Key Points: Pre-excitation means an accessory pathway allows atrial impulses to reach the ventricle without traversing the AV node, producing early ventricular activation. A delta wave is the defining ECG…
Key Points: Definition: A delta wave is a slurred upstroke at the very start of the QRS. It reflects early ventricular activation through an accessory pathway that bypasses the AV…
Key Points: Pattern vs syndrome: WPW pattern is ECG evidence of pre-excitation without symptoms. WPW syndrome is pattern plus symptomatic tachyarrhythmia (palpitations, syncope, “seizure”, aborted sudden cardiac arrest). PR interval…
Key Points: Rare, high-risk rhythm. 1:1 flutter can drive ventricular rates into the 240–320 bpm range and can rapidly cause hypotension, ischemia, or collapse. It often mimics VT. Ask “how…
Key Points: WPW alters ventricular depolarization, producing secondary repolarization abnormalities that can mimic or mask myocardial infarction. ST-segment deviation in WPW is often non-ischemic, driven by abnormal activation via the…
Key Points: Pre-excited AF is the most dangerous WPW rhythm. It can deteriorate quickly to VF because the accessory pathway may conduct atrial impulses to the ventricle at extreme rates….
Key Points: Antidromic AVRT is an AV re-entrant tachycardia that conducts antegrade down the accessory pathway and returns retrograde through the AV node (or another pathway), producing a regular wide-complex…
Key Points: Orthodromic AVRT is the most common tachyarrhythmia in WPW and presents as a regular narrow-complex SVT that is indistinguishable from AVNRT during the tachycardia. Mechanism: antegrade conduction down…
Key Points: AVRT is a re-entrant SVT that requires two limbs: the AV node and an accessory pathway. It is an AV node dependent tachycardia. Orthodromic AVRT conducts antegrade down…
A 29-year-old woman presents to the emergency department with an episode of palpitations and near syncope. She reports several similar episodes in the past that were brief in duration and…