Early changes of cardiac structure and function in COPD patients with mild hypoxemia.
BACKGROUND
COPD is often associated with changes of the structure and the function of the heart. Although functional abnormalities of the right ventricle (RV) have been well described in COPD patients with severe hypoxemia, little is known about these changes in patients with normoxia and mild hypoxemia.


OBJECTIVE
To assess the structural and functional cardiac changes in COPD patients with normal Pa(O2) and without signs of RV failure.


METHODS
In 25 clinically stable COPD patients (FEV1, 1.23 +/- 0.51 L/s; Pa(O2), 82 +/- 10 mm Hg [mean +/- SD]) and 26 age-matched control subjects, the RV and left ventricular (LV) structure and function were measured by MRI. Pulmonary artery pressure (PAP) was estimated from right pulmonary artery distensibility.


RESULTS
RV mass divided by RV end-diastolic volume as a measure of RV adaptation was 0.72 +/- 0.18 g/mL in the COPD group and 0.41 +/- 0.09 g/mL in the control group (p < 0.01). LV and RV ejection fractions were 62 +/- 14% and 53 +/- 12% in the COPD patients, and 68 +/- 11% and 53 +/- 7% in the control subjects, respectively. PAP estimated from right pulmonary artery distensibility was not elevated in the COPD group.


CONCLUSIONS
From these results, we conclude that concentric RV hypertrophy is the earliest sign of RV pressure overload in patients with COPD. This structural adaptation of the heart does not alter RV and LV systolic function.
Vonk-Noordegraaf
Anton
A
Department of Pulmonary Medicine, Institute for Cardiovascular Research, Vrije Universiteit Medical Center, PO Box 7057, 1007 MB Amsterdam, Netherlands. A.Vonk@vumc.nl
Marcus
J Tim
JT
Holverda
Sebastiaan
S
Roseboom
Bea
B
Postmus
Pieter E
PE
D000368:Aged; D000704:Analysis of Variance; D016022:Case-Control Studies; D005260:Female; D006334:Heart Function Tests; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000175:diagnosis*; D017380:Hypertrophy, Right Ventricular / Q000150:complications / Q000175:diagnosis*; D000860:Hypoxia / Q000150:complications / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000175:diagnosis*; D011656:Pulmonary Emphysema / Q000150:complications / Q000175:diagnosis; D012044:Regression Analysis; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012720:Severity of Illness Index; D016277:Ventricular Function, Left / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology