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Biomedical subjects

I Sotobata

Publications and source records attributed to I Sotobata.

At least 73 records · Page 4Linked to original sources
PubMed1985

Evaluation of left atrial rhythm with pulsed Doppler echocardiography.

To evaluate the origin of ectopic atrial rhythms, the beginning of atrioventricular inflow due to left and right atrial ejection was estimated using the pulsed Doppler combined with two-dimensional echocardiography. In ten normal controls, the beginning of transtricuspid flow due to atrial ejection preceded that of transmitral by 0 to 40 msec with an average of 22 msec. In contrast, the beginning of right atrial ejection flow lagged behind that of left atrial by 40 to 80 msec in case 1 and by 20 to 50 msec in case 2 of ectopic atrial rhythm. The significant delay of atrioventricular inflow due to right atrial ejection in these two patients strongly suggests that the ectopic atrial rhythm is of left atrial origin. The pulsed Doppler echocardiography is considered to be a useful clinical tool for noninvasive evaluation of the left atrial rhythm.

Adult↗
PubMed1985

Evaluation of myocardial involvement in Duchenne's progressive muscular dystrophy with thallium-201 myocardial perfusion imaging.

Myocardial involvement in progressive muscular dystrophy of the Duchenne type was evaluated in 19 patients using thallium-201 myocardial perfusion imaging. A qualitative analysis was performed from five projection images by three experienced physicians. Distinct perfusion defects were shown in 13 patients, especially in the LV posterolateral or posterior wall (11 patients). There was no significant relationship between the presence of perfusion defects and the skeletal muscle involvements or thoracic deformities assessed by transmission computed tomography. Extensive perfusion defects were shown in 2 patients who died of congestive heart failure 1 to 2 years after the scintigraphic study. Progression of the myocardial scintigraphic abnormalities were considered to be minimal in 7 of 9 patients who underwent two serial scintigraphic studies over 2 to 3 years. It was concluded that thallium myocardial perfusion imaging is a useful clinical technique to assess myocardial involvement in Duchenne's progressive muscular dystrophy.

Adolescent↗
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

[Ventricular activation sequence estimated by body surface isochrone map].

This study was performed to evaluate the usefulness of the body surface isochrone map (VAT map) for identifying the ventricular activation sequence, and it was correlated with the isopotential map. Subjects consisted of 42 normal healthy adults, 18 patients with artificial ventricular pacemakers, and 100 patients with ventricular premature beats (VPB). The sites of pacemaker implantations were the right ventricular endocardial apex (nine cases), right ventricular epicardial apex (five cases), right ventricular inflow tract (one case), left ventricular epicardial apex (one case), and posterior base of the left ventricle via the coronary sinus (two cases). An isopotential map was recorded by the mapper HPM-6500 (Chunichi-Denshi Co.) on the basis of an 87 unipolar lead ECG, and a VAT isochrone map was drawn by a minicomputer. The normal VAT map was classified by type according to alignment of isochrone lines, and their frequency was 57.1% for type A, 16.7% for type B, and 26.2% for type C. In the VAT map of ventricular pacing, the body surface area of initial isochrone lines represented well the sites of pacemaker stimuli. In the VAT map of VPB, the sites of origin of VPB agreed well with those as determined by the previous study using an isopotential map. The density of the isochrone lines suggested the mode of conduction via the specialized conduction system or ventricular muscle. The VAT map is a very useful diagnostic method to predict the ventricular activation sequence more directly in a single sheet of the map.

Bundle-Branch Block↗
PubMed1985

[Quantitative evaluation of various cardiac diseases using body surface mapping].

Body surface mapping (map) was used to evaluate various cardiac diseases quantitatively. For 30 cases with old anterior myocardial infarction (AMI), map parameters were compared with infarct size assessed by left ventriculography and 201Tl myocardial scintigraphy (LV% asynergy and 201Tl% defect, respectively). Parameters used in the present study were nSubtraction 40 (sigma Subtr. 40), which were obtained by the summation of voltages less than the lower limit of normal range (mean--2SD) at 40 msec from the QRS onset and nSubtraction 10-60 (sigma Subtr. 10-60), which was obtained by the integral of voltages below the normal range, calculated each 10 msec to 60 msec, as well as the number of lead points with Q waves of 30, 40 msec duration (nQ30, nQ40), and the summation of R voltages over the entire body surface (sigma R). In 19 cases with aortic regurgitation (AR), R and S voltages in each lead were compared with left ventricular diastolic dimension (LVDd) obtained by echocardiography. In 43 healthy persons and two patients with RV pacing, the ventricular activation time was measured in each lead (VAT map). In AMI, nSubtr. 40 correlated best with LV% asynergy (r = 0.70, p less than 0.001). EF and 201Tl% defect were related to nSubtr. 10-60 (r = 0.83, p less than 0.001 and r = 0.85, p less than 0.001, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

[Evaluation of the atrial contribution to ventricular filling in patients with DDD pacemakers].

To evaluate the usefulness of physiologic cardiac pacing, the trasmitral flow velocity was recorded using the pulsed Doppler method combined with 2-D echocardiography in 14 patients in whom a DDD pacemaker was implanted. DDD pacemakers were programmed to atrioventricular (AV) sequential pacing with AV intervals of 50, 100, 150, 200 and 250 msec, and VVI pacing modes at a heart rate of 70 bpm. The time-velocity integral (TVI) of the left ventricular (LV) inflow curve was obtained by digitizing the outline of the tracings and expressed in the percentage of that of AV sequential pacing with AV interval of 150 msec (the percent LV filling volume). The percent LV filling volume was 75% for 50 msec, 89% for 100 msec, 96% for 200 msec and 90% for 250 msec of an AV interval in AV sequential pacing. It was significantly smaller at AV intervals of 50, 100 and 250 msec than at an AV interval of 150 msec. It was significantly smaller (68%) in VVI pacing than at AV intervals of 100, 150, 200 and 250 msec in AV sequential pacing. The left atrial (LA) contribution to LV filling was assessed in terms of the fraction of TVI during LA contraction to that during total LV filling at the optimal AV interval (A/Fmax). The optimal AV interval was defined as the interval at which the maximum LV filling volume was achieved in individual patients. The A/Fmax showed a positive correlation with the percent increase of LV inflow volume, with conversion from VVI to AV sequential pacing with the optimal AV interval. It also showed a positive correlation with age. These results suggested that the LV inflow volume was greater in AV sequential pacing with the optimal AV interval than in VVI pacing, especially in patients with a large A/Fmax. In conclusion, pulsed Doppler echocardiography could be a useful, non-invasive technique to determine the indications for implanting a DDD pacemaker and the optimal AV interval in patients in whom DDD pacemakers are implanted.

Adult↗