Biomedical subjects

B Tabatznik

Publications and source records attributed to B Tabatznik.

At least 19 recordsLinked to original sources

PubMed1992

Major electrocardiographic abnormalities in persons aged 65 years and older (the Cardiovascular Health Study). Cardiovascular Health Study Collaborative Research Group.

Electrocardiographic abnormalities are often found in older patients, but their prevalence in free-living elderly populations is not well-defined. In addition, the clinical significance of many of these abnormalities is uncertain. The prevalence of major electrocardiographic abnormalities was determined in 5,150 adults aged greater than or equal to 65 years from the Cardiovascular Health Study--a study of risk factors for stroke and coronary heart disease in the elderly. Ventricular conduction defects, major Q/QS waves, left ventricular hypertrophy, isolated major ST-T-wave abnormalities, atrial fibrillation and first-degree atrioventricular block were collectively categorized as major electrocardiographic abnormalities. Prevalence of any major electrocardiographic abnormality was 29% in the entire cohort, 19% among 2,413 participants who reported no history of coronary artery disease or systemic hypertension, and 37% among 2,737 participants with a history of coronary artery disease or hypertension. Prevalence of major electrocardiographic abnormalities was higher in men than in women regardless of history, and tended to increase with age. Major Q/QS waves were found in 5.2%, and more than half were in those who did not report a previous myocardial infarction. Major electrocardiographic abnormalities are common in elderly men and women irrespective of the history of heart disease.

Age Factors↗

PubMed1989

Comparative efficacy and bioequivalence of a brand-name and a generic triamterene-hydrochlorothiazide combination product.

The clinical efficacy, safety, and bioavailability of a generic triamterene-hydrochlorothiazide product were compared with those of Dyazide. Thirty patients who had a diagnosis of nonlabile essential hypertension and who were receiving Dyazide (triamterene 50 mg and hydrochlorothiazide 25 mg) were continued on Dyazide maintenance for 16 days to determine the stability of blood pressure control and serum chemistry values. After this baseline period, the subjects were randomized to receive either Dyazide or a generic version for 21 days. They were then crossed over to receive the opposite product for another 21 days. Blood pressures were monitored throughout the study period, and blood samples were taken for measurement of serum electrolytes and of serum triamterene and its major metabolite, hydroxytriamterene sulfate. Hydrochlorothiazide was assayed in 24-hour urine samples. There were no statistically significant differences between regimens in recumbent and standing mean diastolic blood pressures or in mean concentrations of serum potassium, chloride, glucose, creatinine, and uric acid. Area under the concentration-time curve from 0 to 24 hours after drug administration, maximum concentration in serum, and time to achieve maximum concentration in serum did not differ significantly between regimens for triamterene and hydroxytriamterene sulfate. Similarly, there were no significant differences in excretion, maximum rate of excretion, and time to achieve maximum rate of excretion for urinary hydrochlorothiazide. Patients treated with a brand-name fixed-combination product containing triamterene 50 mg and hydrochlorothiazide 25 mg were given a generic formulation without loss of therapeutic efficacy or development of toxicity.

Adolescent↗

PubMed1988

Analysis of physician and hospital differences in 'negative' coronary angiogram rates.

A direct relationship has been postulated between high "negative" coronary angiogram rates and physician payment. We conducted a prospective study of coronary angiography in a teaching and community hospital staffed, respectively, by cardiologists who were performing cardiac catheterization as salaried or fee-for-service physicians. The lower overall rate of negative angiograms at the teaching hospital correlated with the presence of a cardiac surgery unit and the increased referral of patients with documented coronary artery disease. The percentage of completely normal angiograms did not differ significantly between hospitals. The number of angiograms positive by a 70% occlusion criterion in patients not previously known to have coronary artery disease also did not differ greatly. Negative angiogram rates appeared to vary inversely with physician ability to set preangiogram probabilities of coronary artery disease. Our findings do not discount reimbursement as a strong incentive, but suggest other important determinants of coronary angiographic variation.

Baltimore↗

PubMed1987

Nifedipine gastrointestinal therapeutic system in stable angina pectoris. Results of a multicenter open-label crossover comparison with standard nifedipine.

To compare the clinical efficacy and dose equivalency of standard nifedipine versus a new gastrointestinal therapeutic system (GITS) formulation of nifedipine, 98 patients with chronic stable angina pectoris participated in a 14-week, multicenter, open-label, crossover trial. All patients were administered nifedipine capsules for one month prior to study entry and continued receiving other antianginal, non-calcium blocker medications. Ninety-one patients (93 percent), 80 men and 11 women, mean age 62 +/- 1 years, completed the trial, which included two weeks receiving standard nifedipine followed by 12 weeks receiving nifedipine GITS starting at a dosage equal to the 24-hour total dose of nifedipine capsules and titrated upward as necessary. However, throughout the trial, mean nifedipine dosage was similar on nifedipine GITS compared with standard nifedipine. Angina frequency was significantly less with nifedipine GITS at Weeks 6, 10, and 14 (0.8 episodes/week) compared with baseline with standard nifedipine (1.3 episodes/week, p less than 0.05). Likewise, nitroglycerin consumption was also less at Weeks 6, 10, and 14, but only significantly less at Week 6 (nifedipine 1.2/week versus nifedipine GITS at six weeks, 0.7/week; p less than 0.05). Resting hemodynamic parameters, including systolic and diastolic blood pressure and heart rate, were not significantly different with standard nifedipine versus nifedipine GITS during the 12-week study. Total incidences of side effects were similar for both treatments (standard nifedipine, 16; nifedipine GITS, 17). However, incidence of vasodilator side effects (flushing, dizziness, and light-headedness) was significantly less frequent with nifedipine GITS (standard nifedipine, 12; nifedipine GITS, six; p less than 0.05). Thus, results from this open-label, crossover trial suggest that nifedipine GITS dosing is similar to multidose standard nifedipine with equivalent 24-hour efficacy for nifedipine GITS.

Aged↗

PubMed1976