Brugada syndrome unmasked by lithium therapy

Lithium-Induced Brugada Pattern: A Case Report and Review of Literature

Lithium-induced type 1 Brugada pattern in asymptomatic patients is an uncommon occurrence that is challenging to manage and to estimate the risk of sudden cardiac death (SCD). We describe a case of a 74-year-old woman who presented with type 1 Brugada pattern while on lithium therapy. Her lithium level was within the therapeutic range at the time of presentation. There was no evidence of ventricular ectopy or malignant arrhythmias. Review of electrocardiogram (ECG) prior to initiation of lithium therapy demonstrated type 3 Brugada pattern. Lithium was promptly discontinued, and the patient was closely monitored in the hospital for 48 hours with serial ECGs and telemetry, as her lithium levels decreased. The Brugada pattern resolved on day 10 of discontinuation of lithium therapy and no further intervention was performed. Early diagnosis and prompt discontinuation of lithium leads to the resolution of type 1 Brugada pattern and may reduce the risk of SCD. The case highlights the importance of obtaining baseline ECG when initiating lithium especially in patients with type 2 or 3 Brugada pattern and provides an overview of the serial changes in ECG pattern until resolution following discontinuation of lithium. Electrophysiology study for risk stratification in asymptomatic patients does not appear to provide any additional benefit.

Electrophysiological changes of cardiac function during antidepressant treatment

Some antidepressant agents can cause electrophysiological changes of cardiac function leading to ventricular arrhythmias and sudden death. However, antidepressants have also protective effects on the heart through their capacity to modulate cardiac autonomic-mediated physiological responses. Heart rate variability and QTc length are two strictly linked parameters that allow us to appreciate the effects of different drugs on cardiac physiology. Heart rate variability reflects functioning of the autonomic nervous system and possibly also regulation by the limbic system. Autonomic regulation of cardiac activity influences also cardiac repolarization and QT length, both directly and via its effects on heart rate. In this review we present the methodologies adopted to study the effect of antidepressant drugs on QT length and heart rate variability and we summarize data on electrophysiological changes related to antidepressant treatment. Clinical implications for the choice of different antidepressants in different clinical populations are discussed.