Accurate diagnosis of myalgic encephalomyelitis and chronic fatigue syndrome based upon objective test methods for characteristic symptoms

Table 6 Manifestations of orthostatic cardiovascular abnormalities

Abnormality	Definition
Orthostatic systolic hypotension	A fall in the systolic blood pressure of 20 mmHg or more[74,193]
Orthostatic diastolic hypotension	A fall in the diastolic blood pressure of 10 mmHg or more[74,193]
Orthostatic diastolic hypertension	A rise in dBP to 98 mmHg or more[74]
Orthostatic postural tachycardia	An increase in heart rate of 28[74]/30[194] beats per minute (bpm) or a pulse of more than 110[74]/120[194] bpm
Orthostatic narrowing of pulse pressure	A fall in the pulse pressure to 18 mmHg or less[74]