What is considered an orthostatic pulse change?

From the Guidelines

An orthostatic pulse change is defined as an increase in heart rate of 30 beats per minute (bpm) or more, or a heart rate exceeding 120 bpm, within 10 minutes of changing from a lying to standing position, as stated in the 2018 ESC guidelines for the diagnosis and management of syncope 1. This change occurs as part of the body's compensatory mechanism when blood pressure drops upon standing. When a person stands up, gravity causes blood to pool in the lower extremities, temporarily reducing blood return to the heart. In response, the heart beats faster to maintain adequate blood flow to vital organs, particularly the brain.

Key Points to Consider

• Orthostatic pulse changes are often measured alongside blood pressure changes during orthostatic vital sign assessments.
• To properly assess for orthostatic changes, measurements should be taken after the patient has been lying down for at least 5 minutes, then immediately upon standing, and again after 1,3, and 5 minutes of standing.
• Significant orthostatic pulse changes may indicate conditions such as dehydration, blood loss, autonomic dysfunction, or medication effects, as noted in the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1.
• The pathophysiology of orthostatic intolerance is debated and likely heterogeneous, involving deconditioning, immune-mediated processes, excessive venous pooling, and a hyperadrenergic state, as discussed in the 2018 ESC guidelines 1.

Assessment and Management

• Establishing the underlying diagnosis is crucial in patients with orthostatic hypotension, as emphasized in the guidelines on management of syncope 1.
• Treatment goals include prevention of symptom recurrence and associated injuries, as well as improved quality of life, as stated in the guidelines on management of syncope 1.
• Non-pharmacological measures, such as gradual staged movements with postural change, mild isotonic exercise, and increased fluid and salt intake, should be attempted first, as recommended in the guidelines for cardiovascular autonomic neuropathy in diabetes 1.

From the Research

Orthostatic Pulse Change

• An orthostatic pulse change refers to the variation in heart rate that occurs when an individual changes from a lying down or sitting position to a standing position.
• According to the study 2, the normal ranges of orthostatic changes in blood pressure and heart rate have been defined in 92 individuals aged 18 to 64 years.
• The study 2 found that in some individuals, orthostatic changes can include tachycardia after standing for at least 3 minutes, which can be a sign of excessive venous pooling.
• The American Autonomic Society defines orthostatic hypotension as a fall in systolic blood pressure of at least 20 mmHg or a fall in diastolic blood pressure of at least 10 mmHg within three minutes of standing, however, there is no specific definition for orthostatic pulse change.
• The study 3 mentions that measuring blood pressure and heart rate at the bedside can help establish whether the cause of orthostatic hypotension is a pathologic lesion in sympathetic neurons or secondary to other medical causes.
• The study 4 states that orthostatic hypotension can be easily diagnosed by measuring blood pressure and heart rate after 3 minutes in upright posture.
• The study 5 found very low-certainty evidence about the effects of fludrocortisone on drop in BP and orthostatic symptoms, but did not provide a clear definition of orthostatic pulse change.
• The study 6 mentions that orthostatic hypotension is a fall in blood pressure after assuming an upright position, but does not provide a specific definition for orthostatic pulse change.

Diagnosis and Measurement

• Orthostatic changes can be measured by taking blood pressure and heart rate readings after a person has been standing for at least 3 minutes 4, 2.
• The study 2 used external gamma counting over a fixed site in the calf to show excessive gravitational pooling of blood in the legs of patients with orthostatic diastolic hypertension, orthostatic narrowing of the pulse pressure, and orthostatic tachycardia alone.
• Plasma norepinephrine concentrations were usually normal in recumbency and elevated above normal limits during standing for 15 to 30 minutes in the 18 patients observed in the study 2.