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Biomedical subjects

S Satake

Publications and source records attributed to S Satake.

At least 109 records · Page 6Linked to original sources
PubMed1981

Conduction disturbances in the middle internodal tract of the rabbit heart.

Conduction properties between the sinus node and the septal branch of the crista terminalis, the so-called middle internodal tract, were studied in the isolated rabbit right atrium. Recordings were obtained from two simultaneously impaled microelectrodes using the extrastimulation technique after cutting the anterior and posterior internodal tracts. Several types of conduction block were observed associated with steplike prepotentials and distortions of perinodal fibers in the absence of pharmacological intervention. Prolongation of sino-septal conduction time occurred with decreasing coupling intervals. The return cycle of the atria gradually increased with prolongation of the retrograde conduction time of premature impulses to the SN until entrance block was seen. Several observations in this data demonstrate the influence of concealed or manifest retrograde conduction into the perinodal fibers of the sinus node after premature stimulation of the atria, as critical delay within the perinodal region could alter conduction time of the premature depolarization, reset the sinus node, and influence subsequent antegrade conduction alone or in various combinations.

Action Potentials↗
PubMed1981

Current status and future direction of clinical electrocardiography: His bundle electrogram.

Recordings of His bundle electrogram combined with stimulation method are very useful to diagnose the locations of conduction disturbance, to understand the mechanisms of arrhythmias and to evaluate the electrophysiologic properties of the A-V conducting system. However, there remain some unsolved problems regarding the electrophysiologic interpretations and prognostic implications based on His bundle electrograms. In this panel discussion, some aspects with regard to the usefulness and limitations of His bundle electrogram will be discussed from our data obtained in 300 patients.

Adolescent↗
PubMed1981

Electrophysiologic studies of Jervell, Lange-Nielsen syndrome.

Electrophysiologic studies were performed in two sibling with Jervell, Lange-Nielsen syndrome. Electrophysiologic parameters were all within normal limits except for prolongation of effective refractory period of the ventricular myocardium. This finding may suggest one of electrophysiologic mechanisms underlying QT prolongation, that is, delayed ventricular repolarization.

Child↗
PubMed1981

Excretion pattern of urinary glycosaminoglycans from orthopedic patients.

To obtain a clue for the metabolic disorder of glycosaminoglycans (GAG) in connective tissue diseases, a screening test for excretion pattern of urinary GAG was applied to urines from orthopedic patients. The results showed a wide variety of excretion pattern of urinary GAG from various orthopedic patients. Several cases gave irregular bands. Also, most cases of bone tumor showed abnormal excretion patterns different from the normal range of percent distribution of bands 1, 2 and 3. The data suggested abnormal metabolism of GAG in these diseases. Percent distribution of band 1 or bands 1 + 2 tended to increase in rheumatoid arthritis (RA), suggesting an elevation of the metabolic rate of chondroitin sulfates in RA. In cases of other orthopedic diseases, a half of them showed an abnormal excretion pattern of urinary GAG, but the excretion pattern of the remaining ones was within the normal range.

Adolescent↗
PubMed1978

Hyaluronuria in a case of progeria. (Hutchinson-Gilford syndrome).

A classic case of progeria (Hutchinson-Gilford syndrome) in a 9-year-old Japanese boy is presented. The characteristic clinical features in this patient were similar to those reported in the literature. The total amount of acid glycosaminoglycans excreted in the urine was within the normal range, but there was an increase in hyaluronic acid excretion. The hyaluronuria was a novel finding in progeria, providing a common linkage with the hyaluronuria found in Werner's syndrome.

Child↗
PubMed1978

Concealed Wolff-Parkinson-White syndrome.

Sixty-nine patients, 23 of whom had documented attacks of paroxysmal supraventricular tachycardia (PSVT), were studied electrophysiologically and the following results were obtained: (1) Antegrade concealed Wolff-Parkinson-White syndrom (AC WPW) was demonstrated in 7 out of 69 patients by atrial stimulation including extrastimulus. Six of these 7 patients presented an accessory pathway (AP) conduction of the Kent type, 5 of which showed Type A and another, Type B. The remaining one of these 7 patients showed an AP conduction of the Mahaim type. One of the 7 patients showed a combination with the James and Kent types AP conduction. (2) Retrograde concealed Wolff-Parkinson-White syndrome (RC WPW) was demonstrated in 8 out of 49 patients in whom the presence of V-A conduction was revealed by ventricular stimulation, while PSVT was documented in 7 of these 8 patients. An AP of the Kent type was identified in the left side of the heart in 5 out of 7 patients with documented PSVT, the right side in one and in the septal region in one. (3) The presence of bilateral or two APs were demonstrated in 3 patients. In another one with documented PSVT, the presence of a branched AP from a left-sided Kent bundle was assumed. In conclusion, our study demonstrated that concealed APs may be more frequent than realized. For example, the frequency of RC WPW in patients with PSVT was 30.4% (7/23) in our series. Accordingly, it is postulated that RC WPW may also be indicated for surgical therapy and that detailed electrophysiologic examination by the physician should be carried out for the sake of determining the indication.

Adolescent↗
PubMed1977

Demonstration of bidirectional dual A-V nodal pathways in the same patient.

In a patient with documented paroxysmal junctional tachycardia (PJT) electrophysiologic studies were performed using an extrastimulus technique. At an A1-A2 interval of 360 msec, atrial extrastimulus revealed sudden prolongation of an A2-H2 interval from 370 to 540 msec and PJT ensued. This finding was consistent with antegrade dual A-V nodal pathways. On the other hand, at a V1-V2 interval of 540 msec, ventricular estrastimulus showed a jump in ventriculo-atrial (V-A) conduction time with evidence of delay in the A-V node from 285 to 565 msec and a ventricular echo followed. This finding was consistent with retrograde dual A-V nodal pathways. Mechanisms of bidirectional dual A-V nodal pathways are discussed.

Aged↗
PubMed1977

Paroxysmal supraventricular tachycardia with unusual induction. Concealed reentry or automaticity?

In a patient with documented paroxysmal supraventricular tachycardia, earlier atrial extrastimuli consistently induced His-ventricle (H-V) block and "atrioventricular junctional" beats, which were always followed by an echo or paroxysmal supraventricular tachycardia. In "atrioventricular junctional" beats, a V wave was preceded by an H deflection with the same intervals as that of the sinus beat. As for the underlying mechanism of paroxysmal supraventricular tachycardia, two possibilities were considered: (1) concealed atrioventricular nodal reentry, and (2) "triggered automaticity."

Adult↗
PubMed1977

Demonstration of two anomalous bypasses in concealed Wolff-Parkinson-White syndrome.

Two patients with a history of paroxysmal supraventricular tachycardia but no evidence of the Wolff-Parkinson-White syndrome in the conventional electrocardiograms were studied utilizing atrial and ventricular extrastimuli. The evidence obtained in these patients was consistent with a concealed Wolff-Parkinson-White syndrome. In one patient, ventricular extrastimuli revealed three different responses in the curve of ventriculoatrial conduction, depending upon the interval of stimulus. In the other patient, intracardiac recordings, including the left atrial potential, showed that paroxysmal supraventricular tachycardia was induced by an impulse via an anomalous bypass which diverged from the main bypass or stemmed independently from the left ventricle and was maintained by impulses via the main bypass which lay between the left ventricle and the left atrium. The mechanisms for initiation of the paroxysmal supraventricular tachycardia were discussed.

Adult↗