HRS Board Review 2025 New Courses (Reviewers Copy)-Workshop 1_Tomaselli_2025

Video Transcription

Video Summary

The video discusses digitalis-induced delayed after depolarizations in a patient with dilated cardiomyopathy who experienced ICD shocks for tachycardia. Her ECG showed PACs and nonspecific STT wave changes, and a rhythm strip revealed bidirectional ventricular tachycardia, a digitalis-associated arrhythmia. Digitalis inhibits sodium-potassium ATPase, altering sodium-calcium exchange and potentially leading to calcium overload and triggered arrhythmias. Though digitalis has a therapeutic parasympathomimetic effect, high concentrations can cause intracellular calcium overload and sympathetic activation, resulting in delayed depolarizations and arrhythmias.

Keywords

digitalis

arrhythmia

cardiomyopathy

ventricular tachycardia

calcium overload