N Milne, J Herman, D Stobbe, K Lyons, M Movahed
cardiomyopathy, chronic obstructive pulmonary disease, copd, ef, left ventricular ejection fraction, lvef, right ventricular ejection fraction, rvef, smoking
N Milne, J Herman, D Stobbe, K Lyons, M Movahed. Right ventricular ejection fraction in patients with chronic obstructive pulmonary disease. The Internet Journal of Cardiology. 2007 Volume 5 Number 2.
This study is a cross-sectional study of a series of 157 patients, who underwent LVEF assessment using blood pooled scintigraphy (MUGA) for clinical indications by their physicians. These patients underwent simultaneous measurement of RVEF for this study. Patients with a history of smoking or COPD were compared to a control group using Chi square and Fisher Exact Test. The diagnosis of COPD was extracted from the patient's past medical history. The severity of COPD was not recorded in this study.
LVEF and RVEF were categorized as normal (EF > 50%) or decreased (mild: EF < 50%, moderate: EF< 40% and severe: EF < 30%). Using univariate analysis, we compared mean LVEF and RVEF in patients with or without a history of COPD.
The patients were required to fast for 4 hours prior to the study, and refrained from caffeine for 24 hours. They were injected with 40 mg of stannous pyrophosphate in 1.5 ml saline. Ten minutes later, the patients were positioned on the bed of the camera with the detector in the right anterior oblique (RAO) position. A rapid bolus of 20 mCi technetium-99m pertechnetate was given intravenously, together with the start of a list mode acquisition. The study was performed as 1000 frames at 0.04 seconds per frame, in a 64x64 matrix. Following the first pass study and after time for equilibration in the blood volume, a standard gated cardiac blood pool study was acquired in the anterior, left anterior oblique (LAO) and left lateral projections. The R to R interval was divided into 16 frames, not greater than 0.04 seconds in length. Acquisition was recorded for 900 seconds in a 64x64 matrix. Quantization was performed on the LAO view.
Our study evaluated the occurrence of low LVEF and RVEF in patients with COPD. We found no differences in the prevalence of low RVEF in patients with or without COPD. Our study is consistent with smaller trials showing normal resting RVEF when considering all comers. 4,5,6 Most of the studies with documented depressed RVEF have been found in patients with severe pulmonary hypertension 1,3,5,7, severe resting COPD,3,8 right heart failure or after exercise. 6 Burghuber et al. found that the assessment of RVEF is a poor indicator of overall right ventricular function in patients with COPD.9 The finding of normal LVEF in COPD patients in our study is consistent with most trial that COPD does not directly effect LVEF unless pulmonary hypertension or coronary artery disease is present.3,8 10 The lack of negative effect of COPD in our study as an independent factor on EF needs to be confirmed in a larger population.
We found that patients with a history of COPD do not have lower RVEF in comparison to other patients. This suggests that COPD patients without evidence of right heart failure or pulmonary hypertension might not be at risk for low right ventricular EF. However, due to small size, our study needs to be confirmed in a larger population.
Men were the predominant gender in our study limiting our results to men. This study was a cross-sectional study and the number of patients with COPD was small limiting our results. Furthermore, we did not have any data about the severity of COPD.
M. Reza Movahed, MD, PhD, FACP, FACC, FSCAI, FCCP Associate Professor Director of Coronary Care Unit University of Arizona Sarver Heart Center Department of Medicine, Division of Cardiology 1501 North Campbell Ave. Tucson, AZ, 85724 Tel: (520)-626-2000 (949)-400-0091 E mails: email@example.com firstname.lastname@example.org