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Biomedical subjects

K Dote

Publications and source records attributed to K Dote.

36 records · Page 2Linked to original sources
PubMed1991

[Quantitative evaluation of right ventricular function by transesophageal echocardiography: report of a case with classical right ventricular infarction].

We were able to diagnose right ventricular infarction (RVI) by transesophageal echocardiography (TEE) in a patient with acute inferior infarction, and it was confirmed by cardiac catheterization. To evaluate right ventricular (RV) function quantitatively, area shortening (AS) and regional AS (rAS) were measured from RV images obtained by TEE. The AS correlated with RV ejection fraction obtained by radionuclide angiography (r = 0.72). The patient with RVI showed depressed RV function by AS measurement with decreased rASs of all regions in the acute phase. In the chronic phase, RV function of the patient improved, especially in the region of the ventricular septum and apex regions. These results indicate availability of TEE and that RV function can be evaluated by TEE.

Aged↗
PubMed1991

[A clinical study of the relation between time to reperfusion and infarct size].

Observations made in animal models of reperfusion in acute myocardial infarction have shown that early reperfusion results in myocardial salvage. But the relation between the time of reperfusion and myocardial salvage is not clear in human patients. If earlier reperfusion provides smaller infarct size, reperfusion therapy initiated in the first 1 hour should be the most beneficial. In this study, we compared the results of therapy initiated in the first 1 hour (group A, n = 19) with treatment started 1 to 24 hours after the onset of chest pain (group B, n = 652). The infarct location, development of collateral vessels, number of diseased vessels and reperfusion rate of thrombolysis in the two groups didn't differ. There was a statistically insignificant trend towards total occlusion of the infarct artery in group A (89.5% vs 69.7%, p less than 0.1). Peak CPK and changes in left ventricular ejection fraction (delta EF) were assessed in patients with total occlusion of the left anterior descending artery and successful reperfusion (n = 8 in group A, n = 120 in group B). There was no difference in peak CPK (3281 +/- 2192Iu/l vs 3490 +/- 1811Iu/l) and delta EF (6.3 +/- 17.1% vs 5.8 +/- 11.9%). These findings suggest that there is no relation between the time of reperfusion and myocardial salvage in human patients.

Coronary Angiography↗
PubMed1990

[Acute myocardial infarction with patent infarct-related artery: selection of treatment based on qualitative analysis of coronary angiograms during the acute phase].

To evaluate the benefit of emergency coronary angioplasty (PTCA) among patients with acute myocardial infarction having patent infarct-related arteries, we investigated 104 patients who received thrombolysis and/or PTCA within 24 hrs after onset of symptoms. The morphology of coronary artery lesions was qualitatively assessed by angiography and categorized as symmetrical or asymmetrical narrowing with smooth margins (S-group, 72 cases) and asymmetrical narrowing in the form of convex intraluminal obstruction representing a thrombus (T-group, 32 cases). Soon after intervention, angiographic success (residual stenosis less than 75%) was achieved in 85% with PTCA (92% in the T-group vs 82% in the S-group) and in 29% without PTCA (53% vs 16%). At hospital discharge, the figures were 82% with PTCA (75% vs 87%) and 43% without PTCA (73% vs 30%). The incidence of re-infarction and/or total occlusion of the infarct-related artery was 9% with PTCA in both the T- and S-groups but 26% in those without PTCA (6% in the T-group vs 31% in the S-group). These data suggest that in patients with patient infarct-related arteries and severe original stenosis, PTCA has an advantage over thrombolysis alone. Qualitative analysis of coronary morphology by angiography provides a framework for selecting adequate therapy.

Adult↗
PubMed1990

[Distinctive response of coronary artery compared acute myocardial infarction with angina pectoris associated with angioplasty].

There has been much controversy over the mechanism of successful percutaneous transluminal coronary angioplasty (PTCA). To examine clinical and angiographic factors that might be related to a successful PTCA, we assessed 224 branches treated with emergent or elective angioplasty in evolving acute myocardial infarction (AMI) and angina pectoris (AP). The patients were divided into three groups; group 1 (G1): AP (n = 113), group 2 (G2): AMI with complete obstruction of infarct-related artery (IRA) (n = 79), group 3 (G3): AMI with incomplete obstruction of IRA (n = 32). The morphology of stenotic lesion was classified into smooth type and irregular type. The former shows concentric smooth border, the latter shows eccentric irregular border and multiple irregular border according to the Ambrose classification. Regarding the severity of the stenosis immediately after successful PTCA, there was no significant differences between G2 and G3, however in G1 it was significantly higher than in other groups (G1 vs G2 vs G3, 56% vs 81% vs 78%, p less than 0.001). Irregular type at stenotic lesions before PTCA were present in 72 of 113 branches in G1 vs 60 of 69 in G2 and G3. Regarding the incidence of acute coronary obstruction during PTCA, there was no significant differences between G1 and G2. However, in G3 it was significantly higher than in other groups (G1 vs G2 vs G3, 8% vs 9% vs 38%, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Secundum atrial septal defect in two families].

Two families having secundum atrial septal defect (ASD) were reported. In one family, a 31-year-old male and his 60-year-old mother had secundum ASD without PR prolongation. His 38-year-old brother was diagnosed as having ASD. His grandmother, who had died at the age of 51, was suspected of having congenital heart disease. From early childhood she was noticed to have heart murmur. It was suspected that this was a case of familial ASD without PR prolongation, because it was consistent with the dominant trait of the defect. In the other family, a 16-year-old female had secundum ASD and her 18-year-old brother was also suspected of having ASD. Her 25-year-old brother had been operated on for tetralogy of Fallot, and her sister had died of an unknown congenital heart disease. All of these family members had mental retardation. Her 22-year-old brother was suspected of having a congenital heart disease, because of heart murmur from his early childhood. The parents, who were blood relations (cousins), had neither heart disease nor mental retardation. The children of this family were considered to be cases of congenital heart disease with ASD, associated with mental retardation. It was also suspected that the cause of the defect was a deleterious autosomal recessive gene.

Adolescent↗
PubMed1990

[Cerebral hemodynamics of post-ischemic delayed hypoperfusion (PDH) and the effects of nicardipine on the PDH].

Post-ischemic delayed cerebral hypoperfusion (PDH) is considered to be one of the most critical factors limiting brain recovery after cerebral ischemia. This experiment was designed to determine the characteristics of PDH and the effects of nicardipine on the PDH. Twenty-four dogs underwent complete cerebral ischemia for 15 min using aortic clamping method with aorto-atrial bypass formation, and cerebral cortical blood flow (c-CBF), brain stem blood flow (s-CBF), intracranial pressure (ICP), and perfusion pressure (PP) were measured for 48h. Eight dogs (1 microgram group) received nicardipine 1 microgram.kg-1.min-1 for 4 h following 10 micrograms bolus iv injection 5 min after declamping of aorta. Another 8 dogs (2 micrograms group) received 10 micrograms + 2 micrograms.kg-1.min-1 nicardipine in the same manner as in group 1. The remaining 8 served as controls. In the control group c-CBF and s-CBF decreased to 60% and 55% of pre-ischemic values, respectively 1 hour after declamping of aorta, and returned to pre-ischemic values 10 and 6 h later, respectively, in spite of no significant changes in PP's. 1 microgram group and 2 micrograms group maintained pre-ischemic CBF value throughout the experimental period, and the values were significantly higher than in control group between 1st and 5th h post-ischemia. There were no significant differences in ICP's among the 3 groups throughout the experiment. In conclusion, PDH appears to be a phenomenon always accompanying transient complete cerebral ischemia, and it is assumed to be caused by constriction of cerebral vessels. Nicardipine improved PDH, indicating that the underlying mechanism of PDH must be related to a disorder in Ca2+ metabolism of cerebral vessels after ischemia.

Animals↗
PubMed1990

[The effects of post-ischemic delayed hypoperfusion on the process of recovery of brain function].

The author studied the effect of post-ischemic delayed hypoperfusion on the recovery process of brain function after complete cerebral ischemia in a dog model in which the existence of PDH had been shown previously by the author, using nicardipine as a tool to ameliorate the PDH, the effect of the drug also having been demonstrated by the author in the previous study. Twenty-four dogs underwent 15 min complete cerebral ischemia using aortic clamping method with aorto-atrial bypass formation. EEG (for 16 h) and brain functions, awakening, cranial nerve reflexes, motor functions, behaviors and respiratory functions were evaluated using neurological deficit score (NDS) periodically (for 120 h) after ischemia. Eight dogs (1 microgram group) received nicardipine 1 microgram.kg-1.min-1 for 4 h following 10 micrograms bolus iv injection 5 min after declamping of aorta, another 8 dogs (2 micrograms group) received 10 micrograms + 2 micrograms.kg-1.min-1 nicardipine in the same manner as group 1, and the remaining 8 served as controls. In 1 microgram group the first appearance of EEG activities after ischemia was earlier than control group (41 +/- 11 vs 80 +/- 33 min), and also the appearance rate of alpha waves was higher than the controls (87.5% vs 25%) 16 h after declamping of aorta. NDS scores for awakening, behavior, and respiratory functions were better in 1 microgram than the controls between 36 and 48 h post-ischemia, but there were no significant changes in the scores between the two groups 120 h after ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Effect of isometric hand-grip exercise on left ventricular diastolic filling in patients with effort angina: a pulsed Doppler echocardiographic study].

To detect myocardial ischemia and to estimate cardiac reserve in patients with effort angina pectoris without history of myocardial infarction, left ventricular diastolic filling was measured using Doppler echocardiography during isometric handgrip exercise. Nineteen patients with effort angina pectoris undergoing coronary angiography and 16 normal subjects were studied. The angina patients were categorized in two groups: 12 with single vessel disease (SVD) and seven with multiple vessel disease (MVD). Fifty percent maximum voluntary contraction isometric handgrip exercise was performed for two minutes. 1. The resting A/R in the angina group was significantly greater than that of the normal subjects (SVD: 1.20 +/- 0.24, MVD: 1.21 +/- 0.27, normal 0.85 +/- 0.10) (p less than 0.001). However, the values of many cases in these three groups overlapped. 2. In SVD, the A/R increased significantly during isometric handgrip exercise (1.20 +/- 0.24 to 1.96 +/- 0.66: p less than 0.001). The delta A/R (0.76 +/- 0.15) was significantly greater than that of patients in other groups (MVD: 0.10 +/- 0.13, normal: 0.09 +/- 0.01) (p less than 0.001). Consequently, the A/R after exercise clearly distinguished the SVD from the normal subjects. 3. In MVD, the A/R did not change significantly during exercise (1.21 +/- 0.27 to 1.31 +/- 0.41), and there were no significant differences in delta A/R as compared to the normal subjects (p less than 0.01). The A/R decreased during exercise in three of the seven patients, and this was markedly different from that of the normal subjects. These findings suggest that assessment of changes in left ventricular diastolic filling during isometric handgrip exercise is useful in detecting myocardial ischemia and in estimating cardiac reserve in patients with effort angina pectoris.

Adult↗
PubMed1989

[Clinical features of patients with spontaneous recanalization of the infarct-related artery during evolving acute myocardial infarction].

The clinical features of 124 patients with incompletely obstructed infarct-related arteries during the early stages of myocardial infarction (Group 1) were compared with those of 212 patients having completely occluded coronary arteries (Group 2). Coronary angiography was performed within 12 hours after onset of symptoms in all cases. Patients treated with emergency coronary angioplasty were excluded from the study. Thrombolytic therapy, performed in both groups whenever intracoronary thrombi were detected, was successful in 61% of Group 2. Results were as follows: 1. In Group 1, three-vessel disease was observed more frequently than one-vessel disease (49 vs 27%, p less than 0.005). 2. The peak level of CPK was higher in Group 2 (p less than 0.001), and left ventricular ejection fraction was higher in Group 1 (66 +/- 16 vs 56 +/- 14%, p less than 0.01). 3. Either significant ST elevation or the Q wave was more commonly absent in Group 1 (31 vs 12%, p less than 0.01; 49 vs 12%, p less than 0.001). 4. Improvement of ejection fraction was observed in Group 1, but not in Group 2 even if the infarct-related artery was recanalized within six hours. 5. Extension of an infarct area was more common in Group 1 compared to Group 2 which was successfully treated with thrombolytic therapy (12 vs 3.9%, p less than 0.05). 6. The most important cause of death was extension of an infarct area in Group 1 and pump failure in Group 2, though hospital mortality rates were similar in both groups. It was concluded that patients with myocardial infarction having incompletely obstructed infarct-related coronary arteries have better left ventricular function and higher rates of non-Q myocardial infarction compared with those who had completely obstructed coronary arteries. However, extensions of infarcted areas commonly occur in these patients.

Aged↗
PubMed1988

Acute myocardial infarction in the elderly.

Cardiovascular disease is the most common cause of death in the elderly. In fact, the cardiovascular disease is the number one cause of death in women and the number two cause in men of 65 years or over in Japan. We studied the clinical characteristics and significances of acute myocardial infarction as they relate to the aged.

Age Factors↗
PubMed1986

A new model for total cerebral ischemia in dogs.

We have developed a new method producing total cerebral ischemia (TCI) in dogs; clamping ascending aorta with aorto-atrial bypass formation. Clamping ascending aorta provides TCI, the duration of which can be controlled up to the periods of 10 min. Beyond this interval, it is difficult to maintain TCI because of heart failure from high afterload. Blood outflow from left ventricle is completely obstructed except for coronary circulation which is small relative to the blood volume expelled from left ventricle, even if venous return to the heart is reduced. Aorto-atrial bypass formation during aortic clamping provides two distinctive advantages. First, adjusting aortic pressure in an appropriate level low enough not to overload myocardium but still high enough to maintain sufficient coronary blood flow is possible by regulating the blood flow through the bypass tubing, and secondly drug administration and blood volume control is possible through the tubing. These result in better preservation of myocardium, enabling longer TCI and longer survivals after TCI. We were successful in having up to 18 min of TCI with this method. Seventy-five percent of dogs of 12 min TCI and 40% of 15 min TCI survived 7 days, limit of experiment, after TCI, but no dogs of 18 min TCI survived for more than 3 days.

Animals↗
PubMed1984

Cerebral blood flow during conventional, new and open-chest cardio-pulmonary resuscitation in dogs.

The following parameters were monitored simultaneously in 15 dogs, in order to evaluate the efficacy of conventional CPR (C-CPR), new CPR (N-CPR), and open-chest CPR (O-CPR) on cerebral perfusion: arterial blood pressure (BP), central venous pressure (CVP), intrathoracic airway pressure, blood flow in carotid artery, intracranial pressure (ICP), sagittal sinus blood flow (sinus BF) and pressure (sinus P), and blood flow in cerebral cortex (cortical BF). The sinus blood flow was measured by the direct-method and with a cannulating electromagnetic flowmeter. The cortical blood flow was measured with a termocouple tissue flowmeter. Intracranial pressure was obtained by measuring subarachnoid cerebrospinal fluid pressure. Ventricular fibrillation was induced electrically. Chest compression and ventilation were always done manually in all cardiopulmonary resuscitation. The mean blood pressures during C-CPR, N-CPR and O-CPR were 52, 68 and 95 mmHg, respectively, and mean carotid blood flows per stroke were 36, 71 and 131% of the control values, respectively. The intracranial pressures were 30, 42 and 36 mmHg, respectively, giving the calculated cerebral perfusion pressures (BP-ICP) of 22, 27 and 60 mmHg, respectively. This should have been reflected in cerebral blood flow. Sinus blood flows/min were 18, 18 and 42%, and sinus blood flows per stroke were 55, 45 and 127% of control values, respectively; the differences between C-CPR and N-CPR were not significant. This was also true for cortical blood flow. From this we conclude that, firstly, N-CPR is not significantly better than C-CPR in cerebral perfusion because of its accompanying high intracranial pressure, secondly, O-CPR is far superior to the other two methods in respect of cerebral perfusion.

Animals↗