Systolic Function and Cardiac Parameters on Cardiopulmonary Exercise Testing

Abstract

SESSION TITLE: Pulmonary Physiology SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, November 1, 2017 at 01:30 PM - 02:30 PM PURPOSE: Dyspnea is a common manifestation of cardiac dysfunction. Cardiac limitation to exercise can be detected on cardiopulmonary exercise testing (CPET). The relationship between cardiac parameters on CPET and echocardiography (ECHO) variables have not been studied. The objective of this study was to determine the correlation between cardiac parameters on CPET with echo parameters of cardiac systolic function. METHODS: Eighty-seven patients who underwent CPET and ECHO at our institution for evaluation of dyspnea were studied to assess the correlation between cardiac parameters on CPET with ejection fraction (LVEF), left atrial size (LAS), left ventricular end-systolic volume (LVESV), and left ventricular end-diastolic volume (LVEDV), which are common markers of systolic function on ECHO. The following data were obtained from records- patient demographics, maximal O2-uptake (VO2max), maximum predicted work (PPW) performed, Heart Rate Reserve [HRR], percent predicted maximal heart rate (PP-HR), anaerobic threshold (AT), O2-pulse, HR/VO2 gradient, Work/VO2 gradient, EF, LVESV, LVEDV. Correlation analysis was performed to determine the relation between EF, LVESV and LVEDV with respect to VO2max, AT, O2 pulse, HR/VO2, HRR, Work/VO2 slope. p<0.05 was deemed statistically significant. RESULTS: Mean age was 51.4 ± 14 years; 70% were females. Mean studied parameters were as follows: VO2 max 17.8 ± 7.8ml/kg/min (69.3 ± 21% predicted); AT 55 ± 22%; O2-pulse 96.8 ± 26 %; HRR was 25 ± 35; PP-HR was 80.7 ± 12%; VO2/work = 9.8 ± 3.4; HR/VO2 3.2 ±1.2. LVESV was 29.6 ± 8.7mm; LVEDV was 44.7 ± 7.7 mm; EF was 60 ± 6%. Only 6% patients had systolic dysfunction on ECHO with EF <50%. On Pearson’s correlation analysis, EF and LVESV did not have a significant correlation with any of the studied parameters on CPET. LVEDV had a significant correlation with HRR (r=-0.307, p=0.004) and O2-pulse (r=0.237, p=0.02) but did not have a significant correlation with the other parameters. CONCLUSIONS: On CPET, HRR and O2-pulse may be an indicator of systolic dysfunction as a cause of exertional dyspnea. CLINICAL IMPLICATIONS: Systolic dysfunction causes dyspnea but most echocardiographic parameters do not have a significant relation to cardiac variables on CPET. The absence of significant relation between EF and studied cardiac parameters on CPET may be because the majority of studied patients had normal LV systolic function. Further studies on patients with systolic dysfunction to discern correlation with cardiac parameters on CPET are needed. DISCLOSURE: The following authors have nothing to disclose: Talal Kaiser, Debapriya Datta No Product/Research Disclosure Information