emergency lectures - syncope
TRANSCRIPT
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?