential activity was measured under waking conditions. In good agreement with the findings of previous workers, skin potential response waveform was always monophasic negative in rats and cats, but in humans it took three forms. By contrast, it was always monophasic positive in simian nonhuman primates, although prosimiae gave monophasic negative waves. A skin potential level-skin potential response relationship could not be observed in any subject except humans. From these results, an attempt was made to relate skin potential activity to the peripheral mechanism involved in these species on the basis of a phylogenetic point of view.

Animals↗