An examination was made of the effects of changes in plasma sodium concentration and water balance during peritoneal dialysis on renin secretion. Plasma renin activity, plasma sodium concentration, plasma volume, and arterial blood pressure were measured in 14 patients with chronic renal failure (chronic glomerulonephritis) before and after peritoneal dialysis. The amount of water removed by peritoneal dialysis was also measured.
The results were as follows: 1) Plasma renin activity was increased significantly after peritoneal dialysis. The average increase was 58.1±15.8 (S.E.)% of the initial value. 2) There was no significant correlation between the amount of water removed and plasma renin activity. 3) Mean arterial pressure rose slightly after peritoneal dialysis but not to a statistically significant degree. 4) Plasma sodium concentration was increased significantly after peritoneal dialysis. There was no significant inverse correlation between plasma sodium concentration and renin activity. There was also no significant inverse correlation between the increased plasma renin activity and changes in plasma sodium concentration. 5) The decrease in plasma volume after peritoneal dialysis was significant. There was a significant correlation between the increased renin activity and the decreased plasma volume.
From the present study, we conclude that the dominant stimulus to renin secretion in peritoneal dialysis is a decrease in plasma volume.

View full abstract

Severe cyanotic cardiac diseases such as extreme type of Fallot or truncus arteriosus present to cardiac surgeons a serious problem, for which up to the present day no satisfactory surgical treatment has been available. A new operative procedure "aorta banding" has been devised by occluding the lower thoracic aorta by placing a Teflon tape around it. Careful experimental studies indicated that this procedure resulted in increased pulmonary flow and was found to be relatively a safe procedure. Application of the aorta banding in clinical cases resulted in dramatic disappearance of anoxic spells and decrease of cyanosis.

View full abstract

In 6 patients with pulmonary edema, the intravenous administration of phentolamine at a rate of 0.3mg./min. resulted in a rapid alleviation of symptoms and signs.
In one patient with severe left ventricular failure a complete hemodynamic study was possible and the infusion of phentolamine produced a striking improvement in the measured hemodynamic functions.
Phentolamine may prove to be a valuable and effective drug for the treatment of patients in pulmonary edema due to left ventricular failure.

View full abstract

Applying electrodes on bilateral chest walls, variations of electrical impedance were recorded during breath holding under various manipulations of the pulmonary hemodynamics with dogs. Pulsatile variations of the impedance recorded either directly from lobe surfaces or chest walls were in constant coupling with ECG and pressure waves in the pulmonary artery. These impedance pulses and their first differential derivatives decreased their height and area when the pulmonary blood flow was decreased, and increased those when the flow was increased. These changes disappeared when the manipulations were released and they returned to the original shapes. These results suggest that the impedance measurement on the chest wall gives informations concerning changes of pulmonary circulatory dynamics and can possibly be employed as a non-traumatic and continuous monitoring techninque for the pulmonary blood flow both experimentally and clinically.

View full abstract

The effects of dextran infusion and subsequent bilateral carotid occlusion on left and right ventricular function were studied in 10 chloraloseurethane-anesthetized intact dogs. Volumes of both ventricles were measured by the thermodilution method during the control period, 10 min. after infusion of isotonic 6% dextran (40ml./Kg.), and after carotid occlusion. Dextran infusion increased cardiac output, stroke volume, and ventricular end-diastolic pressures (EDP) and volumes. Left ventricular end-diastolic volume (EDV) was greater than that on the right both before and after infusion. Bilateral carotid occlusion increased heart rate further, but a slight decrease in stroke volume resulted in no significant increase from infusion values in cardiac output. Left ventricular systolic pressure increased after occlusion, reflecting the increase in total systemic resistance; no significant change occurred in left or right ventricular end-diastolic or end-systolic volume. Right ventricular EDP decreased significantly and although left ventricular EDP also decreased the change was not significant. Plots of stroke work against left ventricular EDV after carotid occlusion lay significantly (P<0.005) above the regression line (r=0.75, P<0.01) for control and infusion points. Derived force-velocity relationships, expressed in terms of normalized mean circumferential shortening rate and peak ventricular force, showed an upward shift after carotid occlusion. We interpret these data as evidence of an increased inotropic effect of the myocardium following carotid occlusion.

View full abstract

The sucrose-gap method was adapted to record the action potentials of bullfrog cardiac muscles. The size and configuration of action potentials recorded from atrial or ventricular strips with the sucrose-gap method were similar to those recorded with intracellular microelectrodes. Action potentials could be maintained at a constant amplitude and time-course for up to 3 hours. Furthermore, during recording of action potentials, it was possible to apply DC current to hyperpolarize or depolarize the muscle membrane. Thus the present method in combination with the intracellular microelectrode method will provide valuable information concerning the physiology of cardiac muscle fibers.

View full abstract

A safe and simple surgical technique for the creation of an atrial septal defect was described. This procedure has advantages that ASD can be created without any interruption of the pulmonary circulation and that atrial septum can be seen directly before being excised.

View full abstract

(1) From the torso model experiments, the measurements of the transfer impedance vectors were carried out for the conventional 12 leads, Frank's lead system and the following 6 different leads commonly used for the ECG-telemetering such as V_5R-V₁-V₉ leads, EEP leads, C₅-M lead, L₁-ST₁ and L₁-TH₁ lead, when the current dipole was placed in turn at 27 points within the space occupied by the heart in the human torso model filled with electrolyte solution. The transfer impedance vectors for all leads above-mentioned were compared to each other.
(2) V_5R-V₁-V₉ leads can be used for the ECG-telemetering, as the equivalent to the precordial leads V₁-V₉. C₅-M, EEP-C₅ and V_5R-V₅ lead could be equivalent to the precordial lead V₅, and L₁-ST₁ and L₁-TH₁ lead were equivalent to the augmented unipolar limb lead aV_F.
(3) Taking into account of the experimental result, the number of electrodes applicable and the possibility to eliminate the interference of muscle potential, C₅-M, V_5R-V₅ and L₁-TH₁ lead can be considered to be the most sensitive leads for detecting coronary artery disease in latent form.

View full abstract

Two new cases of pulmonary infarction with the only electrocardiographic findings of QR or QS type ventricular premature beats in lead II, III and aVF are reported. A similar case was reported 3 years ago by authors. Authors believe that QR or QS type ventricular extrasystoles in lead II, III and aVF are diagnostic for the pulmonary embolism or pulmonary infarction if there are no signs of myocardial infarction.

View full abstract

A 40-year-old housewife with left atrial myxoma was reported and discussed. The following findings, as observed in our case, would be valuable in diagnosis of left atrial myxoma prior to cardiac catheterization: 1) a prolonged first heart sound in the phonocardiogram; 2) one or two notches in the systolic upstroke of the apexcardiogram; and 3) an extra positive wave just after the systolic downstroke of the apexcardiogram.
At right heart catheterization, prominent C and V waves and a rapid Y descent are suggestive of left atrial myxoma in the absence of other features of significant mitral regurgitation. A marked spontaneous fluctuation of the V wave in the pulmonary wedge pressure would be an additional feature suggesting left atrial myxoma. A right pleural effusion was observed to persist in our case and was attributed to impaired venous return from the right pulmonary veins by the tumor.

View full abstract