A 43-year-old female patient with a past medical history of substance use disorder (SUD) was brought to the hospital by emergency medical services (EMS) presenting with multiple episodes of dizziness, shortness of breath, and palpitations. EMS reported ventricular tachycardia (VT) while in transit to the hospital for which she was externally defibrillated 10 times without any resolution of the ventricular arrhythmia. The patient’s past medical history was positive for depression and substance abuse of hydrocodone dating back to 2007. The patient’s husband denied any history of cardiac arrhythmias, structural heart disease, or ischemic heart disease. The patient’s husband denied using any medications, including herbal supplements, but reported drug allergies to amoxicillin and erythromycin. The patient’s social history revealed that she worked at a consignment store and had a history of alcohol and marijuana abuse. The patient’s husband also revealed recreational usage of loperamide at approximately 400 mg in the last 24 hours before the presentation. On physical exam in the emergency department, she appeared to be in moderate distress with pain from the external defibrillations. Her vital signs consisted of an elevated pulse of > 200 beats per minute (bpm), an elevated blood pressure of 157/80, and an increased respiratory rate at 24/minute. The pulmonary exam revealed decreased breath sounds bilaterally with symmetrical chest wall expansion. The cardiovascular exam revealed tachycardia with no murmurs reported. Examination of the head and neck showed moist mucous membranes with no jugular venous distension. The gastrointestinal exam was negative for distention, tenderness, rebound, guarding, hepatomegaly, or splenomegaly. The musculoskeletal exam revealed warm and well-perfused upper and lower extremities free of clubbing, cyanosis, and edema. In the processes of placing the electrocardiogram (EKG) electrodes onto the patient in the emergency room, the patient became unresponsive and the two lead EKG monitors showed polymorphic VT with a heart rate of 220 per minute and blood pressure of 84/58. The patient was immediately defibrillated once again before being sedated, intubated, and started on an amiodarone drip. The patient’s vitals were stabilized for 15 minutes before she went into another episode of polymorphic VT despite the amiodarone drip. The patient underwent synchronized cardioversion, and once her vitals stabilized, she underwent a cardiac catheterization which showed patent coronaries and a normal ejection fraction. The patient got transferred to the Medical Intensive Care Unit (MICU) for continuous monitoring and was started on a lidocaine drip in addition to the amiodarone drip. Her EKG in the MICU is shown below in Figure .\nIn the MICU, the patient continued to have polymorphic VT episodes despite medical management and went in and out of VT episodes approximately 16 times with each episode lasting between 30 seconds to two minutes. Subsequently, the patient had a transvenous cardiac pacer placed which stabilized her vital signs. After 72 hours, the pacer was removed, and the patient remained stable on amiodarone and lidocaine. Transthoracic echocardiogram in the MICU revealed a normal ejection fraction with no valvular abnormality. Serum electrolytes were within normal limits, and the urine drug screen was also negative. After the temporary pacer was removed, the patient subsequently remained in sinus rhythm with a heart rate of 70 bpm, QRS duration of 98 ms, and a QTc interval of 456 ms as seen in Figure .\nAfter five days of hospitalization, the effects of the loperamide had completely resolved, and the patient remained in normal sinus rhythm on amiodarone until discharge and followed up a month later.
46-year-old male was presented in the ER after cardiac arrest. Patient had two-hour flight before he started feeling light-headed and passed out at the airport. The airport emergency services found him in ventricular fibrillation and provided him with two shocks before he regained consciousness. Subsequent EKG showed normal sinus rhythm and prolonged QT (QTc-589 msec); EKG is not available. Upon arrival to ER, patient was alert and oriented but amnesic about past events. Patient was taken for cardiac catheterization which revealed nonobstructive coronaries and normal ejection fraction. Electrolytes were unremarkable except potassium of 3.1 which was replaced. Complete blood counts, renal function, serum troponin, and serum magnesium were within normal limits. MRI of brain revealed no significant abnormalities. Shortly after coronary angiogram, patient again went to cardiac arrest and resuscitated with one shock. Cardiac monitor showed torsades de pointes ventricular tachycardia () with hemodynamic instability. Patient was intubated for airway protection and received IV magnesium and IV amiodarone. Toxicology screen was unremarkable except benzodiazepine he received during intubation (midazolam) for sedation. EKG showed normal sinus rhythm, nonspecific ST-T wave abnormality, and prolonged QT (QTc-620 msec) (). Echocardiogram revealed structurally normal heart. Acute pulmonary embolism was also ruled out with computed tomography pulmonary angiogram. Patient's spouse reported that patient has been taking large amount of Loperamide for irritable bowel syndrome for more than 5 years. However, she was not able to quantify the amount of Loperamide. Patient persistently experienced multiple episodes of sustained ventricular tachycardia requiring multiple defibrillation in setting of significantly prolonged QTc (>600 msec) on multiple serial EKGs. Patient was treated with metoprolol, lidocaine, and magnesium infusion. Over the period of 7 days, patient stopped having sustained ventricular tachycardia. Frequency of nonsustained ventricular tachycardia was also reduced and patient was extubated after several days of CCU monitoring. Lidocaine and magnesium were discontinued and metoprolol was continued. Loperamide levels were not obtained. After extubation, patient denied having similar episode in the past, chest pain, palpitations, syncope, shortness of breath, and any family history of sudden cardiac death or cardiac diseases. However, patient admitted that he has been self-medicating with over-the-counter 2 mg Loperamide approximately 50 tablets a day for diarrhea predominant irritable bowel syndrome for more than 5 years. He also admitted having approximately 100 pills of Loperamide daily for the last 2 days before admission. Since patient was buying over-the-counter Loperamide from different pharmacy; we could not determine exact frequency of purchase. Patient denied using illicit drug use, herbal supplements, or concurrent p-glycoprotein inhibitors. Serial EKG monitoring showed gradual decrease in QTc. However, serial EKG monitoring off Loperamide for several days revealed normal sinus rhythm and QTc of 472 msec () and 456 msec (). Only one EKG revealed QTc of 432 msec (). Thus, patient's QTc interval did not completely normalize after several days off all QTc prolonging medications and subsequently he received dual chamber automated cardioverter defibrillator (AICD) before discharge for secondary prevention of cardiac arrhythmia related death. Since majority of patient's QTc interval was >440 msec even after a week of stopping all QT prolonging medications, at this time, we think that patient may have subclinical long QT syndrome which was unmasked by Loperamide. However, electrophysiological studies were not performed to verify the diagnosis. Patient was instructed not to use Loperamide again.