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Biomedical subjects

Y Tanahashi

Publications and source records attributed to Y Tanahashi.

At least 55 records · Page 3Linked to original sources
PubMed1985

[Gated blood pool imaging in the diagnosis and management of arrhythmia].

The usefulness of multigated cardiac blood pool imaging in evaluating left ventricular function and ventricular activation was studied in patients with cardiac arrhythmias. Subjects consisted of 12 patients with the Wolff-Parkinson-White (WPW) syndrome; 20 with ventricular premature contractions (VPC); 21 with various modes of artificial pacemakers; and two normal controls. Phase analysis was useful in localizing the bypass tract in patients with the WPW syndrome. In four patients with the WPW syndrome and five with VVI pacing, the phase difference between the posterolateral wall of the left ventricle (LV) and the right ventricular apex correlated significantly with the activation time difference between these two regions as assessed by endocardial electrograms (r = 0.94, p less than 0.001). Images of VPC were obtained using the bad beat rejection program in an ADAC computer system. The origin of VPCs evaluated by phase image coincided with results of standard 12-lead electrograms. It was in the right ventricle in four patients, the LV in one, and probably in the interventricular septum in one. The LV ejection fraction (LVEF) decreased significantly (p less than 0.001) after the injection of lidocaine (-3.7%) or disopyramide (-6.2%). The percent reduction in LVEF was significantly greater with disopyramide than with lidocaine (-15.1 vs -11.2%). The plasma concentration of disopyramide was higher in four patients with organic heart diseases than in 11 without. There was a significant correlation between the percent reduction in LVEF and the disopyramide plasma concentrations (r = -0.62, p less than 0.001). The influence of the pacing mode and exercise on LV function was studied in 21 patients with artificial pacemakers. In the VDD and DDD modes, end-diastolic volume (EDV) and cardiac output (CO) decreased after converting to VVI mode. CO increased markedly to approximately 250% of the control value in the VDD and DDD, and moderately in the VVI and AAI modes during ergometer exercise. In conclusion, multigated cardiac pool imaging is considered useful in diagnosing and managing patients with cardiac arrhythmias.

Arrhythmias, Cardiac↗
PubMed1985

[Percutaneous nephroureterolithotomy].

The authors experienced 175 cases of percutaneous nephro-ureterolithotomy during the last thirty-three months. Complete stone removal was successful in 161 cases (92%). Success rate was up to 99%, if we concluded cases which had small residual fragments although the greater part of the stones was removed. Percutaneous nephrolithotomy, using rigid or flexible nephroscopes combined with any of the stone destruction methods (intensive ultrasound, electrohydraulic effect and laser beam) is less invasive for the patients and shortens the hospital stay duration. In combination with extracorporeal shock wave and transurethral ureteral lithotripsy, this method may replace the conventional surgical procedures for urolithiasis in the near future.

Female↗
PubMed1983

Experimental studies on sick sinus syndrome: relationship of extent of right atrial lesions to subsidiary pacemaker shift and its function.

An area where the sinus node was located in 36 dogs was defined as the "SN-area." Five to 7 days after cauterization of the SN-area, a subsidiary pacemaker remained in the SN-area in seven (group S) and shifted to outside the SN-area in 14 dogs (group E). The SN-area in group S had escaped complete destruction, but that in group E was destroyed completely. Heart rate in group S and group E was 154.0 +/- 27.1 and 107.6 +/- 16.8 beats/min (p less than 0.001), respectively. Maximum duration of asystole after overdrive (maxDAO) in group S and group E was 656.7 +/- 260.2 and 2470.2 +/- 2271.6 msec (p less than 0.01), respectively. Propranolol (0.2 mg/kg intravenously) decreased heart rate in group S and group E to 88.3 +/- 7.9 and 71.7 +/- 8.7% (p less than 0.001), and prolonged maxDAO to 140.1 +/- 28.1 and 492.7 +/- 591.4% (p less than 0.025), respectively. It is concluded that the rate and stability of subsidiary pacemakers after cauterization of the sinus node have a close relationship with their location in the right atrium, which is dependent on the extent of lesions in the SN-area. Sympathetic tone played a significant role in maintaining these functions in group E.

Animals↗