Sub-clinical left and right ventricular dysfunction in patients with COPD
Received 23 September 2009; accepted 28 January 2010. published online 25 February 2010.
Summary
Background
Cardiovascular manifestations in COPD include increased arterial stiffness, ischaemic heart disease, chronic heart failure and cor pulmonale. We hypothesised that sub-clinical right (RV) and left ventricular (LV) dysfunction occurs in patients with COPD, related to the severity of airflow obstruction, arterial stiffness and systemic inflammation.
Methods
Thirty six patients and 14 controls, all free of overt cardiovascular disease underwent tissue Doppler echocardiography, spirometry, measurement of aortic pulse wave velocity (PWV) and venous sampling for inflammatory markers.
Results
Mean LV myocardial strain and strain rate were less in patients than controls, p<0.05. LV isovolumic relaxation time (IVRT) was prolonged in patients (125±15.2ms) compared with controls (98.2±21.1ms), p<0.01, indicating LV diastolic dysfunction. The RV free wall strain and strain rate were less in patients than controls, both p<0.05, indicating RV systolic dysfunction. Patients had sub-clinical pulmonary arterial hypertension with a greater RV myocardial relaxation time and Tei index, both p<0.01. Patients with mild airways obstruction had LV and RV dysfunction and evidence of increased RV afterload compared with controls. In multivariate analyses aortic PWV predicted LV IVRT, p<0.01, while FEV1 predicted RV Tei index and myocardial relaxation time, both p<0.01.
Conclusions
Patients with COPD have sub-clinical left ventricular dysfunction related to arterial stiffness, and right ventricular dysfunction related to airways obstruction. Both right and left ventricular dysfunction are present in patients with mild airways obstruction suggesting that cardiac co-morbidities commence early in the development of COPD.
aDepartment of Respiratory Medicine, Wales Heart Research Institute, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom
bDepartment of Cardiology, Wales Heart Research Institute, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, United Kingdom
cOn Behalf of Ely Bridge Surgery, Ely, Cardiff CF5 4AE, United Kingdom
dNottingham Respiratory Biomedical Research Unit, University of Nottingham, Nottingham NG5 1PB, United Kingdom
ABSTRACT