Search

Correlation studies were carried out between thallium-201 myocardial perfusion images and vectorcardiograms in 77 patients with myocardial infarction (48 anterior and 29 inferior infarctions) and 30 patients with hypertrophic cardiomyopathy. A quantitative method was developed; myocardial 201Tl uptake index (a relative myocardial activity to background, MUI) and myocardial 201Tl uptake ratio (a ratio of regional myocardial counts to maximal myocardial counts, MUR) were utilized to differentiate myocardial infarction from hypertrophic cardiomyopathy, and evaluate them. A fairly good agreement between left ventriculograms and myocardial perfusion images was obtained in myocardial infarction (diagnostic accuracy 95.1% in anterior and 75.6% in inferior infarction). In anterior infarction the linear relationship of r = -0.58 (p < 0.001) was obtained between asynergy index and mean anterior MUR. A highly significant correlation was observed between anterior MUR and the instantaneous 24 msec Z component (r = -0.80, p < 0.001). In inferior infarction, Qy/Ry was correlated to inferior MUR (r = -0.58, p < 0.001). In hypertrophic cardiomyopathy, four types of hypertrophic sites were classified with 201Tl images (septal, apical and anterior, apical and septal, and anterior dominant types). Azimuth angles of instantaneous 10 msec vector were directed right-anteriorly (mean 114.5 degrees) in septal hypertrophy, and left-anteriorly (mean 84.9 degrees) in apical and anterior hypertrophy. Elevation angle of maximal T vector in apical hypertrophy was deviated superiorly (mean 102.6 degrees). There was a good correlation (r = 0.60, p < 0.001) between the magnitude of spatial maximal QRS vector and lateral wall MUR.

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.

左室造影(LVG)を施行した陳旧性心筋梗塞患者52名を対象として,安静時における二次元201Tl心筋像(二次元心筋像)および201Tl心筋emission computed tomography (ECT)像のcircumferential profile解析を行ない,梗塞の部位および大きさの診断におけるECT定量解析の有用性を検討した.健常者の長軸および短軸ECT像より求めた正常下限profile curveをもとに判定した梗塞領域は, LVGにおける壁運動異常領域とよく一致し,二次元心筋像の定量解析よりも有意に診断感度および精度が向上した.短軸ECT像から求めた全左室心筋容積に対する梗塞領域容積の百分率(%infarct size)は, %ACS (percent abnormally contracting segment: LVGの拡張期左室全周長に対する無または奇異性収縮領域周囲長の比)との間に, r=0.74(p

A correlative study was performed on 70 patients with old anterior myocardial infarction between each of the orthogonal components of instantaneous QRS vectors and the anterior-wall, lateral-wall and septal myocardial uptake ratios (A-MUR, L-MUR, and S-MUR, respectively). These MURs were calculated from the thallium-201 myocardial perfusion images at 5 projections and used as the index of the infarct size of the respective LV wall. The Z components of the 14-msec and 24-msec instantaneous QRS vectors significantly correlated with the S-MUR (r = -0.51) and the A-MUR (r = -0.66) respectively. The X component of the 32-msec instantaneous QRS vector also showed a significant correlation with the L-MUR (r = 0.59). The regression equations obtained in the present study seemed also applicable to patients with complete right bundle branch block. It is concluded that the quantitative analysis of the Frank vectorcardiograms could afford valuable information as to the size as well as the site of myocardial infarctions.

12GHz帯衛星放送1chを利用し, PCM音声・各種データなどと共に放送できるサービスのひとつとして開発を進めている, ハイビジョンディジタル静止画放送に用いる画像符号化方式について述べる.本論文では, 符号化方式に要求される条件を示した後, サブサンプルDPCMおよびサブサンプル適応的補間残差量子化の2種類の符号化方式について, その特徴と処理画像の符号化特性 (SN比, 画質評価, 符号化率など) を示す.また, 画面の切替時間に応じ, 符号化率を制御する適応手法についても論じる.さらに, 伝送路上のビット誤りにより生じる画質劣化を改善する手法について論じ, 室内実験により, 低C/N時にも充分な画像品質で放送サービスを確保できることを述べる.これらの方式を用いることにより, 伝送速度2.048Mb/sのディジタルチャンネルで, 高品質PCMステレオ音声と共に, 鮮明なハイビジョンディジタル静止画像を伝咲することが可能となる.

The present status of exercise testing in coronary artery disease (CAD) was discussed in respect to test protocols, ECG criteria and lead systems, and hemodynamic responses. Advantages of modern multistage protocols over single-stage ones such as Master two-step tests are obvious in diagnostic accuracy and patient's safety. Clinical significance of horizontal and downsloping ST depression has already been established. Diagnostic significance of other exercise-induced ECG alterations such as slow upsloping ST depression, ST elevation, U-wave inversion, and R-wave amplitude changes was discussed. The latter parameter is still controversial as to its clinical significance. Use of an inadequate ECG lead system is one of major causes of false negative tests. Necessity of multiple lead systems was emphasized for higher diagnostic accuracy. From the view point of cost-efficacy relation, we will recommend simultaneous recording of CC5 or CM5, V3 and CL or III in routine exercise testing for screening of CAD. Test results such as exercise time, and heart rate and systolic blood pressure responses are also useful parameters for the evaluation of the severity and prognosis of CAD. It was emphasized that in exercise monitoring of ECG and blood pressure is indispensible in multistage exercise testing for improvement of diagnostic accuracy as well as patient's safety.

心筋梗塞の既往のない労作狭心症患老28名,陳旧心筋梗塞患考17名および健常対照者10名を対象としてcircumferential profile法による運動Tl心筋emission CT (ECT)像の定量解析の有用性を検討した. (1)健常者の運動Tl心筋ECTの運動直後Tl摂取率およびTl washout rate (WR)の正常下限profile curveを作成した. (2)正常下限profile curveに基づいて「Tl欠損(運動直後Tl摂取率低下)」領域,「TlWR低下」領域および「Tl灌流異常(Tl欠損またはTl WR低下のいずれかまたは両方)」領域の定量解析,およびTl欠損領域の肉眼評価による診断能を比較検討した. (3)有意狭窄枝,特に左回旋枝の診断精度は「Tl欠損」の定量解析を行なつた場合に最も良好であつた(84%). (4) 1枝か多枝病変かの鑑別は肉眼判定に比し,「Tl欠損」基準による定量解析の方が良好であつた(71%vs91%). (5)「Tl灌流異常」領域から求めた虚血心筋容積率は2枝, 3枝病変群では1枝病変群に比し有意に大であつた(p

12GHz帯衛星放送の1チャンネルの帯域を使用して, PCM信号による多数の高品質音声を時分割多重し放送を行う伝送方式を開発した.多重化した信号は, 直交キャリヤ変調方式により, 搬送波を直接ディジタル変調する.この伝送方式では, 衛星テレビ放送のPCM音声伝送信号フォーマットとの共通性を保ち, その伝送速度2.048Mb/sのフレーム構成を基本の1チャンネルとした.誤り訂正符号およびレンジ伝送による誤り制御の効果を改善することにより, これを12または16多重する多チャンネルの伝送を可能とした.試作した装置を用いた衛星伝送実験による伝送特性の測定および音質評価の結果から, 低C/N時にも充分な音声品質で放送サービスを確保できることを確認した.

To evaluate the significance of the left atrial (LA) contribution to left ventricular (LV) filling in cardiac pacing, LV inflow velocity was recorded with pulsed Doppler echocardiography in 20 patients with a DDD pacemaker. The pacemaker was programmed to atrioventricular (AV) sequential pacing with AV intervals of 50, 100, 150, 200 and 250 ms, and then to VVI pacing at a fixed rate of 70 beats/min. To evaluate the relative changes of LV filling volume in individual patients, the percent change in time-velocity integral of LV inflow velocity in each pacing mode was calculated as the ratio to that of AV sequential pacing with an AV interval of 150 ms. To estimate the degree of LA contribution to LV filling, the ratio of time-velocity integral during LA ejection phase to that during total LV filling phase was measured at the optimal AV interval. The percent LV inflow volume in AV sequential pacing was 74% for an AV interval of 50 ms, 87% for 100 ms, 98% for 200 ms and 90% for 250 ms. The percent LV inflow volume in VVI pacing was 72%. The percent LV inflow volume at AV intervals of 150 ms was significantly greater than that at an AV interval of 50, 100 and 250 ms, and in VVI pacing (p less than 0.05). The degree of LA contribution to LV filling showed a positive correlation with the percent increase of LV inflow volume with mode conversion from VVI to AV sequential pacing (p less than 0.005) and also with age (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

In the PCM sound broadcast by digital transmission, the noise due to the bit-error at low reception field intensity degrades the speech quality, which restricts the range of broadcast reception. A method to reduce the bit-error noise is the error control by range transmission, where the information indicating the range of the significant bit in the sample in a specified interval is transmitted as the range data. This paper presents a quantitative analysis for the reduction of the bit-error noise, for the traditional range transmission system and the control system by majority decision, to fully utilize the merit of the method. The improvement from the viewpoint of listening sensation was verified by a subjective evaluation test. It is shown that the proposed method exhibits a remarkable improvement in the low-intensity reception with a high error-rate, where the error-correcting code cannot achieve a sufficient improvement. It is shown by experiment that seven levels of the transmission range are sufficient to achieve the desired performance.

A correlative study was performed to relate the interventricular septal angle (As degrees) evaluated by transmission computed tomography to the azimuth of initial QRS vectors in 52 patients. Patients were divided into five groups: RV volume overloading (RVO), RV pressure overloading (RSO), LV volume overloading (LVO), LV pressure overloading (LSO), and normal control with no cardiopulmonary disease. For measurement of As degrees, the leftward and forward directions were designated as zero and 90 degrees, respectively. The mean value of As degrees was significantly smaller in RVO (14.4 degrees) and RSO (41.1 degrees) than in normal controls (50.4 degrees) and in LVO (53.2 degrees). The mean value of the azimuth of the initial 12-msec instantaneous QRS vectors (H 12 degrees) was significantly smaller in RVO (80.5 degrees), RSO (81.7 degrees), and LSO (81.3 degrees) than in normal controls (113.8 degrees and in LVO (113.7 degrees). A significant linear correlation was shown between As degrees and H12 degrees in a combined group consisting of RVO, LVO, and normal controls (r = 0.70, p less than 0.001), and also in another combined group consisting of RSO, LSO, and normal controls (r = 0.52, p less than 0.01). It was concluded that the orientation of the interventricular septum was one of the major determinants of the direction of initial QRS vectors, especially in patients with ventricular volume overload or without cardiopulmonary disease.

Estimation of diastolic behavior of the left ventricle (LV) in hypertrophic cardiomyopathy (HCM) has been commonly carried out using invasive methods1) which have some limitations to be applied on dynamic exercise. However, using Doppler methods of investigation brings a number of practical advantages. In the absence of intracardiac shunt or valvular regurgitation, 2)–4) transmitral flow velocity represents the rate of LV volume change (dV/dt) in diastole, and is independent either of abnormal LV shape or regional movement of the LV wall. To assess LV diastolic behavior in HCM, the transmitral flow velocity was evaluated before and after dynamic leg exercise using a pulse Doppler flowmeter combined with two-dimensional (2-D) echo-cardiograph.

Immunoglobulins of the IgG class can be divided into four isotypes, IgG1, IgG2, IgG3 and IgG4, on the basis of the amino acid differences in the heavy chain constant region, of variation in the position of attachment of light to heavy chain, and of the number and arrangement of inter-heavy chain disulfide bridges (1,2). These structural differences are reflected in unique antigenic determinants that allow their serologic recognition and in a series of allotypic determinants of gamma markers (Gm) that reflect genetically controlled polymorphisms (1–3).

Near-maximal treadmill exercise testing was performed on 26 normal individuals (NL) and 78 patients with coronary artery disease (CAD) using a modified Bruce's protocol. Exercise-induced changes in orthogonal P wave measurements were made automatically, using an averaging technique, immediately before and 30 sec after treadmill exercise to assess their diagnostic significance in evaluation of left ventricular (LV) function in CAD patients. The maximal inferior and posterior components of the P wave and the maximal P-vector magnitude in the frontal and left sagittal planes showed a statistically significant increase after treadmill exercise both in NL and CAD patients. These changes were considered to be physiological responses of the P wave to dynamic exercise. The percent changes of the maximal horizontal P-vector magnitude (%Hmax) were significantly higher after treadmill exercise in CAD patients than in NL. In patients with effort angina pectoris and without a previous myocardial infarction, the %Hmax showed a highly significant negative correlation with the percent changes of the LV ejection fraction (r = 0.66, p less than 0.01), measured by exercise RI angiography. These results suggest that the exercise-induced increase in %Hmax reflects transient impairment of LV function during exercise. It was concluded that a %Hmax of more than 120% provided a useful, noninvasive index for assessing LV function in treadmill exercise testing.

Serum samples from five populations in China [173 from Huhehote (Naimengu Zhizhiqu), 195 from the Beijing area, 131 from Hefei (Anhui Province), 155 from Hangzhou (Zhejiang Province), and 152 from Guangzhou (Guangdong Province)] were tested for G1m(1, 2, 3, and 17), G2m(23), G3m(5, 10, 11, 13, 14, 15, 16, 21, and 26), and Km(1). The Gm pattern of the Chinese populations are characterized by the presence of four haplotypes, Gm1, 17;..;21, 26, Gm1, 2, 17;..;21, 26, Gm1, 17;..;10, 11, 13, 15, 16, and Gm1, 3;23;5, 10, 11, 13, 14, 26, which are characteristic of Mongoloid populations. Agreement was obtained in all Chinese samples between the observed and expected frequencies on the basis of the Hardy-Weinberg equilibrium of phenotypes. Heterogeneity tests of the haplotypic distributions among the five populations showed no significant differences in the distributions of Gm phenotypes between Huhehote and Beijing nor between Hefei and Hangzhou, whereas highly significant differences were observed among the three districts: northern part (Huhehote and Beijing), central part (Hefei and Hangzhou), and southern part (Guangzhou). The data indicate a south to north genocline, ranging from Huhehote to Guangzhou in which Gm1, 17;..;21, 26 changes from 0.471 to 0.183, Gm1, 17;..;10, 11, 13, 15, 16 from 0.097 to 0.033, and Gm1, 3;23;5, 10, 11, 13, 14, 26 from 0.229 to 0.730. In contrast to the Gm system, no significant regional differences in the frequencies of the Km1 allele were observed among the five populations.

ハイビジョンの音声信号を, MUSE信号の垂直帰線期間にペースバンド多重して伝送する方式を開発した.この方式においては, 音声信号の伝送容量が現行テレビ衛星放送の65%程度に制約されるため, 音声信号の符号化方式として準瞬時圧伸差分PCMを採用し信号の圧縮を行った.本符号化法による一般の番組音の音質評価実験を行った結果, 現行テレビ衛星放送のAモード, Bモードに比べほとんど遜色のない音質が得られることが確認された.また, 差分PCMの符号化, 復号化時に不完全積分を行うことで, 伝送中に生じた符号誤りによる音質劣化の改善を行った.この圧縮音声信号に, 音声以外のデータや訂正符号を付加し, 伝送レートが1.35Mb/sの多重化信号を構成する.これまでに, 本方式を用いたハイビジョンの衛星伝送実験を繰り返し実施し, いずれも良好な結果を得ている.