Tilt-evoked, breathing-driven blood pressure oscillations: Independence from baroreflex-sympathoneural function

Figures

• 

  Fig. 1. Individual values for the log of high-frequency (HF) power of systolic blood pressure (BP) variability before head-up tilt (Baseline) and during head-up tilt (Tilt) in different subject groups. A All study subjects; B healthy volunteers (HV); C Parkinson’s disease without orthostatic hypotension (PD No OH); D Parkinson’s disease with orthostatic hypotension (PD+OH); E pure autonomic failure (PAF); F parkinsonian form of multiple system atrophy (MSA-P); G von Hippel-Lindau disease with a history of neurosurgery for brainstem hemangioblastomas (VHL). Numbers in italics indicate p-values. Across all subjects, the log of HF power increased from Pre-tilt to Tilt. Within most groups, with the exception of PD No OH, there were no significant effects of tilt on HF power in any group

• 

  Fig. 2. Individual values for the log of low-frequency (LF) power of systolic blood pressure (BP) variability during head-up tilt in different subject groups. A All the subjects in the study; B healthy volunteers (HV); C Parkinson’s disease without orthostatic hypotension (PD No OH); D Parkinson’s disease with orthostatic hypotension (PD+OH); E pure autonomic failure (PAF); F parkinsonian form of multiple system atrophy (MSA-P); G von Hippel-Lindau disease with a history of neurosurgery for brainstem hemangioblastomas (VHL). Numbers in italics indicate p values. The log of LF power increased significantly during tilt only in the HV group

• 

  Fig. 3. Individual values for the log of high-frequency (HF) and low-frequency (LF) power of systolic blood pressure variability before tilt (Baseline) and during tilt (Tilt) in groups without orthostatic hypotension (No OH) and with neurogenic orthostatic hypotension (nOH). The No OH cohort consisted of the healthy volunteer and Parkinson’s disease (PD) without OH groups. The nOH cohort consisted of the groups with pure autonomic failure, PD with OH, the parkinsonian form of multiple system atrophy, and von Hippel–Lindau disease with a history of neurosurgery for brainstem hemangioblastomas. Numbers in italics indicate p-values. As shown in A–D, the log of HF power increased with head-up tilt in both the control and nOH cohorts, and the two cohorts did not differ in the mean log of HF power during tilt or in the change in the log of HF power (∆Log HF) during tilt. As shown in E–H, the log of LF power increased with head-up tilt in the control but not in the nOH cohort. HF power in the nOH group is denoted by green circles (C and D) and LF power by blue (G and H)

• 

  Fig. 4. Low-frequency blood pressure (BP) oscillations during head-up tilting in a healthy volunteer. A and B are from the same recording but with different time scales. There is no orthostatic hypotension. During tilt, BP oscillations are not driven by breathing, and there are low-frequency Mayer waves. The blue rectangle is placed to highlight Mayer waves occurring at a lower frequency than that of respiration (Resp.). BP blood pressure (mm Hg), BPs systolic blood pressure (mmHg), EKG electrocardiogram, HR heart rate (bpm)

• 

  Fig. 5. Tilt-evoked, breathing-driven blood pressure oscillations in a patient with neurogenic orthostatic hypotension (nOH) related to pure autonomic failure evolving to Parkinson’s disease with nOH. A and B are from the same recording but with different time scales. The patient develops rapid OH. During tilt, BP oscillations are driven by breathing. BP blood pressure (mm Hg) BPs systolic blood pressure (mmHg), EKG electrocardiogram, HR heart rate (bpm), Resp. respiration, SV stroke volume (mL)

• 

  Fig. 6. Tilt-evoked, breathing-driven blood pressure oscillations in a patient with neurogenic orthostatic hypotension (nOH) related to the parkinsonian form of multiple system atrophy. A and B are from the same recording but with different time scales. The patient develops rapid OH. During tilt, BP oscillations are driven by breathing. BP blood pressure (mm Hg), BPs systolic blood pressure (mmHg), EKG electrocardiogram, HR heart rate (bpm), Resp. respiration