Syncope____________________________Hugh Hemsley MD FACEPDepartment of Emergency MedicineRiverside Regional Medical CenterVirginia, USAFebruary 2011

Goals of lecture____________________________• Definition of syncope• Pathophysiology• Causes• Patient evaluation• Patient disposition

Syncope: definition____________________________ A brief loss of consciousness with the

inability to maintain postural tone followed by a spontaneous and complete recovery without medical intervention

Epidemiology_________________________1-2% of all Emergency Department visits6% of hospital admissionsAffects all age groupsIncreasing incidence with ageIncreasing morbidity and mortality with age

Pathophysiology_________________________Brain needs a constant supply of oxygen and

nutrientsSymptoms start after 5-10 seconds of cerebral

perfusion disruptionSyncope is caused by the lack of adequate blood

flow to the brainSudden decrease in cerebral perfusion: no

symptoms prior to the syncopal eventGradual decrease in cerebral perfusion:

symptoms will develop prior to the syncopal eventWeak, lightheaded, dizzy, blurred vision, warmth, diaphoresis

Pathophysiology___________________________Rapid restoration of consciousness after

cerebral perfusion has been restoredDysrhymia has resolvedPatient becomes supineBlood supply to the brainstem is restored

following a TIA

Same pathophysiology as syncopeCerebral perfusion is restored and symptoms

resolve before the loss of consciousnessSame risks and Emergency Department

evaluation as syncope

Near-Syncope____________________________

Causes of Syncope____________________________Ventricular tachycardiaVentricular fibrillation Supraventricular tachycardiaAsystoleHeart blockSinus bradycardiaSick sinus syndromeCarotid sinus sensitivityProlonged QT SyndromeValvular heart diseasePulmonary hypertensionPulmonary embolismHypertrophic cardiomyopathyRestrictive cardiomyopathyCardiac myxomaPacemaker or Prosthetic valve malfunctionMyocardial infarction Aortic dissectionAortic StenosisCongenital heart diseasePericardial tamponade

HypovolemiaHemorrhageDehydrationVasovagalVasomotor insufficiencyOrthostatic hypotensionCoughUrinationDefecationSwallowNeuralgiaSubclavian stealMedicationsTransient ischemic attackMigraine headacheSubarachnoid hemorrhagePsychiatricBreath holding (pediatrics)HypoglycemiaValsalva maneuver

Causes of syncope___________________________CardiacVasovagal or Neurally-mediated or Reflex-

mediatedOrthostatic hypotensionCerebrovascularPsychiatricMedications

Cardiac syncope____________________________Cardiac syncope has the highest morbidity and

mortalityCan be the initial presentation of undiagnosed

cardiovascular disease

Near-syncope Syncope Sudden death

Identify those patients at a risk for another syncopal event

Cardiac syncope___________________________Inability to maintain an adequate cardiac output

Cardiac output = stroke volume + heart rateStructural heart disease

Mechanical impairment to venous return and cardiac outflow

Usually related to physical exertion and the inability to increase cardiac output

Dysrhythmias Can affect stroke volume, heart rate or both

Structural heart disease____________________________Valvular heart disease

Aortic Stenosis-most common obstructive cardiac lesion in the elderly exertional chest pain, dyspnea, syncope

Mitral, pulmonic, tricuspid stenosisProsthetic valve malfunction or thrombus

CardiomyopathyHypertrophic cardiomyopathy

Assymetric hypertrophy of the right or left ventricle Number one cause of death in competitive athletes Second most common cause of sudden death in

adolescents.

Causes of Syncope_________________________Pulmonary embolismPulmonary hypertensionPericardial tamponade

TraumaticMedical

Congenital heart diseaseMyxomaMyocardial ischemia/infarctionAortic dissection

Can present with transient pain

Dysrhythmias___________________________Tachydysrhythmias

V. Tachycardia, V. Fibrillation, Supraventricular Tachycardia

Bradydysrhythmias Asystole, Sinus bradycardia, heart block, sick sinus syndrome

Conduction system diseasePre-excitation syndromes

Wolf-Parkinson-White syndromeLong-QT syndromeBrugada syndromeObtain a family history of sudden death

Pacemaker malfunction

Wolf-Parkinson-White

Brugada Syndrome

Dysrhythmias____________________________Can present with sudden loss of

consciousness or preceding symptoms < 5 seconds

Consider when a patient has syncope at restSyncope depends upon:

Degree of underlying heart diseaseAbility of the nervous system to compensate for

the decrease in cardiac output

Ventricular tachycardia

Vasovagal syncope____________________________Also referred to as reflex-mediated or neurally-

mediated syncopeMost common cause of syncopeGood prognosisInappropriate vagal tone causing bradycardia

and vasodilationSlow progression of symptoms

Nausea, diaphoresis, weak, dizzy, lightheaded, blurred vision, warmth

Less common in the elderly population due to an impaired autonomic nervous systemConsider life-threatening etiologies first

Vasovagal syncope___________________________Etiologies-fainting

Prolonged standingFear, fatigue, emotional distress, pain,

unpleasant sight, smell, or soundCoughUrinationDefecationSwallowing

Vasovagal syncope____________________________Carotid sinus sensitivity

Carotid Body-stretch sensitive structures located at the carotid bifurcation

Stimulation causes bradycardia and hypotension

More common in males, elderly, history of heart disease

Can be stimulated by shaving, turning the head, or tight fitting collar.

Carotid Body

Orthostatic hypotension___________________________Venous pooling occurs in the lower

extremities when a person standsNormal compensatory response-increase in heart rate

and peripheral vascular resistance causing an increase in cardiac output and blood pressure.

If the normal autonomic response is inhibited then blood pressure continues to drop, cerebral perfusion decreases and syncope occurs if the patient remains upright.

Symptoms usually occur with 3 minutes of standing.

Orthostatic hypotension____________________________Causes of impaired autonomic response

Volume loss Dehydration Bleeding-ectopic pregnancy, leaking aneurysm Medications- diuretics

Heart disease and poor vascular tone Elderly Medications

Medications___________________________AntihypertensivesAntidysrhythmicsAntipsychoticAntiparkinsonism drugsAntidepressantsNitratesAlcohol

Cerebrovascular____________________________Uncommon cause of syncope

Persistent neurologic symptoms following loss of consciousness: stroke-not syncope

Transient ischemic attack (TIA) Vertebrobasilar circulation disease causing transient

brainstem ischemia Subclavian Steal Syndrome-exercise of the arm shunts

blood away from the vertebrobasilar system to the subclavian artery causing transient ischemia

Migraine headacheSubarachnoid hemorrhage

Bleeding causes increased intracranial pressure, decreased cerebral perfusion pressure and syncope

Subclavian steal syndrome

Syncope versus Seizure______________________________

Psychiatric _____________________________Common with anxiety and depressionYounger populationMultiple preceding symptoms

Crying, shouting, increased motor activityEtiology-hyperventilationMake the diagnosis of psychiatric syncope

only after all other causes have been ruled out

Pediatric syncope____________________________Usually orthostatic hypotension, vasovagal,

or breath holdingRarely cardiac

Congenital heart diseasedysrhythmia

Breath holding syncope____________________________Unusual after age 6 yearsMajority occur between 6 and 18 monthsCrying starts following an emotional trigger

Pain, fear, angerBreath holding occurs during end expiration

causing the patient to become pale or cyanoticDecreased cerebral perfusion causes loss of

consciousnessSyncopal episode is briefSeizure-like activity may occurSpontaneous resolution, no intervention needed

Evaluation of syncope_____________________________Goal of ED evaluation is to identify those patients

with immediate life-threatening conditions and those with a future risk of serious morbidity or sudden death

Thorough history and physician exam will determine the cause of syncope in the majority of patients in whom an etiology can be determined

HistoryHistory

Events and symptoms prior to, during, and after the syncopal event Chest pain, abdominal or back pain, shortness of

breath, palpitations, headache, focal neurologic deficit suggest a serious etiology

Single car motor vehicle accident, driver passed out and wrecked the car

Historical information could be limited due to patient amnesia, no eyewitnesses, or conflicting eyewitness reports

Syncope versus seizure

Evaluation of syncope___________________________Past medical history

History of cardiovascular or neurologic disease-CHF

Risk factors for atherosclerotic vascular disease

Previous syncopal event, is the etiology known?Medications-include non-prescription drugsFamily history of sudden death or “fainting”

Evaluation of syncope____________________________Physical exam

Vitals signs-resting pulse and blood pressureBlood pressures in both armsOrthostatic vital signs

Supine 5 minutes, measure the pulse and blood pressure 1 and 3 minutes after standing

A decrease in blood pressure of 20mm Hg with symptoms or a decrease in systolic pressure less than 90mm Hg is considered positive. Interpret results with caution in high risk patients. Up

to 40% of patients older than 70 and 23% of patients younger than 60 will have a positive orthostatic test, a 20mm Hg decreased in pressure, look also for symptoms

Evaluation of syncope___________________________Physical exam

Cardiac-murmurs or bruitsNeurologic exam- new deficitsTrauma without defensive injuries to the hands or

legsRectal exam-check for gastrointestinal bleeding

Laboratory testing, CT scans, MRILow yieldTesting should be directed by findings obtained

during the history and physical exam.Pregnancy test in reproductive females

Evaluation of syncope____________________________EKG and cardiac monitoring

Low yield <5%Still obtain as part of the routine workup

because life-threatening disorders can be diagnosed Acute ischemia Evidence of prior cardiovascular disease New EKG changes Rhythm or conduction abnormalities Brugada Syndrome

Disposition____________________________Cause of syncope has been determined

Cardiac or cerebrovascular syncope should be admitted for further testing and treatment.

Vasovagal, orthostatic, and psychiatric syncope can be discharged if causative condition has been treated in the ED. This group of patients are not at an increased risk of cardiovascular morbidity or mortality

Disposition___________________________Cause of syncope cannot be determined

A cause for the syncopal event can not be determined in up to 4o% of patient following a thorough evaluation.

Risk stratification. Identify those patients at risk for another event and

admit for monitoring and further evaluation

Risk stratification___________________________Martin et al. Annals of EM 1997

Risk factors for dysrhythmia or death at one year Abnormal EKG History of dysrhythmia Age greater than 45 History of CHF No risk factors 4.4%-7.7% occurrence 3 or 4 risk factors 57%-80% occurrence

Risk stratification____________________________Sarasin, et. al. Annals of EM 2003

Risk factors for dysrhythmic syncope at one year in a group of patients experiencing syncope of unknown etiology Abnormal EKG History of CHF Age greater than 65 O% no risk factors 6% one risk factor 41% two risk factors 60% three risk factors

Risk stratification______________________________Colivicchi et. al. European Heart Journal 2003

OESIL score to predict one year mortality Age greater than 65 History of cardiovascular disease Syncope without preceding symptoms Abnormal EKG Score O- O% 12 month mortality Score 1- .8% 12 month mortality Score 2- 19% 12 month mortality Score 3- 35% 12 month mortality Score 4- 57% 12 month mortality

Risk stratification___________________________Quinn et al, Annals of Emergency Medicine,

2004San Francisco Syncope Rule-predicting

another cardiac event in 7 days History of CHF Hematocrit < 30 Abnormal EKG Shortness of breath Triage systolic BP < 90

Risk stratification____________________________Risk factors associated with increased

mortalityHistory of CADHistory of CHFElderlyAbnormal cardiovascular examSudden onsetOccurs during exertionAbnormal EKG

Thank you

Questions?