Fifty-six consecutive patients with various cardiac diseases were studied with a third-generation whole body computed tornographic system. Enhancement was performed by intravenous injection of angiographic contrast medium.
Identification of the great vessels, atria and ventricles, and evaluation of abnormalities in these structures were possible by cardiac computed tomography.
For example, enlarged left ventricle in the left ventricular volume load, enlarged right ventricle in the right ventricular volume load or hypertrophied interventricular septum in idiopathic hypertrophic sub-aortic stenosis were revealed with a satisfactory resolution. Pericardial effusion and intracardiac thrombi were most precisely assessed by computed cardiac tomography.

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Vectorcardiographic and echocardiographic correlations were made in 160 patients with no clinical evidence of cardiovascular diseases except for the Wolff-Parkinson-White syndrome. Frank vectorcardiographic classifications of the patients were based on both the morphology of the delta loop and the direction of the mean delta vector in the horizontal plane as follows; group I (93 patients) with a delta loop inscribed nearly straightly anteriorly and either to the left or right and a mean delta vector directed more anteriorly than +20°, group II (31 patients) with a hook-shaped delta loop inscribed initially anteriorly but soon posteriorly and to the left, and group III (36 patients) with a delta loop inscribed nearly linearly to the left and either posteriorly or slightly anteriorly and a mean delta vector directed more posteriorly than +20°. Abnormal echocardiographic patterns of ventricular contractions in the syndrome were seen at the left ventricular posterior wall (LVPW), the interventricular septum (IVS), and the right ventricular anterior wall (RVAW).
In group I abnormal LVPW motions were observed in 91 patients (98%), and both abnormal LVPW and IVS motions in 1. The remaining 1 showed no echocardiographic abnormalities either at LVPW or IVS. In contrast, abnormal IVS motions were observed in 29 patients (94%) of group II. No patient of group II showed abnormal LVPW motions. In 17 patients (47%) of group III abnormal LVPW motions alone were observed. Two patients showed both abnormal LVPW and IVS motions. In the remaining 17 patients (47%), no abnormal motions were noted either at LVPW or IVS. Abnormal RVAW motions were invariably observed in 19 patients of group II with satisfactory RVAW echograms, but never seen in groups I and III. Above findings could be explained by the pre-excitation at LVPW in group I, RVAW in group II, and posterior right ventricle in group III.
In 19 patients (8 in group I and 11 in group III) frontal QRS loops were very similar to that in left anterior hemiblock. All of these patients except for 1 showed abnormal LVPW motions, so that the site of pre-excitation was presumably located at the posterior paraseptal region or the posterior IVS. Three cases with a combination of a frontal QRS loop of left anterior hemiblock pattern and abnormal IVS motions in addition to abnormal LVPW motions may be explained by the pre-excitation at the right-sided IVS near LVPW.
We feel that combinations of vectorcardiographic and echocardiographic approaches are clinically quite useful as an auxiliary non-invasive means of locating the pre-excitation site.

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One hundred and thirty-eight cases of cerebral venous/venous sinus thrombosis during the puerperium have been studied. Maximum number of cases (112 cases) occurred in the age below 30 years. Signs and symptoms appeared in most of the cases (72 cases) during the first 7 days of post partum period. One hundred and eleven cases were multipara. Commonest signs and symptoms were fever (85 cases); headache (66 cases), convulsions (64 cases), altered consciousness (57 cases), hemiplegia (60 cases), papilloedema (48 cases), etc. Carotid angiography done in 55 cases revealed block in middle part of superior sagittal sinus in 24, and localised, dilated and tortuous cortical veins in 5. A statistically significant rise in serum triglycerides, phospholipids, free fatty acids, blood platelet count, platelet adhesive index, and fall in blood fibrinolytic activity were found as compared with normals. These factors may be playing a role in the etiology of cerebral venous/venous sinus thrombosis during puerperium.

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Coronary artery aneurysm was demonstrated in 7 patients, whose ages ranged from 38 to 66 years, by selective coronary angiography. Four patients had atypical chest pain probably not caused by cardiac ischemia, 1 patient had aortic stenosis and recurrent bouts of atrial fibrillation, and 2 were evaluated following myocardial infarction and found to have triple vessel atherosclerotic coronary disease. Mitral valve prolapse and varicosities of the coronary venous tree found in one individual suggest that mucoid degeneration which replaces the normal fibrous tissue resulting in weakness of vessel wall may be responsible for the formation of coronary artery aneurysm and varicosities of the coronary venous system. The unsuspected presentation and benign course of these patients are emphasized and the pertinent literature is reviewed.

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The effects of intravenous disopyramide phosphate on myocardial function were evaluated by non-invasive indices of cardiac performance (systolic time intervals, STI) in 15 patients with atherosclerotic heart disease and different degrees of cardiac failure. Disopyramide (1.5mg/Kg) was given intravenously over a period of 5min. This drug induced in patients in I-II classes of NYHA a significant decrease of LVETc, while PEP, ICT, and PEP/LVET ratio rose significantly.
STI were affected much more markedly in patients in III-IV classes of NYHA. Particularly affected were contractility indices (PEP, ICT, PEP/LVET), which were reduced significantly more in patients in III-IV classes as compares to patient in I-II classes. In contrast, LVETc, which correlates to stroke volume and cardiac output, was similarly worsened by the drug in the 2 groups of patients.
Therefore, this study shows that disopyramide has relevant depressant effects on myocardial performance, simultaneously reducing stroke volume and contractility, and that the effect on contractility is more marked in patients with severe left ventricular impairment.

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Different forms of renin in the kidney and their relations were investigated by gel-filtration with sephadex G-75. Low molecular weight renin (M.W. 45, 000) was found in both of intact Wistar-Kyoto rat (WKY) and WKY whose renin-angiotensin system was stimulated by adre-nalectomy and feeding no salt diet, by extracting with 0.05M pyrophosphate buffer, at pH 6.5. An addition of 10mM N-ethylmaleimide (NEM) to the buffer did not change the molecular weight of renin extracted.
From human cadaver kidney, low molecular weight renin (M.W. 45, 000) was extracted by the same procedure.
In hog kidney, on the other hand, high molecular weight renin (M.W. 67, 000) was extracted with 0.05M pyrophosphate buffer, at pH 6.5. High molecular weight renin (M.W. 67, 000) was extracted also with the buffer containing 10mM tetrathionate (TT), a sulfhydryl blocker. However, with the same buffer containing another sulfhydryl blocker, NEM, low molecular weight renin (M.W. 45, 000) was extracted. With the buffer containing a sulfhydryl compound, 100mM dithiothreitol (DTT), low molecular weight renin (M.W. 45, 000) was extracted. When NEM was added to the high molecular renin extracted with 0.05M pyrophosphate buffer, approximately a half of the renin was converted to low molecular weight renin. After acidification to pH 3.3 for 10min, the high molecular weight renin was converted to low molecular weight renin.
The results were against the assumption that a sulfhydryl requiring enzyme (SH-enzyme) participated in the interconversion between high molecular weight renin and low molecular weight renin.
It is reasonable to assume that the actions of NEM, TT, and DTT are not through a SH-enzyme, but affect directly the interconversion of sulfhydryl group and disulfide (S-S) bond which exists in the renin molecule, and high molecular weight renin may be formed by a combination of low molecular weight renin and another protein with a S-S bond(s).

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Ischemic changes in the left ventricular wall were investigated during graded coronary constriction in 9 dogs. Epicardial and intramyocardial electrograms were recorded and changes in ST-segment voltage were correlated with the changes in intramyocardial gas tensions in outer and inner layers of the myocardium measured using a mass spectrometer. Electrographic and metabolic changes appeared first in inner layer and proceeded to outer layer with increasing severity of coronary constriction. In both layers intramyocardial ST-segment elevation was closely related with the increase in carbon dioxide tension (r=0.78 in inner layer and r=0.67 in outer layer). Epicardial electrogram, however, reflected the regional ischemia less sensitively than intramyocardial electrograms and has a limited function to detect myocardial ischemia.

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The relationship between the grade of a decrease in the regional coronary blood flow and the movement of ventricular myocardium of that region was investigated in open chest dog. Blood flow in left anterior descending artery (FLAD) was reduced by stepwise constriction of LAD with ligature. Ventricular segment length was measured in a circumferential plane on the endocardial surface by ultrasonic dimension system. For the elimination of the noise caused by ultrasonic dimension system, the synchronizer was inserted between sample clock of the dimension system and the trigger circuit of the electromagnetic flowmeter.
A 20% reduction of FLAD affected the pattern of ischemic myocardial shortening very little. Discontinuance of shortening to the end of systole was occurred by a 20 to 60% reduction in FLAD. Early and/or late systolic bulging was induced by a 60% reduction of FLAD. Systolic bulging with early diastolic shortening was seen in the cases with a 60 to 80% reduction in FLAD. Frank systolic bulging which was always seen by complete occlusion of LAD was produced by a 60 to 90% reduction of FLAD in few cases.

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The relations among coronary vascular reserve, regional myocardial contractile force and myocardial metabolism were investigated in anesthetized dogs under open-chest condition. The reactive hyperemia response was examined during stepwise occlusion of circumflex artery. A change in percent repayment was used as an index of the coronary vascular reserve. Contractile force was measured with strain gauge arches sutured to ischemic and nonischemic areas of the left ventricle. The nonischemic muscle contractile force (NIMCF) increased or showed no significant change with the reduction of repayment by stepwise constriction of circumflex artery. The ischemic muscle contractile force (IMCF) began to decrease markedly following reduction of repayment below 50%. NIMCF was found to be slightly decreased by the severe reduction of coronary blood flow (CBF) in ischemic region. Thus there was a low (r=0.39) correlation between NIMCF and CBF in ischemic region. However, the correlation between IMCF and CBF in ischemic region was relatively high (r=0.68).
The arterial and coronary sinus blood samples were obtained for the determination of oxygen content, lactate and potassium concentrations. In the range of constriction without reduction of CBF, IMCF decreased significantly following reduction of repayment below 50%, but O₂ lactate and potassium extraction ratios were not significantly different. Application of further constriction revealed significant reductions of CBF, stroke volume, aortic pressure, IMCF and lactate extraction ratios, and it also revealed significant elevation of O₂ extraction ratio.
The above observation suggests that a reduction of coronary vascular reserve might affect regional contractile force without change in CBF, and reduction of CBF could decrease regional and global left ventricular performance with changes in myocardial metabolism.

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The electrophysiological effects of verapamil (racemic compounds) and its optical (d- and 1-) isomers on canine ventricular myocardial fibers were investigated in current clamp conditions using single sucrose gap chamber and microelectrodes. The current-voltage (I-V) relationships were obtained in normal and low Na (12mM)-low Ca (0.45mM) solu-tions with and without the drugs. Verapamil and its optical isomers blocked repetitive action potential discharges (slow responses) induced by depolarizing DC-currents. However, 1-isomer was more potent than d-isomer in suppressing these responses. The difference in the potency was attributed to their different actions on the steady state I-V relationships. Namely, 1-isomer increased time independent membrane conductance to potassium ions (probably gkl), while d-isomer did not. This effect of 1-isomer may favor the suppression of phase 4 depolarization and hence reduce the frequency of repetitive action potential discharges in depolarized ventricular muscle more effectively than d-isomer.

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For the purpose of obtaining fundamental data to make the diagnostic criteria for coexisting electrocardiographic abnormalities in right bundle branch block (RBBB), the Frank-vectorcardiographic and electrocardio-graphic parameters were studied in both normal and RBBB conductions in 25 patients (16 males and 9 females, aged 6 to 78 years) with intermittent or transient RBBB.
There were no statistically significant differences in the corresponding instantaneous QRS vectors between normal and RBBB conductions during the first 10.4 (±3.2)msec of the QRS duration on the average. No statistically significant differences existed in the mean Q amplitudes of the Frank leads between normal and RBBB conductions. After the development of RBBB, voltages of Rx and Ry, and the planar maximum QRS vectors decreased approximately by 10% on the average, and Rz decreased significantly by 63.9% on the average, and S amplitudes of the 3 Frank leads increased significantly. We observed 3 patients showing a complete reversal of the sense of inscription of the horizontal QRS loop from counterclockwise to clockwise after the development of RBBB. Two of these patients showed no clinical evidence of cardiac or pulmonary diseases except for RBBB. After the appearance of RBBB, maximum T vectors deviated significantly posteriorly in the horizontal and left sagittal planes. Twenty-three patients showed counterclockwise inscription of the T loop both in the horizontal and left sagittal planes, and 9 patients in the frontal plane. After the development of RBBB, we observed a complete reversal in the sense of inscription of the T loop from counterclockwise to clockwise in 13 cases (56.5%) in the horizontal plane, in 15 cases (65.2%) in the left sagittal plane, and in 8 cases (88.9%) in the frontal plane.
On the basis of the present study, we made the following conclusions: 1) the lesion in most of clinical complete RBBB was highly likely to lie in the main stem of the right bundle branch; 2) the traditional Q wave criteria for myocardial infarction could be used without modifications in the presence of RBBB except for high posterior myocardial infarction; 3) specific criteria should be established for the diagnosis of ventricular hypertrophy, especially RVH in the presence of RBBB; and 4) clockwise inscription of QRS and T loops and posterior displacement of T loops in the horizontal plane could not be applied to the diagnosis of RVH in the presence of RBBB.

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Atrio-Arterial Bypass (AAB) and concomitant use of Intra-Aortic Balloon Pumping (IABP) and Veno-Arterial Bypass (VAB) were performed, using 7 dogs with induced cardiogenic shock. AAB was established by draining blood from the left atrium and subsequently returning this blood to the carotid artery. VAB was also accomplished by draining blood from the right atrium and then returning this blood to the femoral artery. And bypass flow rates were set at approximately one third of the baseline cardiac output.
Evaluation of hemodynamic effects of concomitant use of IABP and VAB was carried out, compared with AAB.
The following findings were obtained.
1) In concomitant use, the left ventricular afterload was decreased to lower level (mSPr and TTI) and the total perfusion flow was increased to higher level than in AAB.
2) In AAB the left ventricular preload (mLAP) decreased to lower level than in concomitant use.
3) In concomitant use and AAB, the left ventricular stroke work decreased to the same level.

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A case of metastatic left ventricular osteosarcoma detected during life by conventional echocardiography was reported, and by 2-dimensional real-time echocardiography the spread and localization of osteosarcoma in the left ventricle were visualized directly. Our report is the first description of echocardiographic detection of osteosarcoma of the heart.

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Pulmonary artery banding was performed on an 11-year-old female with a large patent ductus arteriosus to control pulmonary hypertension.At catheterization 3 years later the band on the right pulmonary artery was present. At catheterization 13 years later the right pulmonary artery band could no longer be demonstrated.

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