James E. Hansen

Pulmonary Function in Primary Pulmonary Hypertension

OBJECTIVESnThe study was done to ascertain the degree to which abnormalities in resting lung function correlate with the disease severity of patients with primary pulmonary hypertension (PPH).nnnBACKGROUNDnPatients with PPH are often difficult to diagnose until several years after the onset of symptoms. Despite the seriousness of the disorder, the diagnosis of PPH is often delayed because it is unsuspected and requires invasive measurements. Although PPH often causes abnormalities in resting lung function, these abnormalities have not been shown to be statistically significant when correlated with other measures of PPH severity.nnnMETHODSnResting lung mechanics and diffusing capacity for carbon monoxide DL(CO) were assessed in 79 patients whose findings conformed to the classical diagnostic criteria of PPH and who had no evidence of secondary causes of pulmonary hypertension. These findings were correlated with severity of disease as assessed by cardiac catheterization, New York Heart Association (NYHA) class, and cardiopulmonary exercise testing.nnnRESULTSnWhen PPH patients were first evaluated at our referral clinic, the DL(CO) and lung volumes were decreased in approximately three-quarters and one-half, respectively. The decreases in DL(CO), and to a lesser extent lung volumes, correlated significantly with decreases in peak oxygen uptake (reflecting maximum cardiac output), peak oxygen pulse (reflecting maximum stroke volume), and anaerobic threshold (reflecting sustainable exercise capacity) and higher NYHA class.nnnCONCLUSIONSnPatients with PPH commonly have abnormalities in lung mechanics and DL(CO) levels that correlate significantly with disease severity. These measurements can be useful in evaluating patients with unexplained dyspnea and fatigue.

Paroxysmal ventricular tachycardia associated with myxedema a case report

Abstract A 42-year-old woman with myxedema and paroxysmal ventricular tachycardia is reported. Her electrocardiogram became normal, and premature ventricular contractions ceased after the administration of thyroid extract. In the absence of other known causes for the ventricular tachycardia, it seems likely that myxedema was the initiating cause. The relationship of the thyroid gland to cardiac arrhythmias is briefly discussed.

The value of exercise in testing beta blockade and airway reactivity in asthmatic patients

On separate days, in double-blind fashion, 23 subjects with mild or moderate asthma were injected intravenously with a placebo or 0.4 mg pindolol. Plethysmographic and spirometric measurements were performed before and after injection and repeatedly after exhausting incremental bicycle ergometer exercise. The mean reduction in maximal exercise heart rate of 26 bpm after pindolol compared to placebo confirmed significant cardiovascular beta blockade. Baseline 1-second vital capacity (FEV1) values and other flow rates were similar in both trials. There were similar reductions in FEV1 (median of 1% to 2% and mean of 3% to 5%) and other flow rates immediately after injection of placebo or pindolol. Exercise-induced bronchospasm (EIB) occurred in 34 of 46 trials and tended to be more severe in subjects with more baseline airway obstruction. Minimal EIB (FEV1 to 80% to 90% of baseline values) developed in eight after taking placebo and in seven after taking pindolol; mild EIB (FEV1 to 60% to 79% of baseline) developed in the five after placebo and six after pindolol and moderate EIB (FEV1 to 40% to 59% of baseline) developed in three after placebo and five after pindolol. In five subjects, FEV1 was reduced to a greater extent after placebo than after pindolol (median of 6%), whereas in 13 subjects, FEV1 was reduced to a greater extent after pindolol than after placebo (median of 10%). These small differences in FEV1 between placebo and pindolol were significant by the t test after exercise but not before exercise. Thus, exercise appears to increase the sensitivity in evaluating airway reactivity in asthmatic patients and also tests the effectiveness of cardiovascular beta blockade.

Staphylococcus endocarditis; a report of three cured cases.

Abstract Three cases of hemolytic Staphylococcus aureus endocarditis are reported. One patient was cured with penicillin and aureomycin while the other two patients responded favorably to chloramphenicol.

A Better Way to Assess Bronchoreversibility

after aerosol drug administration in the laboratory. All of these criteria 1 are based on population-based “clinical” limits rather than the variability of the individual being tested. All criteria compare only the “best of three” predrug and postdrug FEV 1 and/or FVC spirometry values that meet American Thoracic Society standards 2 and ignore data from other forced exhalations. It is surprising that these authors (as well as many others) did not use more of the data available from bronchodilator testing by considering all six spirometric maneuvers so that each patient’s response could be analyzed statistically. As reported previously, a Student t test or rank-order test allows determination of when changes in FEV 1 , FEV 3 , FEV 6 , and/or FVC are statistically signifi cant and markedly changes the detection of responsiveness. 3 , 4 As pointed out recently by Dolmage et al 5 in evaluating the 6-min walk test, it is the consistency of change that determines whether a response to an intervention is statistically signifi cant. For example, as the result of an intervention, a vehicle mileage change from 13, 12, and 11 miles per gallon to 16, 15, and 14 miles per gallon (25% average increase) would be statistically signifi cant and usually important. Among the current American Thoracic Society guidelines, 6 the guideline requiring a . 200 mL response in those with a low FEV 1 to identify bronchoreversibility is the most troublesome. An intervention changing FEV 1 from 560, 600, and 640 mL to 750, 700, and 800 mL (25% average increase) may well improve dyspnea and the quality of life in a patient with COPD. Despite any added disclaimer, to report such a patient as nonresponsive is misleading. Whenever possible, should not we, who see the raw spirometric data, report the consistency, statistical signifi cance, and percent age of the patient’s change when we are asked to measure bron choreversibility?