AVNRT With Intermittent Aberrancy-Mimicking Ventricular Tachycardia: One Tachycardia, Two QRS Morphologies
Division
West Florida
Hospital
Largo Medical Center
Document Type
Case Report
Publication Date
7-29-2026
Keywords
electrophysiology, supraventricular arrhythmias, ventricular tachycardia
Disciplines
Cardiovascular Diseases | Internal Medicine | Medicine and Health Sciences
Abstract
BACKGROUND: Regular wide-complex tachycardia often prompts concern for ventricular tachycardia, yet supraventricular tachycardia with aberrancy is a frequent mimic.
CASE SUMMARY: A 36-year-old male presented with palpitations, dizziness, and presyncope after ambulatory monitoring documented tachycardia >200 beats/min. Telemetry showed recurrent regular tachycardia with alternating narrow and wide QRS morphologies at a similar cycle length. Vagal maneuvers, adenosine, and diltiazem transiently slowed/terminated the rhythm, but it recurred, necessitating cardioversion. Electrophysiology study induced typical atrioventricular nodal re-entrant tachycardia with rate-dependent aberrancy; slow-pathway ablation rendered the tachycardia noninducible.
DISCUSSION: Unchanged cycle length during narrow-to-wide transitions supports a single supraventricular tachycardia mechanism with a functional bundle branch block.
TAKE-HOME MESSAGE: When QRS morphology alternates without cycle-length change, suspect supraventricular tachycardia with aberrancy and confirm with electrophysiology testing.
Publisher or Conference
JACC Case Reports
Recommended Citation
Madishetty V, Sojitra B, Sachs V, Xiang K. AVNRT With Intermittent Aberrancy-Mimicking Ventricular Tachycardia: One Tachycardia, Two QRS Morphologies. JACC Case Rep. 2026;31(30):108792. doi:10.1016/j.jaccas.2026.108792