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Biomedical subjects

K Miwa

Publications and source records attributed to K Miwa.

At least 415 records · Page 23Linked to original sources

Radical mastectomy with intrapleural en bloc resection of internal mammary lymph node by sternal splitting.

An operative method of extended radical mastectomy involving intrapleural en bloc resection of the internal mammary lymph nodes by sternal split was proposed. The operation enables complete resection of axillary and internal mammary lymph nodes. Seventy patients with primary breast cancer underwent the extended operation and two patients with recurrence in the internal mammary lymphnode chain following standard radical mastectomy underwent resection of internal mammary lymphnodes by sternal split, with no fatalities and no increase in postoperative disabilities. Metastases to the internal mammary lymphnode chain were histopathologically found in 14 of 70 patients with primary breast cancer and in two with recurrence in the internal mammary lymphnode chain, following standard radical mastectomy; The location of the metastatic internal mammary lymphnodes was from just below the subclavicular vein to the third intercostal space along the internal mammary vessels. Cancer cells were seen not only in the lymphnodes, but also in lymphatics of areolar tissue near the node or in lymphatics between the parietal pleura and endothoracic fascia in patients with primary breast cancer. And cancer invasion to parietal pleura was seen in patients with recurrence in the internal mammary lymphnode chain following standard radical mastectomy. All these findings indicate the rationality of our extended procedures.

Adult↗

U wave inversion during attacks of variant angina.

Sequential 12 lead electrocardiograms were recorded during angina pectoris induced by ergonovine maleate in 38 patients with variant angina. Transient U wave inversion was observed in 17 patients with ST segment elevation in anterior chest leads, but in only three of 21 patients with ST segment elevation in the inferior leads associated with right coronary artery spasm. In the 17, all of whom had spasm of the left anterior descending coronary artery, the sensitivity of ST segment elevation in V5 was only 41%, and that of U wave inversion 71%. U wave inversion without ST segment elevation occurred during attacks in 35% of patients. During the recovery phase, the sensitivity of U wave inversion was 82% in V4 and 65% in V5, though ST segment elevation was absent in both V4 and V5. Thus, inverted U waves without ST segment elevation often appear in marginal ischaemic zones or during the time of recovery from temporary ischaemia. Detection of inverted U waves should aid in the diagnosis of variant angina when only lead V5 is used as a monitor and when electrocardiograms are recorded only during the recovery phase.

Adult↗

Two electrocardiographic patterns with or without transient T-wave inversion during recovery periods of variant anginal attacks.

Continuous electrocardiographic recordings during anginal attacks in patients with variant angina were reviewed. Twenty-seven attacks in 15 patients were associated with transient T-wave inversion during recovery periods of angina (type A), while in another 69 attacks in 28 patients there was no T-wave inversion (type B). In none of the patients was there an ischemic T-wave inversion during angina-free periods. Both the maximum elevation (0.79 +/- 0.57 mV) and duration (5.3 +/- 1.2 min) of ST-segment deviation of type A attacks were significantly higher and longer than those of type B (0.44 +/- 0.27 mV, 2.8 +/- 1.4 min). Ten patients who had both type A and type B attacks one time or the other were selected for further evaluation. In these 10, the duration of ST-segment elevation was significantly longer during type A attacks (5.2 +/- 1.2 min, n = 18) than during type B attacks (2.7 +/- 1.2 min, n = 20) but there was no significant difference in the maximum ST-segment elevation. Giant U-wave inversion appeared in 15% of the type A attacks, but never in type B. Therefore, the T-wave abnormality related to ischemic episodes in patients with variant angina seems to be associated with more severe ischemia of longer duration than milder episodes of transient ischemia.

Adult↗

Exercise-induced angina provoked by aspirin administration in patients with variant angina.

The effects of aspirin (4.0 g/day) given orally to eight patients with variant angina were observed. An exercise stress test performed in the morning was positive in two of seven patients during placebo administration, whereas a test performed in the afternoon at the same exercise work load resulted in negative findings. During aspirin administration, the afternoon exercise test repeatedly provoked anginal attacks associated with electrocardiographic changes (S-T segment elevation in five and S-T depression in two). Rate-pressure product at the end of the exercise test during aspirin administration was significantly lower than that during placebo administration (p less than 0.01). During aspirin administration, the frequency of angina increased markedly, and the attacks occurred not only during the night or early morning but also in the daytime in six of the eight patients. Our observations suggest that aspirin, in this large dose, reduces the capacity for exercise and provokes exercise-induced coronary arterial spasm in patients with variant angina.

Adult↗

[Echocardiographic findings of variant angina (author's transl)].

Two-dimensional echocardiographic studies of left ventricular wall motion were performed in three patients with ergonovine induced variant angina, who were diagnosed by electrocardiography and/or coronary angiography. The two-dimensional echocardiogram during anginal attack demonstrated hypokinesis or akinesis of the left ventricular wall where ischemia was suspected by the electrocardiogram. This change in the wall motion occurred earlier than that of the electrocardiogram, and the abnormal wall motion in ischemic region returned to normal earlier than the electrocardiographic recovery after the attack. In some cases non-ischemic region showed hypokinesis probably because ergonovine caused coronary artery narrowing in a whole region including spastic region. With relief of the chest pain and restoration of ST segment elevation in the electrocardiogram following nitroglycerin administration, the left ventricular wall tended to be hyperkinetic on the echocardiogram.

Aged↗

Exertional angina pectoris caused by coronary arterial spasm: effects of various drugs.

In four patients with exertional angina induced by arm exercise, coronary arteriograms taken before, during and after the attack demonstrated that spasm appeared in the large coronary artery supplying the area of myocardium shown to be ischemic in the electrocardiogram during the attack. The spasm disappeared with subsidence of the attack after administration of nitroglycerin. Anginal attacks induced by treadmill exercise were not suppressed by propranolol, 60 mg orally, in two of the four patients. However, such attacks were suppressed in all patients by oral administration of diltiazem (90 mg, four patients) or nifedipine (20 mg, three patients) or intramuscular injection of phentolamine (0.2 mg/kg body weight, three patients). It is concluded that coronary arterial spasm can be induced by exercise and can cause exertional angina in some patients. Diltiazem and nifedipine, calcium antagonistic drugs, prevent spasm.

Adult↗

Circadian variation of exercise capacity in patients with Prinzmetal's variant angina: role of exercise-induced coronary arterial spasm.

Thirteen patients with Prinzmetal's variant angina performed treadmill exercise tests in the early morning and in the afternoon of the same day. The attacks with ST elevation were induced repeatedly in all 13 patients in the early morning, but in only two patients in the afternoon. Propranolol did not suppress the exercise-induced attacks in all 13 patients. Diltiazem suppressed the attacks in all 13 patients and phentolamine in eight of the nine patients. Coronary arteriograms demonstrated that spasm occluding completely or almost completely the large coronary artery supplying the area of myocardium showing ST elevation appeared during the attacks and disappeared along with the attacks after nitroglycerin administration in all four patients in whom the attacks were induced by arm exercise in the catheterization laboratory. We conclude that there is circadian variation of exercise capacity in patients with Prinzmetal's variant angina caused by coronary arterial spasm induced by exercise in the early morning but not in the afternoon.

Adult↗

Coronary arterial spasm and Prinzmetal's variant form of angina induced by hyperventilation and Tris-buffer infusion.

Vigorous hyperventilation was induced for five minutes immediately after a five-minute infusion of 100 ml of Tris-buffer (pH 10) in nine patients with Prinzmetal's variant angina. In eight of the patients, chest pain with ischemic changes in the electrocardiogram occurred during this procedure or within five minutes after it ended. Coronary arterial spasm appeared after the procedure and disappeared after the administration of nitroglycerin in all four patients in whom coronary cinearteriography was performed. This was evident both before and after the procedure and after sublingual administration of nitroglycerin (0.6 mg). The oral administration of 90 mg of diltiazem, a calcium antagonistic drug, two hours before, completely suppressed the attack induced by the procedure in all of the five patients who received this drug. We conclude that hyperventilation plus Tris-buffer infusion induces coronary arterial spasm and anginal attack in patients with Prinzmetal's variant angina and that diltiazem suppresses these reactions.

Angina Pectoris↗

Pathogenesis and treatment of angina pectoris at rest as seen from its response to various drugs.

To twenty six patients with angina at rest (including 13 patients with Prinzmetal's variant angina), propranolol 40--50 mg, dilitiazem 60--90 mg, dipyridamole 50 mg, atropine sulfate 0.6 mg and phenoxybenzamine 10--20 mg were given at 9:00 p.m. and 2:00 a.m. (except phenoxybenzamine which was given only at 9:00 p.m.) to examine the effect of these drugs on the attack. Propranolol was not only ineffective in suppressing the attack but rather tended to aggravate it in all the cases of Prinzmetal's variant angina. It was effective to some degree in 5 of 13 cases of angina at rest other than Prinzmetal's variant angina. Diltiazem suppressed the attack completely and dramatically in all the cases of angina at rest (including Prinzmetal's variant angina). Dipyridamole was ineffective in all the cases except one in suppressing the attack. Atropine sulfate and phenoxybenzamine suppressed the attack in 13 of 21 cases and in 6 of 12 cases respectively. Coronary arteriography was done before and after the intravenous administration of 10 mg of diltiazem in 8 patients and it was demonstrated that diltiazem dilates large coronary arteries in all these patients. It is concluded that diltiazem, a calcium antagonistic drug, is specifically effective in suppressing the attack of angina at rest by dilating large coronary arteries and that the autonomic nervous system plays a role in the genesis of the attack probably by constricting large coronary arteries by way of alpha adrenergic receptors.

Aged↗