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Biomedical subjects

T Takanashi

Publications and source records attributed to T Takanashi.

At least 55 records · Page 3Linked to original sources
PubMed1979

Noninvasive recording of His-Purkinje activity in patients with complete atrioventricular block. Clinical application of an "automated discrimination circuit".

In seven patients with complete atrioventricular (AV) block, His bundle electrograms (HBEs), standard ECG recordings, bipolar esophageal ECGs and highly amplified, filtered, bipolar chest lead ECGs were simultaneously recorded. The filtered chest lead ECG was averaged to determine His-Purkinje activity (HPA). A simplified device, the "automated discrimination circuit," was used to selectively eliminate the superimposed atrial and ventricular potentials that are characteristic of complete AV block and unsuitable for signal averaging. The processed chest lead ECG was amenable to conventional techniques of signal averaging. In four patients with block proximal to the AV node diagnosed by HBE, there was no activity after the P wave in the surface-averaged ECGs. HPA was consistently recorded before the QRS in the surface-averaged ECG. The measurements of the HV and HPA-V intervals were very close, with a difference of less than 2 msec. Three patients with block distal to the His bundle by HBE showed a loss of electrical potential before the QRS in the surface-averaged ECG, but had a consistent HPA after the P waves. The P-HPA intervals coincided well with PH intervals, with a maximal difference of 5 msec.

Action Potentials↗
PubMed1978

The metabolism of digitoxin in hepatic cirrhosis of human subjects.

Digitoxin, 1 mg, was orally administered to 12 cirrhotic patients (the 6 in a clinically compensated and the 6 in a decompensated state) and their serum concentrations were measured at 6 hours and everyday through 7 days by radioimmunoassay. The serum half-life of digitoxin in these groups and normal subjects, determined from the serum concentrations, was as follows: 4.7 +/- 0.55 days for controls, 4.9 +/- 0.45 days for the compensated group and 5.3 +/- 0.35 days for the decompensated group. No statistically significant difference could be found in half-life among these groups. (P less than 0.2). The same dose of digitoxin was orally administered to 6 cirrhotic patients and 6 control subjects and their left ventricular systolic time intervals, LVET and QS2, were determined at 6 hours and every morning for 7 days. Cardiac responses, exhibited by decrease in the systolic time intervals, in both control subjects and cirrhotic patients dissipated in fair parallel during the ensuing 4 days and returned to base line level by 5 days. From these both biological half-life and physiological effect, it may be concluded that overall metabolism of digitoxin in cirrhotic patients is not disturbed.

Administration, Oral↗