Repercussions of the cardiomegaly on the pulmonary function of adult individuals with chronic heart failure: a systematic review

To analyze the repercussions of the cardiomegaly on lung function in adults with chronic heart failure (CHF), the databases PUBMED, BIREME, ISI Web of Knowledge and COCHRANE were considered to review observational studies published in the last decade without language restriction. It was used the descriptors "cardiomegaly" and "respiratory function tests", and denied "exercise". It was included papers with CHF, of both sexes between 19 and 64 years accepting samples with congestive HF and dilated cardiomyopathy and excluding with acute heart failure, post-intervention assessment clinic or by exercise. The quality of papers was evaluated by using the scale of Agency for Healthcare Research and Quality (AHRQ) and accepted papers with score>50 points (0-100). We selected 5 studies from total of 1093 and grouped by parameters related to flows and lung volumes, respiratory pattern and muscle performance. At AHRQ, two studies were in the range of 50-75% and the others>75%. These studies showed lower inspiratory vital capacity (IVC), forced expiratory volume in 1st second (FEV1) and maximal inspiratory pressure (PImax) as a function of cardiomegaly, with a slight reduction in the ratio VEF1/IVC and diffusion capacity for carbon monoxide (DLCO). Therefore, the studies suggest that the cardiomegaly leads to a restrictive lung pattern, with reduction in alveolar volume that interferes with DLCO. The strongest correlations involve the reduction of PImax, IVC and FEV1 in this population.