ABSTRACT
Chronic obstructive pulmonary disease (COPD) primarily affects the lungs; however, cardiovascular conditions are among the most common extrapulmonary comorbidities. Besides shared risk factors such as cigarette smoking, pathophysiological connections between the lung and the heart have been identified as mediators of reduced cardiac output. Recent research has focused on hyperinflation of the lung as a pulmonary cause for heart dysfunction. Hyperinflation is a typical lung abnormality seen in COPD; it is characterized by increased residual volume, intrathoracic gas volume, and total lung capacity while vital capacity is decreased. The degree of hyperinflation with airway obstruction is inversely related to left ventricular filling, stroke volume, and cardiac output. The underlying mechanisms are assumed to be compression of the pulmonary veins and thus reduced preload of the left heart as well as decreased pulmonary microvascular blood flow due to compression of the pulmonary vasculature. Treatment with a dual bronchodilator antagonizes this detrimental lung-heart unbalance effectively: Pulmonary blood flow, left ventricular end-diastolic volume, and stroke volume increase in COPD patients without cardiac abnormalities. Similar effects, yet less pronounced, were reported with single bronchodilator therapy. Future work needs to investigate whether these promising findings can be reproduced in COPD patients with cardiovascular diseases.
Subject(s)
Bronchodilator Agents , Pulmonary Disease, Chronic Obstructive , Stroke Volume , Heart/physiopathology , Humans , Respiratory Function TestsABSTRACT
The reliability of different investigators' assessment distinguishing carious cavities from caries-free ones was examined in an in vitro study. In 23 recently extracted human teeth caries was completely removed by the principal investigator, while in 17 teeth caries was only incompletely removed. On two occasions at an interval of 2 weeks, 5 investigators established the diagnosis "carious" or "caries-free" after clinical inspection using probe and mirror. Decalcified thin sections were examined in order to determine objectively if a tooth was caries-free or not. On an average, 8 out of 10 carious and 6 out of 10 caries-free cavities were correctly diagnosed. An analysis of the erroneous diagnoses showed that it was deep interproximal lesions that went unnoticed most frequently. Lesions at the enamel-dentin junction were also overlooked. False positive diagnoses were three times more frequent than false negative results. The reliability of caries detection (sensitivity 83.5%) was far higher than reported in the literature.
