What are the requirements for the diagnosis of Hyperadrenergic Postural Orthostatic Tachycardia Syndrome (POTS)?

From the Guidelines

Hyperadrenergic orthostatic intolerance requires specific diagnostic criteria including an excessive orthostatic increase in heart rate (≥30 beats per minute) or heart rate ≥120 beats per minute within 10 minutes of standing, accompanied by elevated plasma norepinephrine levels (≥600 pg/mL) measured while standing. Patients must demonstrate orthostatic symptoms such as lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, or fatigue that develop upon standing and improve with recumbence. These symptoms should occur in the absence of other causes of orthostatic symptoms, such as medications, prolonged bed rest, or significant dehydration. The condition represents an excessive sympathetic nervous system response to upright posture, with the body producing too much norepinephrine when standing. Management typically begins with non-pharmacological approaches including increased fluid intake (2-3 liters daily), increased salt consumption (10-12 grams daily), compression garments, and physical counter-maneuvers. Pharmacological treatment may include beta-blockers like propranolol (10-40 mg three times daily), central sympatholytics such as clonidine (0.1-0.3 mg twice daily), or alpha-1 agonists like midodrine (2.5-10 mg three times daily) 1. The underlying pathophysiology involves dysregulation of the autonomic nervous system with exaggerated catecholamine release during orthostatic stress, leading to the characteristic symptoms when upright. Key points to consider in the diagnosis and management of hyperadrenergic orthostatic intolerance include:

• Orthostatic symptoms that develop upon standing and improve with recumbence
• Excessive orthostatic increase in heart rate or elevated plasma norepinephrine levels
• Absence of other causes of orthostatic symptoms
• Non-pharmacological approaches as first-line management
• Pharmacological treatment options for refractory cases. It is essential to note that the diagnosis and management of hyperadrenergic orthostatic intolerance should be individualized and based on the specific needs and circumstances of each patient 1.

From the Research

Requirements for Hyperadrenergic Orthostatic Intolerance

The requirements for hyperadrenergic orthostatic intolerance are not explicitly stated in the provided studies. However, the characteristics of hyperadrenergic orthostatic intolerance can be identified as follows:

• Elevated plasma norepinephrine levels 2
• Attenuated plasma renin activity and aldosterone 2
• Reduced supine blood volume coupled with dynamic orthostatic hypovolemia 2
• Impaired clearance of norepinephrine from the circulation 2
• Evidence of partial dysautonomia 2
• Increase in systolic blood pressure of ≥ 10 mm Hg during the head up tilt test (HUTT) with concomitant tachycardia or serum catecholamine levels (serum norepinephrine level ≥ 600 pg/mL) upon standing 3

Diagnostic Criteria

The diagnostic criteria for hyperadrenergic postural orthostatic tachycardia syndrome (POTS) include:

• Symptoms of orthostatic intolerance (of greater than six months' duration) accompanied by a heart rate increase of at least 30 bpm (or a rate that exceeds 120 bpm) that occurs in the first 10 min of upright posture or HUTT 3
• Increase in systolic blood pressure of ≥ 10 mm Hg during the HUTT with concomitant tachycardia or serum catecholamine levels (serum norepinephrine level ≥ 600 pg/mL) upon standing 3

Treatment

Treatment for hyperadrenergic POTS may include:

• Bisoprolol, a cardioselective beta-blocker 4
• Fludrocortisone, a mineralocorticoid analog that promotes sodium reabsorption 4, 5 Note that the treatment for hyperadrenergic POTS is not standardized and may vary depending on the individual patient's needs and response to treatment 3