1. Sinus rhythm with ventricular bigeminy due to digitalis toxicity
Sinus rhythm with ventricular bigeminy due to digitalis toxicity. Ventricular premature complexes follow each sinus-conducted QRS at a fixed coupling interval. ST-segment depression and T wave inversion in the sinus-conducted beats is seen in V6; however, since each sinus-conducted beat is a postextrasystolic one, correct interpretation of ST-T abnormalities is difficult. The sinus rate is not measurable when ventricular bigeminy is present since consecutive sinus complexes are not present. Although ventricular bigeminy in this patient was associated with a toxic serum level of digoxin, this arrhythmia is not specific for digitalis intoxication. If a ventricular arrhythmia is due to digitalis toxicity, it is expected to disappear as the serum level of digitalis is lowered. Note the presence of P waves deforming the ST segments of the premature ventricular depolarizations (arrows); since the intervals between them and the preceding sinus P waves is not half the measured sinus cycle length, they are probably retrogradely conducted. (Reproduced, with permission, from Goldschlager N, Goldman MJ. Principles of Clinical Electrocardiography, 13th ed. Originally published by Appleton & Lange. Copyright © 1989 by The McGraw-Hill Companies, Inc.)
Source: Heart Disease, Current Medical Diagnosis & Treatment 2018
Citation: Papadakis MA, McPhee SJ, Rabow MW. Current Medical Diagnosis & Treatment 2018; 2017 Available at: Accessed: October 14, 2017
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