Tissue Doppler Imaging may help detect subclinical systolic LV dysfunction in COPD
A recent study has suggested that subclinical left ventricular (LV)
systolic dysfunction is likely to be detected when measured by tissue
Doppler imaging (TDI), in COPD patients and, even in patients
without pulmonary hypertension (PH).
The study results have been published in PLoS ONE.
Researchers pointed out that in chronic obstructive pulmonary
disease (COPD), and in particular in those with severe emphysema,
pulmonary hypertension and right ventricular (RV) enlargement, the
left ventricle is compressed. However, LV ejection fraction by two-
dimensional echocardiography can be normal despite LV
dysfunction.
Tissue Doppler imaging (TDI) is a more sensitive tool to detect
subclinical systolic LV dysfunction.
Janne M. Hilde and a team from the Department of Cardiology, Oslo University Hospital-Aker, Norway, carried out the study to assess
the prevalence of left ventricular (LV) systolic and diastolic function in a stable cohort of COPD patients, where LV disease had been
thoroughly excluded in advance.
The sample population included a hundred outpatients with stable
COPD of different severity and free of clinical cardiovascular
disease from 2006 to 2010.The diagnosis of COPD was based on a
history of cigarette smoking with at least 10 pack-years and
spirometry irreversible airway obstruction according to current
guidelines. The COPD patients were compared to an age and
gender-matched control group (n = 34) and evaluated healthy by
clinical, biochemical, and
imaging investigations.
All study patients underwent a comprehensive Doppler
echocardiographic examination before and within 120 minutes of
right-heart catheterization.
The following facts emerged. LV MPI ≥0.51 was found in 64.9% and
88.5% and LV strain ≤-15.8% in 62.2.% and 76.9% in the COPD-
non-PH and COPD-PH patients, respectively.
Similarly, LV MPI and LV strain were impaired even in patients with
mPAP <20 mmHg. In multiple regression analyses, residual volume
and stroke volume were best associated with LV MPI and LV strain, respectively.
Except for isovolumic relaxation time, standard diastolic echo
indices as E/A, E´, E/E´, and left atrium volume did not change from
normal individuals to COPD-non-PH.
"Subclinical LV systolic dysfunction was a frequent finding in this
cohort of COPD patients, even in those with normal pulmonary
artery pressure. Evidence of LV diastolic dysfunction was hardly
present as measured by conventional echo
indices.' authors said.