A Study on Propranolol as Anti-Arrhythmic Agent

The excitatory influence on heart rate is generally considered by beta-adrenergic neuroreceptors of Ahlquist's classificantion. Blockade of the beta adrenergic system would therefore be expected to alter heart rate and consequently to have an effect of patients with a variety of cardiac arrhythmias. In 1964 a clinically useable agent was produced by the name of propranolol which would effectively block beta action of adrenergic system and safe from side effects. The purpose of this study is to determine and estimate the immediate therapeutic effects of propranolol on 29 cases with various cardiac arrhythmias, administered intravenously. The following results were obtained: 1. It is apparent that propranolol by the intravenous route offers a rapid means of inducing A-V block and hence a reduction of the ventricular response in atrial fibrillation and atrial flutter. 2. Propranolol may be of value in improving digitalis-resistant atrial tachyarrhythmias with the therapeutic supplement. 3. Propranolol diminishes the automaticity of ectopic pacemakers because this is evident in the slowing of atrial rate or conversion of paroxysmal atrial tachycardia to sinus rhythm and the abolition or diminution of ventricular extrasystoles. 4. Digitalis-induced ventricular arrhythmias respond to propranolol well, and propranolol may well be the drug of choice in treating digitalis-induced ventricular arrhythmias. 5. Ventricular arrhythmias not related to digitalis were not satisfactorily treated with propranolol in our series. 6. Side effects associated with propranolol treatment were not remarkable except for development of transient hypertension in 2 cases.

Estimation of Intracardiac Shunts in Congenital Heart Disease: A comparison of the dy-edilution and the Fick methods

During cardiac catheterizations in 20 cases with congenital heart disease, intracardiac shunts were measured by two methods, dye dilution method and the Fick method, and the results were compared. Arterial dilution curves were used for the estimation of both the right-to-left and left-to-right shunts-Venous dilution curves were used for measurement of left-to-right shunts. In cases with a left-to-right shunt, the amount of the shunt was expressed as per cent of total pulmonary blood flow and, in cases with a right-to-left shunt, as per cent of total systemic blood flow. The following results were obtained. 1. In 8 cases with a right-to-left shunt, the amount of the shunt was 35.6 +/-18.1% by the Fick method and 34.0 +/-19.2% by arterial dilution curves. The difference was not statistically significant(p> 0.l). In 15 cases with a left-to-right shunt, the amount of shunt was 41.3 +/-26.6% by the arterial dilution curve and 36.6 +/-14.O% by the Fick method. The difference was not statistically significant(p> 0.1). Also venous dilution curve was performed in 8 cases of left-to-right shunt and the amount of the shunt was 33.0 +/-21.0%, as compared to 35.5 +/-17.3% by the Fick methods. The difference was not statistically significant (p> 0.1). 2. Arterial dilution curves could be used to localize right-to-left shunts and venous dilution curves left-to-right shunts, whereas tile Fick method was helpful only for the localization of left-to-right shunts. 3. It was possible to detect small left-to-right (less than 10%) and right-to-left (less than 5%) shunts by dye dilution curves, which was not possible with the Fick method. 4. In detection of small intracardiac shunts as well as in shunt localization, the dye dilution method was more accurate than the Fick method. The difference of the amount of the shunt estimated by the two methods was not statistically significant.

Blood Pressure Levels in Koreans

The present study was undertaken in an attempt to establish the range of normal blood pressure levels in Koreans. A representative group of the working population, consisting of 39,859 persons (23,834 men and 16,025 women) who were able to work regularly on daily duty and who lived in various parts of the country, was studied, using casual blood pressure readings. The arithmetic mean, the standard deviation and the frequency distribution of the blood pressure readings were determined for each sex and for each age group from five to seventy nine years of age. The normal range was assumed to include the 80% of all the readings which were within 40% of either side of the mean. Any blood pressure which the mean was considered to be abnormal. The readings falling between these two limits were regarded as borderline. The limits of normal blood pressure, as determined by this method, were found definitely to vary with age and sex. The effect of body weight on the blood pressure was investigated. It was found that the systolic and diastolic blood pressure were progressively increased with the increase in body weight regardless of sex and age. The incidence of systolic hypertension was 6.0% in adult males and 6.2% in females, diastolic hypertension occurred 6.8% in males and 5.8% in females. The incidence of hypotension, below 90 mmHg. systolic, was 0.6% in males and 1.7% in females, and below 60 mmHg. diastolic was 6.6% in males and 9.1% in females. A Comparison of the mean blood pressure was made between the rural and the urban population of Koreans. The mean blood pressure readings in the urban population are higher than those in the rural population, both in systolic and diastolic blood pressures and in all age groups. A comparison of the mean blood pressure also was made between Koreans and Americans, Chinese, Japanese, Filippinos and Indians. The systolic and diastolic blood pressure in Americans (U.S.A.) is higher than that in Koreans. Those in the Japanese and Chinese are similar until the age of fifty, from the age of fifty, the pressures are higher than those in Koreans. The blood pressure of Filippinos is similar to the blood pressure of Koreans all through the age groups. In Indians, pressures are lower than in Koreans.

Analysis of Various Renal Functions in the Korean

Various renal functions were studied in 45 young Koreans, 41 males and 4 females. The glomerular filtration rate, the renal plasma and blood flows and the filtration fraction were comparable to those in the occidental. The renal diluting capacity, as judged by the value of positive free water clearance (CH2O), was also comparable to that in the occidental. However, the renal concentrating ability, as judged by values of both the maximum urine osmolality induced by pitressin injection or during dehydration and the maximum negative free water clearance (TcmH2O) during mannitol diuresis, was somewhat low in the Korean. The tubular reabsorptive capacity of glucose (TmG) Was significantly low in the Korean while the tubular secretory capacity of PAH (TmPAH) was not altered. The urea clearance and its ratio with the inulin clearance were generally low. Moreover, the normal osmolar composition of urine indicated that urea is responsible for only 20 to 30%, while salt accounts for nearly 2/3 of the total urine osmolality. In view of the fact that the Korean is chronically maintained on a low or poor protein diet, these results are discussed in the light of this peculiar dietary habit of the Korean. Although the reduction of both the renal concentrating ability and the urea clearance could be reasonably attributed to a low protein intake, the observed low value of Tmc could not be explained thus at present.