Title : Postural orthostatic tachycardia syndrome (POTS)

Background: Postural Orthostatic Tachycardia Syndrome (POTS) is a complex and heterogeneous autonomic nervous system disorder characterised by orthostatic intolerance. Key diagnostic criteria include a sustained increase in heart rate of ≥30 bpm (or ≥40 bpm in children/adolescents) or to ≥120 bpm within 10 minutes of standing or on a head-tilt test, in the absence of orthostatic hypotension, and the presence of orthostatic intolerance symptoms. While the exact prevalence is difficult to ascertain due to its varied nature, the literature suggests that it disproportionately affects young, Caucasian females. The pathophysiology is multifactorial and includes hypovolaemic, hyperadrenergic, and neuropathic phenotypes. Symptoms are diverse, ranging from fatigue, presyncope, dizziness, and palpitations to gastrointestinal issues, headaches, and exercise intolerance, often exacerbated by factors like heat, dehydration, and physical exertion.

Aims: A study was carried out in my cardiology clinic on all the female patients below age 45 who were referred because of dizziness and/ or palpitation.

Results: All the 680 female patients below age 45 who were referred to our cardiology clinic within 12 months because of dizziness and/or palpitation were reviewed. A total of 51 patients (7.5%), age 18-43 (mean 30.5) were identified with POTS based on the symptoms of feeling dizzy upon standing from sitting position associated with a significant increase in heart rate of >30BPM but without change in blood pressure, and positive table tilt test suggestive of POTS. Nine of the patients (18%) were Caucasian, one patient was a Caribbean while the rest n=41 (80%) were of Indo-Asian origin. Gastrointestinal symptoms of abdominal pain, diarrhoea and vomiting were present in 8 patients (Caucasian and Caribbean) but in none of the Indo-Asian. Migraine with aura was present in 1 Caucasian and in 5 (12%) of the Indo-Asian while hemiplegic migraine with aura was present in 1 of the Caucasian and in 14 (34%) of the Indo-Asian.

Conclusion: A significant number of female patients below age 45 had POTS (7.5%), majority of whom were of Indo-Asian origin. The high prevalence of POTS in the females of Indo-Asian origin is probably due to the high Indo-Asian population in the district covered by our centre. Although migraine without aura is the most common headache associated with POTS, hemiplegic migraine with aura was common in our Indo-Asian group.

Consultant cardiologist at London Northwest University Healthcare NHS Trust and Clinical senior lecturer at the Imperial college London. He edited/wrote 4 textbooks in cardiology and published significant original articles and reviews in cardiology. He previously held the position of the Chief examiner of the Royal college of Physicians till October 2023. He is a chair of International MRCP examiners. He innovated few techniques in cardiology and studying cardiac ultrasound during exercise both physical and isometric. His main interest is hypertension, relationship between abnormal glucose tolerance and hypertension and heart diseases in women. He won medals and prizes in his academic and medical professions.