Abstract 9399: Right Ventricular Dysfunction during Exercise: Potential Markers of Exercise Intolerance in Pulmonary Hypertension

Abstract

Background: Development of exercise-induced pulmonary hypertension (exPH) is a clinically important; but poorly characterized hemodynamic event. Even though bicycle echocardiography (BE) has been suggested as a useful non-invasive test to estimate pulmonary artery pressures (PAP) during exercise; simple measurement of pressures appears to be an unreliable approach to detect exPH. Consequently, we queried our BE database to examine if objective parameters of right ventricular (RV) function might be useful in distinguishing abnormal responses to exercise. To accomplish this goal, we identified patients who develop mild exPH and compared them to normal controls. Methods: In this retrospective analysis, we measured RV fractional area change, tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (RV MPI), and systolic velocity of the tricuspid annulus (TA TDI). All these measures were collected at each stage of the BE protocol from 10 control individuals, and 10 patients who developed mild exPH with estimated exercise PAP of 62 ± 9. Results: Tricuspid regurgitation signal was an unreliable measure to estimate PAP with increasing workloads; however, all objective parameters were collected in all patients at every stage. In control individuals, not only TAPSE and TA TDI increased with each stage but also baseline RV MPI was significantly lower and remained largely unchanged during exercise. In sharp contrast, TAPSE and TA TDI remained largely unchanged (Fig 1 A&B) while the baseline RV MPI not only was higher but also continued to increase with exertion in the mild exPH group (Fig 1 C). Also individuals with exPH were older in age (p value<0.001). Conclusion: Even though age might be an unaccountable variable in this pilot study; our data seems to suggest that objective measures of RV function during BE, might be useful for the assessment of RV response to increasing exercise workloads.