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Dan Sorajja, MD, FACC, FHRSAssociate Professor of MedicineProgram Director Clinical Cardiac ElectrophysiologyAssociate Program Director Cardiovascular DiseasesMayo Clinic Arizona
Clues for Syncope Etiology From HistoryWhat Is The Trigger?Syncope Occurs . . . Think:With noxious stimulus (needle sticks, nausea) VasovagalWhile exercising Cardiac etiologyIn any position Cardiac etiologyAfter exercise Situational syncopeWhile coughing, swallowing, laughing, urinating, defecating Situational syncopeOften during morning Orthostatic hypotensionGoing from sitting to standing Orthostatic hypotensionAfter eating Post-prandial hypotensionVomiting, diarrhea, hemorrhage, poor PO intake DehydrationWhile shaving or turning head (in elderly) Carotid sinus hypersensitivityVertigo ENT problem
Clues for Syncope Etiology From HistoryWarning Symptoms
• Nausea, flushing, or sweats? • Think vasovagal• And frequently prodrome is long enough to get into safe position
• Abrupt symptoms/syncope (minimal if any prodrome) • Think arrhythmia / cardiac
• Of note, seizure usually lacks a prodrome• Unable to protect head Think arrhythmia or seizure• Did the person ease him/herself down Usually not arrhythmia
• Family with any inheritable conditions (1st degree relative with SCD < 50 years old)• Long QT syndrome• Brugada syncope• Premature sudden cardiac death
• Want to know blood pressure at various times of day
• Low BP at baseline• Screen for orthostatic hypotension (old and frail people)• Screen for polypharmacy• Check hydration (how much water/fluid intake and urine color)
• To take orthostatic vital signs• Patient lays down for 2 minutes before supine BP and HR check• Have the patient stand up with the cuff on, but not inflated• Then measure the BP and HR
• At 1 minute At 3 minutes At 5 minutes • Document any symptoms
• If a patient cannot stand for any measurement, take the BP while sitting, but not supine position if possible
Other Testing To ConsiderAmbulatory MonitoringWe expect longer monitoring to be more sensitive in detecting arrhythmias, conduction abnormalities, and their correlation to arrhythmias1
• Record now and analyze later• SmartWatch (< 1 minute)• Continuous ECG (Holter) monitor (1-2 days)• Event (loop) monitor (1 week to 30 days)• Patch monitor (3-30 days)• Implantable Loop Recorder (2 – 4 years)
• Record now and analyze now (real-time continuous monitoring transmitted to a station)• AliveCor (real-time only if patient still in arrhythmia)• Lead-based monitor (7-14 days)• Patch-based monitor (3-30 days)
• 25 year old woman hammers her finger while hanging a picture. With her finger bleeding profusely, she quickly develops nausea and sweats. She loses consciousness for 2 minutes during which she has some shaking of her arms, per her boyfriend. She spontaneously awakes without confusion, and just notes flushing and weakness. She has had similar episodes previously.
• Precipitating event (noxious stimuli):• Site of blood / needle stick• Severe pain / unpleasant sight / sound / smell• Emotional distress / happiness• Prolonged standing in hot, crowded place• After significant, prolonged exertion• After a big meal
• Prodrome usually lasts long enough to get to a safe position
• Evaluation:• If certain diagnosis and rare episodes
No further evaluation needed• If suspected diagnosis or syncope during high-risk setting
• Driving / flying• Heavy machinery operation• Athletics
• Testing:ECG: look for bradyarrhythmia, conduction block, ventricular arrhythmias, long QT, etcEchocardiogram: look for structural heart disease especially if abnormal exam or ECG
Exercise ECHO for athletes or if syncope around exerciseTilt testing with CSM / Valsalva
• 62 year old woman with cardiac amyloidosis presents with frequent syncope. Usually, her episodes occur with position change (e.g. sitting to standing), and worse in the morning or with hot showers.
Orthostatic HypotensionDefinition and Types• Symptomatic postural decrease in BP
• SBP ≥ 20 mmHg or DBP ≥ 10 mmHg (usually within 3 minutes)• Diagnosis made whether symptomatic or asymptomatic
• Closely related to changes in position• Lying Sitting• Sitting Standing
• Time Frame of Symptom onset• Within 15 seconds of standing Initial OH (recovery in < 1 minute)• Within 3 minutes of standing Classic OH• After 3 minutes of standing Delayed OH
• The definition is a hemodynamic one, and does not depend on symptoms
• 70 year old man, who is touring Sedona, has abrupt syncope. He had maybe 1 second of warning symptoms (“curtains being lowered”) then was unconscious for 10 seconds before recovery. He had no other symptoms. There are no new medications. ECG shows new LBBB.
• SVT• Uncommon cause of syncope as its only symptom (usually HR > 115% of MPHR)
• Bradycardia (suspect if no warning symptoms)• If AV block, typically requires 2nd or 3rd degree AV block to cause syncope• Sinus bradycardia is unlikely especially if asymptomatic on monitoring
• Bundle branch block• If BBB, 50% have asystole and 50% have VT
• Echo: looking for depressed LVEF, ischemic cardiomyopathy, HCM• Do a stress ECHO if there is exertion-related syncope or suspect a relation to catecholamine
Other Testing To ConsiderAmbulatory MonitoringLonger monitoring is more sensitive in detecting arrhythmias and conduction abnormalities, and then correlating findings to arrhythmias1
• Record now and analyze now (real-time continuous monitoring transmitted to a station)• AliveCor (real-time only if patient still in arrhythmia)• Lead-based monitor (7-14 days)• Patch-based monitor (3-30 days)
• As a society, we accept a certain level of risk by letting higher risk drivers
• Young drivers: their risk is 0.007 or 0.7% per year• 2650 teenagers (aged 16-19) in the USA were killed by motor vehicle crashes1
• 292,000 teenagers injured in motor vehicle crashes1
• Elderly drivers: their risk is 0.005 or 0.5% per year• 5560 older adults (aged > 65 years) in the USA were killed by motor vehicle crashes• 214,000 older adults injured in motor vehicle crashes2
• The risk of young drivers causing an accident is about 142 times higher than what society accepts as the risk of the average driver losing consciousness and causing an accident