Sixteen patients with endocardial cushion defects were studied by echocardiography and ultrasonocardiotomography. Three characteristic findings, common to both complete and partial forms, were observed. They were the ostium primum defect of the interatrial septum, the left ventricular outflow narrowing and the atrioventricular valve abnormalities which are the anatomic bases of endocardial cushion defects. Several additional findings were observed in patients with complete form. Most strikingly, the anterior leaflet echo locating in the left ventricle had the direct connection to that in the right ventricle without the interposition of the interventricular septum by echocardiogram. Ultrasonocardiotomogram, on the other hand, demonstrated beautifully the common anterior leaflet and the high interventricular septal defect. There were, in addition, the absence of the paradoxical motion of the interventricular septum and the difficulty in detecting the interatrial septum.
The intact interatrial septum continuous with the anterior mitral leaflet was demonstrated in patients with the interventricular septal defect of atrioventricular canal type, in which there were the typical abnormalities in the atrioventricular valves and the left ventricular outflow narrowing as well.
This study indicates that ultrasonic examination may provide a direct, yet noninvasive method in the diagnosis of various types of endocardial dushion defects.

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A method for quantitative detection of tricuspid regurgitation is proposed. In cases without tricuspid insufficiency or intracardiac shunt, l/slope (tsFV) of the earpiece dye-dilution curve after injection of dye into the femoral vein (FV curve) was significantly correlated with that (tsPA) of the curve after injection into the pulmonary artery (PA curve) within each range of right heart blood volume (RBV) calculated as a product of cardiac output and mean transit time difference between FV curve and PA curve. The relationship among the 3 parameters was expressed as a statistically significant regression equation; log(tsFV)=0.9858 log(tsPA)+0.2980 log(RBV)-0.6418 (p<0.005, sd of predicted tsFV=±0.591). The assumption was made that tricuspid regurgitation causes prolongation of tsFV without any changes in tsPA or RBV, being based on the concepts of the indicator dispersion and of the path-length distribution. The ratio of tricuspid regurgitation to cardiac output was claculated from (observed tsFV-predicted tsFV)/predicted tsFV, in which predicted tsFV is the value calculated from tsPA and RBV using the equation shown above.
In 2 patients who manifested clinical tricuspid insufficiency, large amount of tricuspid regurgitant fraction was determined by this method. It is suggested that the present method utilizing double injections-single sampling dye-dilution technique is useful for clinical quantitation of tricuspid regurgitation.

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An attempt was made to derive a useful noninvasive index to evalute a change in myocardial contractile state using transcutaneous Doppler flow-velocity curve from the carotid artery.
In 5 mongrel dogs and in 43 patients with various heart disease, Doppler flow velocity curves were obtained from the ascending aorta intravascularly using a Doppler catheter and/or from carotid artery transcutaneously using a Doppler probe. The first derivative of left ventricular pressure (dp/dt) and electrocardiogram (ECG) were recorded simultaneously. The following 3 indices were measured from the Doppler flow velocity curves: (1) maximum acceleration of blood flow (dv/dt), (2) time from onset of ejection to peak flow (time-to-peak), (3) time interval between the beginning of Q wave of ECG to the peak of Doppler flow velocity curve (ECG Q-Doppler peak). Among these 3 indices, only ECG Q-Doppler peak demonstrated a significant correlation between the values measured intravascularly and transcutaneously. Also, only ECG Q-Doppler peak showed significant correlation with maximum of dp/dt (max dp/dt).
Since ECG Q-Doppler peak showed correlation with heart rate, the difference between observed and predicted ECG Q-Doppler peak (_??_ECG Q-Doppler peak) was calculated to exclude the effect of heart rate. Predicted value of ECG Q-Doppler peak was calculated from the regression equation between heart rate and ECG Q-Doppler peak in the separate experiments. There was a significant correlation between _??_ECG Q-Doppler peak and max dp/dt.
In 15 patients with coronary artery disease and in 16 healthy subjects, _??_ECG Q-Doppler peak and the other noninvasive method (systolic time intervals) were measured. JECG Q-Doppler peak showed better result in the separation of 2 groups than by systolic time intervals. Itwas concluded that 4ECG Q-Doppler peak is a useful index to evaluate the myocardial contractile state since this index is readily obtained noninvasively.

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The sympathetic tone of the splanchnic nerve was quantified in renal and deoxycorticosterone (DOG) hypertensive rats under pentobarbital anesthesia by measuring equivalent stimulation frequency (ESF). ESF is the frequency of stimulus to the peripheral cut end of the nerve required to restore the preseverance level of arterial pressure. It is assumed to represent the average discharge rate of the nerve before severance. ESF was markedly increased in DOG hypertension 2 weeks after initiation of the DOC-salt treatment. It was relatively decreased after 10 weeks, but was still higher than in the controls. In renal hypertension (clipping of the left renal artery), ESF was decreased considerably 2 weeks and slightly 10 weeks after clipping. When the contralateral kidney had been removed simultaneously with clipping (clip+uninephrectomy), ESF was not sig-nificantly changed. It is suggested that the sympathetic nervous system participates greatly in the pathogenesis of DOC hypertension but not of renal hypertension.

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The effects of 2hours of renal artery occlusion were studied in pre-viously uninephrectomized rabbits. Oliguric renal failure by arterial clamping was produced. Renal blood flow was maintained during ob-servation periods, except for an early decrease in outer cortical blood flow without change elsewhere. During the oliguric stage medullary osmolality was markedly diminished, concomitantly with reduced (U/P)osm. Cin, EPAH and sodium reabsorption were decreased, accompanied by tubular necrosis and intratubular casts. During the early diuretic stage Cin, medullary osmolality and (U/P)osm were still reduced. Intratubular casts disappeared while regenerated tubular cells were focally observed. Two weeks after the occlusion, improved Cin, EPAH, sodium reabsorption, medullary osmolality and (U/P)osm, and regenerated tubular epithelium were found. In 7 weeks Cin and EPAH had returned to the preclamping values whereas medullary osmolality remained decreased with the ap-pearance of medullary fibrosis. (U/P)osm was not completely restored. The findings indicate that during the oliguric stage of acute renal failure of rabbits renal blood flow is maintained, except for a decrease in outer cortical flow, and urine concentrating ability is restored more slowly than other measured functions.

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The relationship between the increase in coronary blood flow (CBF) following contrast material injection and that following temporary occlusion was studied in the anesthetized dogs. The peak flow following a contrast injection was almost equivalent to the peak reactive hyperemia flow following a 10sec occlusion (r=0.86). An increase in coronary sinus blood oxygen pressure (Peso₂) occurred in associated with an increase in CBF.
Administration of dipyridamole diminished the increment of CBF following contrast injection with little changes in Pcso₂.
Thus, in the coronary system the increase in CBF after contrast injection, similar to that observed after temporary occlusion, is related to coronary vascular reserve and measurement of Pcso₂ after coronary arteriography might be an aid to evaluate the coronary vascular reserve.

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In 11 mongrel dogs (14.5 to 26.3Kg) during complete heart block and right ventricular pacing, the cardiovascular dynamics were observed with the effect of isoproterenol infusion (8μg/min intravenously). During complete heart block, cardiac output 2.01±0.17L/min, heart rate 57.6±3.5beats/min, and stroke volume 35.5±2.8ml. Left ventricular (LV) residual fraction was 54±2%. LV end-diastolic volume (EDV) in which almost complete filling is performed due to the long filling period was 4.01±0.35ml/Kg by thermodilution method. Right ventricular (RV) residual fraction and EDV were 39±3% and 3.01ml/Kg, which were significantly smaller than the left. Infusion of isoproterenol increased cardiac output (2.67±0.21L/min), heart rate (66.9±3.5beats/min), and stroke volume (40.4±3.1ml), but both ventricular residual fractions and EDV's did not change significantly, although mean blood pressure decreased remarkably. During right ventricular pacing the effects ofisoproterenol were essentially the same as in complete heart block except no change of heart rate and relatively improved cardiac functions.The plots of derived force-velocity relationship expressed in normalized mean circumferential shortening rate (MCSR) and peak ventricular force (F) showed that isoproterenol increases the velocity of shortening of muscle contraction significantly without significant change of F, while increase of heart rate did not. It is concluded that isoproterenol affects the myocardium mainly through its direct action and the improvement of contractile state via positive chronotropic effect (Bowditch's effect) is relatively small

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The hyperreactive arterial endothelial cells have been introduced in this paper. They are characterized by their ability to transport particles too large for the small holes of the internal elastic lamina locating underneath the endothelial cells, such as carbon particles with the similar size of LDL, floating β-lipoprotein, Lp(a) and especially of VLDL, into the subendothelial space from the blood stream by their abnormally strong contracting and phagocytosis-like activity. Large particles such as carbon particles with a size of 200 to 700Å are too large to penetrate further through holes of the internal elastic lamina from the subendothelial space to muscular layers of the arterial wall, resulting in stagnating for a long time in the subendothelial space, thus showing the atherogenic property of the hyperreactive arterial endothelial cells.
Such endothelial cells appear spotty and streaky in the localized endothelial lining of predominantly susceptible parts to atherosclerosis in susceptible animal species such as rabbit, chicken, and rhesus monkey especially densely in their atheromatous lesions, but do not generally appear in non-susceptible animals to atherosclerosis like rat and dog. They are extremely few in infant rabbit, but increase by age. They appear in hypertensive rat, showing a characteristic distribution even in small groups of arteries such as the circle of Willis.
Cyclic AMP, and especially dibutyryl cyclic AMP, exhibited an inhibitory effect on the hyperreactivity of those cells. Cyclic AMP phosphodiesterase inhibitors, EG467 and EG626, exhibited a powerful inhibitory effect on the contracting and phagocytosis-like activity of those cells, as in the case of pyridinolcarbamate, which enhances enzymes to produce ATP and inhibits slightly cyclic AMP phosphodiesterase, although its inhibitory effect on cyclic AMP phosphodiesterase is weaker than that of EG467 and EG626.
The usefulness of the inhibitors on cyclic AMP phosphodiesterase of arterial endothelial cells and platelets and on that of brain, such as EG467 and EG626, has been suggested in the treatment of atherosclerotic disorders, especially of cerebral atherosclerosis. Some of the hitherto desperate mental disability of the aged seem to be a promising target for treatment with cyclic AMP phosphodiesterase inhibitors.

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A case of left ventricular aneurysm associated with repeated supra-ventricular tachyarrhythmias was successfully treated by ventricular aneurysmectomy. Ventricular aneurysmectomy should be considered for supraventricular tachyarrhythmia as well as ventricular tachycardia, if they are symptomatic and refractory to medical therapy.

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