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Biomedical subjects

N Takekoshi

Publications and source records attributed to N Takekoshi.

At least 55 records · Page 3Linked to original sources
PubMed1989

Body surface potential mapping in anterior myocardial infarction--a longitudinal study in acute, convalescent and chronic phases.

Body surface potential mapping (BSPM) was performed to evaluate the infarct size and the viability of myocardium in the infarct area in 20 patients with anterior myocardial infarction (MI). BSPM was performed at the early acute phase, 1 week, 1 month and 2 months after onset of the symptoms. The departure areas were obtained according to the potential distribution below the mean normal range and were compared with the value for creatine phosphokinase (CPK), hemodynamic parameters, ejection fraction measured by radionuclide ventriculography, extent score (ES) and severity score (SS) of thallium-201 single photon emission computed tomogram. Two months after the infarction, the ergometer exercise was performed and departure areas before and after exercise were compared. With the departure map technique, the departure areas in all cases were found in the anterior region of the thorax; From 1 week to 2 months after MI, the departure areas were significantly reduced. One week after MI, the departure areas had a positive significant relation with peak CPK and sigma CPK. One month after MI the departure areas also had a positive relation with ES or SS. One week and 1 month after MI, the departure areas had a negative relation with the left ventricular stroke work index or the left ventricular ejection fraction. After exercise test in the chronic phase, the departure areas were significantly enlarged. In conclusion, the departure map is useful in evaluating the location, sequential changes of size of anterior MI including the ischemic area around the infarct site and the left ventricular function. It is suggested that the enlarged departure areas after exercise might be the ischemic areas provoked by exercise.

Adult↗
PubMed1988

[A case of chemical hyperthyroidism induced by antiarrhythmic agent amiodarone].

Amiodarone, an antiarrhythmic agent, is known to occasionally induce alterations in thyroid function because of its iodine content and ability to inhibit T4 5'-monodeiodination. We herein describe the drug-induced chemical hyperthyroidism in a diabetic patient with ventricular premature beats. A 46-year-old man with well controlled diabetes mellitus revealed neck swelling during a 4 months' treatment with amiodarone for his frequent occurrence of ventricular premature beats. Physical findings were unremarkable other than grade III diffuse struma. Routine laboratory studies were almost normal. The results of thyroid function studies showed hyperthyroidism, including increases in T4 and free T4, slight increases in T3 and free T3, a marked increase in reverse T3 and a decrease in 123I 24-h uptake. TSH was low and did not respond to TRH. Antithyroid antibodies and TSH receptor antibodies were negative. The findings of the thyroid biopsy were unremarkable except for a mild follicular hyperplasia. After cessation of the drug, T3 and free T3 were returned to normal within 2 weeks, T4 and free T4 within 2 months and reverse T3 after 6 months. These data suggest that the struma and chemical hyperthyroidism observed in our patient were induced by amiodarone treatment.

Amiodarone↗
PubMed1988

[Differentiation of hypertrophic cardiomyopathy from left ventricular hypertrophy induced by essential hypertension using magnetic resonance imaging].

To examine the efficacy of magnetic resonance imaging (MRI) in diagnosing hypertrophic cardiomyopathy (HCM), 16 patients with HCM and 14 hypertensives with left ventricular hypertrophy (LDH) were studied using a 0.5 Tesla Siemens MRI apparatus equipped with cardiac gating. In HCM, left ventricular hypertrophy was localized to the septal wall in four, to the apical wall in two, to both the septal and apical walls in two, and to the apical and inferior walls in one, and it was diffuse in seven patients. In hypertensives, LVH was localized to the septal wall in three, to both the septal and anterior walls in two, to the free wall in one, and it was diffuse in eight patients. The distribution of the hypertrophic portion was nearly equal in both groups. The thickest portion of the left ventricular wall was 24.6 +- 4.8 mm in HCM and 21.6 +- 5.4 mm in hypertension, and there was no significant difference between them. The T2 relaxation time of the hypertrophic portion was 52.2 +- 4.8 msec in HCM and 45.3 +- 6.1 msec in hypertension, and there was a significant difference between them (p less than 0.01). However, there were no significant differences between the T2 relaxation times of the hypertrophic and non-hypertrophic portions in both groups. In conclusion, it may be difficult to differentiate HCM from hypertension based on the distribution of hypertrophic portions, but measurements of the T2 relaxation times may be useful for making the differential diagnosis.

Cardiomegaly↗
PubMed1987

Efficacy of dibutyryl cyclic AMP in heart failure unresponsive to catecholamines.

The efficacy of dibutyryl adenosine 3',5'-cyclic monophosphate (DBcAMP) was evaluated in eight patients with heart failure unresponsive to catecholamine therapy. Seven patients who were hemodynamically at Forrester's hemodynamic subset stage H-IV and had a left ventricular stroke work index (LVSWI) of less than 20 g-m/m2 despite administration of unloading drugs and catecholamines were studied both hemodynamically and clinically. Another patient with dilated cardiomyopathy, in whom invasive hemodynamic monitoring could not be carried out, was studied clinically. The DBcAMP was administered intravenously at a mean (+/- SD) of 0.05 +/- 0.036 mg/kg/min, and hemodynamic measurements were made 63 +/- 37 min after administration. The cardiac index (CI) increased from 1.92 +/- 0.22 to 2.49 +/- 0.59 L/min/m2, and LVSWI from 14 +/- 4.0 to 18 +/- 5.1 g-m/m2, both significantly (CI, P less than 0.01; LVSWI, P less than 0.025). The total systemic vascular resistance index (TSVRI) decreased significantly from 2,746 +/- 427.2 to 2,218 +/- 582.6 dan.sec.cm-5.m2 ( P less than 0.01). The increase in CI was accompanied by a proportional decrease in TSVRI in all patients. Left ventricular function, which was estimated by the relation between pulmonary arterial end-diastolic pressure and LVSWI, was improved in five of seven patients after administration of DBcAMP. Two patients in whom DBcAMP was given intermittently improved clinically and survived. The authors conclude that DBcAMP has powerful vasodilating and mild positive inotropic effects and hence can be useful for treating heart failure unresponsive to catecholamines.

Adolescent↗
PubMed1985

Idiopathic dilated right ventricular cardiomyopathy: a report of eight cases.

From 1970 to 1983, eight patients who had severe right ventricular dilatation with little or no left ventricular abnormality were referred to our hospital. There were two men and six women, whose ages ranged from 16 to 38 years and averaged 27. Five patients were members of two families, which had definite hereditary histories of this disease. ECGs of seven patients suggested right ventricular abnormalities. Ventricular arrhythmias were documented in seven, whose ECGs suggested that the origins of the arrhythmias were in the right or both ventricles. Cardiothoracic ratios ranged from 0.50 to 0.66 and averaged 0.59. Five patients had wide respiratory splitting of the second heart sound. Echocardiography showed a marked increase in the right ventricular dimension. Right ventricular diastolic pressure was increased in three; left ventricular diastolic pressure was increased in two. Right ventricular angiography revealed marked dilatation and low ejection fractions of the right ventricle in all, but left ventricular function was nearly normal in them, except two patients who had minimal abnormality. The average follow-up period was 6.3 years and ranged from 3 months to 11 years. During the follow-up period, only two patients had ventricular tachycardia and three developed overt heart failure. Three patients died, two suddenly, and one from an attack of ventricular tachycardia. Autopsies of these two showed extreme dilatation of the right ventricle and one of them showed concentric hypertrophy of the left ventricle. Histological abnormalities were found in both ventricles. In summary, it is suggested that idiopathic dilated right ventricular cardiomyopathy can be classified in the spectrum of dilated cardiomyopathy.

Adolescent↗
PubMed1984

Clinical significance of myocardial squeezing of the coronary artery.

We investigated the coronary angiography (CAG) of 1,022 patients to clarify the clinical significance of myocardial squeezing and obtained the following results. Of 1,022 patients undergoing CAG, 164 patients (16.0%) had myocardial squeezing of the left anterior descending artery (LAD) and 16 patients (1.6%) had only the first septal perforating branches producing a squeezing of the artery during systole. The association of myocardial squeezing of the LAD with different diagnosis was anterior chest pain syndrome (26.6%), arrhythmia (23.6%), cardiomyopathy (21.7%), angina pectoris (15.8%) and myocardial infarction (6.9%). The degree of narrowing of the LAD was classified into 4 grades; 25-49%: 36 patients (22.0%), 50-74%: 82 patients (50.0%), 75-89%: 35 patients (21.3%) and greater than 90%: 11 patients (6.7%). The morphology of the vessel subjected to myocardial squeezing was classified into 4 patterns on CAG. Type A is localized narrowing. Type B is bead-like narrowing. Type C is diffuse narrowing. Type D is tapering and obstructive narrowing. All type D patients had the septal perforating branches. We investigated whether only myocardial squeezing has ischemic ST-T segment changes in the ECG. Fifty-five of 87 patients (63.2%) with myocardial squeezing of greater than 75% and organic stenosis of less than 50% of the LAD had ischemic changes in the ECG during exercise or pacing-induced tachycardia. There was no special feature between myocardial squeezing and subjective symptoms.

Adolescent↗
PubMed1984

Nifedipine in hypertension and heart failure.

The use of nifedipine in patients with hypertension, heart failure, and acute myocardial infarction is discussed. Data from over a ten-year period are presented. Results indicate that nifedipine, although frequently prescribed as an antianginal agent, is also useful as an antihypertensive agent, especially when used concomitantly with other drugs. Its ability to cause fluctuations in blood pressure remains a shortcoming, however.

Adult↗
PubMed1983

Hemodynamic effects of dibutyryl cyclic AMP in congestive heart failure.

To evaluate the hemodynamic effects of dibutyryl cyclic AMP (DBcAMP) in congestive heart failure (CHF), right-sided cardiac catheterization was performed in 11 patients with CHF, and hemodynamic variables were investigated before and after infusion of various doses of DBcAMP at a rate of 0.025 to 0.2 mg/kg/min (mean 0.14 +/- 0.077 [standard deviation]). DBcAMP reduced total systemic vascular resistance index from 3,171 +/- 1,158 to 1,880 +/- 554 dynes s cm-5 X m2 (mean +/- standard deviation) and pulmonary arterial end-diastolic pressure from 23 +/- 13 to 20 +/- 11 mm Hg, and increased cardiac index from 2.24 +/- 0.60 to 3.41 +/- 1.02 liters/min/m2. Mean arterial blood pressure decreased from 91 +/- 14 to 84 +/- 13 mm Hg, and heart rate increased from 91 +/- 16 to 99 +/- 13 beats/min. The increase in cardiac index was accompanied by a proportional decrease in total systemic vascular resistance index in all patients except 1. In 8 patients the decrease in pulmonary arterial end-diastolic pressure was accompanied by an increase or no change in the left ventricular stroke work index. In 6 patients, DBcAMP was given in incremental doses of 0.05, 0.1, and 0.2 mg/kg/min every 20 minutes, and 5 of 6 patients tolerated the full dose and showed dose-related hemodynamic changes for the incremental doses of DBcAMP. These data suggest that DBcAMP has powerful vasodilating effects on resistance vessels in patients with CHF; hence, it can be a useful vasodilating agent for treatment of CHF.

Aged↗
PubMed1983

Congenital coronary arterial aneurysm without arteriovenous fistula resulting in myocardial infarction--case report and review of the literature.

A 38-year-old woman with coronary arterial aneurysm, which resulted in myocardial infarction, was reported. By coronary arteriography, an aneurysm of the left anterior descending branch was found, but no arteriovenous shunt could be revealed. The patient has neither clinical history of severe febrile inflammatory disease nor any coronary risk factors. The etiology of her coronary arterial aneurysm was considered to be congenital. The patient underwent aorto-coronary saphenous vein bypass graft surgery successfully. We believe that this is the first case report in Japan on congenital aneurysm of the coronary artery without arteriovenous fistula, which was diagnosed during life by coronary arteriography.

Adult↗
PubMed1983

Clinical characteristics and prognosis of patients with unstable angina treated medically and surgically--results in patients with ST-segment elevation and depression.

A randomized prospective study was carried out and the therapeutical effects of intensive medical management in the acute stage of unstable angina were compared with those of urgent coronary bypass surgery on patients admitted to Kanazawa Medical University Hospital, who showed an ST elevation or depression during their attacks. Seventy patients with unstable angina were evaluated clinically, angiographically and hemodynamically: 41 of them had a transient ST elevation (26 treated medically; 15 surgically) and 29 had a transient ST depression (15 treated medically; 14 surgically). The hospital mortality rates were 12.2% for the medical group (3.8% in patients with an ST elevation; 26.7% in an ST depression) and 17.2% for the surgical group (6.7% in an ST elevation; 28.6% in an ST depression). These differences were not significant. The incidence of myocardial infarction among in-patients was 7.3% in the medical group (0% in the patients with an ST elevation; 20% in an ST depression) and 13.8% in the surgical group (13.3% in an ST elevation; 14.3% in an ST depression). These differences were also not significant. On their coronary angiograms, single vessel disease was significantly frequent in unstable angina with an ST elevation and so was triple vessel disease in patients with an ST depression. Left ventricular function was markedly improved in patients with an ST elevation after coronary bypass surgery. However, in unstable angina with an ST depression, there was no amelioration of left ventricular contractility and relaxation. It is concluded that by medical or surgical treatment, patients with unstable angina showing an ST elevation during their attacks had a fairly better prognosis than those showing an ST depression; the left ventricular function of the ST elevation group was improved considerably after AC bypass surgery, while those of the ST depression group showed no improvement.

Adult↗
PubMed1983

Studies on concurrent alpha- and beta-adrenoceptor blocking action of S-596 (arotinolol).

The effects of a therapeutic dose of oral S-596 upon the cardiovascular response to intravenous isoproterenol and noradrenaline were studied in 2 hypertensive and 4 normotensive subjects in order to evaluate the drug's mode of action. After oral administration of S-596, mean blood pressure rose slightly and the heart rate decreased. In addition, cardiac output decreased considerably and total peripheral resistance increased. However pulmonary arterial end-diastolic pressure and right atrial pressure were not affected by S-596 administration. Before S-596, intravenous isoproterenol increased both heart rate and pulse pressure in a dose-dependent manner. Similarly, intravenous noradrenaline increased both systolic and diastolic pressures. Following 15 mg of S-596, the effects of isoproterenol were antagonized such that the cumulative log-dose-response curves of the mean isoproterenol-induced increases in heart rate and reductions in diastolic pressure were shifted in parallel to the right. At the same time, the mean noradrenaline-induced increases in blood pressure were also antagonized in a competitive manner. The mean ratio of alpha- and beta-components was calculated as: (formula: see text) From this result it can be suggested that the alpha-adrenoceptor blockade potency of this drug is approximately one-eight of its beta-adrenoceptor blockade potency.

Adrenergic alpha-Antagonists↗
PubMed1981

Treatment of severe hypertension and hypertensive emergency with nifedipine, a calcium antagonistic agent.

Nifedipine, the Ca++ antagonistic coronary vasodilator, was administered by oral, sublingual and enema routes. 1) In 6 severe hypertensive patients (systolic pressure greater than or equal to 200 mmHg, diastolic greater than or equal to 120 mmHg), nifedipine, administered orally, induced prompt and reliable fall of arterial pressure (systolic pressure: -28% of control level, diastolic: -27%). 2) In 10 patients with hypertensive emergencies, including malignant hypertension, intracranial bleeding, hypertensive encephalopathy and acute hypertensive heart failure, sublingual and enema administration of nifedipine were performed with excellent hypotensive efficacy. 3) Pressure began to fall within 5--15 min, 30 min and 30--60 min after sublingual (or dissolved), enema and oral (capsule), respectively, and reached its lowest levels in the next 10--20 min. The fall of pressure lasts for 2--4 hours. 4) In the combination of nifedipine with alpha-methyldopa, antihypertensive response in short-term was increased about +11% over nifedipine alone and lasted for 8 hours. In combination with beta-blocker (propranolol), hypotensive efficacy increased +39% over nifedipine alone, but the effective duration of this combination was the same as nifedipine alone. 5) Side effects, including dryness of the mouth and burning sensation in face and legs, were observed in few patients.

Administration, Oral↗