Hemodynamic characteristics of postural hyperventilation: POTS with hyperventilation versus panic versus voluntary hyperventilation

Abstract

Upright hyperventilation occurs in approximately 25% of our patients with postural tachycardia syndrome (POTS). Poikilocapnic hyperventilation alone causes tachycardia. Here we examined changes in respiration and hemodynamics comprising cardiac output (CO), systemic vascular resistance (SVR) and blood pressure (BP) measured during head-up tilt (HUT) in 3 groups: patients with POTS and hyperventilation (POTS-HV), patients with Panic Disorder who hyperventilate (Panic), and healthy controls performing voluntary upright hyperpnea (Voluntary-HV). Though all were comparably tachycardic during hyperventilation, POTS-HV manifested hyperpnea, decreased CO, increased SVR and increased BP during HUT; Panic patients showed both hyperpnea and tachypnea, increased CO and increased SVR as BP increased during HUT; and Voluntary-HV were hyperneic by design and had increased CO, decreased SVR, and decreased BP during upright hyperventilation. Mechanisms of hyperventilation and hemodynamic changes differed among POTS-HV, Panic and Voluntary-HV subjects. We hypothesize that the hyperventilation in POTS is caused by a mechanism involving peripheral chemoreflex sensitization by intermittent ischemic hypoxia.

Postural orthostatic tachycardia syndrome: A respiratory disorder?

“…24). Returning to breathing in POTS, we have shown that respiratory response to pain or panic is a combination of hyperpnea and tachypnea consistent with the literature ( Stewart et al, 2018c , 2018a ). In contrast, minute volume increased in POTS patients who exhibited postural hyperpnea during tilt-table test by an increase in tidal volume with either no change or a small decrease in respiratory rate.…”

“…Patients presenting with dyspnea but without evidence of cardiopulmonary disease on standard tests (electro- and echo-cardiogram, pulmonary function tests, chest radiograph) are often diagnosed with hyperventilation syndrome (HVS), anxiety, or panic. Yet, we now know that breathing in panic disorder differs from breathing pattern(s) seen in patients with POTS ( Stewart et al, 2018c ) ( Fig. 1 ).…”

“…Whereas this compensation may be common to many or all patients with POTS, dyspnea is reported by ~25% ( Stewart et al, 2018c , 2018a ). Recent emphasis on a multi-dimensional approach differentiates affective and cognitive responses to perceiving dyspnea, from the sensation of breathlessness ( Herigstad et al., 2011 ; De Peuter et al., 2004 ).…”

Cerebral blood flow remains reduced after tilt testing in myalgic encephalomyelitis/chronic fatigue syndrome patients

“…Third, a large number of studies using transcranial Doppler have shown that cerebral blood flow velocity is influenced by P ET CO 2 ( Del Pozzi et al, 2014 , Immink et al, 2014 , Laffey and Kavanagh, 2002 , Novak et al, 1998 , Sato et al, 2012 , Stewart et al, 2018a , Stewart et al, 2018b ). Using extracranial Doppler, this finding was also confirmed in our previous study ( van Campen et al, 2020c ).…”

The Logic of Carotid Body Connectivity to the Brain

“…However, this predominance appears to be disease-dependent. For example, in postural tachycardia syndrome (162), idiopathic hyperventilation syndrome (69), and a genetic brain disorder known as Rett syndrome, characterized by breathing instability (1,147), peripheral chemoreflex hyperreflexia manifests as hyperventilation. Its excessive sensitivity and tonicity may also contribute to the sensation of dyspnoea (35,164).…”