Delayed Cardiovascular Response to Acute Hypotension in Heart Failure Patients Compared to Healthy Adults

Heart failure (HF) patients exhibit autonomic dysfunction. Orthostatic hypotension occurs often in HF and may be linked with altered cardiovascular responsiveness in HF. However, the cardiovascular response to acute hypotension in HF patients compared to healthy adults is unknown. Therefore, data were retrospectively analysed from eight patients with HF with reduced ejection fraction (7 male/1 female) and seven healthy adults (CON; 6 male/1 female) who underwent acute hypotension via thigh cuff deflation following 7.5 min of unilateral lower limb occlusion. Mean arterial blood pressure (MAP; photoplethysmogram) and heart rate (HR; electrocardiogram) were continuously recorded. Statistical analysis involved independent-samples t-tests. Baseline cardiovascular values were not different between groups (all p > 0.05). The magnitudes of the MAP peak decrease during acute hypotension and consequent HR peak increase were not different between groups (MAP: HF -11 ± 3 mmHg vs. CON -12 ± 5 mmHg, p = 0.756; HR: HF 3 ± 2b · min^-1 vs. CON 4 ± 3b · min^-1, p = 0.243). However, the MAP time to peak decrease and HR time to peak increase were longer in HF than CON (MAP: HF 11 ± 5 s vs. CON 6 ± 3 s, p = 0.041; HR: HF 10 ± 4 s vs. CON 6 ± 2 s, p = 0.044). HF patients exhibit a delayed cardiovascular response to acute hypotension compared to healthy adults, which may be linked with more frequent orthostatic hypotension in HF.