Brugada-like ECG abnormalities during thioridazine overdose

Pathogenesis and management of Brugada syndrome in schizophrenia: A scoping review

CONTEXT

Excess cardiovascular morbidity and an increased prevalence of sudden cardiac death (SCD) contributes to premature mortality in schizophrenia. Brugada syndrome (BrS) is an important but underrecognized cause of SCD. It is more commonly seen in schizophrenia than in general population controls.

METHODS

We conducted a scoping review to describe the pathogenesis of BrS in schizophrenia and to identify the psychotropic medications that increase the risk of unmasking BrS and associated ventricular arrhythmias resulting in SCD.

FINDINGS

Schizophrenia and BrS share similar calcium channel abnormalities, which may result in aberrant myocardial conductivity. It remains uncertain if there is a genetic pre-disposition for BrS in a subset of patients with schizophrenia. However, the unmasking of Brugada ECG patterns with the use of certain antipsychotics and antidepressants increases the risk of precipitating SCD, independent of QT prolongation.

CONCLUSIONS AND FUTURE DIRECTIONS

Specific cardiology assessment and interventions may be required for the congenital or unmasked Brugada ECG pattern in schizophrenia. The current long-term standard of care for BrS is an implantable cardioverter defibrillator (ICD), but post-implantation psychological effects must be considered. Careful use of antipsychotic and other psychotropic medications is necessary to minimize proarrhythmic effects due to impact on cardiac sodium and calcium ion channels. When prescribing such drugs to patients with schizophrenia, clinicians should be mindful of the potentially fatal unmasking of Brugada ECG patterns and how to manage it. We present recommendations for psychiatrists managing this patient population.

Cardiovascular Safety of Psychiatric Agents: A Cautionary Tale

Psychiatric agents are among the most commonly prescribed medications. Despite the advent of newer generation agents, patients receiving them still experience cardiovascular (CV) side effects. However, these agents may have heterogeneous properties, calling for an individualized approach based on efficacy and also on the particular side effect profile of each specific agent. Proarrhythmic effects arising from drug-induced long-QT syndrome and consequent potentially life-threatening polymorphic ventricular arrhythmias in the form of torsade de pointes, the metabolic syndrome contributing to atherosclerosis and acute coronary syndromes, and drug-induced orthostatic hypotension raise major concerns. Of course, it is also crucial that fear of potential CV adverse effects does not deprive psychiatric patients of appropriate drug therapy. Modification of CV risk factors in psychiatric patients together with optimal management of their CV diseases and appropriate selection of psychotropic agents with greater efficacy and least CV toxicity are of paramount importance in mitigating CV risks and enhancing safety. Identifying patients at high risk of CV complications and close monitoring of all patients receiving these agents are crucial steps to prevent and manage such complications. All these issues are herein reviewed, relevant guidelines are discussed, and schemas are depicted that illustrate the interrelated connections among the psychotropic agents and their CV effects.

Anesthetic and Perioperative Management of Patients With Brugada Syndrome

Brugada syndrome (BrS) is an arrhythmogenic disease reported to be one among the leading causes of cardiac death in subjects under the age of 40 years. In these patients, episodes of lethal arrhythmias may be induced by several factors or situations, and for this reason, management during anesthesia and surgery must provide some precautions and drugs restrictions. To date, it is difficult to formulate guidelines for anesthetic management of patients with BrS because of the absence of prospective studies, and there is not a definite recommendation for neither general nor regional anesthesia, and there are no large studies in merit. For this reason, in the anesthesia management of patients with BrS, the decision of using each drug must be made after careful consideration and always in controlled conditions, avoiding other factors that are known to have the potential to induce arrhythmias and with a close cooperation between anesthetists and cardiologists, which is essential before and after surgery. In conclusion, given the absence of large studies in literature, we want to focus on some general rules, which resulted from case series and clinical practice, to be followed during the perioperative and anesthetic management of patients with BrS.

Brugada phenocopy: new terminology and proposed classification

Brugada syndrome is a channelopathy characterized on ECG by coved ST-segment elevation (≥2 mm) in the right precordial leads and is associated with an increased risk of malignant ventricular arrhythmias. The term Brugada phenocopy is proposed to describe conditions that induce Brugada-like ECG manifestations in patients without true Brugada syndrome. An extensive review of the literature identified case reports that were classified according to their suspected etiological mechanism. Future directions to learn more about these intriguing cases is discussed.

Drugs and Brugada syndrome patients: review of the literature, recommendations, and an up-to-date website (www.brugadadrugs.org)

BACKGROUND

Worldwide, the Brugada syndrome has been recognized as an important cause of sudden cardiac death in individuals at a relatively young age. Importantly, many drugs have been reported to induce the characteristic Brugada syndrome-linked ECG abnormalities and/or (fatal) ventricular tachyarrhythmias.

OBJECTIVE

The purpose of this study was to review the literature on the use of drugs in Brugada syndrome patients, to make recommendations based on the literature and on expert opinion regarding drug safety, and to ensure worldwide online and up-to-date availability of this information to all physicians who treat Brugada syndrome patients.

METHODS

We performed an extensive review of the literature, formed an international expert panel to produce a consensus recommendation to each drug, and initiated a website (www.brugadadrugs.org).

RESULTS

The literature search yielded 506 reports for consideration. Drugs were categorized into one of four categories: (1) drugs to be avoided (n = 18); (2) drugs preferably avoided (n = 23); (3) antiarrhythmic drugs (n = 4); and (4) diagnostic drugs (n = 4). Level of evidence for most associations was C (only consensus opinion of experts, case studies, or standard-of-care) as there are no randomized studies and few nonrandomized studies in Brugada syndrome patients.

CONCLUSION

Many drugs have been associated with adverse events in Brugada syndrome patients. We have initiated a website (www.brugadadrugs.org) to ensure worldwide availability of information on safe drug use in Brugada syndrome patients.

Pediatric thioridazine poisoning as a result of a pharmacy compounding error

The adverse effects or overdose of thioridazine including sudden death, fatal arrhythmia, or retinopathy, in addition to the neurological signs have been reported. A three-year-old boy with bronchitis was prescribed erythromycin by a local clinic, but he started to complain of severe drowsiness and became unconscious. It was decided that this was a result of a compounding error of thioridazine instead of erythromycin owing to their similar commercial names. The thioridazine concentration in the child's serum on admission was two to three times higher than the Cmax for adults with the same dosage. The concentration of the lavage saline on admission was only 0.3% of the ingested amount, indicating that the lavage was not effective in our case. Pharmacokinetic analysis revealed the parameters as Tmax, 1.5 hr; Cmax, 1700 ng/mL; Ka, 2.01 L/hr; Vd, 3.6 L/kg; and T1/2, 6.8 hr. Further investigations on clinical cases with a pharmacokinetic analysis should be done to confirm the pharmacokinetic evidence obtained here and to give specific therapeutic guidelines for overdose management especially in children.

Incidence of Brugada electrocardiographic pattern and outcomes of these patients after intentional tricyclic antidepressant ingestion

Brugada syndrome is a genetic dysfunction of the myocardial sodium channel that leads to ventricular dysrhythmias. The electrocardiographic (ECG) pattern of Brugada syndrome is occasionally seen after tricyclic antidepressant (TCA) ingestion; however, the outcome and complication risk for these patients is not clear. The objective of our study was to describe the incidence of Brugada ECG pattern (BEP) and serious complications of these patients in a large case series of intentional TCA ingestions. We also compared the proportion of complications of patients with BEP versus those without BEP. We evaluated 402 TCA ingestions, of which 9 (2.3%) were associated with the development of BEP. We compared the adverse outcomes of all TCA ingestions versus TCA ingestions with BEP. A increase in the adverse outcomes in the BEP group was found: seizures (relative risk [RR] 4; 95% confidence interval [CI] 1.5 to 10.8), widened QRS (RR 4.8; 95% CI 1.8 to 12.9), and hypotension (RR 3.9; 95% CI 2.1 to 7.4). To reduce confounding ingestants, we also compared all patients with an isolated TCA ingestion versus those with BEP. A significant increase in adverse outcomes was again found with the BEP group: seizures (RR 3; 95% CI 1.1 to 8.6), widened QRS (RR 4.8; 95% CI 1.5 to 15.1), and hypotension (RR 3.4; 95% CI 1.9 to 22.3). No deaths or dysrhythmias were found in the BEP group. In conclusion, BEP after TCA ingestion is rare, and death or dysrhythmias did not occur. However, patients with BEP are likely at increased risk for TCA-induced complications.