[Persistent juvenile T wave in adults].
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
S Haraoka
Publications and source records attributed to S Haraoka.
Effect of graded coronary constriction on the flow reserve in regional myocardium in dog.
Effects of coronary constriction on the flow reserve of regional myocardium were studied in the anesthetized open-chest dogs. Regional myocardial blood flow (RMBF) was continuously measured using heated crossthermocouple method. Left circumflex coronary artery (LCX) was constricted gradually with a screw type constrictor. The coronary constriction decreased subendocardial myocardial blood flow, while subepicardial myocardial blood flow was not affected until reactive hyperemia in LCX nearly disappeared. Recovery and arrival to peak flow rate of RMBF following the release of 15-second's occlusion of LCX were progressively delayed with an increase in the constriction, especially in the subendocardial myocardium. Repayment of flow debt, however, was remained relatively well since the duration of reactive hyperemia in RMBF was prolonged by an increment of the constriction. From these findings, it might be concluded that in the heart with coronary stenosis recovery from ischemia was caused by prolonged duration of reactive hyperemia, and is suggested that the time required for recovery from ischemia or ischemic abnormalities after the cessation of stress might be an important marker for the severity of coronary insufficiency.
Animals↗
Vectorcardiogram of complete right bundle branch block with left axis deviation by the Frank and Kimura systems.
Vectorcardiogram (VCG) recorded by both the Frank and Kimura systems were examined in 45 patients with complete right bundle branch block (RBBB) and left axis deviation (LAD) to investigate the relationship seen on electrocardiogram (ECG) between RBBB with LAD and bilateral bundle. The sample included: 13 cases of type SI, SII, SIII, SaVF; 21 cases of type SI, SII, SIII, aVF; and 11 cases of types SI, SII, SIII. VCG recorded by the Frank system were classified into seven types according to the QRS loop pattern on the frontal plane and into three types according to the horizontal plane. The main findings were: (a) In the Frank system the QRS loop in the frontal plane showed a variety of patterns in RBBB with LAD. (b) On VCG of complete RBBB judged complicated by a left anterior hemiblock by the Frank system, the main portion of the QRS loop extended to the left superior or merely to the left in the frontal plane. The direction of rotation and position on the horizontal plane were not consistent. (c) The results of this study suggest the usefulness of the Kimura system as an auxiliary diagnostic technique.
Adult↗
[Experimental study on the leads of vectorcardiography in dogs (a study using a uniform model)].
Explore the source record for details and available documents.
Animals↗
Effect of atrial fibrillation on coronary circulation and blood flow distribution across the left ventricular wall in anesthetized open-chest dogs.
Effects of atrial fibrillation on coronary circulation and on blood flow distribution across the left ventricular wall were studied in anesthetized open-chest dogs. Atrial fibrillation was induced by pressing down mechanically the left atrial appendage or by stimulating electrically the left atrial appendage. Heated cross-thermocouples were used for measuring regional myocardial blood flow. The results showed a marked decrease in coronary blood flow with a significant increase in coronary vascular resistance; average values (SD) of flow and resistance during control simus rhythm were 71.6 +/- 7.36 ml/min . 100g heart muscle and 1.38 +/- 0.15 mmHg/ml/min . 100g heart muscle, respectively, and 54.0 +/- 13.60 ml/min . 100g and 1.54 +/- 0.18 mmHg/ml/min . 100gjust prior to cessation of atrial fibrillation. The termination of fibrillation caused a remarkable rise in coronary flow and a fall in coronary resistance. Pacing-induced tachycardia, similar to the average ventricular rate during atrial fibrillation, increased coronary blood flow and decreased coronary vascular resistance. These show that active coronary vasodilatation and an increase in extravascular support of coronary bed are produced by atrial fibrillation. Subendocardial myocardial blood flow during atrial fibrillation was reduced 22.0 +/- 14.8% from control levels followed by marked increase in flow after cessation of fibrillation, while subepicardial flow decreased only slightly. Thus, atrial fibrillation itself diminishes coronary flow reserve, especially in the subendocardial layer, partly due to the increase in myocardial component of coronary vascular resistance, and it is possible that irregular ventricular rhythm may play an important part in a rise in extravascular support.
Animals↗
Comparative vasodilator effects of nitroprusside, phentolamine, and nitroglycerin on hemodynamics, regional myocardial function and epicardial electrogram in dogs with acute myocardial ischemia.
The effects of nitroprusside (NP), phentolamine (PH), and nitroglycerin (NTG) were studied on systemic hemodynamics, regional contraction and epicardial ST segment in the border and non-ischemic zones of the left ventricle of anesthetized open chest dogs. The anterior descending coronary artery (LAD) was completely occluded. NP (5 microgram/Kg/min) or PH (100 microgram/Kg/min) was drip-infused, or a bolus injection of NTG (20 microgram/Kg) was administered intravenously. The 3 vasodilator agents produced somewhat similar reductions in systemic arterial pressure. However, NP caused a greater reduction in total peripheral resistance (TPR) than in left ventricular end-diastolic pressure (LVEDP), and caused a decline, in the ischemic marginal zone, in both ST segment eievation and paradoxical systolic lengthening. PH decreased TRP without reducing LVEDP and elevated the ST segment. NTG markedly reduced LVEDP and TPR slightly. NTG improved the elevated ST segment and paradoxical systolic expansion of the segmental myocardium in the border zone. Cardiac output rose with NP and PH, whereas injected NTG caused a reduction in cardiac output. These findings suggest that NP favourably affects the ischemic myocardium mainly by reducing the afterload and that the NTG-induced improvement of myocardial ischemia can be attributed mainly to preload reduction, while PH enhances cardiac function with slight or no improvement of myocardial ischemia in the border zone.
Acute Disease↗
Effect of myocardial ischemia and nitroglycerin on systolic time intervals in the segmental myocardium.
Effects of ischemia and nitroglycerin on systolic time intervals in the segmental myocardial length were studied in anesthetized open-chest dogs. Two strain-gauges were sutured on the surface of the left ventricular wall; one was in the central area perfused by the left circumflex coronary artery (LCX) and the other was in the area perfused by the left anterior descending coronary artery. LCX was partially occluded with a screw type constrictor to the degree at which reactive hyperemia after the transient total coronary occlusion almost disappeared. After the hemodynamics stabilized nitroglycerin (20 microgram/kg) was injected into the femoral vein. In the ischemic area, contraction time was shortened and precontraction time was prolonged in association with an elongation of end-systolic and early systolic segment-length, respectively. The systolic time intervals in the ischemic segment were improved as a result of the recovery in the segment-length toward the control. The results suggest the usefulness of analyzing the segmental myocardial systolic time intervals for verifying the asynchronous contraction of the ventricle and the favourable effects of nitroglycerin on segmental myocardial function in the ischemic area.
Animals↗
Correlation of systolic time interval with abnormal myocardial contraction by coronary occlusion in anesthetized open-chest dogs.
The correlation between the systolic time interval and abnormal contraction in ischemic myocardium was studied in anesthetized open-chest dogs. A strain-gauge was sutured on the surface of the left ventricular wall perfused by the left anterior descending coronary artery (LAD) for measuring segment-length. The left ventricular stroke volume decreased progressively after occlusion of LAD. The left ventricular ejection time (LVET) was progressively shortened in close correlation with the elongation of segment-length at the onset of isometric relaxation in 20 seconds after LAD occlusion when early systolic myocardial contraction and isometric contraction time (ICT) were not affected. ICT was gradually prolonged and closely related with the lengthening of the early systolic segment-length, while LVET recovered toward the control level in spite of further decrease in stroke volume. A close relationship was observed between ICT/LVET and stroke volume (gamma = 0.76, P less than 0.01). The results suggested the possibility that LVET was normalized even when the left ventricular function was impaired, and ICT/LVET ratio was the most sensitive index of LV dysfunction.
Animals↗
Effect of propranolol on regional myocardial function in anesthetized open-chest dogs with myocardial ischemia.
Effects of propranolol on ischemic segmental function were studied in anesthetized open-chest dogs. Two segment-length gauges were used for measuring the regional myocardial function: one was sutured on to the left ventricular surface perfused by the anterior descending coronary artery (ischemic zone) and the other was on to that perfused by the circumflex coronary artery (normal zone). A bolus of propranolol (0.5 mg/kg) was injected into the right femoral vein. Five min later, the left anterior descending coronary artery (LAD) was completely occluded for one mine and thereafter released. Then a second coronary occlusion for 20 min was performed; an interval of 20 min was allowed between two occlusions. Propranolol, in the ischemic segment, apparently decreased the extent of paradoxical lengthening in the late systole following one min LAD occlusion, and facilitated improvement of segmental function after release of the occlusion. Moreover, the extent of abnormal stretching induced by 20 min occlusion during early systole, was also reduced by propranolol pretreatment. In contrast, compensatory increase in shortening by the normal segment was disturbed by propranolol. These results suggest that propranolol might exert a favourable influence on the segmental myocardial function during either transient or maintained myocardial ischemia.
Animals↗
A patient with repeated syncopal attacks after using isosorbide dinitrate.
The case of a patient with repeated attacks of collapse induced by sublingual isosorbide dinitrate is reported. The patient was an 81 year-old female who was admitted to Yura Hospital because of attacks of precordial pain. Several minutes after the sublingual administration of isosorbide dinitrate (10 mg) for an anginal attack, she developed a sensation of general weakness, and thereafter because unconscious. Arterial blood pressure fell and became unmeasurable. Electrocardiograms recorded during the syncopal attack showed sinus tachycardia and significant elevation of ST-segment in right precordial leads. In response to a drip infusion of noradrenaline, arterial blood pressure returned to normal with recovery of consciousness. Two similar syncopal attacks induced by sublingual isosorbide dinitrate occurred in the next three days. These attacks were not due to augmentation of the vagal reflex. Decrease of venous return probably was the primary etiological factor.
Aged↗
Effect of diltiazem on coronary blood flow of the heart with experimental coronary sclerosis and on regional myocardial blood flow of the heart with acute myocardial ischemia.
Effects of 3-acetoxy-2,3-dihydro-5[2-(dimethyl-amino)ethyl]-2-(p-methoxyphenyl)-1,5-benzothiazepin-4 (5H)-one hydrochloride (diltiazem) on coronary circulation of the heart with experimental coronary sclerosis induced by i.v. allylamine (Group A), and on regional myocardial blood flow in acutely-induced ischemic myocardium (Group S) were studied in anesthetized open-chest dogs. Regional myocardial blood flow was continuously measured with heated cross thermocouple method and following results were obtained: 1. In Group A coronary blood flow and coronary flow resistance remained unchanged essentially after the injection of diltiazem, whereas coronary blood flow markedly rose and coronary flow resistance decreased in the normal heart. 2. Local blood flow in both of the inner and outer thirds of the ischemic myocardium was not affected by diltiazem in Group S. In the normal myocardium, however, it increased definitely. 3. From these findings it is concluded that the clinical effectiveness of diltiazem is independent of its vasodilator properties.
Acute Disease↗
[Experimental studies of vectorcardiographic inductions. Studies with a simple model].
Explore the source record for details and available documents.
Animals↗
[Changes of body surface potential caused by heterogeneity in conductivity in the torso--studies with a torso model].
Explore the source record for details and available documents.
Animals↗
A case of alcaptonuria with fatal cardiovascular disturbance.
A case of alcaptonuria combined with aortic insufficiency was found in a 28-year-old male. The patient was palpitating at admission. The daily excretion of homogentisic acid was 2.0-6.0 g. Electrocardiography indicated atrial fibrillation and left ventricular hypertrophy with a ST-T change and right axis deviation. Cartilage tissues in the knee-joints showed no pigmentation. Vertebral X-ray revealed no calcification. The patient's history disclosed a family intermarriage in his grandparents. The patient's mother noticed the presence of black stains on diapers in his infancy and brown pigmentation on the skin and sclera in childhood. No kin had similar symptoms.
Adult↗
[A case of hypocholinesterasemia induced by trichlorfon].
A case of hypocholinesterasemia induced by ingestion of trichlorfon is presented. A female patient took 20 gm of this insecticide for the purpose of the suicide. She was brought to the hospital one hour later, and her life was saved by gastric lavage. Cyanosis on lips and nails, pupils with sluggish light reaction and fibrillary muscle twitch were observed upon arrival. Laboratory examination performed on the admission disclosed a serum cholinesterase activity of 0.3deltapH per hour. The enzyme activity was depressed to 0.05 deltapH per hour on the second day of hospitalization. The enzyme activity then increased gradually in the two subsequent weeks and the patient recovered.
Adult↗