A 35-year-old male with a history of AICD placement for long QT syndrome by a local cardiologist six months ago presented to the ED by ambulance for altered mental status and frequent shocks from AICD secondary to a loperamide overdose. He was unable to provide a history of more than “yes" or "no” because of his agitation, so the most history was obtained from emergency medical services (EMS), with confirmation by the patient. EMS stated that the patient was having dinner with his spouse when the spouse noticed that he had a brief loss of consciousness for several seconds. The spouse stated that when the patient awoke, he became very anxious, diaphoretic, and irritable; it was unclear if the defibrillator had fired at that time. On arrival, EMS gave the patient 2 mg of naloxone IV without any effect. They stated that en route to the facility, they noted that the AICD had fired several times, causing the patient much anxiety and pain. EMS also stated that they found a bag full of loperamide tablets inside a purse-string bag near the patient, which they brought into the department for identification. They stated that the patient had a history of IV drug abuse and had overdosed on loperamide in the past when he had been unable to obtain opiate medications. In the ED, the patient was anxious and diaphoretic and was shocked by his defibrillator every three to four minutes for runs of polymorphic ventricular tachycardia (Torsades). A review of symptoms was negative, except for tachycardia, anxiety, and diaphoresis. Initial vital signs were a heart rate of 120, respiratory rate of 24, oxygen saturation 99% on room air, and blood pressure 138/64. Physical exam showed that the patient could not hold an extended conversation; he was anxious, had reactive mydriasis, and an AICD in place in the left chest, without signs of infection; otherwise, the physical was normal.\nPotassium was found to be 2.7 so IV potassium, magnesium, bicarbonate, and saline were started with lidocaine chosen as an antiarrhythmic (with which cardiology and poison control had agreed). The remaining basic labs, as well as toxicology and cardiac enzymes, were normal. Lorazepam was also used to control agitation. The electrocardiogram (ECG) showed tachycardia, which was different from the patient’s baseline atrial-paced rhythm. This ECG (Figure ) was obtained when the patient was not in polymorphic ventricular tachycardia, which was only shown on the monitor for several seconds before being detected and electrically cardioverted by the AICD. Chest X-ray was normal. After treatment in the ED and intensive care unit (ICU), the shocks eventually became less frequent as electrolytes normalized. The patient was eventually removed from the lidocaine drip and discharged home five days later with the normalization of ECG over time (Figures -).
A 38-year-old female with an extensive history of poly-substance abuse presented after an outside hospital cardiac arrest that was recognized in the field to be caused by ventricular fibrillation of uncertain duration in the field. Her family reported daily use of two boxes of loperamide (144 tabs, 288 mg) daily for an indefinite period of time for the purpose of controlling symptoms of heroin withdrawal. She formerly used codeine and suboxone for opioid withdrawal symptom control but no longer had access to those treatments. Other than the polysubstance abuse, she was not known to have any known chronic medical illness and was not taking any prescription medications. There was no family history of cardiac arrhythmias or sudden cardiac death (SCD). The patient was successfully resuscitated in the field as per ACLS protocol with defibrillation, and, for airway protection, was intubated. She was initially taken to an outside facility and then emergently transferred to a tertiary care center. Hypothermia protocol was not initiated because of non-availability at the outside hospital. At the time of arrival, electrocardiogram (EKG) revealed a wide complex undetermined atrial rhythm at a rate of 58 bpm with prolonged QT and QTc intervals (). The patient had no available baseline EKG for comparison. Emergent coronary angiography indicated normal coronary arteries. Urine toxicology screen was negative. The regional poison control center was notified and recommended sodium bicarbonate and lipid infusions. Electrolytes, including potassium, magnesium, and calcium, were maintained within normal limits through intravenous supplementation.\nDue to bradycardia, the patient was started on an isoproterenol drip. The following day, her telemetry alarmed for a very wide QRS; EKG showed wide complex tachycardia () that culminated with a ventricular cardiac arrest. She was successfully resuscitated as per ACLS protocol with amiodarone push and lidocaine infusion. Six hours later, she developed sustained polymorphic ventricular tachycardia without loss of pulse that responded to magnesium supplementation. A temporary transvenous pacer was inserted with overdrive strategy. She was reliably paced as shown in the EKG (). Shortly after that, however, she developed a third ventricular fibrillation cardiac arrest that was successfully resuscitated as per ACLS protocol with multiple shocks (>10 times). Higher electrolytes levels were targeted with a potassium goal of 4.5 mmol/L and magnesium goal of 2–2.5 mg/dL. It was expected that the loperamide side effect would last for 24–48 hours. On Day 3, she was extubated without any residual neurologic deficit. She remained bradycardic when the pacemaker was turned down (EKG, ). Isoproterenol was weaned. On Day 5, she developed another episode of ventricular fibrillation that responded to four shocks of 200 Joules. Isoproterenol infusion was restarted transiently due to bradycardia. She was discharged to the medical floor on Day 6. However, on Day 11, she had multiple episodes of Torsade de Pointes (TdP), that were self-limiting and without symptoms. She was readmitted to the ICU due to these episodes, and temporizing measures were restarted (lidocaine and isoproterenol) with positive results. The patient threatened to leave the ICU against medical advice, so AICD/DDD ICD was placed to prevent ventricular fibrillation cardiac arrest given her recurring TdP. Repeat EKG () showed progressive shortening of the QTc and QT intervals. The patient changed her mind about leaving the ICU after the AICD placement and was discharged after medical stabilization two days later. She followed as outpatient with the EP team. She denied any symptoms or any further use of loperamide. Office EKG showed normal sinus rhythm at a rate of 85 bpm with normal QTc at 437 msec. Device interrogation demonstrated normal sensing and pacing pacemaker. She was enrolled in remote device monitoring every three months and has had no detected device shocks.