Abstract 16259: Pulmonary Arterial Pressure Patterns During Recovery From Incremental Exercise Reflect Right Ventricular-Pulmonary Vascular Reserve
Introduction: Despite growing evidence of the functional and prognostic significance of pulmonary vascular (PV) response patterns during exercise, post exercise pulmonary arterial pressure (PAP) decrement patterns remain unexplored. We hypothesized that PAP recovery patterns would be related to PV reserve during exercise.
Methods: We studied 93 consecutive patients referred to our center for maximum cardiopulmonary exercise testing with invasive hemodynamic monitoring to evaluate dyspnea on exertion. PAP was measured every 20 sec during exercise and recovery. Fick CO was measured every minute during exercise. Exercise PAP- flow response was defined by the ratio of change in PAP to change in CO (ΔP-CO) as normal (≤3:1) or abnormal (>3:1).
Results: Patients (age 57±1, 52% male, BMI 28±1, LVEF 63±1%; mean±SEM) had resting and peak exercise PAP of 17±1 and 37±1 mmHg, respectively. PAP recovery was characterized by a steep decline for ~2 min followed by a plateau from 2-4 min (Figure). At 2 min post exercise, PAP in patients with normal ΔP-CO (n=65) decreased to within 4.0±0.4 mmHg of baseline (BL), while patients with high ΔP-CO (n=27) remained 9±1 mmHg above BL (between group comparison p=0.01). From 2-4 min of recovery, the high ΔP-CO group maintained a mean elevation in PAP above BL that was 2.2x that of normal ΔP-CO group. In regression models adjusted for age and sex, at 2 min into recovery, both %ΔPAP from peak and ΔPAP above BL were related to peak exercise PV resistance and RVEF (all p<0.05).
Conclusions: Through characterization of PAP during incremental exercise and recovery we defined rapid descent and plateau phases of exercise PAP recovery. A slow initial descent in PAP and persistent PAP elevation above BL were associated with impaired PV performance during exercise. Our findings may inform the interpretation of invasive and non-invasive (i.e. echocardiographic) assessments of PV responses to exercise during a period that is conducive to performing PAP measurements.
Author Disclosures: A.S. Eisman: None. P.P. Pappagianopoulos: None. S.S. Hough: None. L.A. Farrell: None. A.E. Dress: None. R.V. Shah: None. R.B. Weiner: None. A.L. Baggish: None. G.D. Lewis: None.
- © 2014 by American Heart Association, Inc.