Hemodynamic characterization of hypertensive patients with an exaggerated orthostatic blood pressure variation

Abstract

Exaggerated orthostatic blood pressure variation (EOV) is a poorly understood phenomenon related to high cardiovascular risk. We aimed to determine whether hypertensive patients with EOV have a distinct hemodynamic pattern, assessed through impedance cardiography. Methods: In treated hypertensive patients, we measured the cardiac index (CI), systemic vascular resistance index (SVRI), blood pressure (BP), and heart rate (HR) in the supine and standing (after 3 minutes) positions, defining three groups according to BP variation: 1) Normal orthostatic BP variation (NOV): standing systolic BP (stSBP)-supine systolic BP (suSBP) between −20 and 20 mmHg and standing diastolic BP (stDBP)-supine diastolic BP (suDBP) between −10 and 10 mmHg; 2) orthostatic hypotension (OHypo): stSBP-suSBP≤-20 or stDBP-suDBP≤-10 mmHg; 3) orthostatic hypertension (OHyper): stSBP-suSBP≥20 or stDBP-suDBP≥10 mmHg. We performed multivariable analyses to determine the association of hemodynamic variables with EOV. Results: We included 186 patients. Those with OHyper had lower suDBP and higher orthostatic SVRI variation compared to NOV. In multivariable analyses, orthostatic HR variation (OR = 1.06 (95%CI 1.01–1.13), p = 0.03) and orthostatic SVRI variation (OR = 1.16 (95%CI 1.06–1.28), p = 0.002) were independently related to OHyper. No variables were independently associated with OHypo. Conclusion: Patients with OHyper have a distinct hemodynamic pattern, with an exaggerated increase in SVRI and HR when standing.

Keywords

• exaggerated
• hemodynamic
• hypertension
• impedance cardiography
• orthostatic blood pressure variation