Scenario: A 48-year-old male has come to the emergency department with complaints of his heart “skipping beats.” He has no significant medical history and is currently taking no medications. Below is a lead II rhythm strip from his bedside monitor.
The sinus rhythm is 60/min with a premature junctional beat with retrograde atrial capture and a premature ventricular beat.
The third beat of this rhythm strip is premature and proceeded by an inverted P wave. The narrow QRS and atrial retrograde conduction (inverted P wave) met the criteria for a junctional focus. After a compensatory pause, sinus returns for 2 beats but is interrupted by another premature beat. The wide and bizarre QRS morphology meets the criteria for a ventricular focus, again followed by a compensatory pause.
The presence of premature beats is not uncommon in healthy individuals and is usually not a...