Study population cohorts
We designed a cross-sectional study in which we recruited consecutive
patients who were evaluated in the Nuclear Cardiology Department (NCD)
at the National Institute of Cardiology Ignacio Chavez, between the
period of June 2018 to December 2019. The patients attended our
institution’s outpatient clinic due to dyspnea on exertion, fatigue, and
dizziness and were sent for a transthoracic echocardiogram for further
evaluation. All patients underwent conventional two-dimensional and
Doppler transthoracic echocardiography, along with velocity vector
imaging to assess the right heart chamber strain parameters. We excluded
subjects with congenital heart diseases, prior myocardial infarction,
sarcoidosis, mild or severe valvular disease, or subjects classified
with unspecified cardiomyopathies. Patients with low echocardiographic
image quality were excluded in the final analysis. We defined a control
group which comprised of subjects who had normal pulmonary artery
pressure values by echocardiographic measurement of peak tricuspid
regurgitation velocity within our cohort sample. To assess inter-rater
reliability and reproducibility of echocardiographic sPAP parameters,
thirteen selected subjects from our first cohort were assessed at heart
catheterization performed 10 days after the echocardiographic study.
Written informed consent was obtained from all participants.