Syncope resident survival guide
|Syncope Resident Survival Guide Microchapters|
Syncope is the transient loss of consciousness (LOC) due to cerebral hypoperfusion and it is characterized by a rapid onset, a short duration and a spontaneous complete recovery. It is important to identify the cause of syncope and recognize high risk patients with structural heart disease or abnormal ECG findings. The initial management of syncope depends on the etiology of the syncope which can be either reflex, orthostatic hypotension or cardiovascular.
Life Threatening Causes
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.
- Aortic stenosis
- Medications (vasodilators, diuretics, antiarrhythmics, antipsychotics)
- Orthostatic hypotension
- Vagal stimulation
- Vertebrobasilar insufficiency
Click here for the complete list of causes.
- Primary autonomic failure (pure autonomic failure, Parkinson's disease)
- Secondary autonomic failure (diabetes, uremia)
- Drug-induced (alcohol, vasodilators, diuretics)
- Hypovolemia (hemorrhage, diarrhea)
- Situational syncope (cough, sneeze, postprandial, post-exercise)
- Carotid sinus hypersensitivity
FIRE: Focused Initial Rapid Evaluation
A Focused Initial Rapid Evaluation (FIRE) should be performed to identify patients in need of immediate intervention.
Boxes in the red signify that an urgent management is needed.
Abbreviations: CT: Computed tomography; DVT: Deep vein thrombosis; ECG: electrocardiogram; STEMI: ST elevation myocardial infarction
Identify cardinal findings that increase the pretest probability of syncope
❑ Immediately order an ECG
Complete Diagnostic Approach
Abbreviations: AF: atrial fibrillation; ARVC: arrhythmogenic right ventricular cardiomyopathy; BBB: bundle branch block; CAD: coronary artery disease; EEG: electroencephalography; HF: heart failure; MI: myocardial infarction; SCD: sudden cardiac death; SVT: supraventricular tachycardia; TIA: transient ischemic attack; VT: ventricular tachycardia
Characterize the symptoms:
❑ Loss of consciousness (LOC)
Obtain a detailed past medical history:
❑ Previous syncope episodes
❑ Cardiovascular disease
❑ Neurological diseasestrauma
Identify possible triggers:
Suggestive of reflex syncope
Examine the patient:
Order labs and tests:
❑ EKG (most important initial test)
|Confirm diagnosis of syncope |
Must have this 3 characteristics:
❑ Short duration, AND
❑ Rapid onset, AND
❑ Complete spontaneous recovery
|Known etiology||Unknown etiology|
Determine the etiology:
Determine if there are any high risk criteria:
❑ Severe structural heart disease
❑ Clinical or ECG features suggesting arrhythmic syncope
❑ Important comorbidities
Consider alternative diagnoses:
|High risk||Low risk|
❑ Immediate in-hospital monitoring (in bed or telemetry) to look for abnormalities suggestive of arrhythmic syncope (Class I; Level of Evidence: B)
|Recurrent episodes of syncope |
❑ Order a Holter if > 1 episode/week (Class I; Level of Evidence: B)
❑ Order external loop recorder (ELR) if interval between episodes < 4 weeks (Class IIa; Level of Evidence: B)
❑ Perform carotid sinus massage in patients > 40 years with uncertain syncopal etiology (Class I; Level of Evidence: B)
|Single episode of syncope|
|Is any of the following high risk setting present? |
❑ Potential risk of physical injury
❑ Occupational implications
|Presence of structural heart disease||Absence of structural heart disease|
|❑ Treat accordingly||Perform a tilt test (Class I; Level of Evidence: B)||No further investigation|
Shown below is an algorithm summarizing the therapeutic approach to syncope based on the 2009 ESC Guidelines for the Diagnosis and Management of Syncope and the 2006 AHA/ACCF Scientific Statement on the Evaluation of Syncope.
Abbreviations: AF: Atrial fibrillation; SVT: Supraventricular tachycardia; VT: Ventricular tachycardia; MI: Myocardial infarction; BBB: Bundle branch block.
|Determine the etiology|
|Cardiovascular syncope||Reflex Syncope||Orthostatic hypotension|
❑ Treat the arrhythmia according to the type
❑ Schedule for cardiac pacing surgery in patients with:
❑ Schedule for catheter ablation in patients with:
❑ Administer antiarrhythmic drug therapy in patients with:
❑ Schedule for implantable cardioverter defibrillator surgery in patients with:
❑ Provide adequate hydration and salt intake (Class I; Level of Evidence: C)
❑ Provide additional therapy if needed:
Contraindicated in severe heart disease, acute renal failure, pheochromocytoma, severe hypertension or thyrotoxicosis
❑ Position the patient in a head-up tilt sleeping position (>10°) to increase fluid volume (Class IIb; Level of Evidence: C)
❑ Explain the diagnosis and provide reassurance (Class I; Level of Evidence: C)
❑ Explain the risk of recurrence and educate regarding avoidance of triggers (Class I; Level of Evidence: C)
❑ Educate patients with prodrome about isometric physical counterpressure maneuvers (PCM) (Class I; Level of Evidence: B):
❑ Consider cardiac pacing in:
- Consider a tilt test:
- To differentiate between reflex syncope and orthostatic hypotension (Class IIa; Level of Evidence: C)
- If syncope is due to a psychiatric disease (Class IIb; Level of Evidence: C)
- To differenciate syncope with jerking movements from epilepsy (Class IIb; Level of Evidence: C)
- If syncope happened after standing up from a seated position due to possible orthostatic hypotension(Class IIb; Level of Evidence: C)
- Consider implantable loop recorder before cardiac pacing in patients with suspected or confirmed reflex syncope presenting with frequent or traumatic syncopal episodes.
- Perform exercise testing in patients who experience syncope during or after exertion (Class I; Level of Evidence: C).
- Don't perform carotid sinus massage in patients with previous TIA or stroke within the past 3 months and in patients with carotid sinus bruits unless carotid sinus doppler studies excluded significant stenosis (Class III; Level of Evidence: C).
- Don't perform tilt testing for the assessment of response to treatment. (Class III; Level of Evidence: B).
- Don't perform isoproterenol tilt test in patients with ischemic heart disease (Class III; Level of Evidence: C).
- Don't use adenosine stress test as a diagnostic test to select patients for cardiac pacing due to the lack of correlation with spontaneous syncope (Class III; Level of Evidence: B).
- Don't perform electrophysiologic study if there is already indication for implantable cardioverter defibrillator in patients with ischemic heart disease with suspected arrhythmic cause.
- Don't perform electrophysiologic study in patients with normal ECG, no heart disease and no palpitations unless non-syncopal LOC is suspected (Class III; Level of Evidence: B).
- Don't give beta blockers for patients with reflex syncope (Class III; Level of Evidence: A).
- Khoo, C.; Chakrabarti, S.; Arbour, L.; Krahn, AD. (2013). "Recognizing life-threatening causes of syncope". Cardiol Clin. 31 (1): 51–66. doi:10.1016/j.ccl.2012.10.005. PMID 23217687. Unknown parameter
- Kapoor, WN. (2000). "Syncope". N Engl J Med. 343 (25): 1856–62. doi:10.1056/NEJM200012213432507. PMID 11117979. Unknown parameter
- Task Force for the Diagnosis and Management of Syncope. European Society of Cardiology (ESC). European Heart Rhythm Association (EHRA). Heart Failure Association (HFA). Heart Rhythm Society (HRS). Moya A; et al. (2009). "Guidelines for the diagnosis and management of syncope (version 2009)". Eur Heart J. 30 (21): 2631–71. doi:10.1093/eurheartj/ehp298. PMC 3295536. PMID 19713422 Check
- Strickberger, S. A. (2006). "AHA/ACCF Scientific Statement on the Evaluation of Syncope: From the American Heart Association Councils on Clinical Cardiology, Cardiovascular Nursing, Cardiovascular Disease in the Young, and Stroke, and the Quality of Care and Outcomes Research Interdisciplinary Working Group; and the American College of Cardiology Foundation: In Collaboration With the Heart Rhythm Society: Endorsed by the American Autonomic Society". Circulation. 113 (2): 316–327. doi:10.1161/CIRCULATIONAHA.105.170274. ISSN 0009-7322.