Ventricular premature beats and mortality of men with coronary heart disease

Frequency and qualitative characteristics of ventricular premature beats (VPB) are determined from 1 hour of electrocardiogram (ECG) monitoring of men with coronary heart disease in a continuing study among members of the Health Insurance Plan of Greater New York. Mortality among 924 such men during an average observation period of 10 months was higher among men with VPB than among those free of VPB. In comparison with the routine 12-lead ECG, the hour of ECG monitoring increased the proportion of men identified as showing ectopic activity from 15% to 52%. Only half of men with 10 or more VPB in the hour of monitoring were noted as having VPB on the routine ECG; mortality among these men was relatively high whether or not VPB appeared on the short sample ECG.

Preparation, isolation, and identification of 4-dedimethylamino-11-methoxyanhydrotetracycline

The reaction of diazomethane with 4-dedimethylaminoanhydrotetracycline produced a number of mono-, di-, and tri- methylated products. The isolation of one monomethylated product (4-dedimethylamino-11-methoxyanhydrotetracycline) and its subsequent identification utilizing mass spectral and NMR data are described.

Dehydration of tetracycline

The dehydration of tetracycline at the C-5a-C-6 position as a function of acidity was investigated at various temperatures. The rate was first order with respect to tetracycline and with respect to [H+]. Rate constants and an activation energy are reported. Tetracycline was unstable in dilute acid.

Effects of DC electric countershock on ventricular function, cation balance and endogenous norepinephrine in the dog heart

Effects of DC electric countershock on cardiac function in thoracotomized dogs were evaluated from recordings of ECG, aortic pressure, left ventircular pressure and its first derivative, and coronary sinus flow. Samples of arterial and coronary venous plasma and left ventricular myocardium obtained before and after countershock at times corresponding to post-shock arrhythmias and recovery were analyzed for Mg++, K+ and Ca++, and norepinephrine. At 1 min after countershock, ECG changes included transient cardiac arrhythmias and ST segment alterations, accompanied by depressed ventricular function and decreased myocardial Ca++ concentration. At 5 min postshock, coronary venous Mg++ and K+ concentrations had risen and ventricular function was still depressed. Function recovered within 10-20 min. There was no evidence of consistent loss of endogenous myocardial norepinephrine.

Quantitative measure of mercury vapor emission from setting dental amalgam

The rate of mercury vapor emission from setting dental amalgam was measured by use of an ultraviolet light absorption technique under nondiffusion-controlled conditions. An average of 0.3 X 10-6 gm mercury per square centimeter was emitted at the experimental temperature. At 37 C, this amount was estimated to be 1.2 × 10 -6 gm/ cm2.

Angina pectoris in men. Prognostic significance of selected medical factors

Prognosis of men whose first manifestation of coronary heart disease was angina without antecedent infarction was found to resemble closely that of men followed after an initial MI. Overall mortality over a period of 4.5 years following a baseline examination was the same in the two cohorts: 17.5%.

In both groups of men electrocardiographic abnormalities and blood pressure elevation identified subsets of coronary patients with a relatively poor prognosis, but the course of disease was apparently not influenced by the serum cholesterol level. Among the men with angina no relationship emerged between symptomatic status at time of baseline and risk of mortality in the ensuing observation period.

The findings are from the HIP (Health Insurance Plan of Greater New York) study of the incidence and prognosis of coronary heart disease, a prospective study of a general population of 110,000 men and women aged 25-64 years.

Incidence of coronary heart disease in a population insured for medical care (HIP): myocardial infarction, angina pectoris, and possible myocardial infarction

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Prognosis of men with coronary heart disease as related to blood pressure

Hypertension prior to the onset of the initial myocardial infarction in men is associated with an excess early mortality rate: among men with elevated blood pressure the proportion dead within 1 month is more than twice that found among normotensive men with a first infarction. Hypertensives who survive the acute attack show twice the risk of recurrence and more than five times the risk of cardiac death over the next several years in comparison with men with normal blood pressure prior to infarction.

Among men whose first clinical evidence of coronary disease is angina pectoris, those with an elevated blood pressure have two and one half times the likelihood of experiencing a first myocardial infarction and cardiac death within a follow-up period of 30 months.

These findings are from the HIP (Health Insurance Plan of Greater New York) study of the incidence and prognosis of coronary heart disease, an ongoing prospective study of a general population of 110,000 men and women aged 25 to 64 years.