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Biomedical subjects

T Ohe

Publications and source records attributed to T Ohe.

At least 181 records · Page 10Linked to original sources
PubMed1989

[Analysis of hepatic hemodynamics by a new method of per-rectal portal scintigraphy using 99mTcO4- (direct intramural administration of radioisotope)].

To depict of porto-systemic collaterals clearly, and to analyze of hemodynamics of liver, we developed new method of per-rectal portal scintigraphy (direct intramural administration of 99mTcO4- by 23G needle). And we used this method in patient with liver diseases (acute hepatitis: 5, chronic hepatitis: 7, liver cirrhosis: 25 cases). From time activity curve of the liver and the heart, liver/heart ratio; index of porto-systemic shunt via inferior mesenteric vein (IMV) and first flow ratio(k); index of portal blood flow from IMV pathway/index of hepatic total blood flow were calculated. In our method, the images of portal vein, liver, heart, especially porto-systemic collaterals were visualized more clearly than enema methods. The liver/heart ratio was significantly lower in patients with liver cirrhosis than that in non-cirrhotic patients (p less than 0.01), which indicated that patients with liver cirrhosis had more porto-systemic collaterals than non-cirrhotic diseases. The k was more lower in liver cirrhosis than in acute hepatitis (p less than 0.01). And the k was also more lower in chronic hepatitis than in acute hepatitis (p less than 0.1), which indicated that portal blood flow via IMV reduced in early stage of chronic liver diseases. In conclusion, new method of per-rectal portal scintigraphy has more advantage for analysis of hepatic hemodynamics than enema methods.

Hepatitis↗
PubMed1989

[A case of myocardial infarction with ventricular tachycardia, which had discrepancy of defect size between 123I-MIBG and 201TlCl myocardial imaging].

123I-MIBG and 201TaCl myocardial imaging were carried out in 69 years-old man who had anterior myocardial infarction with ventricular tachycardia. In planar and SPECT imaging, the defect size of 123I-MIBG was larger compared to that of 201TlCl. The zone of fractionated activity was corresponded with the defect of 123I-MIBG. Thus, the denervated but viable myocardium could be detected by 123I-MIBG and 201TlCl myocardial imaging. 123I-MIBG may give a useful clinical information, since denervation may play a role in causing ventricular arrhythmia after myocardial infarction.

3-Iodobenzylguanidine↗
PubMed1988

Physiologic changes during supraventricular tachycardia and release of atrial natriuretic peptide.

Plasma levels of atrial natriuretic peptide (ANP) increase markedly during supraventricular tachycardia (SVT). Although natriuresis associated with SVT may be secondary to the augmented secretion of ANP, whether or not physiologic changes other than natriuresis can be attributed to the release of ANP has not been determined. In the present study, plasma ANP levels in 10 patients with SVT were found to be significantly (p less than 0.05) increased, from 37 +/- 11 pg/ml (mean +/- standard error of the mean) during the control period to 160 +/- 54 pg/ml at 60 minutes after the induction of SVT. Urinary sodium excretion, although insignificant, tended to increase during the 30-minute period after SVT termination. The filtration fraction determined by the ratio of creatinine to para-aminohippurate clearance significantly increased during SVT. An increase in capillary permeability seemed to have occurred as there was a rise of hematocrit, the changes of which showed a different time course from that of the urine volume. The ratio of plasma aldosterone concentration to plasma renin activity significantly decreased during SVT. As the same effects are observed after ANP infusion, these changes were attributed to ANP activity.

Adult↗
PubMed1988

Histopathological analysis of surgically resected myocardium in patients with sustained ventricular tachycardia.

Surgical resection of the endocardium and subendocardium often abolishes sustained ventricular tachycardia (VT) in patients with old myocarcial infarct (OMI), unknown myocardial disease, and arrhythmogenic right ventricular dysplasia (ARVD), presumably by interrupting the reentrant pathway. In order to define the morphologic characteristics of histologic components in the reentrant pathway, we carried out histopathological analysis of surgically resected specimens from 17 patients who underwent this procedure. Bundles of apparently viable and hydropic myocardial fibers embedded in dense fibrous and adipose tissues were identified throughout the specimens obtained from OMI, ARVD and idiopathic VT cases. In 3 patients with idiopathic VT, most of the resected areas were composed of ventricular muscle, the components of which appeared histologically similar to Purkinje fibres. In all patients, the abnormal muscle cells were characterized by a loss of contractile elements, hydropic cytoplasm and an elliptic shape. Such an abnormal structure and arrangement of surviving cardiac fibers following tissue injury might play an important role in creating abnormalities of transmembrane potential, leading to the micro-reentrant circuits that give rise to ventricular tachycardias.

Adipose Tissue↗
PubMed1988

Narrow QRS complex tachycardia with atrioventricular dissociation.

We describe the case of a 22-year-old man who had frequent episodes of narrow QRS complex tachycardia with atrioventricular dissociation. The ECG during sinus rhythm showed normal PR and QRS intervals, but it showed a left bundle branch block configuration during atrial pacing or after injection of verapamil. An electrophysiological study demonstrated that the patient had nodoventricular Mahaim fibers. The narrow QRS complex tachycardia was explained by a circuit involving antegrade conduction via the atrioventricular nodo-His axis and retrograde conduction via the nodoventricular bypass tract.

Adult↗
PubMed1988

Idiopathic sustained left ventricular tachycardia: clinical and electrophysiologic characteristics.

Electrophysiologic studies were performed in 16 patients 11 to 45 years old (mean 33 years) with idiopathic sustained (lasting more than 5 min) ventricular tachycardia (VT) originating from the left ventricle. Endocardial mapping during VT showed that the earliest site of activation was at the apical inferior portion of the left ventricle in 14 patients whose QRS morphology during VT showed a right bundle branch block pattern and left-axis deviation, but at the apical anterosuperior portion of the left ventricle in two patients whose QRS morphology during VT showed a right bundle branch block and right-axis deviation. Single programmed ventricular stimulation induced VT in 13 patients, and rapid ventricular pacing induced VT in the remaining three patients. Rapid ventricular pacing terminated VT in all patients. The relationship between the coupling interval and the echo interval was inverse in all eight patients with a wide VT inducible zone. Entrainment was recognized in three of six patients. The initiation of VT by constant pacing depended on the number of pacing beats but not the duration of pacing in all four patients tested. Intravenous verapamil terminated the VT in 13 of 14 patients. Long-term oral verapamil was also effective in all five patients who required long-term oral therapy for their symptoms associated with VT. In conclusion (1) idiopathic left ventricular tachycardia has unique electrocardiographic, electrophysiologic, and electropharmacological properties, (2) the electrophysiologic characteristics suggest that the mechanism is reentry, and (3) verapamil is effective in both the short- and long-term treatment of VT.

Adult↗
PubMed1988

Improved accuracy of the exercise electrocardiogram in detection of coronary artery and three-vessel coronary disease.

The study objective was to assess the widespread applicability of ST/HR slope for the modified Bruce exercise test using a computerized electrocardiogram (ECG); compare the usefulness of the ST/HR slope with standard ECG criteria in detection of coronary artery disease (CAD) and identification of three-vessel or left main CAD; and then develop a new, modified ST/HR score (MSHS) for improving the diagnostic accuracy of ST/HR slope. The studies were retrospective and prospective in design, conducted in referral-based cardiology clinics at a national cardiovascular center. A selected sample of 142 patients underwent exercise ECG and coronary angiography, as did a normal control group of 402 patients who were apparently free from CAD. Sixty three other patients who underwent coronary angiography were also studied prospectively. No limitations of medical treatment were exacted for the test except digitalis treatment. Linear regression analysis, from which ST/HR slope was derived, was done with seven measurements of HR and ST displacement at 60 ms from J point in leads a VF and V5 during 6 min before the end of exercise. MSHS was derived from a multiple regression model with peak HR (% maximum HR), ST index (ST depression + ST slope), and ST/HR slope. Although the usual ST criteria (sensitivity = 63 percent, specificity = 73 percent), ST index (71 percent, 80 percent), and ST/HR slope (70 percent, 97 percent) were equally accurate in detection of CAD, MSHS showed significantly improved sensitivity (88 percent) with similar specificity (81 percent). In identification of three-vessel or left main CAD, when compared with other criteria, ST/HR slope and MSHS provided improved diagnostic accuracy: sensitivity (74 and 78 percent, respectively), specificity (88 and 93 percent) and overall test accuracy (85 and 89 percent). The improved accuracy of ST/HR slope and MSHS was prospectively validated in 63 other patients. ST/HR slope was applicable to computerized ECG data for the standard treadmill test, and showed improved accuracy in detection of three-vessel or left main CAD. The new, modified ST/HR score more accurately predicted not only the presence but also the severity of CAD.

Adult↗
PubMed1987

Maladaptation after successful revascularization in anginal patients without transmural infarction.

In order to elucidate how peripheral or cardiac function maladaptations play a role in deconditioning after coronary bypass surgery, we have evaluated effects of successful coronary artery bypass grafting (CABG) and percutaneous transluminal angioplasty (PTCA) on exercise capacity in anginal patients without myocardial infarction. Symptom-limited treadmill exercise tests were performed in 46 patients before and after CABG and in 28 patients before and after PTCA. None of the patients carried out a cardiac rehabilitation program after their discharge. PTCA patients showed significant improvement of exercise capacity, from 6.4 +/- 1.6 to 10.5 +/- 2.5 METs in 4 weeks after PTCA, and even elderly PTCA patients showed improvement from 6.0 +/- 1.1 to 10.3 +/- 2.5 METs. However, the exercise capacity of CABG patients improved only from 5.9 +/- 1.4 to 8.5 +/- 3.1 METs in the first 6 months after CABG, and from 5.9 +/- 1.7 to 10.0 +/- 3.6 METs thereafter. The 15 elderly CABG patients showed only slight increase of physical activity, from 6.0 +/- 1.7 to 6.9 +/- 1.9 METs in the first 6 months after CABG and from 6.3 +/- 1.9 to 8.7 +/- 2.9 METs thereafter. Furthermore, 6 of 15 elderly CABG patients showed no improved exercise capacity after CABG. There was no correlation between the duration of anginal symptoms before CABG and exercise capacity before or after CABG. These findings suggest that CABG itself and/or physical restriction during admission produces peripheral function maladaptation and may be the main contributors to deconditioning after CABG, especially in elderly patients. This deconditioning can be treated by a rehabilitation program after the discharge.

Aged↗
PubMed1987

The effects of cycle length on the fragmented atrial activity zone in patients with sick sinus syndrome.

To determine whether atrial pacing effectively decreases the fragmented atrial activity zone (FAZ) in patients with sick sinus syndrome (SSS), we compared FAZ at atrial pacing cycle lengths of 1000-1500 msec (CL1) with that of 750 msec (CL2) in 19 patients with SSS. The FAZ decreased in all patients except two when CL was reduced from CL1 to CL2. The mean decrease was 61.1 msec and was significant (P less than 0.001). Seven patients had frequent episodes of paroxysmal atrial fibrillation or flutter (AFF) prior to atrial pacemaker implantation. Chronic atrial pacing effectively prevented paroxysmal AFF in five of them. We concluded that the normalization of the slow atrial rate decreased FAZ in patients with SSS and may be helpful in preventing atrial tachyarrhythmia in some patients with SSS.

Adult↗
PubMed1986

Plasma atrial natriuretic polypeptide and polyuria during paroxysmal tachycardia in Wolff-Parkinson-White syndrome patients.

The human atrial natriuretic polypeptide (hANP) concentration in plasma was measured during paroxysmal supraventricular tachycardia provoked in 2 patients with Wolff-Parkinson-White syndrome. A 10- to 20-fold increase in plasma hANP concentration was observed during the tachycardia: from 12 to 291 pg/ml in 1 case and from 14 to 174 pg/ml in the other. Although polyuria was associated with the tachycardia, urinary sodium excretion as well as urinary osmolality were decreased. The urinary arginine vasopressin was appreciably decreased during the tachycardia. These results suggest that hANP released by paroxysmal tachycardia might not act as a natriuretic factor in this range of plasma concentration. Polyuria during paroxysmal tachycardia was attributed mainly to the inhibition of arginine vasopressin release.

Adult↗
PubMed1986

The role of initial minimum potentials on body surface maps in predicting the site of accessory pathways in patients with Wolff-Parkinson-White syndrome.

Forty-one patients (23 men and 18 women, ages 20 to 66 years) with Wolff-Parkinson-White syndrome were studied with isopotential body surface maps during sinus rhythm to find the most reliable index for predicting the sites of single accessory pathways. The sites predicted by surface maps were compared with those confirmed by multicatheter electrophysiologic study or in the course of surgical operation. Location of the initial minimum by a time criterion, 40 msec after onset of the QRS complex, was not reliable enough for prediction in patients with the small delta wave on their electrocardiograms, because ventricular activation via the normal conduction pathway significantly influenced the location of the minimum. Location of the minimum by an amplitude criterion, -0.15 mV or slightly deeper, was influenced minimally by fusion of ventricular activation, the patient's body size, or age and corresponded well to the site of the accessory pathway in 36 of 41 patients. Those minima appeared on circumscribed areas of the map in accordance with the anatomic subdivisions of the atrioventricular ring. Thus location of the minimum by the amplitude criterion was an excellent index for predicting the site of the accessory pathway, regardless of the degree of ventricular fusion. These amplitude-based map features suggest that nonstandard electrocardiograms recorded from selected positions on the body surface can be used as accurate predictors of the sites of accessory pathways.

Adult↗