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Biomedical subjects

K Hamai

Publications and source records attributed to K Hamai.

33 records · Page 2Linked to original sources
PubMed1991

[Efficacy of isoproterenol, magnesium sulfate and verapamil for torsade de pointes].

The efficacy of isoproterenol, MgSO4 and verapamil for torsade de pointes was evaluated in 60 dogs. Torsade de pointes was induced in 28 out of 60 dogs (46.7%) by ventricular stimulation after administration of quinidine sulfate (30 mg/kg). The electrophysiologic effect of isoproterenol (0.5 micrograms/min drip infusion) was studied in 9 dogs with torsade de pointes, in 9 dogs with MgSO4 (30 mg/kg), and in 10 dogs with verapamil (0.1 mg/kg bolus injection followed by 0.01 mg/kg/min drip infusion). If the first dose of these drugs was ineffective, ventricular stimulation was performed after the additional administration of the same dose. Isoproterenol significantly decreased QTc, ERP and dispersion of ERP but increased ERP/QT. MgSO4 significantly increased ERP and ERP/QT, however dispersion of ERP did not change. Verapamil induced no electrophysiologic changes in ventricular refractions . Isoproterenol prevented the occurrence of torsade de pointes in all dogs (100%), MgSO4 in 7 of 9 dogs (77.8%, 30 mg/kg in three and 60 mg/kg in four) and verapamil in 4 of 10 dogs (40%, 0.1 mg/kg in two and 0.2 mg/kg in two). These findings suggest that isoproterenol and MgSO4 increased ERP/QT, showing one of their antiarrhythmic effects. It also shows that isoproterenol and MgSO4 may be useful in the treatment of torsade de pointes.

Animals↗
PubMed1990

Differentiation between left circumflex and right coronary artery occlusions: studies on ST-segment deviation during percutaneous transluminal coronary angioplasty.

To distinguish between acute occlusion of the right coronary artery (RCA) and the left circumflex artery (LCx) by electrocardiography, we studied ST-segment deviation during balloon inflation in percutaneous transluminal angioplasty. The composite electrocardiographic criteria based on ST-segment deviations increased the diagnostic specificity: that is, the finding of inferior infarction (ST-segment elevation in leads II, III, aVF) without lateral infarction (ST-segment elevation in leads V5,6) was highly suggestive of RCA occlusion (sensitivity and specificity: 35 of 43 cases, 81.4%; and 33 of 36 cases, 91.7%), whereas ST-segment elevation in leads V5,6 (LCx: 23 of 36 cases; 63.9%, RCA: 5 of 43 cases; 11.6%) or isolated ST-segment depression in leads V2-4 (LCx: 9 of 36 cases; 25.0%, RCA: none of 43 cases) was highly suggestive of LCx occlusion. These results indicate that the composite electrocardiographic criteria were useful in predicting the artery involved in acute myocardial infarction, although any single criterion was not sensitive or specific enough to differentiate right from left circumflex coronary artery occlusion.

Angioplasty, Balloon, Coronary↗
PubMed1990

Carboxypeptidase activity in human urine from healthy subjects and renal disease patients.

We have attempted to estimate the carboxypeptidase activity in unconcentrated human urine by means of a colorimetric method in which Bz-Gly-Lys is employed as a substrate. Upon addition of both 1.6 mmol/l CoCl2 and 0.18 g/l bovine serum albumin to the assay solution at pH 5.6, the carboxypeptidase activity in human urine can be evaluated. Using our method, the daily excretion of carboxypeptidase in both healthy subjects and patients with renal diseases has been examined. The level is increased in patients with nephrotic glomerulonephritis (24.9 +/- 14.9 (SD) U/day; n = 8) and patients with nephritic glomerulonephritis (11.4 +/- 7.55 (SD) U/day; n = 14) as compared to that in healthy subjects (5.10 +/- 1.88 (SD) U/day; n = 18). However, it is decreased in patients with chronic renal failure (2.70 +/- 2.13 (SD) U/day; n = 12).

Cadmium↗
PubMed1990

Effect of magnesium sulfate on ventricular refractoriness and its efficacy for torsade de pointes.

The effect of magnesium sulfate on ventricular refractoriness and its efficacy for torsade de pointes (TdP) were studied in nineteen dogs. After the administration of quinidine sulfate (30 mg/kg), TdP was induced by ventricular pacing in ten of 19 dogs (52.6%), polymorphic ventricular tachycardia in seven (36.8%), ventricular fibrillation in two (10.5%). Quinidine sulfate caused significant increases in QTc interval, ventricular effective refractory period (ERP) and dispersion of ERP(dERP), and decrease in ERP/QT. Magnesium sulfate significantly increased ERP (p less than 0.01), but it did not change QT interval, resulting in significant increasing of ERP/QT (0.41 +/- 0.05 to 0.61 +/- 0.05, p less than 0.01). It decreased dERP but not significantly. Magnesium sulfate prevented the induction of TdP in eight of 10 dogs (80.0%) (30 mg/kg in four and 60 mg/kg in four). In conclusion, magnesium sulfate has value as first aid therapy for drug-induced TdP. If patients have ischemic heart disease or hypertension, we recommend infusion of magnesium for the initial therapy of TdP.

Animals↗
PubMed1990

[Coronary artery disease in patients with abdominal aortic aneurysm].

Selective coronary angiography to determine the prevalence of coronary artery disease (CAD) has been performed in patients with abdominal aortic aneurysm (AAA). Thirty patients in this series consisted of 26 men and 4 women with an age range of 48-87 years (mean +/- SD: 67.5 +/- 8.2 years). As the atherosclerotic risk factors, cigarette smoking was present in 19 patients (63.3%), hypertension was in 18 (60%), hypercholesteremia was in 10 (33.3%), and diabetes mellitus was in 2 (6.7%). Cerebral vascular disease was present in 11 patients (36.7%). Regarding CAD, angina pectoris or old myocardial infarction was found in 9 patients (30%), and abnormal electrocardiography (ECG) was in 16 patients (53.3%). Coronary angiography prior to operation of AAA was performed to 22 patients (73.3%), and 15 patients (68.2%) among them had significant coronary artery stenosis, and 9 patients underwent myocardial revascularization (4 CABG, 5 PTCA). CAD was frequently complicated both in patients without symptoms or ECG abnormalities and in less than 65-year patients. In order to prevent fatal myocardial infarction, we recommend routine coronary angiography to patients with AAA. And if necessary, myocardial revascularization must be indicated prior to aneurysmectomy.

Aged↗
PubMed1990

[A case of myonephropathic-metabolic syndrome after urgent aortic valve re-replacement due to prosthetic valve thrombosis].

Acute cardiac failure due to prosthetic valve thrombosis is a rare, but lethal complication after cardiac valve replacement. A 40-year-old female admitted to our hospital, because of cardiac failure after aortic valve replacement with a #21 Björk-Shiley valve in 1975. After admission, echocardiography showed thrombotic obstruction of the prosthetic valve, and we underwent urgent aortic valve re-replacement. Postoperative period, she was complicated with myonephropathic-metabolic syndrome (MNMS). But, we performed intermittent veno-venous hemofiltration (IVVH) in early period, and successfully could save her life and her lower limb.

Adult↗
PubMed1989

[Electrocardiograms during acute occlusion of the left circumflex artery as compared with that of the right coronary artery].

To assess the characteristic electrocardiographic (ECG) ST changes during acute occlusion of the left circumflex artery (LCX), we observed ECG changes during percutaneous transluminal coronary angioplasty (PTCA) of the LCX and compared the results with those obtained during right coronary angioplasty. Results were as follows: 1. In the 30 patients who had LCX angioplasty (group LCX), ST-segment elevation occurred most frequently in lead V6 (67.7%) and in lead III (46.7%), but rarely in leads and aVL. ST depression occurred most frequently in lead V3 (80.0%) and in lead V2 (73.3%), but rarely in other leads except for leads I and aVL (23.3%, 33.3%). 2. Four types of ST change in lead combinations were observed. These included: (1) ST elevation in the inferior leads (II, III and aVF), (2) ST elevation in the lateral leads (V5 and V6), (3) ST depression in the anterior leads (V2-V4) and (4) ST depression in the high lateral leads (I and aVL). In group LCX, nine cases (30.0%) manifested all four changes, and six cases (20.0%) revealed only ST depression in the anterior leads without ST changes in other leads. 3. ST depression in the anterior leads and ST elevation in the inferior and lateral leads were observed in nearly equal frequency in patients who received PTCA at the proximal site (Seg. 11) and at the distal site (Seg. 13) in the group LCX. However, ST depression in the high-lateral leads was more frequently observed in the distal than in the proximal cases (66.7% vs 33.3%).(ABSTRACT TRUNCATED AT 400 WORDS)

Acute Disease↗
PubMed1989

Chronic effects of nicorandil on exercise tolerance in patients with stable effort angina pectoris.

To examine the chronic effects of nicorandil, a new coronary vasodilator, on exercise tolerance, we gave this drug for ten days at 15 mg/day orally in three divided doses to 10 patients with stable effort angina. An increase in exercise capacity by more than 1 stage of modified Bruce's protocol was observed in 6 of 10 patients on the 5th and 10th day after the administration. The exercise duration was significantly prolonged from 294 +/- 86 sec (mean +/- SD) before the administration to 363 +/- 106 sec and 405 +/- 139 sec on the 5th and 10th day after the administration, respectively. With nicorandil administration, the time to 0.1 mV of ST-segment depression was also significantly delayed from 3.1 +/- 1.9 minutes to 4.5 +/- 2.6 minutes on the 10th day. On the other hand, systolic blood pressure, heart rate and pressure rate product did not demonstrate any significant change before and after the administration. These results indicate that oral nicorandil of 5 mg 3 times a day can chronically increase exercise tolerance without decreasing myocardial oxygen consumption in patients with stable effort angina.

Adult↗
PubMed1989

[Influence factors on coronary collateral development].

In order to evaluate the influence factors on coronary collateral development, we compared various factors between two groups. Group I consisted of the 69 patients performed coronary angiography within 6 hours after the onset of acute myocardial infarction (MI) and Group II consisted of the 56 patients without MI because having good collaterals nevertheless whose one coronary artery was totally occluded or had a 99% stenosis. Group I (24/69, 35%) had a higher frequency of Diabetes mellitus than Group II (11/56, 20%) and had a lower frequency (30/69, 43%) of multivessel disease than Group II (39/56, 70%). The patients having angina duration more than 6 months were more in Group II (37/56, 60%) than in Group I (18/69, 26%). No significant differences existed between these two groups in age, smoke, hyperlipidemia and hypertension. In conclusions, the patients with good collateral have high frequency of multivessel disease and long history of angina pectoris. Diabetes mellitus is a inhibit factor on coronary collateral development.

Adult↗
PubMed1989

[The effect of open heart surgery and an operation on thoracic aneurysm on organs and the prevention of an organ system failure: comparison between the group using ulinastatin and not using group].

We studied the effect of the open heart surgery and the thoracic aortic aneurysm surgery on renal, liver and respiratory function and the coagulofibrinolytic system. We also investigated as to whether ulinastatin was effective or not with regard to preventing an organ system failure. The renal function, liver function and the coagulofibrinolytic system were preserved, although there was a greater number of severe cases in the group which used ulinastatin (US group) than in the group that did not use ulinastatin (non-US group). In the US group, PaO2 did not decrease postoperatively. However, in the non-US group, PaO2 decreased significantly after the operation. The variables in relation to using ulinastatin, examined by a stepwise method, included kind of disease, emergency operation, PaO2, BUN and serum plasminogen. The multiple coefficient for these five variables was 0.623 (p less than 0.01) and the contribution was 38.8%. It was suggested that ulinastatin could prevent an organ system failure, especially respiratory failure, after open heart surgery and the thoracic aortic aneurysm surgery.

Aged↗
PubMed1989

[The results of an investigation of the various factors influencing the late patency ratio of coronary bypass grafting].

The purpose of this communication was to find out the factors influencing the late patency ratio of coronary artery bypass grafts of 42 patients in our institution. The following results were obtained: 1. The size of the measured diameters of coronary arteries and the graft flow rates were correlated well to the late patency ratio (p less than 0.05). 2. The regular physical exercise trainings were significantly important to keep patent grafts (p less than 0.01). 3. In blood serum studies, serum uric acid levels were significantly lower (p less than 0.05), the average mean HDL cholesterol levels were much higher (p less than 0.001) and the ratio of total cholesterol to HDL cholesterol were significantly lower in the group with late patent grafts than with grafts occluded. Therefore, we found out the variables affecting graft patency ratio which were examined by a stepwise method were the diameter of the coronary artery, regular physical exercise training, the average of lower serum uric acid levels and higher HDL cholesterol levels. The multiple coefficient for these four variables was 0.562 (p less than 0.001) and the contribution was 31.6%. According to the base of this studies, we have concluded that postoperative regular physical exercise, low fat and restricted calorie intake were very important to keep the late patent grafts in long-term follow up period after coronary bypass surgery.

Adult↗
PubMed1989

[Correlation of arteriosclerosis obliterans of the lower extremity with coronary artery disease].

To ascertain the correlation between arteriosclerosis obliterans (ASO) of the lower extremities and coronary artery disease (CAD), 69 patients with lower extremity ASO were observed. Based on clinical symptoms, the patients were categorized as group A: 52 with intermittent claudication and group B: 17 with angina pectoris. All patients underwent angiography of both lower extremities and the heart. Results were as follows: 1. In group A, 33 patients had significant coronary stenosis with single (16 cases), double (12 cases) and triple (five cases) vessel disease. Sixteen patients had histories of myocardial infarction and two had vasospastic angina. In group B, 15 patients had significant coronary stenosis with single (five cases), double (six cases) and triple (four cases) vessel disease including two cases involving the left main trunk. Six patients had histories of myocardial infarction and two had vasospastic angina. 2. Electrocardiography revealed that 37 patients in group A and 14 patients in group B had abnormal ECGs as abnormal Q waves and ST-T changes. However, 10 patients in group A and three patients in group B had significant coronary stenosis despite their normal ECGs. 3. According to the sites of stenotic lesions, all 69 patients with ASO were classified in four types; as diffuse, pelvic, ilio-femoral and femoral. The incidence of CAD did not differ among these four types. 4. In group A, 38 patients experienced revascularization of ASO; 36 cases by bypass grafting, and two by percutaneous transluminal angioplasty (PTA). Ten patients received cardiac revascularization including three cases with coronary artery bypass graft (CABG) and seven cases with percutaneous transluminal coronary angioplasty (PTCA). In group B, 13 patients received revascularization of ASO with bypass grafting. Eleven patients had coronary revascularization including seven cases with CABG and four cases with PTCA. 5. Fourteen of the 69 patients received revascularization for both ASO and CAD. In conclusion, there is a highly significant coincidence of CAD in patients with ASO, and CAD is often silent. These data indicate that routine coronary angiography is necessary for detecting and preventing CAD in all patients with ASO. Coronary artery revascularization, especially PTCA, can be indicated prior to lower extremity revascularization.

Aged↗
PubMed1988

ST-segment depression in inferior ECG leads during percutaneous transluminal coronary angioplasty for left anterior descending artery.

The mechanism of inferior ST depression during percutaneous transluminal coronary angioplasty (PTCA) for the left anterior descending artery (LAD) was studied in 108 patients with isolated LAD lesion. In 49 patients (Group I) ST depression in inferior leads was observed, and 59 patients (Group II) showed no inferior ST depression. In the lateral lead (I or a VL), the incidence (43 cases; 88% vs. 5 cases; 9%) and degree (1.5 +/- 0.8 mm vs. 0.2 +/- 0.4) of ST elevation were significantly greater in Group I than in Group II. There was a significant inverse correlation (r = -0.57, p less than 0.01) between ST depression in the inferior lead and ST elevation in the lateral lead, but no correlation was found between anterior leads (V2-4) and the inferior leads. Elevation of diastolic pressure of the pulmonary artery (8.7 +/- 4.8 vs. 5.7 +/- 2.8 mmHg) and lowering of systolic pressure of the femoral artery (-25.7 +/- 24.3 vs. -11.8 +/- 8.3 mmHg) were significantly greater in Group I. These findings suggest that ST depression in the inferior leads during LAD angioplasty was due to a purely electrical phenomenon and not to the concomitant ischemia of the inferior wall. However, this change was more frequently seen in patients with larger myocardial ischemia and, presumably, was more often related to ST elevation in the lateral lead, which is reciprocal in position.

Angioplasty, Balloon↗