Clinical and experimental studies were carried out in order to evaluate the role of myocardial dysfunction in the genesis of circulatory congestion associated with renal failure.
Among the patients with chronic renal failure, those with circulatory congestion had greater blood volume and higher venous pressure while lower cardiac index and stroke work index than those without circulatory congestion. After peritoneal dialysis, although blood volume and venous pressure decreased in both groups, cardiac index increased in the former while it decreased in the latter group. In 15 dogs, acute renal failure was produced by ligating both ureters. As uremia developed, blood volume and left ventricular end-diastolic pressure increased with or without an increase in cardiac index. The depression of ventricular function curve was evident in all the dogs. The peritoneal dialysis performed at this stage resulted in a prompt recovery of left ventricular end-diastolic pressure with minimum change in cardiac index. The measurement of dp/dt/IIT also indicated a depression of myocardial contractility at uremic stage and its recovery after dialysis.
We conclude that impairment of myocardial function is implicated in the development of circulatory congestion in renal failure.

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(1) Narrowness of the early-diastolic and presystolic peaks on the echo curve of the anterior mitral leaflet and an abnormal step formation at the middle or higher level on the descending limb of the presystolic peak were observed in 7 cases with congestive cardiomyopathy or myocardial fibrosis, 1 case with myocardial infarction, and I case with cardiomyopathy due to progressive muscular dystrophy.
(2) This abnormal pattern is considered to be closely related to the myocardial condition in the above-mentioned diseases.
(3) Probable mechanisms for this pattern formation are considered as folllows: (i) a sudden reduction of distensibility of the left ventricle after filling of the ventricle over a certain limit near full-filling, and impaired ventricular contractility, (ii) restriction in the mobility of the mitral valve and its chordae due to their inability to adapt themselves to a de-veloped dilatation of the left ventricle.
(4) A similar presystolic step formation on the echo curve of the anterior mitral leaflet was observed in 3 of 25 cases of hypertrophic cardiomyopathy of Goodwin's sense. Differences between the myocardial state in congestive cardiomyopathy or in similar myocardial diseases and that in hypertrophic cardiomyopathy were also discussed.

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Exercise tests with bicycle ergometer were performed in 9 normals and 54 patients with ischemic heart disease (IHD), in order to evaluate the heart rate (HR) as a parameter for determining the physical working capacity and controlling the daily activities, and to observe the circulatory and metabolic effects of β-blockers and moreover to study the strength-duration relationship of exertion. The following results were obtained and discussed:
1. Reliable correlation between heart rate and O2 consumption during all phases of exercise, including the recovery period (R=0.60-0.87, p<0.001) and parallelism of heart rate and pressure rate product allows the heart rate to be used as a parameter for myocardial O2 demand and ST•T changes. It is reasonable to evaluate the exercise effect by the net increment of heart rate during and after exercise, and to utilize the increment of heart rate in the recovery period for the evaluation of physical fitness and adaptability.
2. Similar to other studies made on β-blockers, in this study too, the agents including Ko 1366 suppressed the exercise responses of heart rate (p<0.01), the product of heart rate and blood pressure (p<0.01), and O2 consumption (p<0.01). But a relatively slow recovery of O2 consumption from the peak response towards pre-exercise level and a higher O2 pulse in the early recovery period was observed after β-blocker medication.
3. Capillary (ear lobe) pH decreased and recovered in correlation with the strength of exertion. This corresponded with the response of other factors such as ST•T, heart rate, pressure-rate product, and O2 consumption, showing that the exercise strength was one of the more dominant factors to determine allowable work load for ischemic heart disease patients.4. Recovery of pH was delayed after medication with Ko 1366 (p<0.01).

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Consecutive autopsy of 1, 000 cases of the aged disclosed coronary sclerosis in 428 cases, myocardial infarction in 137, cardiac hypertrophy in 237, valvular heart disease in 120, conduction disturbances in 96, cor pulmonale in 41, pericarditis in 39, and congenital heart disease or anomalies in 28. There were 343 morphologically normal hearts. A total of 1, 022 heart diseases were found in 657 cases, corresponding 1.6 heart diseases per one heart.
Heart diseases in the aged were divided into (1) those continuing from the younger period and (2) those specifically found in the aged. The latter were non-inflammatory valvular diseases and chronic conduction disturbances.
Mitral regurgitation, including mitral ring dilatation (10), mitral ring calcification (9), spontaneous rupture of the chordae tendineae (2) and calcified aortic stenosis (12) and degenerative aortic regurgitation of prolapsed cusp (35) were produced by various degeneration of the connective tissue of the valves.
A total of 59 cases of conduction disturbances consisted of complete or advanced heart block (15), right bundle branch block (RBBB) (16), RBBB with left axis deviation (17), and left bundle branch block (LBBB) (11). Forty-seven cases showed main lesions in the branching portion of the AV bundle and origin of the bilateral bundle branches, which were closely related to the degeneration of the central fibrous body and fibrosis at the summit of the ventricular septum.
The common field, where the valvular diseases and conduction disturbances occurred, was the fibrous trigone of the heart.

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Clinical open trials of β-methyldigoxin were carried out in 15 institutions in order to examine the effect, usefulness and ease of its oral administration.
In the case of oral digitalization with 0.2mg, 3 times daily, an effect was obtained in all of 13 cases of congestive heart failure accompanied by atrial fibrillation or flutter. The average time and dose required for digitalization were about 50 hours and 1.27mg respectively. In 9 of the 13 cases, the effect was achieved within 48 hours.
The average maintenance does of β-methyldigoxin in 102 cases of congestive heart failure with atrial fibrillation was 0.177mg per day. About 75% of the cases were maintained with 0.15 to 0.2mg. This range of dose of β-methyldigoxin was much smaller than that of digoxin in our series. This can be ascribed to a higher absorption rate of β-methyldigoxin from the digestive tract.
Studies on the cases in which patients previously treated with other glycosides were switched over to β-methyldigoxin revealed that 1mg of β-methyldigoxin is equivalent to 1.8mg of digoxin or to 0.59mg of digitoxin.
The usefulness and ease of β-methyldigoxin in maintenance was evaluated as being somewhat superior to other cardiac glycosides, according to the global judgement of the physicians. The observed side effects were similar to those of other glycosides in frequency and character.

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The effect of vagal stimulation on activity of afferent sympathetic nerve fibers from the dog's left ventricle has been examined. During partial constriction of the coronary artery, a brief electrical stimulation of the cervical vagus nerves resulted in a decrease in blood flow of the constricted artery, systolic bulge of the left ventricle, elevation of the ST segment of electrocardiogram and excitation of the afferent nerve fibers, which continued for up to 15min. These changes were not produced without coronary artery constriction. Intravenous injection of phentolamine eliminated the decrease in blood flow, and suppressed systolic bulge, elevation of the ST segment and excitation of afferent fibers. Propranolol could not eliminate the decrease in blood flow while suppressed the other changes. Atropine eliminated all of these changes. The results indicate participation of adrenergic α-receptors in sustained decrease of coronary blood flow and excitation of afferent cardiac sympathetic nerve fibers which can be produced by a brief vagal excitation.

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Although the recordings of the His potential have been shown to be very useful in the study of cardiac conduction and rhythm disturbances, there remain some problems regarding the clinical His bundle electrogram. Some of the studies were performed to solve in the perfused dog hearts and in situ dog hearts, and consequently the following results were obtained. In some experiments, recording of the His potential could not be achieved even in the perfused hearts in spite of the preserved A-V conduction, suggesting that, as experienced sometimes in the clinical cases, inability to record the His potential might not be due to the technical failure or the anatomical abnormalities of the His bundle. On the other hand, real "splitting of H" occurred in association with the increase in the duration and decrease in the amplitude of the His potential after the ligation of the anterior septal artery. In addition, the true Mobitz II type A-H block, and Wenckebach type intra-Hisian and H-V block could be produced experimentally.

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Acute responses of blood pressure and turnover of norepinephrine in the brain to intracisternally injected guanethidine were studied in rats. Systolic blood pressure in guanethidine-treated rats showed a dose-relating rise for over 9 hrs, while norepinephrine contents in cortex-cerebellum, brain stem and heart were not affected.
The endogenous norepinephrine in brain samples, however, did not decrease against a-methyl-p-tyrosine to result in regression coefficients significantly different from those in the saline-treated group whereas norepinephrine in heart was reduced similarly in the 2 groups, indicating a slowered turnover of norepinephrine selectively in the brain. The results may indicate that the retarded norepinephrine turnover in the brain is causatively related with an acute elevation in blood pressure.

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Short-term, repeated myocardial ischemia was produced in 20 opened-chest anesthetized dogs by left anterior descending (LAD) branch occlusion. Left ventricular pressure (LVP) and its dP/dt were recorded by Satham SF-I transducer, and isometric local force (F) was measured by a Walton-Brodie strain gauge arch sewn onto LV free wall. In all experiments, within a few beats after LAD occlusion, peak negative dP/dt started to diminish its amplitude, reaching a nadir after 20-30 sec (63± 5% of control, 9 dogs). It recovered to 83± 3% of control level in 45 sec and remained essentially unchanged thereafter. This change preceded those of LVP and max dP/dt, which showed only minor falls, In 6 dogs, changes by occluding root of LAD were compared with those by its branch occlusion. The greater the extent of ischemia, the more marked and prolonged were the changes. While F in the ischemic center (Fc) rapidly lost its contractile activity following LAD occlusion, F in marginal zone between infarcted and non-infarcted region (Fm) showed variable extent and different time-course of its diminution. Thus, it was concluded that the change in peak negative dP/dt following LAD occlusion was one of the sensitive signs of early ischemic changes, and was attributed at least in part to characteristic changes in contractile activity of myocardium surrounding the ischemic injury.

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Effects of 2 different types of beta blockers, CS-359 and practolol, on mechanical performance and myocardial oxygen consumption (MVO2) in the isovolumic contraction of the isolated, blood-perfused canine heart with a support dog were studied. Two dose levels of the beta blockers were given intravenously to the support dog, one of which was enough to produce a significant beta adrenergic blocking action and other of which was a higher dose to reveal a direct depressant action on the isolated heart.
CS-359 in the lower dose produced significant decreases in heart rate (HR), peak ventricular systolic pressure (peak VSP), and peak dp/dt while practolol caused no change in these parameters. The HR of the support dog was significantly decreased to the same degree in the lower dose of respective blocker. In the higher dose CS-359 decreased all parameters more definitely whereas practolol diminished peak VSP and peak dp/dt but did not significantly HR. MVO2 was decreased dose-relatedly by CS-359, but not affected significantly by practolol.
From the analysis of relationships of MVO2 to peak VSP and HR in the isolated heart it is concluded that the effective reduction in MVO2 by CS-359 resulted mainly from a reduction in the peak VSP in the lower dose and additional decrease in HR in the higher dose of CS-359.

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A 14-year-old boy, admitted with intractable chest pain, was found to have an enlarged heart and calcification in the apical region, with electrocardiographic features of massive inferolateral myocardial infarction. Left ventricular angiography revealed a large left ventricular aneurysm. He died following resection of the aneurysm and post mortem examination showed changes of a non-specific chronic myocarditis. A vasculitis involving small coronary arterioles was also found in the vicinity of the aneurysm, and the possibility of a rheumatic vasculitis was suggested by a transient episode of an erythema marginatum-like eruption. It is concluded that the association of infarction pattern on the electrocardiogram together with calcification of the heart in children is highly suggestive of a ventricular aneurysm secondary to a myocarditis or a vasculitis involving small, intramyocardial branches of the coronary arteries.

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The Romano-Ward syndrome is very rare as hereditary disease. Only 5 families have been reported in Japan before the present report. The patient, a 15-year-old female, had been treated for epilepsy due to syncopal attacks. Electrocardiography revealed occurrence of an augmented and labile U wave and prolongation of the Q-T interval, with recordings of frequent multifocal extrasystoles and transient ventricular fibrillation. Also noticed was sinus bradycardia. Clinical examinations presented no results coinciding with those specific ECG findings. It was inferred through surveys of her family tree that the present case had an autosomal dominant trait, heterozygously affected through the male line. Severe arrhythmias detected on her ECGs were suppressed by oral administration of 30 mg/day propranolol. Judging from the fact, propranolol may be the first to be administered among a variety of anti-arrhythmic agents in the Romano-Ward syndrome.

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An electrocardiogram (ECG) of bilateral bundle branch block (BBBB) which may be attributable to a mixture of 2:1 and 3:1 atrioventricular (A-V) block is described. The irregularity of QRS complexes with left bundle branch block (LBBB) pattern during 2:1 A-V block may be ascribable to "Wenckebach periods", which might be due either to A-V nodal or His bundle or bundle branch delay. However, it was impossible to distinguish between them precisely because appropriate His bundle studies were not performed during the active arrhythmic phase. Although the exact mechanisms involved were not established with certainty, different rates of recovery in conduction in the bundle branches in association with a marked prolongation of the refractoriness would seem to be the unique feature of this complex arrhythmia.
An ECG tracing of BBBB indicating high grade second degree (2:1 and 3:1) A-V block, in which "spontaneous" occurrence of "Wenckebach periods" with 2 consecutive blocked P waves can be observed during 2:1 A-V block, has never been reported previously as far as can be ascertained from published records

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