Drug-induced arrhythmia: Are we cautious enough?

Abstract

Dear Editor, Many drugs, like antiarrhythmic agents, psychotropic medications, neurological drugs, and even antimicrobial agents, may trigger multiple types of arrhythmias.[1] Some arrhythmias may cause serious consequences, including death. We report a rare incident where psychotropic medications not only precipitated a life-threatening arrhythmia but also a stroke! A 64-year-old man with a history of bipolar disorder had no other comorbidity. He presented to the ER (emergency room) with hypotension and bradycardia. His GCS (Glasgow Coma Scale) score was 15/15 and had no neuro-deficit. We detected idioventricular rhythm, and a temporary pacemaker was implanted. His hypotension improved, and it stabilized him. We planned a permanent pacemaker the next morning. The family gave a history that he was on 400 mg of lithium and 400 mg of carbamazepine for more than a year. Considering their arrhythmogenic potential, they were withheld. (Blood lithium level was in the normal range.) The next morning we detected him to have right gaze deviation and left-sided complete hemiplegia (NIHSS of 17). He had established an infarct at the right frontal–temporal region with hemorrhagic conversion in the MRI (magnetic resonance imaging) brain [Figure 1a]. MRA (magnetic resonance angiography) brain revealed right M2 occlusion [Figure 1b]. Conservative stroke treatment along with rehabilitation was executed. TEE (transesophageal echocardiography) ruled out intracardiac clot and other cardiac pathology. Details of stroke workup were also not contributory. Since his sinus rhythm persisted even after removal of the temporary pacemaker, we canceled a permanent pacemaker implantation. We withdrew his offending drugs permanently. Henceforth, the cardiology team monitored the cardiac rhythm and until 2 years of follow-up, he had no further event. His Modified Rankin Scale (mRS), however, remained 5 (with no significant improvement).Figure 1: (a) Acute infarct with hemorrhagic conversion in the right frontal and temporal region. (b) Right M2 division of middle cerebra artery occludedThey associated junctional bradycardia with ischemic stroke, particularly in the absence of an identifiable retrograde P-wave.[2] He had the stroke just after his rhythm got converted to sinus rhythm from junctional bradycardia (like thromboembolism as happens in AF (atrial fibrillation) patients shortly after they get cardioverter).[3] Carbamazepine and lithium both can precipitate bradyarrhythmia.[45] Although we found his lithium level to be within range, there are reports where lithium has precipitated bradyarrhythmia even when the drug level was within therapeutic range.[5] The drugs might have had a synergistic action in our case causing precipitation of the bradyarrhythmia. Interesting learning points in our case are as follows: Arrhythmogenic drugs can precipitate stroke. While on these types of drugs, caregivers should monitor the heart rate and blood pressure regularly. Careful selection of drugs in psychiatric patients is important because they may have a synergistic action in causing arrhythmogenic insults. Before opting for a permanent pacemaker, careful history taking is important to isolate culprit drugs if any which might have precipitated arrhythmia. The status of the arrhythmia needs to be observed after their withdrawal before taking further action. In cardioversion, conversion to sinus rhythm may cause sudden dislodgement of clots from the heart, leading to systemic embolization. Similarly, the stoppage of the arrhythmogenic drugs may precipitate a similar event. So, we need to be more cautious during this time. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest. Acknowledgement We acknowledge the faith the patient and family kept on us during difficult times.