Ventricular trigeminy

Ventricular trigeminy

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Striking feature in the ECG is the presence of frequent bizarre wide QRS complexes. These wide QRS complexes are not preceded by a P wave and occurs soon after the previous T wave. ST segment and T wave of the wide QRS complex is opposite in direction to the dominant QRS polarity (discordant ST-T) indicating secondary repolarization abnormality. The wide QRS complexes are followed by a compensatory pause (coupling interval to the ectopic beat from the previous sinus beat + compensatory pause = twice the sinus cycle length). The ventricular ectopics in the initial part of the recording show a pattern of ventricular trigeminy, with two sinus beats followed by one ventricular ectopic beat. There are four cycles of ventricular trigeminy visible in the rhythm strip at the bottom of the tracing. The ventricular ectopic beats are monomorphic (of the same morphology). They originate in the upper part of the ventricle as indicated by the positive complexes in the inferior leads.

Hypokalemia is a recognized cause for ventricular arrhythmia as are several drugs including digitalis. Hypophosphatemia during treatment of diabetic ketoacidosis in a 10 year old has been reported. It was treated with oral phosphate supplementation and arrhythmia subsided [1].

Anesthetic agents as well as well as enhanced sympathetic activity can predispose to ventricular trigeminy. A thirteen year old had trigeminy during anesthesia for a dental procedure, but persisted after recovery [2].

Structural heart disease and cardiac ion channelopathy can also cause ventricular trigeminy.

References

1. Miszczuk K, Mroczek-Wacinska J, Piekarski R, Wysocka-Lukasik B, Jawniak R, Ben-Skowronek I. Ventricular bigeminy and trigeminy caused by hypophosphataemia during diabetic ketoacidosis treatment: a case report. Ital J Pediatr. 2019 Apr 2;45(1):42.
2. Waxman BN. A 13-Year-Old Girl in Trigeminy During Anesthesia for Outpatient Dental Surgery: A Case Report. Anesth Prog. 2015 Fall;62(3):110-3.