Citation

Alqahtani S, Zipursky J, Salehian O, Thompson M. CJEM 2019; 21(5): 676-679.

Copyright

(Copyright © 2019, Canadian Association of Emergency Physicians, Publisher Cambridge University Press)

DOI

10.1017/cem.2019.366

PMID

35176845

Abstract

Bidirectional ventricular tachycardia is a rare ventricular dysrhythmia characterized by beat-to-beat variation in the QRS axis. The differential diagnosis for this dysrhythmia is limited to severe digitalis/digoxin toxicity,Reference Richter and Brugada1 familial catecholaminergic polymorphic ventricular tachycardia,Reference Femenia, Barbosa-Barros and Sampaio2 and herbal aconite poisoning.Reference Smith, Shah, Hunt and Herzog3 Importantly, if bidirectional ventricular tachycardia is recognized on ECG, digoxin toxicity should always be at the top of the differential diagnosis because it is this poisoning alone that has antidotal treatment. Consideration should be given to catecholaminergic polymorphic ventricular tachycardia and aconite toxicity as possible etiologies once digoxin toxicity has been ruled out.

... Aconite (aconitum species) is a highly toxic plant that contains aconitine and related alkaloids. Aconite roots have been used in traditional Chinese medicine, only after processing, which reduces the toxic alkaloid content by up to 90%, for its analgesic, anti-inflammatory, and cardiotonic effects. Soaking and boiling during processing or decoction preparation will hydrolyze aconite alkaloids into less toxic and non-toxic derivatives. Inadequate processing, consumption of large amount, or ingestion of the raw plant will increase the risk of toxicity.Reference Chan4 Aconite poisoning is more common in East Asia. Recognition of this entity may pose a considerable challenge in both diagnosis and management, particularly in parts of the world where aconite use is less common.Reference Chan4 There are many different species of aconitum. In Europe and North America, aconite poisoning usually occurs after ingestion of aconitum napellus, commonly called monkshood, wolfsbane, or devil's helmet.Reference Chan4

Ingestion of any part of the aconite plant or its extracts can cause cardiotoxicity, neurotoxicity, and gastrointestinal (GI) manifestations.Reference Chan4 Aconite binds to the open state of voltage-sensitive sodium channels and induces its persistent activation in the myocardium and the nervous system, rendering cells refractory to further excitation. Tachydysrhythmias occur predominantly because of triggered activity due to delayed and early after-depolarization within the cardiac myocytes...

Language: en