Cardiac | Atrioventricular block Pulmonary hypertension Constrictive pericarditis Carotid sinus syndrome Postural hypotension Aortic stenosis Structural heart disease [16] |
Neurological | Epilepsy Intracranial tumours [17] Subclavian steel syndrome [18] Autonomic dysfunction |
Others | Drug induced (vasodilators, diuretics) Diabetes (resulting in autonomic dysfunction) |
Information from [15].