Orthostatic dyspnea: a neglected symptom of orthostatic hypotension

Abstract

Dyspnea is a common symptom in patients with pulmonary and cardiac disease. Orthostatic hypotension is rarely considered a cause of dyspnea. We reviewed the medical records of 651 consecutive patients referred for the evaluation of dysautonomia to investigate the prevalence of dyspnea and its association with OH and other autonomic abnormalities. Dyspnea was reported by questionnaire in 30% of patients with OH, compared to 10% of age and sex matched patients without OH (P<0.05, chi(2)). There was a trend toward earlier blood pressure falls in patients with dyspnea. During autonomic testing, 25% of patients (10 of 40) with OH who reported dyspnea on the questionnaire had shortness of breath coincident with blood pressure falls during tilt table and active standing. The time to maximal blood pressure fall was shorter in patients with OH who experienced shortness of breath during testing compared to those without dyspnea (11 minutes vs. 21 minutes, P<0.05). In this study, dyspnea was frequently associated with OH. Ventilation perfusion mismatch, due to inadequate perfusion of ventilated lung apices may be the most likely underlying cause of orthostatic dyspnea in patients with OH.

Hyperventilation during orthostatic challenge in spinal cord-injured humans

“…It is also found frequently in patients with orthostatic hypotension [19]. It is thought that ventilation perfusion mismatch due to inadequate perfusion of ventilated lung apices is the most likely cause underlying the occurrence of platypnea in patients with orthostatic hypotension [19]. Standing therapy is often used for individuals with SCI in the clinical field because this therapy includes several positive effects such as the preventive effect of orthostatic hypotension [21], protective effect against loss of bone mineral density [1], effect of attenuating spasticity [4,33] and effect of promoting psychological well-being [16,24].…”

“…Platypnea is found in patients with hepatopulmonary syndrome and with an anatomical cardiovascular defect increasing positional right-to-left shunting. It is also found frequently in patients with orthostatic hypotension [19]. It is thought that ventilation perfusion mismatch due to inadequate perfusion of ventilated lung apices is the most likely cause underlying the occurrence of platypnea in patients with orthostatic hypotension [19].…”

The Orthostatic Hypotension Questionnaire (OHQ): validation of a novel symptom assessment scale

“…Furthermore, orthostatic hypotension may result in focal symptoms due to tissue or end-organ hypoperfusion. Thus, patients may report visual blurring due to retinal or occipital lobe ischemia; cognitive slowing, concentration difficulties and leg buckling due to cerebral ischemia; neck pain due to neck muscle ischemia; orthostatic dyspnea due to ventilation perfusion mismatch; and anginal pains due impaired myocardial perfusion [6,14].…”

Hypoventilation during passive leg movement in spinal cord-injured humans

“…Two subjects who had severe breathlessness during standing felt only slight or moderate breathlessness during PWE. Although the change in breathlessness score would be related to the change in VEeq, the direct cause of breathlessness sensation may be ventilation-perfusion ratio [5]. Further study is needed to clarify the mechanism by examining the change in the cardiac output.…”