Cardiovascular Responses During Graded Lower‐Body Negative Pressure in Heart Failure with Preserved Ejection Fraction

Abstract

Heart failure with preserved ejection fraction (HFpEF) represents approximately half of the known cases of heart failure in the United States, with equally poor outcomes and rising prevalence compared to heart failure with reduced ejection fraction (HFrEF). While changes in autonomic nervous system function is a well‐known feature of HFrEF pathophysiology, whether patients with HFpEF experience a similar decrement remains unknown. Therefore, we sought to evaluate the reflex cardiovascular responses to baroreflex unloading achieved via graded levels of lower‐body negative pressure (LBNP) in patients with HFpEF compared to healthy, age‐matched controls (CON). In six participants (three HFpEF (1 male, 70±3 yrs) and three CON (2 male, 74±2 yrs)), we assessed forearm blood flow (FBF; Doppler ultrasound), mean arterial blood pressure (MAP; Finapres), heart rate (HR; electrocardiogram) and forearm vascular conductance (FVC) at rest and throughout graded levels of LBNP (−10, −20, −30 and −40 mmHg). At rest, there were no significant differences between HFpEF and CON in FBF (109±32 vs. 85±29 ml/min), MAP (90±4 vs. 96±3 mmHg), HR (60±5 vs. 61±5 bpm), or FVC (1.19±0.33 vs. 0.89±0.28 ml/min/mmHg). The reflex tachycardic response to baroreflex unloading induced by LBNP was similar between patients with HFpEF and CON. Vasoconstriction in response to LBNP decreased FBF to a similar level in both HFpEF and CON (−10: 102±31 vs. 88±28 ml/min; −20: 95±30 vs. 76±25 ml/min; −30: 91±30 vs. 78±28 ml/min; −40: 91±33 vs. 71±21 ml/min, HFpEF vs. CON), with similar changes in FVC. Together, these preliminary data suggest that baroreflex‐mediated cardiac and vascular responses are not altered in patients with HFpEF, suggesting an absence of overt autonomic dysfunction is this patient group.Support or Funding InformationThis project is funded in part by the National Institutes of Health (HL118313, R56AG057584, T32HL139451) and the U.S. Department of Veterans Affairs (I01RX001311, I01RX001697, I01RX002323, I01RX000182).