The American journal of the medical sciences
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The authors describe the clinical characteristics and response to therapy of seven patients with hyperthyroidism, dilated cardiomyopathy, and low-output cardiac failure. All patients (4 women and 3 men, age 47 +/- 4 years, mean +/- standard error of the mean) were admitted with the primary diagnosis of congestive heart failure. The cause of hyperthyroidism was Graves' disease in six patients, and toxic multinodular goiter in one. ⋯ During follow-up (5 months to 9 years), left ventricular ejection fraction improved from a mean of 28% to a mean ejection fraction of 55% (P < 0.01). Resolution of dilated cardiomyopathy with normalization of systolic function was achieved in five patients, and improvement from severe to mild left ventricular dysfunction was observed in two patients. We conclude that some patients with hyperthyroidism may have a reversible form of dilated cardiomyopathy and "low-output failure." Assessment of thyroid hormone status in patients with heart failure might permit the identification of patients with dilated cardiomyopathy and thyrotoxicosis who are likely to have reversible cardia dysfunction.
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Sixty thousand electrocardiograms were analyzed for 5 years. Six hundred (1%) revealed early repolarization (ER). Features of ER were compared with race-, age-, and sex-matched controls (93.5% were Caucasians, 77% were males, 78.3% were younger than 50 years, and only 3.5% were older than 70). ⋯ Sixty patients exercised normalized ST segment and shortened QT interval (83%). In another 60 patients, serial studies for 10 years showed disappearance of ER in 18%, and was seen intermittently in the rest of the patients. The authors conclude that in these patients with ER: 1) male preponderance was found; 2) incidence in Caucasians was as common as in blacks; 3) patients often were younger than 50 years; 4) sinus bradycardia was the most common arrhythmia; 5) the PR interval was short and depressed; 6) the T wave was slightly asymmetrical; 7) exercise normalized ST segment; 8) incidence and degree of ST elevation reduced as age advanced; 9) possible mechanisms of ER are vagotonia, sympathetic stimulation, early repolarization of sub-epicardium, and difference in monophasic action potential observed on the endocardium and epicardium.
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Comparative Study
Clinical validation of the Welch-Allyn Pneumocheck hand held spirometer.
Pulmonary function is predictive of morbidity and mortality. Therefore, in epidemiologic studies, researchers seek to measure pulmonary function with portable spirometers feasible for use in clinics or participants' homes. The purpose of this study was to validate a hand held spirometer, the Welch-Allyn Pneumocheck, against standard pulmonary function tests. ⋯ Of the 46 subjects originally classified by the Pneumocheck as having FEV1/FVC ratios of less than 0.75, 10 (22%) had ratios greater than or equal to 0.75 after correcting for the FVC difference between methods. Therefore, there was an excellent correlation between the Welch-Allyn Pneumocheck and pulmonary function laboratory values for FVC and FEV1. Small systematic differences in FVC measures can lead to substantial misclassification rates when evaluating FEV1/FVC ratios.
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Randomized Controlled Trial Clinical Trial
Bedtime dosing of glyburide and the treatment of type II diabetes mellitus.
Suppression of nocturnal hepatic glucose production is key in the treatment of noninsulin-dependent diabetes mellitus (NIDDM). In this article, the authors compare the effectiveness of dosing glyburide at bedtime versus in the morning on glycemic control in patients with NIDDM under suboptimal control. In a placebo-controlled, double-blind crossover trial, 32 patients with NIDDM with suboptimal control on chronic glyburide treatment fulfilling entry criteria were randomized to receive one of two regimens: (1) glyburide at bedtime and placebo in morning or (2) placebo at bedtime and glyburide in the morning. ⋯ At the end of 12 months, nighttime dosing resulted in better home glucose monitoring values, fasting blood sugar results, and Sustacal tolerance profiles, but the differences were not statistically significant. No hypoglycemia was observed in the monitored data collected. Bedtime dosing of glyburide resulted in measurable improvement in fasting blood sugar and carbohydrate tolerance curves, but not to a degree justifying general recommendation of this technique in patients with NIDDM with secondary failure to oral agents.