Syncope
Life-threatening
- Cardiac:
- Structural - AS, hypertrophy, PHTN, cardiomyopathy
- Arrhythmia
- AV block
- long QT syndrome
- catecholamine VT (sudden fright) aka Catecholaminergic polymorphic ventricular tachycardia
- Brugada syndrome: pseudo-right bundle branch block and persistent ST segment elevation in leads V1 to V3
- Preexcitation syndrome
- WPW (delta wave)
- Congenital short QT syndrome (≤0.30 sec)
- Heat illness
- Anaphylaxis
- Toxin
Common
- Vasovagal (neurocardiogenic, reflex, or situational syncope, fainting)
- reduced vaso (SVR) and vagal (HR) tone leading to drop in BP
- prodrome: lightheadedness, dizziness, visual changes (decrease acuity, tunnel vision, or double vision), nausea, pallor, and diaphoresis
- triggers: standing, stress (physical or emotional), reflex precipitants (swallowing, hair grooming, and micturition)
- Breathholding
- Orthostatic hypotension