In a comparative trial practolol was found to be quite superior to propranolol in the treatment of spontaneous angina pectoris. Propranolol did not reduce the number of anginal attacks in the 24 hours, as evaluated through the patients' charting and continuous electrocardiographic recording, and induced exaggerated bradycardia as well as clinical and hemodynamic signs of poor cardiac performance. In the same patients practolol achieved complete disappearance of the anginal attacks, and returned cardiac function to quite satisfactory levels. The forcedly low doses might be one of the possible reasons of the failure of propranolol.
The attacks of the angina here investigated occurred at rest and in absence of any detectable eliciting factor. They were not triggered by circulatory modifications interfering with the oxygen requirement of the heart. These findings make the favorable therapeutic response to betablockade of difficult interpretation on the basis of the mechanisms usually indicated for the antianginal action of these drugs, and suggest that some other, still unknown effect must be at work.

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The clinical profile of 11 cases of puerperal cardiomyopathy is presented.
Poor socioeconomic condition and malnutrition were observed in all the patients and its importance as an etiological factor is discussed.
A brief review of the etiopathogenesis with relevant literature is mentioned.

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During the last 10 years, 7 hypertensive patients due to segmental renal ischemia or infarction among total 48 cases of renovascular hypertension have been observed in our clinic.
These 7 cases of renal arterial branch stenosis consist of 5 men and 2 women. The youngest case was aged 12 and the oldest 31. Their blood pressures were ranged from 160-225mmHg in systolic and from 84 to 150 in diastolic. Abnormal intravenous pyelogram was found in 4 out of 7 cases. So far as our experience was concerned, clinical features, urinalysis, radioisotope renography, renoscintigraphy and split renal function study were of little value for screening of the patients with renal arterial branch stenosis. However, angiography and provocation test of renin secretion are the best tools for making diagnosis of this type of hypertension. Surgical treatment including nephrectomy and revascularization relieved the hypertension in 5 patients. Antihypertensive drugs were given in one of 5 operated cases and in 2 non-operated cases. Six out of 7 patients remained normotensive.

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The effect of a constant intracoronary infusion of potassium chloride and calcium chloride upon myocardial hemodynamics and clearance of ⁸⁶Rubidium in the heart was studied in the isolated supported dog heart preparation (ISHP). In the ISHP with a constant coronary blood flow, potassium chloride in doses up to 4mg/min had no significant effect upon either the myocardial hemodynamics (MH), clearance of ⁸⁶Rubidium (C⁸⁶Rb) or the capillary transport coefficient, PS. Calcium chloride in small doses had no effect upon the MH, C⁸⁶Rb or PS. A higher dose of calcium chloride (4mg/min) produced an increase in myocardial contractile force, left ventricular peak systolic pressure, myocardial oxygen consumption and a decrease in C⁸⁶Rb and PS. Pretreatment of the ISHP with practolol (0.25mg/Kg), an agent which blocks adrenergic β-receptors, did not modify the effects of calcium chloride upon the MH, C⁸⁶Rb or PS. It is concluded that the effects of calcium chloride are exerted directly, independent of a β-receptor mediation.

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A small amount of angiotensin not to cause a significant elevation of systemic arterial pressure was infused into vertebral arteries of dogs anesthetized with morphine and α-chloralose. Electrical stimulation of carotid sinus nerve caused a smaller reduction in arterial pressure and heart rate during the period of angiotensin infusion than the control period. Arterial pressure response to occlusion of the common carotid artery was not affected by the infusion of angiotensin. The results suggest that angiotensin may sensitize medullary vasomotor centre in a manner of suppressing the tonic inhibition of baroreceptor reflex, resulting in an increase of central sympathetic vasomotor outflow.

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An activity of prostaglandin (PG)-like substances was measured in venous blood and renal medullary tissue of dogs. The PG-like substances were extracted by silica gel column chromatography and their activity was measured by rat vasodepressor bioassay. The activity of PGE-like substance both in renal venous blood and medulla was greater in saline infused dogs than in control, non-infused dogs. The possibility was discussed that the increased activity of PGE in kidney may be involved in the mechanisms of natriuresis in saline-loaded animals.

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The time course and mode of deterioration of the heart under prolonged maximal work load were studied in open-chest dogs, the hearts of which were loaded at maximal cardiac output while the aortic pressure was kept constant. During the period of loading, the maximal level of cardiac output that could be attained was relatively stable for 30min to 1 hour and then began to fall suddenly and rapidly. This terminal deterioration appeared to be caused by mechanical factors, possibly over-distention of the heart, rather than by fatigue of the muscle per se.

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1) Neither significant differences in plasma corticosterone level at rest nor marked differences in its diurnal variation except for a possible displacement of the peak in female SHR were observed between spontaneously hypertensive rats (SHR) and normotensive rats (NR). 2) Response in plasma corticosterone to various stress loadings was not increased in SHR, but rather decreased under certain conditions in comparison with NR. 3) Biological half-life of plasma corticosterone determined from the decline in exogenously loaded corticosterone in adrenalectomized rats was not significantly different between SHR and NR. 4) Analysis of adrenal venous steroid profile in SHR and NR under the maximum stimulation by ACTH showed that the conversion ratio from progesterone to DOC was decreased in SHR. 5) These results indicate that there probably is no acceleration of synthesis and metabolism of adrenal corticosterone itself in SHR compared with NR, and raised a possibility of relative impairment of 21-β-hydroxylase in SHR. A speculated compensatory metabolic pathway from progesterone via 18- or 17-α-hydroxylation as well as the substrain difference in steroidogenesis in relation to vascular vulnerability still remains to be clarified by further study.

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(1) There were definite differences in incidence of the hypertensive vascular changes in the brain and kidneys among the substrains of SHR.
(2) The loading of sodium chloride in drinking water accelerates the development of hypertensive vascular changes and sequential pathological changes in the brain and kidneys of SHR.
(3) The substrains A₃ and C of SHR have a peculiar nature with regard to cerebrovascular diseases. A₃ develops spontaneously cerebrovascular diseases with a high incidence, and shows the highest incidence of the changes among various substrains by salt loading. The substrain C shows the lowest incidence of cerebrovascular diseases in the nontreated animals as well as in the NaCl group. This substrain does not appear to be salt-sensitive.
(4) These facts suggest that inherited factors play an important role in developing hypertensive vascular diseases.

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Supplementary experiments to the previous one were performed to complete the chronological observation of the development of cardiac hypertrophy in SHR from birth to the age of 1 year. So far, the increased activity of β-HBDH in SHR seems not to be a genetic strainspecific character, but to be pertinent to the development of its cardiac hypertrophy, because the activity of β-HBDH was not increased in the early suckling SHR, and its increased activity was also seen in the elder control rats.

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A case of a 29-year-old man with abnormal shadow of the heart complicated with bacterial endocarditis and hemiplegia is presented.
Cardiac catheterization and angiography revealed a right coronary artery to left ventricle fistula which was saccularly dilated and tortuous. This is the sixth case in the literature.
The literature is reviewed and shortly discussed.

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