TY - JOUR T1 - Right ventricular contractile reserve is markedly impaired and correlates with exercise capacity in pulmonary arterial hypertension: A dobutamine stress echocardiography study JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - 4844 AU - Edmund Lau AU - Phillip Munoz AU - Tripura Sharma AU - Preeti Choudhary AU - David Celermajer Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/4844.abstract N2 - Background: Right ventricular (RV) function is the main determinant of prognosis and exercise capacity in pulmonary arterial hypertension (PAH). We hypothesized that assessment of RV contractile reserve using dobutamine stress echocardiography would provide information additional to resting measurements.Methods: We used a low-dose dobutamine protocol (peak dose 20 mcg/kg/min) to assess RV contractile reserve in 16 PAH patients and 18 age-matched controls. Contractile reserve was assessed by the change (Δ = peak stress minus resting value) in two echocardiographic indices of RV longitudinal systolic function: (1) Δ tricuspid annular plane systolic excursion (ΔTAPSE) and (2) Δ tricuspid annular systolic velocity (ΔS'). A subgroup of 13 PAH patients underwent cardiopulmonary exercise testing to determine peak oxygen consumption (VO2).Results: At rest, TAPSE and S' were reduced in PAH group compared with controls (1.7±0.4 vs. 2.4±0.3 cm and 10.1±3.0 vs. 12.5±1.2 cm/s, respectively, both p <0.001). Contractile reserve was markedly attenuated in PAH compared to controls (ΔTAPSE: 0.1±0.4 vs. 0.6±0.3 cm; and ΔS': 5.0±3.3 vs. 11.2±3.6 cm/s, both p <0.001). In the subgroup of PAH patients with preserved RV systolic function at rest, contractile reserve remained depressed compared to controls. Peak VO2 was significantly correlated with ΔS' (r=0.87, p=0.0003) and Δ stroke volume (r=0.59, p=0.03).Conclusions: RV contractile reserve can be assessed using DSE and may reveal subclinical RV dysfunction not apparent at rest. A correlation with exercise capacity suggests potential clinical value beyond resting measurements. ER -