Table 1.

Screening criteria for PoTS and OH used in analysis.

Haemodynamic Postural Tachycardia Syndrome (PoTS) Criteria
Definition	A increase in heart rate of more than 30 BPM from lying to standing sustained across 2 consecutive readings at least 1 minute apart
Exceptions	An increase of 40 BPM was required in patients up to 18 years of age
Invalid cases	Orthostatic Hypotension
Haemodynamic Orthostatic Hypotension (OH) Criteria
Systolic definition	Decrease in blood pressure of 20 mmHg from lying to standing in the first 3 min
Diastolic definition	Decrease in blood pressure of 10 mmHg from lying to standing in the first 3 min
Delayed OH definition	Systolic or diastolic OH after the first 3 min of standing
Additional Analysis
An increase in heart rate of more than 25 BPM (T25) and 20 BPM (T20) from lying to standing in 2 consecutive readings