Unusual Chronotropic Incompetence in a Young Patient: Mitigating the Fear of Fatal Bradyarrhythmia When...

Severe chronotropic insufficiency, while uncommon in psychiatric populations, presents unique challenges in patients with psychotic disorders because many antipsychotics can adversely affect cardiac rhythm by exacerbating bradycardia or prolonging the QT interval. This case report describes a young male with a complex psychiatric history, severe substance use disorder, and coexisting cardiac abnormalities, who presented with profound sinus bradycardia and a prolonged QT interval. The patient's psychiatric symptoms were compounded by medication nonadherence and illicit drug use. The patient had a history of profound sinus bradycardia (heart rates in the 20s to 30s) with a mean heart rate of 41 beats/min (SD = 4), yet remained asymptomatic from a cardiovascular perspective. Despite the presence of bradycardia and a prolonged QT interval (mean QT = 495 ms (66), QTcB = 427 (30) (Bazett), and QTcF = 448 (32) (Fridericia)), he was treated with oral olanzapine and valproate. His psychiatric symptoms improved significantly, with no exacerbation of bradycardia or QTc prolongation noted during treatment. This is a rare case of a hemodynamically stable young man treated with second-generation antipsychotics, without any notable effect on the length of the QT interval. QT prolongation is a side effect of many antipsychotics, and bradycardia tends to further prolong the QT interval, increasing the risk of adverse cardiac outcomes, such as torsades de pointes or sudden cardiac death, for patients taking antipsychotics. An interprofessional, interdisciplinary, and cohesive team can reduce the cardiac risk to the patient while effectively treating the underlying psychiatric disorders. Nonetheless, it is essential for psychiatrists to have a solid understanding of psychotropic medications and cardiac rhythms, particularly because many free-standing psychiatric facilities do not have direct access to a cardiology consult team. In this report, the authors will attempt to provide a structured framework for psychiatrists managing patients with bradycardia who require antipsychotic therapy.