Comment
This case highlights an unusual cause for persistent post-operative sinus tachycardia in a young patient, with only 2.8% of POTS cases being attributed to surgery [2]. The diagnosis of POTS is based on three factors. Firstly, a clinical syndrome characterised by symptoms of light-headedness, blurry vision, palpitations, exercise intolerance and fatigue. Secondly, an increase of more than 30bpm (≥ 40bpm in 12-19 years) when the person stands up from recumbent position. Thirdly, absence of orthostatic hypotension [3, 4, 5]. The onset of POTS may be precipitated by typical immunological stressors such as surgery, viral infection, vaccination, trauma, pregnancy or psychological stress [1].
Non-pharmacological treatment remains first-line and involves increasing aerobic exercise, lower extremity strengthening, increasing salt and fluid intake, psychological training for anxiety or pain management and education. Pharmacological therapy is considered on an individual basis and consists of beta-blockers to blunt orthostatic increases in heart rate, alpha-adrenergic agents to increase peripheral vascular resistance, mineralocorticoids to increase blood volume and serotonin reuptake inhibitors to improve serotonin regulation [4].
There has only been one other case report in the literature reporting on the development of POTS following thoracic surgery, involving a repair of an aortic coarctation [6]. Similarly, they identified potential risk factors including surgery, prolonged bed rest, and use of antihypertensives that are known to worsen orthostatic intolerance (amlodipine and valsartan). Additional risk factors in our case include reduced oral intake, anaemia, autonomic insufficiency and poor sleep [1]. Correct assessment of post-operative tachycardia including postural telemetry is the key to identifying this condition and its successful management.