Digitalis Intoxication: Junctional Tachycardia With and Without AV Block-KH
Frank Yanowitz
Copyright 1996
In a patient with longstanding atrial fibrillation being treated with digoxin, a regular tachycardia, as seen in 'A', with a RBBB suggests a junctional or supraventricular tachycardia. Group beating, in 'B', is likely due to a 2nd degree, Type 1, exit block below the ectopic junctional focus. This is highly suggestive of digitalis intoxication.