Conference: 2012 International PHA Conference and Scientific Sessions
Release Date: 06.22.2012
Presentation Type: Abstracts
Godara, G, Cohen MC, Atherton D, Hacobian M, and JA.
Division of Pulmonary & Critical Care Medicine and Department of Cardiac Services. Maine Medical Center, Portland, ME 04102 USA
BACKGROUND: Right ventricular (RV) dysfunction and reduced exercise capacity in patients with pulmonary arterial hypertension (PAH) are associated with a poor prognosis. We investigated RV morphometric and function parameters during recumbent exercise stress testing using real-time echocardiography (ESE) to better understand RV structure-function relationships.
METHODS: We used a Phillips IE 33 ultrasound and recumbent bicycle ergometer for exercise in incremental stages of 25 watts every 3 minutes. Heart rate and blood pressure were recorded in each stage and the test was considered diagnostic at a rate-pressure product (RPP) of 20,000. Tests were terminated early if subjects developed limiting symptoms. PAH subjects (WHO FC I-II) and non-PH control subjects were enrolled. Values for RV diameters (basal diameter - BD, mid-ventricular diameter MD, and longitudinal diameter - LD), RV areas (RV end diastolic area - RVEDA, and RV end systolic area - RVESA), fractional area change (FAC) and tricuspid annular plane systolic excursion (TAP SE) were obtained at rest and exercise. The PAH and control subject groups were subsequently compared with respect to rest and exercise RV morphometric and functional parameters. Statistical differences were considered significant at p < 0.05.
RESULTS: Thirty PAH subjects with an established diagnosis of PAH and seven non-PH control subjects were enrolled. The mean of each parameter for the PAH group vs. the control group was compared using Student’s t-test as shown. The PAH group had a significant exercise-induced increase in RV LD and RVEDA which was not observed in the control group. We define this finding as right ventricular "transient exertional dilation". The control group had a significant exercise-induced increase in RV FAC and TAPSE over their resting state, which was not observed in the PAH group.
CONCLUSION: During exercise, PAH patients demonstrate RV transient exertional dilation and failure to augment RV FAC and TAPSE. Right ventricular morphometric and functional measurements obtained during recumbent exercise stress echocardiography may have a role in the diagnosis of pulmonary hypertension.