A Practical Approach to Syncope

Causes of true syncope• Neuro-cardiogenic (Reflex) syncope– Vasovagal– Situational– Carotid sinus– Atypical form• Orthostatic (hypotensive)– Iry autonomic failure– IIry autonomic failure– Drug induced– Volume depletionDue to impaired sympathetic efferent activityDue to inappropiate function of reflexes thatand/or reduced venous returnmaintain BP in the upright posture leading to• Iry Cardiac ANF – multiple system atrophy, purehypotension (vasodeppressor) or bradycardiaautonomic • Bradyarrhythmias failure, Lewy – SSS body or CHB dementia, ass.(cardioinhibitory)with •Tachy Parkinsons arrythmias – VT, SVT with LVVasovagal – prolonged standing/sitting,• IIry dysfunction, ANF – DM, AVNRT, amyloidosis, WPW ureamiaemotion, pain, blood.• Drug • Structural induced abnormalities – vasodilators, – AS, diuretics, MS, HOCM,Situational – cough, micturition, GI– Postural orthostatic tachycardia syndrome phenothiazines, Ischaemic/Dilated (POTS) antidepressantsCardiomyopathiesstimulation, laughing• Volume depletion – diorrhoea, vomitingCarotid sinus – hypersensitivity• POTS - ?inadequate venous return, excessiveAtypical – uncertain, absent triggersblood pooling• Cardiac– Brady-arrhythmias– Tachy-arrhythmias– Structural abnormalitiesNeurocardiogenicOrthostaticsyncope