Conference: 2018 PHA International PH Conference & Scientific Sessions
Release Date: 06.28.2018
Presentation Type: Abstracts
File Download: Conference 2018_1037
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Abstract presented at the 2018 International PH Conference and Scientific Sessions in Orlando, Fla., June 28-July 1, 2018.
The role of exercise stress echocardiography (ESE) in PH diagnosis is not established. The aim of this study is to examine changes in right ventricular (RV) morphometry during rest and exercise in normal subjects compared with PH patients.
Adult subjects (normal and those with well characterized PH) of both genders exercised on a recumbent bicycle ESE using a progressive workload protocol. Exercise was stopped at a rate-pressure product of 20,000 or for limiting symptoms. The echocardiographic recordings were subsequently analyzed by two independent sonographers. Five echocardiographic RV morphometric parameters [RV end systolic area (RVESA), RV end diastolic area (RVEDA), RV basal diameter (RVBD), RV mid diameter (RVMD) and RV longitudinal diameter (RVLD)] were measured at rest and maximal exercise. Each parameter was evaluated for inter-rater reliability. Acceptably reproducible RV measurements were analyzed by Mann-Whitney U test to determine statistical differences between the normal and PH subjects at rest and exercise.
PH subjects (40) and normal subjects (38) between 18–66 years old were enrolled. Within the PH group 75% were female vs. 50% in the normal group (p=NS). RV measurements were adjusted for gender, height, BSA and workload. During exercise, RVESA, RVEDA and RMD significantly decreased in normal group (p<0.05) but significantly increased in PH group (p<0.01). Changes in RVESA, RVEDA, RVMD and RVLD during exercise were significantly different between PH and normal group (p < 0.001). An increase in RV size measurements during exercise had a ROC c-statistic of 0.93 for detecting pulmonary hypertension.
During recumbent exercise, normal subjects demonstrate a statistically significant reduction in RV dimensions, while PH subjects demonstrate a statistically significant enlargement in RV dimensions which we term RV Transient Exertional Dilation (TED). Hence, right ventricular TED is a pathological feature in PH subjects not seen in normal subjects and is likely related to increased RV afterload. We postulate that recumbent ESE may have utility as a screening tool for patients with suspected pulmonary vascular disease or unexplained dyspnea.
Changes in RV parameters during exercise
Sensitivity and specificity of increase in RV parameters for diagnosis of PH
ROC curve of increase in RV parameters to detect PH