SYNCOPE

Question 1

DDx

Answer 1

REFLEX (VAGAL) MEDIATED:
Vasovagal (21%)
Situational:
-cough
-micturition
-defecation
-swallow
-neuralgia
Carotid Sinus Syndrome

ORTHOSTATIC:
Drug Induced
Volume Depletion
Neurogenic

CARDIAC (10%):
Mechanical (AS, tamponade, PE, HOCM)
Dissection
Dysrhythmias

MEDICATION:
-CCBs
-BBs
-Digoxin
-Insulin
-QT Prolonging Drugs
-Drugs of Abuse

Question 2

APPROACH

Answer 2

1. DISTINGUISH SYNCOPE FROM SEIZURE BASED ON HISTORY & PHYSICAL

Ask about:
Events preceding the loss of consciousness
Duration of the Syncope
Events After the Syncope

Recent Illnesses / vomiting / diarrhea
Alcohol Ingestion
Dieting / weight loss

Indentify Seizure:
Patient has no recall of unusual behaviors before the loss
of consciousness (Sn53%; Sp 87%; LR 4.0)
Head Turning During the Event (Sn 43%, Sp 97%; LR 13)
Unusual Posturing During Event (Sn 35%, Sp 97%, LR 13)
Absence of Presyncope (Sn 77%, Sp 86%, LR 5.6)
Number of limb jerks – The 10:20 Rule: witnessed > 20 myoclonic jerks after sudden loss of
consciousness is more likely seizure
Post ictal state (96% of pts with seizure)
Urinary Incontinence (Sn 24%, Sp 96%, LR 6.7)

The presence of a cut tongue (SN 45%; Sp
97%; LR 17)
Lateral tongue bite (100% Sp for tonic clonic seizure)

History of Epilepsy

Identify Syncope:
Loss of consciousness with prolonged sitting or standing (Sn 40%; Sp 98%; LR 20)
Dyspnea before loss of consciousness (Sn 24%; Sp 98%; LR 13)
Palpitations before LOC (Sn 34%; Sp 96%; LR 8.3)
Muscle tone (increased tone more likely seizure, decreased tone more likely syncope)
Number of limb jerks – The 10:20 Rule: patients with witnessed <10 myoclonic jerks after sudden loss of
consciousness is more like syncope

2. DISTINGUISH CARDIAC SYNCOPE FROM NON-CARDIAC SYNCOPE

a. CARDIAC SYNCOPE CLINICAL CLUES

Sudden syncope with no prodrome
Exertional syncope
Prodrome that includes palpitations, shortness of breath or chest pain
Associated facial injury (including dental injury, eye glasses damage, tip of tongue bite)
Aortic stenosis murmur – high mortality rate in patients
with critical aortic stenosis and syncope

Structural heart disease (especially HCM, aortic stenosis)
Pacemaker
Family history of unexplained sudden death, drowning or
single MVC <50 years of age

b. REFLEX SYNCOPE CLINICAL CUES

prodrome of feeling warm/nausea
history of recurrent syncope after an unpleasant sight, sound, smell or
pain
prolonged standing
during a meal
being in crowded/hot places
autonomic activation (carotid sinus massage/shaving
pressure on the eye/ocular-bradycardic reflex
micturition
defecation

c. ORTHOSTATIC SYNCOPE CLINICAL CUES

prodrome of lightheadedness after changing from lying/sitting to sitting/standing position
post-prandial hypotension
temporal relationship with start or change of dosage of vasoactive drugs/diuretics autonomic neuropathy (diabetes, Parkinsonism)
volume losses

3. ECG INTERPRETATION

ECG: check PR, QRS, QT

1.Brady- or tachydysrhythmias:
including heart blocks
ventricular tachycardia etc

2.Hypertrophic Cardiomyopathy (HCM):
a) Voltage criteria for LVH in precordial and limb leads
b) Narrow, “dagger-like” Q waves in inferior and lateral leads

3. Wolf-Parkinson-White (WPW):
   short PR, delta wave (upsloping
   QRS)
4. Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC):
   Twave inversion in V1,V2, V3 (unlike Wellen’s that is V1-V4)
   epsilon wave (looks like a reverse delta wave, with slurring of the downstroke of the QRS from the nadir of the S wave to the isoelectric line +/- a notch)

5.Brugada:
down-sloping ST elevation in V1/2

6. Long QT
7. Bifascicular block (especially in the presence of a first-degree
   block) in a patient with syncope are at high risk of degenerating
   into 3rd-degree block and often require a pacemaker
8. INVESTIGATIONS

Draw based on clinical suspicion

Suspect a bleed (CBC +/- coags)
Suspect a PE (Dimer/CTPA)
Suspect/possible pregnancy (B-HCG)
Suspect an electrolyte abnormality based on medication
change/ECG (lytes, extended lytes)
Suspect ACS (i.e., chest pain or equivalent – troponin)

Question 3

DDX: ECG 2 basic things and 6 exotic things

Answer 3

Basic Things:
Arrythmia
Ischemia

Exotic Things:
Arrythmogenic Right Ventricular Dysplasia (epsilon waves, flipped t waves V1-V3)

Brugada (RBBB, STE, V1-V3)

Left Ventricular Hypertrophy (marked high voltage)

Pulmonary Embolism (Right axis shift, S1Q3T3, RBBB, Deep flipped t waves V1-V3)

QT too long / too short (Qt > 1/2 RR)

Wolf-Parkinson White