Torsade de pointes

Torsade de Pointes Due to Hypokalemia and Hypomagnesemia

Audience

This scenario was developed to educate emergency medicine (EM) interns but can be used to educate medical students and junior residents.

Introduction

Torsade de Pointes (TdP) is a rare but potentially fatal arrythmia if not quickly diagnosed and properly treated. TdP is defined as a polymorphic ventricular tachycardia (VT) characterized by an oscillatory change in amplitude around an isoelectric line that is associated with a QTc prolongation on the electrocardiogram (ECG).1 It has been well described to predispose to ventricular fibrillation and arrhythmic death. QTc prolongation can be congenital or acquired. Between 1 in 2000 to 20,000 have the genetic mutation for QTc prolongation.1 Acquired QTc is most commonly drug related leading to electrolyte abnormalities. 2 Around 28% of cases of TdP are associated with hypokalemia and hypomagnesemia.2 Several European centers estimate 0.8 to 1.2 per million people per year are drug induced.1 Patients with TdP most commonly presents with syncope, palpitations, and dizziness.2 While 50% are asymptomatic, up to 10% of patients will present in cardiac arrest.1 It is imperative for EM physicians to be able to recognize TdP as it can quickly decompensate into a ventricular fibrillation and sudden death. These patients require management of electrolyte abnormalities, ventricular dysrhythmias, and cardiac death.2 This simulation case will demonstrate treatment strategies for TdP with electrolyte repletion, antiarrhythmics, and defibrillation.

Educational Objectives

By the end of this simulation session, learners will be able to: 1) formulate appropriate work-up for altered mental status (AMS) 2) recognize hypokalemia and associated findings on ECG 3) address hypomagnesemia in a setting to hypokalemia 4) manage pulseless VT by following advanced cardiac life support (ACLS) 5) recognize and address TdP 6) provide care after return of spontaneous circulation (ROSC) 7) consult intensivist and admit to intensive care unit (ICU).

Educational Methods

This session was conducted using high-fidelity simulation, which was immediately followed by an in-depth debriefing session. Each session had three EM first-year residents and six observers. There was one simulation instructor running the session and one simulation technician who acted as a nurse.

Research Methods

After the simulation and debriefing session was complete, an online survey was sent via surveymonkey.com to all the participants. The survey collected responses to the following questions: (1) was the case believable? (2) did the case have the right amount of complexity? (3) did the case help improve medical knowledge and patient care? (4) did the simulation environment gave a real-life experience? (5) did the debriefing session after simulation help improve knowledge? A Likert scale was used to collect the responses.

Results

This case was performed once a year for 2 years in a row. There was a total of 19 respondents from both years. One hundred percent of them either agreed or strongly agreed that the case was beneficial in learning and in improving medical knowledge and patient care. All of them found the post-session debrief to be very helpful. Two of them felt neutral about the case being realistic.

Discussion

This high-fidelity simulation was a realistic way of educating learners on how to manage hypokalemia and hypomagnesemia leading to TdP. Cost-effectiveness varies depending on what is available at individual simulation laboratories. Learners are forced to start with a broad differential for the patient who presents with AMS. As they manage the case, the patient quickly decompensates into a fatal arrhythmia due to electrolyte abnormalities. Learners enforced their knowledge on leading ACLS, intubation skills, and treating TdP with electrical conversion and electrolyte repletion.

Topics

Hypokalemia, hypomagnesemia, torsades de pointes, altered mental status, medical simulation.

A tale of two extremities: A dynamic case of Covid-19 induced hypokalemia and bradycardia leading into Torsade's de pointes

INTRODUCTION

As researchers and academics around the world scramble ahead to dissect and analyse every aspect of the SARS-CoV2 virus, one such study explored the various underlying electrolyte abnormalities that were precipitated in patients suffering from a confirmed COVID-19 infection. A significant proportion of such patients were noted to be hypokalemic. Hypokalemia can be life threatening as it is known to cause cardiac arrhythmia.

CASE PRESENTATION

Our encounter with said presentation was incidental. The on-call medical team was involved in a cardiac arrest call for a 74-year -old gentleman who developed torsades de pointes, Retrospective analysis of the clinical picture pointed out the fact that he was found to be persistently hypokalemic and bradycardic solely triggered as a result of COVID-19.

CONCLUSION

Although initially thought to be a pulmonary disease but along with time extra-pulmonary manifestations of Covid-19 has demonstrated significant consequences. Electrolyte abnormalities and cardiac dysfunction are examples of such extra-pulmonary pathologies. Therefore, it is important to keep close monitoring for such abnormalities otherwise could lead into life threatening arrythmias.

Electrocardiographic abnormalities associated with poisoning

This article will review the cardiovascular toxicities of various medications, stressing the electrocardiographic presentation--both rhythm and morphological issues--and emphasizing recognition and management issues. Cardiovascular toxins are grouped into categories causing similar electrocardiographic effects, including the potassium efflux blockers, sodium channel blockers, sodium-potassium adenosine triphosphatase blockers (ie, digitalis compounds), calcium channel blockers, and beta-adrenergic blockers. This article reviews the various electrocardiographic abnormalities associated with these 5 classes of agents, ranging from morphological abnormalities and conduction blocks to brady- and tachyarrhythmias.

ECG Manifestations: The Poisoned Patient

Despite that drugs have widely varying indications for therapeutic use, many unrelated drugs share a common cardiac pharmacologic effect if taken in overdose. The purpose of this article is to group together agents that cause similar electrocardiographic effects,review their pharmacologic actions, and discuss the electrocardiographic findings reported in the medical literature.

Cardiovascular challenges in toxicology

The diagnoses and subsequent treatment of poisoned patients manifesting cardiovascular compromise challenges the most experienced emergency physician. Numerous drugs and chemicals cause cardiac and vascular disorders. Despite widely varying indications for therapeutic use, many agents share a common cardiovascular pharmacologic effect if taken in overdose. Standard advanced cardiac life support protocol care of these patients may not apply and may even result in harm if followed. This chapter discusses com-mon cardiovascular toxins and groups them into their common mechanisms of toxicity. Multiple agents exist that result in human cardiovascular toxicity. The management of the toxicity of each agent should follow a rationale approach. The first step in the care of all poisoned patients focuses on good supportive care.