Exercise impedance cardiography reveals impaired hemodynamic responses to exercise in hypertensives with dyspnea

Patients with arterial hypertension (AH), especially women, often report exercise intolerance and dyspnea. However, these symptoms are not frequently reflected in standard assessments. The aim of the study was to evaluate the clinical value of impedance cardiography (ICG) in the hemodynamic assessment of patients with AH during exercise, particularly the differences between subgroups based on sex and the presence of dyspnea. Ninety-eight patients with AH (52 women; 54.5 +/- 8.2 years of age) were evaluated for levels of N-terminal pro-B-type brain natriuretic peptide (NT-proBNP), exercise capacity (cardiopulmonary exercise testing (CPET) and the 6-min walk test (6MWT)), and exercise ICG. Patients with AH were stratified into the following four subgroups: males without dyspnea (MnD, n = 38); males with dyspnea (MD, n = 8); females without dyspnea (FnD, n = 27); and females with dyspnea (FD, n = 25). In comparison with the MnD subgroup, the FnD subgroup demonstrated significantly higher NT-proBNP levels; lower exercise capacity (shorter 6MWT distance, lower peak oxygen uptake (VO2), lower O-2 pulse); higher peak stroke volume index (SVI); and higher SVI at the anaerobic threshold (AT). In comparison with the other subgroups, the FD subgroup walked a shorter distance during the 6MWT distance; had a steeper VENCO2 slope; had lower values of peak stroke volume (SV) and peak cardiac output (CO); and had a smaller change in CO from rest to peak. However, no other differences were identified (NT-proBNP, left ventricular diastolic dysfunction, or CPET parameters). Exercise impedance cardiography revealed an impaired hemodynamic response to exercise in hypertensive females with dyspnea. In patients with unexplained exercise intolerance, impedance cardiography may complement traditional exercise tests.