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We conducted a retrospective study (1981-1990) to determine whether the efficacy of intracoronary thrombolysis (ICT) could be evaluated from data obtained solely after recanalization. We investigated 55 successful ICT patients (38 with anterior and 17 with inferior myocardial infarction (MI)), and 31 control infarct patients without recanalization. The total serum creatine phosphokinase release (sigma CPK), the extent of infarction measured by T1-201 single photon emission computed tomography (total DS) and the disturbance of regional wall motion (asyn.%) were investigated as parameters for distinguishing the successful ICT and control groups. Discriminatory ability for the two groups was highest with the total DS in all patients. Only the total DS differed significantly between the two groups in patients with inferior infarction. Misidentification of control patients as successful patients was least frequent (25.5%) when using the total DS. These findings suggest that the effectiveness of ICT for acute MI may be assessed on the basis of data obtained solely after recanalization, with the total DS being particularly useful.

The electrophysiologic properties of SUN1165 and its suppressive effect on supraventricular tachycardia were assessed in 14 patients, nine with atrioventricular reentrant tachycardia (AVRT) and five with atrioventricular nodal reentrant tachycardia (AVNRT). This new agent prolonged the PR interval and QRS duration but did not alter the QT interval or the corrected QT interval. It did not alter the sinus cycle length or sinus node recovery time. The drug prolonged the AH interval, HV interval, and intraatrial conduction time but did not change the effective refractory periods of the right atrium or right ventricle. SUN1165 prevented the induction of tachycardia in six of nine patients with AVRT by a complete retrograde block of the accessory pathway and prevented AVNRT in four of five patients by a complete retrograde block of the fast atrioventricular nodal pathway as well. We conclude that SUN1165 is very effective in preventing AVRT or AVNRT. Larger studies with more patients are warranted.

To evaluate the clinical usefulness of Doppler-derived cardiac output and the effect of altered left ventricular function during maximal treadmill exercise, this study was performed using continuous wave (CW) Doppler technique through the suprasternal notch acoustic window. Subjects consisted of 22 patients with coronary artery disease (study 1) and 21 healthy male volunteers (study 2)

The effects of physical training on hemostatic parameters were evaluated in 56 postmyocardial infarction (MI) patients before and after one month of systematic physical training and in 30 control post-MI patients, who did not undergo such training. There were no significant changes in prothrombin time (PT) and alpha 1-antitrypsin (alpha 1AT) at the beginning and end of the study in either group. Levels of fibrinogen, Factor VIII: C (VIII:C) and von Wildebrand antigen (vWf:Ag), and activities of ATIII and plasminogen (Plg) were significantly decreased in the group with physical training (p less than 0.05), while values were unchanged in the control group. Hematocrit, platelet counts, and alpha 2-plasmin inhibitor (alpha 2PI) activities also decreased in the physical training group (p less than 0.05). In contrast, these variables increased in the control group (p less than 0.05). Activated partial thromboplastin time (aPTT) tended to be prolonged in the group with physical training, while it was shortened in the control group. In a subset of 20 patients with physical training, resting levels of plasmin-alpha 2PI complex (PIC), thrombin-antithrombin III complex (TAT), protein-C (P-C:Ag), plasminogen activator inhibitor-1 (PAI-1), VII:C, and P-C activities had significantly decreased after one month of physical training (p less than 0.05), although tissue plasminogen activator activities remained unchanged. Physical training appeared to suppress coagulability as indicated by the decrease in fibrinogen, VIII:C, vWf:Ag, VII:C, and TAT, and prolongation of aPTT. The decrease in plasminogen, t-PA:Ag, alpha 2PI, PAI-1, and PIC after physical training may result from the decreased coagulability. In conclusion, physical training appears to induce a suppression of the coagulation system in patients in the recovery phase of MI.

An active orthostatic stress test was conducted on 32 elderly patients over 65 years (elderly group) and 17 normal adults, for a comparative evaluation of their blood pressure, heart rates, and plasma catecholamine responses. In addition, 8 patients in the elderly group underwent a study of orthostatic responses with or without sublingual administration of isosorbide dinitrate (ISDN). The results of the orthostatic responses were evaluated by Schellong's method. The elderly group produced a positive reaction in one (3.1%), and a weakly positive reaction in two (6.3%), while the remaining 29 (90.6%) and all of the normal adults showed negative responses. The systolic blood pressure pattern that developed in response to rising among the elderly group was significantly different (p less than 0.001) from that of the normal adult group, but the response pattern seen in the heart rates of the former approximated that of the latter. The plasma norepinephrine concentration 10 minutes after rising increased significantly (p less than 0.001) in both the elderly and normal adult groups. This increase amounted to 1.5-fold in the elderly group and 2-fold in normal subjects, with a less prominent increase shown by the elderly. The norepinephrine levels of the elderly group were significantly higher than those of the normal adults both before and 10 minutes after rising (p less than 0.001 and p less than 0.01, respectively). In the elderly, ISDN caused a significant drop in the systolic blood pressure immediately after rising and a significant increase in the heart rate. Sublingual ISDN administration resulted in a significant increase in the norepinephrine level (p less than 0.05) in association with rising. These findings indicated that the circulatory responses to orthostatic stimuli are inappropriate as clinical data among the elderly and the administration of ISDN exaggerates this shortcoming further.

In 13 patients with an implanted dual-chamber atrioventricular (AV) demand pacemaker, left ventricular performance was elicited by pacing mode manipulation for study using gated cardiac pool scintigraphy at rest and during exercise. There was no significant difference between DDD and VVI at 70 and 90 beats/min with respect to cardiac output, peak ejection rate or peak filling rate. At 110 beats/min, the cardiac output was greater with DDD as compared to VVI. The peak filling rate was also significantly greater with DDD as compared to VVI (DDD : 3.6 vs VVI : 2.8 EDV/s, p

Sex and age differences of ventricular gradient (G) were analyzed and normal ranges were determined in normal Japanese subjects (120 men and 74 women), whose resting heart rate was within the range of 65 to 75 beats/min. Women showed a larger Z component in ÂT and a smaller Y and larger Z component in G than men. The common trend in age differences was a decrease in Y component of G in both men and women. The ranges obtained in the present study can be applied in automatic VCG analysis, in particular for the differentiation of primary and secondary ST-T changes.

To assess the prognostic value of an abnormal postexercise response in systolic blood pressure (SBP), treadmill exercise testing was performed in 217 survivors of acute myocardial infarction at an average of 9.3 weeks after infarction. During the mean follow-up period of 4 years, cardiac events were noted in 34 patients (16%), including cardiac death in 13 (6%), nonfatal reinfarction in 12 (6%), and coronary artery bypass graft surgery in nine (4%). An abnormal postexercise SBP response was defined as the ratio of SBP at 3 minutes of recovery to peak exercise SBP of 0.9 or more, on the basis of the cutoff point with the highest sensitivity and specificity to predict cardiac events. An abnormal postexercise SBP response occurred in 90 patients (42%). Patients with an abnormal postexercise SBP response had more exercise-induced myocardial ischemia. more left ventricular impairment, and more extensive coronary artery lesions than those without. Cox proportional hazards model demonstrated that the abnormal postexercise SBP response was ranked first in ability to predict cardiac death (p = 0.025, relative risk 15.41). Bypass surgery was associated with an abnormal postexercise SBP ratio (p less than 0.05). Nonfatal reinfarction could not be predicted by any clinical or exercise variables. In conclusion, an abnormal postexercise SBP response could be useful for predicting cardiac death and the need for bypass surgery after myocardial infarction. This response is probably the result of myocardial ischemia and left ventricular impairment.

The authors investigated the usefulness of the Karhunen-Loeve technique applied to body surface maps to study regional cardiac excitation. Eigenvectors were derived from the body surface potential maps of 120 healthy adults using the Karhunen-Loeve expansion theory. Then, in the maps of various types of ventricular hypertrophy, each eigenvector coefficient was calculated for a statistical comparison. The first eigenvector coefficient in early QRS and the second in mid QRS were larger in patients with asymmetrical septal hypertrophy and in patients with left ventricular hypertrophy, respectively. The third was larger in patients with right ventricular hypertrophy. In the maps of patients with previous anteroseptal myocardial infarction, the second eigenvector coefficient decreased with asynergy of the anterior to apical wall, and the first decreased with the asynergy of the interventricular septum. They conclude that some eigenvector components and coefficients at particular times in the QRS are sensitive to changes in regional cardiac excitation and that they may facilitate the detection of local excitation changes such as occur in hypertrophy or infarction.

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.

To evaluate the determinants of left ventricular filling, left ventricular filling velocity was measured by pulsed Doppler flowmetry during catheterization of the right and left sides of the heart in 37 patients with cardiac disease before and during leg elevation. During leg elevation, despite no significant change in the time constant of isovolumic relaxation (T), the peak rapid filling velocity (PVRF) increased in association with an increase in pulmonary wedge pressure (PWP), but the peak atrial filling velocity was unchanged. The PVRF correlated with the pulmonary wedge V wave — left ventricular minimum pressure difference ( r = 0.68) and in multivariate regression with both T and mean PWP (R = 0.73). These results indicate that left ventricular filling is determined by both left ventricular relaxation and left atrial pressure and that an increase in left atrial pressure changes the left ventricular filling velocity profile in a manner that mimics the pattern with normal diastolic function.

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.

心室期外収縮96心拍と, 心室内変行伝導を伴う上室期外収縮29心拍のFrank法ベクトル心電図QRS環の特徴を分析し, 両者の鑑別基準の作成を試みた。心室期外収縮は心室変行伝導収縮に比してQRS時間および空間最大ベクトル到達時間の延長, 初期描記速度の低下, 正常伝導収縮との初期ベクトル空間夾角の開大という特徴を示した。心室期外収縮を心室変行伝導収縮から鑑別する基準として, (1) QRS時間≧120msec, (2) 空間最大ベクトル到達時間≧50msec, (3) 空間速度心電図初期30msec間のQRS環最大描記速度

健常成人 (NL) 20名および冠動脈疾患 (CAD) 患者52名を対象とした。多段階臥位自転車ergometer運動 (MBEX) に対するR波高変化を解析し, CADの診断あるいは重症度判定におけるその有用性について検討した。NL群とCAD群においてR波高は運動につれて減少し, 最大運動時に最も小さくなった。R波増高または不変を陽性とするBonorisらのR波高診断基準を用いたCAD診断の感度は21%であるが, ST基準による感度は65%であり, R波高基準はST基準に比し有意に低感度であった (p

健常成人の体表面電位図のKarhunel Loeve展開による基底ベクトルを用い,心肥大を持つ患者の電位図における展開係数を求め各基底ベクトルと局所心筋の興奮との対応を検討した.第一基底ベクトルは後から前へ向い,中隔肥大のQRS初期で展開係数が増大,第二基底ベクトルは右上から左下へ向い左室肥大のQRS中期で展開係数が増大,第三基底ベクトルは左上から右下へ向かい右室肥大のQRS中期で展開係数が増大した.このことから第一基底ベクトルは心室中隔,第二基底ベクトルは左室前側壁,第三基底ベクトルは右室の興奮とよく対応することが示唆された.これらを利用して心筋局所の電気現象の変化を捉えやすくすることが期待できると考えられた.

心筋梗塞発生の risk factor として従来から高血圧症, 高脂血症, 糖尿病, 肥満, 喫煙などが報告されている. 本論文では急性心筋梗塞660例と対照群18,117例の臨床データを retrospective に比較することにより, これら risk factor の意義およびその性差, 年齢差について検討を行った. 喫煙者, 高血圧, 高 cholesterol 血症は対照群に比べて梗塞群で有意に多くみられたことから, これらの risk factor は従来の報告どおり心筋梗塞発症の重要な risk factor であると考られた. ついで糖尿病も risk factor の一つと考えられた. 一方肥満の程度は梗塞群と対照群の間に有意差をみとめず, 肥満のみでは risk factor となりえないという結果をえた. 高 triglyceride 血症も独立した risk factor としての意義はうすく, 肥満とともに間接的な risk factorであると考えられた. Risk factor の性差に関して, 糖尿病や高 cholesterol 血症では梗塞群と対照群間の有意差の程度が女性よりも男性で大であった. このことは女性における閉経と関係があると考えられる. 女性における estrogen などの内分泌因子が本来の risk factor のもつ危険性を低下させることにより, 血管のアテローム硬化を抑制し, ひいては梗塞発症の risk を低下させるものと考えられる. 以上から糖尿病や高 cholesterol 血症などの risk factor の重要性は女性よりも男性で大きいと考えられた. Risk factor の年齢差に関して, 多くの risk factor は老年者よりも若年者の梗塞群で有意に高率にみられた. このことは多くの risk factor を持つ若年者では血管のアテローム硬化が早期に進展し, 梗塞発症に至るばかりでなく, 他の疾患 (脳血管障害, 心不全, 腎不全など) にも罹患しやすく比較的若年で淘汰されるものと考えられる. 一方 risk factor を有しない者は老年まで生きのびるが, やがては冠動脈硬化をきたし, 梗塞発症に至るためと考えられる.以上から risk factoor の重要性は老年者よりも若年者で大きいと考えられた.

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.

To define the clinical significance of T wave map changes in patients with angina at rest, body surface isopotential T distributions were obtained in 48 patients with single-vessel disease (left anterior descending artery, 34; right coronary artery, eight; left circumflex artery, six) documented angiographically and were compared with those in 120 healthy subjects and those in 19 patients with left ventricular overload whose electrocardiograms showed negative T waves accompanied by an increase in R wave amplitude in left precordial leads. The T wave map abnormalities were observed in 24 of 48 patients (50%) with angina and were classified into three types: (1) type I (18 patients, 37.5%) was characterized by a segmental negative potential in the positive area located at the left thorax and the minimum at the peak of T wave positioned in the upper portion of the left anterior chest, (2) type II (three patients, 6.3%) was characterized by a negative potential with a minimum in the inferior thorax and an indentation of negative potential at the lower margin of the positive potential located over the upper thorax, and (3) type III (three patients, 6.3%) was characterized by a negative potential with a minimum at the back throughout the period of T wave. All patients showing T wave map abnormalities of type I had a significant stenosis of the left anterior descending artery. Likewise, all patients with type II or III had single-vessel disease of the right coronary or left circumflex artery, respectively. All types of T wave map changes observed in patients with angina were different from those in patients with left ventricular overload, whose maps showed the generalized negative potential at the inferior thorax and the left back and the minima clustered at the precordium. In seven patients with lesions of the left anterior descending artery, T wave map abnormalities of type I recovered to normal after successful percutaneous transluminal coronary angioplasty. The behavior of the negative potential and its extrema on the T wave map, which was not available from routine electrocardiography, was indicative of the involved coronary artery and probably of its associated ischemic area in one-half of our patients with angina pectoris.

Body surface potential maps were recorded for 52 patients with solitary anterior myocardial infarction and 57 normal subjects. All patients had pure anterior wall asynergy on a left ventriculogram but no diagnostic Q wave on the standard 12-lead electrocardiogram. Q wave (greater than 30 msec) distributions on the body surface of the patients and normals were compared. The frequency of Q waves in the area above V1-V2 and in the right middle chest was significantly higher in patients than in normals. The sensitivity of Q waves for asynergy in leads from both these areas was 19-60%. The positive predictive value was 67-94%. The frequency of Q waves was significantly higher in severe asynergy than in mild asynergy. A combination of two selected unipolar leads from these areas yielded a sensitivity and specificity of 33% and 95%, respectively. With a combination of three leads, these values were 42% and 93% and with four leads 48% and 88%, respectively. The results indicate that several unipolar leads from the area above V1-V2 and from the right middle chest in addition to the standard 12-lead electrocardiogram may improve the electrocardiographic diagnostic accuracy of myocardial infarction.

The effects of elastase on lipid metabolism, platelet function, and blood coagulability were evaluated in 18 patients with diabetes mellitus. Blood sampling was made before medication, and after oral administration of 10800 units of elastase per day 8 and 16 weeks. Measurements were made for platelet counts, platelet sensitivity to ADP-aggregation, serum concentrations of total cholesterol·HDL-cholesterol·triglyceride and plasma concentrations of, β-thromboglobulin (β-TG)·fibrinogen (Fbg)·antithrombin III (AT III).After the administration of elastase, HDL-cholesterol increased (0W: 45.6±10.3mg/dl; 8W: 49.2±10.1mg/dl, p

To investigate hemodynamic effects of a new coronary vasodilator, 2-nicotinami doethyl nitrate (nicorandil), 12 patients with prior myocardial infarction were stu died. Patients with angina pectoris were excluded.Hemodynamic measurements were made during supine bicycle ergometer exercise testings before and 60 min after single oral administration of 15 mg of nicorandil. Symptom-limited exercise testing was performed before nicorandil, and after nicoran dil the same workload was assigned to each patient. At peak exercise, there was a significant increase in cardiac index, while stroke volume index remained unchanged after nicorandil. Both at rest and at peak exercise, there was a significant decrease in systolic and diastolic blood pressure, systemic vascular resistance, and pulmonary capillary wedge pressure after nicorandil. Coronary sinus blood flow was significant ly increased and coronary vascular resistance was significantly decreased after nicor andil both at rest and peak exercise. The average value for plasma nicorandil concen tration was 215ng/ml 60min after dosing.These data would indicate that nicorandil exhibits a beneficial effect on hemodyna mic responses to exercise in patients with prior mycoardial infarction by reduction of left ventricular preload and afterload and by increment in coronary blood flow.

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.

To investigate the hemodynamic effects of isosorbide-5-mononitrate (ISMN), 11 patients with effort angina pectoris were studied.Hemodynamic and echocardiographic measurements were observed at rest and during angina-limited supine multi-stage bicycle ergometer exercise testings before and 120 min after oral administration of 20 mg of ISMN. Compared with the control exercise test, the mean ST-segment at peak exercise showed less depression after ISMN (P

We studied the entire distribution of cardiovascular lesions with the use of intravenous digital subtraction angiography (DSA) in 24 patients having Takayasu's sortitis. The aorta, its branches, pulmonary vessels, and left ventricle were assessed by neck (anteroposterior), abdominal (anteroposterior), and chest (right and left anterior oblique) images. DSA showed multiple arterial lesions (n = 24) including proximal renal artery stenoses (n = 4), pulmonary arterial stenoses (n = 4), inferior-superior mesenteric arterial anastomoses (n = 3), brachiocephalic arterial aneurysms (n = 2), aortic root aneurysm (n = 1), diffuse left ventricular hypokinesis (n = 1), subclavian steal phenomenon (n = 1), and right aortic arch (n = 1). The incidence of total occlusion was highest in the right subclavian artery (n = 12). Average percent luminal stenosis (mean ± S.D.) over the aorta and its branches tended to be smaller in patients with prior corticosteroid therapy (17.3 ± 14.6%) than in those without (22.0 ± 9.8%), but the difference was not significant. DSA (four-series) was useful in assessing the whole disease spectrum and often revealed subclinical lesions in this disease.

The effects of dilazep dihydrochloride on prostanoid metabolism and platelet functions were evaluated in 15 patients with ischemic heart diseases or ischemic cerebral diseases. Blood samples were obtained from the antecubital vein before and after oral administration of 300mg of dilazep dihydrochloride per day for 4 weeks. Measurements were made for plasma concentrations of thromboxane B2 (TXB2), 6-keto-prostaglandin F1α (6-keto-PGF1α) and β-thromboglobulin (β-TG) and platelet aggregtion by ADP.After administration of dilazep dihydrochloride, TXB2 showed a tendency to decrease [from 82.2±48.6 (M±SD)pg/ml to 66.4±55.0pg/ml], and 6-keto-PGF1α showed a tendency to increase (from 51.1±27.2pg/ml, to 63.8±35.4pg/ml). A TXB2/6-keto-PGF1α ratio significantly decreased after the medication (from 2.3±2.2 to 1.3±1.0, p

Noise-free and enlarged P loops of the Frank lead system were obtained from 164 normal Japanese males and 137 females (mean age: 34.4 and 33.2 years, respectively) with computer-averaging technique of 8 consecutive beats. Automated measurements concerning 17 parameters of the P loop (P durations, magnitudes, and directions of 3 planar, spatial maximal, and mean polar P vector) were carried out. At the same time, sex and age differences were statistically analyzed. I. Sex differences: Significant sex differences were found in 5 items in the first age group (20-29 years), 3 items in the second (30-39 years), and 7 items in the third (40-49 years). II. Age differences: In males, the effect of aging was observed in 5 parameters out of 17, in time durations extended and maximal vectors displaced posteriorly. In females, changes with advancing age were observed in 13 items out of 17, thus leaving only 4-parameter, including frontal maximal P vectors and directions of mean polar P vectors as unaffected.

Frank vectorcardiographic P loops with satisfactory signal-to-noise ratio were obtained from 44 patients with ostium secundum atrial septal defect (OSASD), confirmed at operation, by using computer-averaging technique of 8 successive beats. Morphological and quantitative analyses of the P loop were made in order to reveal those characteristics of the P loop in OSASD which seemed most typically to show volumetric or diastolic overloading of the right atrium. Twenty-three automatically measured parameters of the P loop were compared with hemodynamic variables such as the systolic right ventricular pressure (s-RVP) and the left-to-right shunt ratio.A majority of the maximal P-vector directions in 3 projection planes and the P duration were within normal 95 percentile ranges. The magnitude of the maximal horizontal, the magnitude of mean polar and the magnitude of the maximal spatial P-vector increased above the 97.5 percentile values considered as the upper limit of normality in 66%, 55%, and 50% of the cases, respectively. These findings seem to suggest that the vectorcardiographic analysis of the P loop with computer-averaging technology is a valuable screening tool of right atrial diastolic overloading.Although the horizontal P loop of normal subjects showed many different patterns, the horizontal P loop of OSASD could be divided morphologically into 3 groups (Type A, Type B, and Type C). Thirteen cases (30%) out of 44 were of Type A, 22 cases (50%) Type B, and 9 cases (20%) Type C. There was a significant age difference between the individual mean values in the 3 groups (p

A multicenter, double-blind study was performed in 46 patients with stable effort angina pectoris on maintenance doses of long-acting nitrate in order to evaluate the effect of levocarnitine chloride (LC-80) tablets, containing 200 mg of levocarnitine chloride, on exercise tolerance. Multistage treadmill exercise testing was performed according to the modified Bruce protocol at the pre-treatment period and after 4 and 8 wk of oral daily doses of 1800 mg of LC-80 or placebo therapy.In the pre-treatment period, there were no significant differences in treadmill exercise duration, time to the onset of angina, pressure-rate product (PRP), and ST deviation between the placebo and LC-80 groups.The time to the onset of angina was significantly longer after 4 (P

左室駆出分画(LVEF)が50%未満に低下しているにもかかわらず良好な運動耐容能を示すとともに狭心症を認めない陳旧心筋梗塞患者(II群; 13例)における運動耐容能の規定因子を究明するために,障害群と同等の運動耐容能を有しLVEF50%以上の陳旧心筋梗塞患者(I群; 13例)を対照として仰臥位多段階自転車ergometer運動試験を施行した. peak運動時心係数は両群間に有意差を示さなかった.運動時間を従属変数とする重回帰分析にて, I群では運動時心拍数および平均肺動脈楔入圧の増加分が, II群では運動時末梢血管抵抗の減少分および心拍数の増加分が高い寄与度を示した.以上より, I群に比しII群では運動時の後負荷減少が運動耐容能の重要な規定因子であると考えられた.

The clinical significance of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF-4) levels were evaluated in 26 patients with atrial fibrillation (af) complicated by valvular heart disease (VHD), 73 patients with af but without valvular heart disease and 57 normal subjects. The beta-TG level was significantly higher in af patients without VHD than in normal subjects (49.4 +/- 35.8 ng/ml vs 31.2 +/- 14.0 ng/ml, p less than 0.01) and in af patients with VHD than in normals (64.1 +/- 52.8 ng/ml vs 31.2 +/- 14.0 ng/ml, p less than 0.01). Af patients with or without VHD tended to show high levels of PF4 compared with normals (af patients without VHD: 34.1 +/- 45.5 ng/ml, af patients with VHD: 18.6 +/- 27.2 ng/ml, normals: 11.6 +/- 8.2 ng/ml). There was no correlation between beta-TG levels and age in af patients without VHD or in normals. There was also no correlation between beta-TG levels and heart rate in af patients without VHD. The activation of platelets was suggested in patients with atrial fibrillation on the basis of increased levels of platelet releasing substances, especially in those with VHD. The high levels of beta-TG and PF4 in patients with atrial fibrillation may be one explanation for the high incidence of thromboembolism in these patients, indicating the necessity of antiplatelet therapy.

We studied heart rate response and blood lactate changes during treadmill exercise testing in 10 patients with sick sinus syndrome (SSS) and normal atrioventricular (AV) conduction in whom an activity detecting multi-programmable rate responsive pacemaker was implanted for atrial pacing (AAI pacing). Treadmill exercise testing was performed twice in each patient under the two different AAI pacing modes: rate responsive function off (fixed rate 60 pulses per minute [ppm]; RR-off) and rate responsive function on (rate response 10, activity threshold medium, basic rate 60 ppm, and maximum rate 150 ppm; RR-on). Chronotropic response and blood lactate change during exercise were compared among patients under each pacing mode and eight healthy volunteers of ages matching those of the patients. In patients under the RR-off pacing mode (RR-off patients), chronotropic response was lower (P less than 0.01) and blood lactate level was higher (P less than 0.05) than those in patients under the RR-on pacing mode (RR-on patients) and volunteers during exercise. In RR-on patients, however, both chronotropic response and lactate level changes during exercise were comparatively improved, with no significant differences between RR-on patients and volunteers. These data suggested that improvement of chronotropic response by rate responsive pacing, in comparison with nonrate responsive pacing, increased the blood supply to the working muscles and resulted in less lactate production during exercise. It was concluded that rate responsive AAI pacing which could maintain AV synchrony and normal intraventricular conduction was an optimal physiological pacing mode for SSS patients with normal AV conduction.

陳旧性心筋梗塞66例と狭心症18例の87誘導体表面電位図を記録し, T mapの分析を行なつた. T mapにおいて,胸部の正領域の中に,左肩から下方へ向けて舌状に負領域が陥入する所見を示した梗塞13例(20%, MI群)および狭心症6例(33%, AP群)の冠動脈および左室造影所見の検討を行なつた. MI, AP群共に全例に左冠動脈前下行枝(LAD)に有意狭窄を認め, MI群の全例およびAP群の3例(50%)に前壁の壁運動異常を認めた. T mapにおいて,負領域が左肩部から舌状に正領域に陥入する所見は, LAD病変あるいは,左室前壁,中隔部の壁運動異常を示唆すると考えられた.

標準12誘導心電図による心筋梗塞の診断が困難であるが,心血管造影にて,左室前壁に限局する収縮異常を示した冠動脈疾患患者48名(疾患群)を対象とし,体表面電位図を記録し,各誘導点のQ30(Q波≧30msec)の出現率を健常群57名のそれと比較した.疾患群ではV1・V2誘導点の上方領域および右胸部でQ30の出現率が有意に高かつた. Q30による感度は17～56%であつたが,陽性予測率は63～92%と高かつた.収縮異常高度群は軽度群に比べ,同様の領域でQ30の出現率が高かつた.これらの結果から,標準12誘導心電図誘導にV1・V2誘導点の上方領域および右胸部の誘導を加えることにより前壁収縮異常の心電図診断の精度が向上すると考えられた.

The pattern of left ventricular contraction or relaxation is not uniform and also changes depending on hemodynamic states. Accordingly, the measurement of myocardial segment length only may have limitations for the analysis of regional myocardial function, and a two-dimensional analysis of regional myocardial function was developed and characterized by utilizing measurement of regional myocardial surface area on the epicardial surface. In eight anesthetized open-chest dogs, the relationship between regional myocardial function and total cardiac function was examined. The extent of the reduction of regional myocardial surface area during the ejection phase or during the systolic phase correlated more closely with stroke volume over wide ranges of left ventricular end-diastolic pressure, aortic pressure, left ventricular contractility, and heart rate (r = 0.75–0.96) than the shortening of myocardial segment length alone. Thus, the results demonstrated that regional myocardial function estimated by the measurement of regional myocardial surface area represents total cardiac function more accurately than myocardial segment length over wide ranges of hemodynamic states despite the changes in the left ventricular contraction and relaxation pattern.

体表面87点の単極誘導心電図から求めた, QRST isointegral map (I-map)と, QRST subtraction I-mapにより,前壁梗塞の診断および左室駆出率の推定を行なった.対象は陳旧性前壁梗塞47例であり,健常成人46例を正常対照群とした.前壁梗塞のQRST I-mapでは負領域が左胸部に張り出し,極大および極小の位置が健常人に比して有意に左下方に偏位した.またQRST subtraction I-mapにおけるn subtraction, ∑ subtraction, ∑ DIの指標は駆出率と比較的良い負相関を示した.また梗塞例の標準12誘導心電図V4誘導におけるQRST積分値と正常のそれとの差も駆出率と負相関を示し,簡便な方法として臨床応用が可能と考えられた.

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)