Assessment of subclinical left ventricular systolic dysfunction and structural changes in patients with chronic obstructive pulmonary disease

Background Patients with chronic obstructive pulmonary disease (COPD) can develop left ventricular (LV) systolic dysfunction and geometric changes due to several reasons. Aim To investigate subclinical LV systolic dysfunction and structural features in patients with COPD, and its correlation with the severity of airway obstruction, identified by GOLD classification. Methods We studied 52 patients with COPD and 29 age and sex-matched controls, without any cardiac disease. In addition to conventional echocardiographic evaluation speckle tracking echocardiography (STE)-based strain imaging were performed to analyse sub-clinical LV systolic dysfunction. Also LV volumes were measured by using three-dimensional real time echocardiography (3DRTE). All patients underwent spirometry. Results Conventional echocardiographic parameters (LV wall thickness and diameters, LV EF) and LV volume measurements were similar between the groups. LV global longitudinal peak systolic strain (-14.76 +/- 2.69% to -20.27 +/- 1.41%, P < 0.001) and strain rate (0.75 +/- 0.25 1/s to 1.31 +/- 0.41 1/s, P < 0.001) were significantly impaired in patients, compared to controls demonstrating sub-clinical ventricular systolic dysfunction. Significant positive correlation was obtained between LV strain/strain rate and spirometry parameters (FEV1, FEV%, FEV1/FVC, PEF%) (r = 0.78/0.68, P < 0.001; r = 0.83/0.70, P < 0.001); r = 0.74/0.55, P < 0.001; r = 0.72/0.65, P < 0.001 respectively). In addition, there was significant negative correlation between LV strain/strain rate and GOLD classification (r = -0.80/ -0.69, P < 0.001 respectively). Conclusion Subclinical LV systolic dysfunction can occur in COPD patients despite normal EF. STE is a technique that provides additional information for detailed evaluation of subtle changes in LV myocardial contractility, significantly associated with the severity of the disease in COPD patients.