Severe caffeine poisoning treated with intermittent hemodialysis under circulatory support.

Caffeine poisoning can cause fatal ventricular arrhythmias. In this report, we describe a case of severe caffeine poisoning with extraordinarily high blood caffeine levels. Despite developing refractory ventricular fibrillation, the patient was successfully treated with intermittent hemodialysis (IHD) under circulatory support by venoarterial extracorporeal membrane oxygenation (VA-ECMO). A 22-year-old male was transported to our hospital approximately 2.5 h after ingesting 200 highly caffeinated tablets (200 mg/tablet) (40 g caffeine total) in a suicide attempt. On arrival, the patient vomited frequently with a Glasgow Coma Scale score E3V2M5, heart rate 185 beats/min, and a blood pressure of 97/62 mmHg. Shortly after arrival, the patient developed ventricular fibrillation which was refractory either to three electrical defibrillations or antiarrhythmic drugs, resulting in endotracheal intubation for mechanical ventilation and VA-ECMO. Starting from 2 h after arrival, intermittent hemodialysis (IHD) was performed for 11 h, which markedly improved clinical symptoms and circulatory parameters. Serum caffeine level was 454.9 mg/dL upon arrival at the hospital, but it decreased to 55.5 mg/dL by the end of IHD treatment. Renal replacement therapy (RRT) including intermittent hemodiafiltration, continuous hemodiafiltration, and IHD was continued because of rhabdomyolysis with myoglobinuria and secondary caused acute kidney injury. The patient was weaned off VA-ECMO on hospital day 7, extubated on hospital day 18, weaned from RRT on hospital day 46, and was transferred to another hospital for physical rehabilitation on hospital day 113. IHD under circulatory support by VA-ECMO should be considered in severe caffeine poisoning causing potentially fatal arrhythmias.

Polymyoclonus, ventricular fibrillation and Takotsubo after accidental spinal injection of tranexamic acid.

Several factors have been identified as contributing to medication administration errors, including look-alike, sound-alike (LASA) errors. LASA errors are important causes of serious adverse events arising from spinal injection of tranexamic acid, which can be confused with ampoules of local anaesthesia.We present a case of accidental injection of 250 mg of tranexamic acid rather than prilocaine during spinal anaesthesia. The patient developed lower extremities myoclonus, followed by generalised convulsions and ventricular fibrillation, that was reverted within 6 min. Severe cardiogenic shock requiring both inotropic and vasopressor therapy followed, along with a classic apical ballooning pattern on echocardiography and elevated myocardial injury markers, indicating Takotsubo cardiomyopathy. The patient's condition progressively improved to full recovery, and she was discharged from hospital after 1 month with no neurological deficit or cardiac dysfunction.To our knowledge, this is the 28th reported case of accidental spinal injection of tranexamic acid. We present a brief review of previously published cases.

Ventricular fibrillation in a 21-year-old after inhalation of an isobutyl nitrite "popper" product.

BACKGROUND: Alkyl nitrite analogs known as "poppers" have been inhaled recreationally for decades. They are available to be purchased from gas stations marketed as "nail polish remover not for human consumption". These rapid-onset, short-acting, vasodilators cause the user to experience euphoria, dizziness, tachycardia and flushing. While chronic use may lead to problems such as methemoglobinemia or neuropathy, nitrites rarely lead to acute life-threatening side effects such as ventricular dysrhythmias. CASE REPORT: We report a case of ventricular fibrillation cardiac arrest in a 21-year-old male after inhaling from a solution labeled to contain isobutyl nitrite, a rarely reported adverse effect of "popper" use. The product was analytically confirmed to contain mainly isobutyl alcohol, volatile hydrocarbons, and isobutyl nitrite, as well as smaller quantities of other substances. The patient was also prescribed escitalopram and hydroxyzine may have contributed. Return of spontaneous circulation was achieved in the field after initiation of CPR and defibrillation. He was found to have no clear predisposition to arrythmias during his care or on follow up. CONCLUSION: Alkyl nitrite "popper" users and clinicians should be aware that products labeled to contain nitrites may contain volatile hydrocarbons along with nitrites and have the potential to cause arrhythmia.

Pharmacokinetics and pharmacodynamics of amiodarone in patients with hypertriglyceridemia: Two case reports.

BACKGROUND: The antiarrhythmic drug amiodarone has noncardiac adverse effects, leading to restrictive therapeutic plasma ranges. Despite the significant positive correlation between triglyceride and amiodarone levels, the effect of fluctuations in amiodarone levels in patients with hypertriglyceridemia on amiodarone therapy has not been fully characterized. This study is the first to report on the effect of hypertriglyceridemia on the efficacy and safety of amiodarone therapy. CASE PRESENTATION: The first patient was a 58-year-old man with hypertriglyceridemia who was diagnosed with ventricular fibrillation (patient #1). The second patient with hypertriglyceridemia was a 72-year-old man with sustained ventricular tachycardia (patient #2). Both patients received implantable cardioverter-defibrillator therapy. During the study period, amiodarone and N-desethylamiodarone concentrations were measured 12 times in patient #1 and 26 times in patient #2. Triglyceride concentrations in patient #1 and patient #2 ranged from 102 to 765 mg/dL and from 125 to 752 mg/dL, respectively. For both patients, amiodarone dosage was maintained at 100 mg/day, and the administration of concomitant drugs that could affect amiodarone pharmacokinetics was neither initiated nor discontinued. However, amiodarone concentrations fluctuated (patient #1, 0.52 - 1.86 µg/mL; patient #2, 0.73 - 2.82 µg/mL). Although amiodarone concentrations fluctuated, neither of the patients had defibrillation shocks to stop the abnormal rhythm via an implantable cardioverter-defibrillator, and laboratory data showed that thyroid-stimulating hormone, free thyroxine, KL-6, and surfactant protein-D remained close to normal. CONCLUSION: In patients with hypertriglyceridemia, it may be necessary for clinicians to pay more attention to the clinical symptoms along with fluctuations in amiodarone levels and accordingly adjust amiodarone dosage.

Oral Adrenergic Agents Produced Ventricular Fibrillation and QT Prolongation in an Elderly Patient Carrying an RYR2 Variant.

Mutant cardiac ryanodine receptor channels (RyR2) are "leaky," and spontaneous Ca2+ release through these channels causes delayed afterdepolarizations that can deteriorate into ventricular fibrillation. Some patients carrying RYR2 mutations in type 1 catecholaminergic polymorphic ventricular tachycardia exhibit QT prolongation and are initially diagnosed with long QT syndrome. However, none have been reported to cause drug-induced ventricular fibrillation in patients with RYR2 variants. We describe the first case of an elderly woman with drug-induced QT prolongation and ventricular fibrillation who carried a novel RYR2 variant but no other mutations related to long QT syndrome. Oral adrenergic agents might induce QT prolongation and subsequent ventricular fibrillation in patients carrying an RYR2 variant. Screening for RYR2 could be valuable in patients with suspected drug-induced long QT syndrome.

Flecainide-Induced Atrial Flutter With 1:1 Conduction Complicated by Ventricular Fibrillation After Electrical Cardioversion.

Flecainide, a widely prescribed class IC agent used to treat atrial arrhythmias, can in rare cases cause 1:1 atrial flutter with rapid conduction. We describe the case of a 59-year-old man who was on a maintenance regimen of flecainide for refractory atrial fibrillation. When 1:1 atrial flutter with rapid conduction developed, emergency medical technicians attempted synchronized cardioversion, which caused ventricular fibrillation necessitating defibrillation. The patient ultimately underwent radiofrequency ablation and cryoablation to resolve his symptomatic atrial flutter. We discuss the atrial proarrhythmic effects of flecainide and how to mitigate complications in high-risk patients.

QT interval prolongation and the rate of malignant ventricular dysrhythmia and cardiac arrest in adult poisoned patients.

INTRODUCTION: Prolongation of QTc interval, a common electrocardiographic (ECG) abnormality encountered in the toxicology patient, is reportedly associated with an increased risk of malignant ventricular dysrhythmias (MVD), such as ventricular tachycardia (VT, with and without a pulse), ventricular fibrillation (VF), and/or cardiac arrest. Quantifiable cardiac arrest risk in relation to specific QTc interval length is not known in this population. METHODS: We conducted a retrospective, observational study to assess the rate of cardiac arrest and its association with degree of QTc prolongation in a cohort of patients requiring toxicology consultation. RESULTS: 550 patients were included in our analysis (average age 36 years and 49% male). Average QTc was 453 milliseconds (ms). Overall incidence of cardiac arrest in the study cohort was 1.1% with 6 reported cases; when considering patients with QTc > 500 ms, incidence was 1.7%. Two patients with cardiac arrest experienced ventricular dysrhythmia with decompensation prior to cardiac arrest; four patients developed sudden cardiac arrest. CONCLUSIONS: The risk of malignant ventricular dysrhythmia, including cardiac arrest, is low in this poisoned patient population with an overall rate of 1.1%. Two-thirds of cardiac arrest cases occurred in patients with normal QTc intervals. When considering patients with prolonged QTc intervals, the rate of cardiac arrest remains very low at 0.8%. Considering QTc greater than 500 ms, the rate of cardiac arrest is 1.7%. Further prospective studies are required to quantify the risk of malignant ventricular dysrhythmias, including cardiac arrest, and its relation to the degree of QTc interval in poisoned patients.

Massive suicidal ingestion of caffeine: a case report with investigation of the cardiovascular effect/concentration relationships.

BACKGROUND: Caffeine poisoning may cause life-threatening arrhythmias and hemodynamic failure. We aimed to investigate the toxicokinetics (TK), toxicodynamics (TD) and TK/TD relationships of caffeine in a case of poisoning. CASE REPORT: A 47-year-old male ingested pure anhydrous caffeine powder (70 g) in a suicide attempt. He developed agitation, tachycardia, and two episodes of ventricular fibrillation treated with defibrillation and tracheal intubation. He was successfully managed using intravenous infusions of esmolol and norepinephrine. METHODS: We modelled the time-course of plasma caffeine concentration (TK study using online liquid chromatography-tandem mass spectrometry), the time-course of blood lactate concentration and infusion rates of esmolol and norepinephrine (TD studies) and the TK/TD relationships. RESULTS: Caffeine TK was of first-order peaking at 258 mg/L with an elimination half-life of 46.2 h and clearance of 2.2 L/h. Caffeine-related effects on blood lactate (peak, 10 mmol/L at 1.25 h postingestion) were described by a Bateman-type equation (formation rate, 0.05 mmol/mg.h; elimination rate, 0.9 mmol/mg.h). Esmolol and norepinephrine infusion rates to reverse caffeine-related cardiovascular effects (peaks at 51-h postingestion) fitted well with a sigmoidal Emax model (EC50, 180.0 and 225.9 mg/L, respectively; Hill coefficient, 10.0). CONCLUSION: Massive caffeine ingestion is characterized by prolonged caffeine elimination. TK/TD relationships are helpful to quantify caffeine-related catecholaminergic effects.

Ventricular fibrillation due to coronary spasm after pepper spray.

Pepper spray is used as a crowd control agent and for self-defense. It has been thought to be safe; however, 27 persons have died in police custody after exposure to pepper spray. We report on a 21-year-old man, with no underlying heart disease and a normal ECG and echocardiogram in the past, who was pepper sprayed and developed ventricular fibrillation. An admission ECG showed marked ST segment elevation but subsequent coronary arteriography was normal. We hypothesize that pepper spray triggered coronary spasm, resulting in ventricular fibrillation. This report adds to a body of information that pepper spray is dangerous.

Absence of relevant QT interval prolongation in not critically ill COVID-19 patients.

SARS-CoV-2 is a rapidly evolving pandemic causing great morbimortality. Medical therapy with hydroxicloroquine, azitromycin and protease inhibitors is being empirically used, with reported data of QTc interval prolongation. Our aim is to assess QT interval behaviour in a not critically ill and not monitored cohort of patients. We evaluated admitted and ambulatory patients with COVID-19 patients with 12 lead electrocardiogram at 48 h after treatment initiation. Other clinical and analytical variables were collected. Statistical analysis was performed to assess the magnitude of the QT interval prolongation under treatment and to identify clinical, analytical and electrocardiographic risk markers of QT prolongation independent predictors. We included 219 patients (mean age of 63.6 ± 17.4 years, 48.9% were women and 16.4% were outpatients. The median baseline QTc was 416 ms (IQR 404-433), and after treatment QTc was prolonged to 423 ms (405-438) (P < 0.001), with an average increase of 1.8%. Most of the patients presented a normal QTc under treatment, with only 31 cases (14.1%) showing a QTc interval > 460 ms, and just one case with QTc > 500 ms. Advanced age, longer QTc basal at the basal ECG and lower potassium levels were independent predictors of QTc interval prolongation. Ambulatory and not critically ill patients with COVID-19 treated with hydroxychloroquine, azithromycin and/or antiretrovirals develop a significant, but not relevant, QT interval prolongation.

Holter ECG diagnosis of nicotine-spray induced ventricular fibrillation. An unusual case of Prinzmetal variant angina.

We report on an interesting case of resuscitated sudden cardiac death (SDC) in a 51-year-old with hypertension and positive family history for SDC. The patient was resuscitated and an emergency angiogram ruled out coronary artery disease. Cardio-MRT ruled structural disease or infection. Holter and telemetry monitoring revealed premature ventricular complexes and transient ST-changes followed by anginaepisodes in correlation with the use of the nicotine-replacement-spray. The patient was urged to quit smoking and smoking-substitutes. Medical therapy with calcium-channelblocker and a long acting nitrate was administered. One-month follow up reported no arrhythmic or angina events.

Ventricular fibrillation induced by 2-aminoethoxydiphenyl borate under conditions of hypoxia/reoxygenation.

BACKGROUND: Ventricular fibrillation is an electrophysiological disorder leading to cardiac arrest that can be caused using chemicals. The 2-aminoethoxydiphenyl borate (2-apb) is a poorly understood compound that modulates store operated calcium entry and gap junctions and can provoke ventricular fibrillation. Our study aimed to investigate the effect of 2-apb on the work of an isolated rat heart and coronary vessels under normoxic conditions, as well as under conditions of hypoxia/reoxygenation, that affect intracellular calcium. METHODS: In order to accomplish this task, we used Langendorff rat heart preparation and multi-electrode registration of bioelectric activity of the heart with flexible arrays. An analysis of changes in the volume of coronary blood flow was also performed. RESULTS: Arrhythmogenic effect of 2-apb on an isolated rat heart was shown: an increase in the frequency and variability of the heart rhythm, a decrease in the electrical conductivity of the myocardium, and the appearance of ventricular fibrillation. Under hypoxic conditions, the arrhythmogenic effect of 2-apb decreased and no ventricular fibrillation was observed. In addition, 2-apb had a stabilizing effect on coronary vessels and weakened the effect of reoxygenation on the electrical activity of the heart. CONCLUSIONS: Obtained results indicate that the effect of arrhythmogenic chemicals, for example, proarrhythmic drugs that affect the myocardial [Ca2+]in, depended on the oxygen supply to the heart. The components of the store operated calcium entry and gap junctions can become promising therapeutic targets for controlling the physiological disorders of the heart and blood vessels caused or accompanied by reoxygenation.

ST segment depression and ventricular fibrillation in a dog after contrast agent administration.

An 11-year-old Toy Poodle underwent a computed tomography examination with contrast (iohexol) enhancement under anesthesia. Heart rate and R-wave amplitude on electrocardiogram (ECG) increased 2.5 min after iohexol administration, and end-tidal carbon dioxide decreased to 12 mmHg. A progressive ST segment depression was observed on ECG. Subsequently, the ECG waveform changed to ventricular fibrillation. However, spontaneous circulation returned following cardiopulmonary resuscitation. Myocardial ischemia or anaphylactic shock was suspected in the dog, which explains the ST segment depression observed on ECG. When performing radiological examinations with a contrast agent, the ECG waveform changes, such as an increase in heart rate, R-wave amplitude, or ST segment depression, should be carefully monitored. This might enable early detection of cardiac dysfunction and the ensuing cardiac arrest in dogs.

Lacosamide-induced recurrent ventricular fibrillation: A case report.

Lacosamide, a new antiepileptic drug, acts at central nervous system level but may also affect the heart, increasing the risk of cardiac arrhythmias. Only few cases of lacosamide-induced cardiac dysrhythmia have been published. We report a case of several episodes of a life-threatening ventricular fibrillation requiring cardioversion following the first doses of lacosamide as adjunctive epilepsy treatment.

Successful Use of Early Therapeutic Hypothermia in an MDMA and Amphetamine Intoxication-Induced Out-of-Hospital Cardiac Arrest: A Case Report.

BACKGROUND: Deaths caused by recreational drug abuse have increased considerably in recent years. Therapeutic hypothermia offers the potential to improve neurological outcomes in post-resuscitation patients. CASE REPORT: A 19-year-old man was brought to our emergency department after suffering out-of-hospital ventricular fibrillation (VF) cardiac arrest. He was resuscitated at our emergency department again due to VF. Urine analysis showed high levels of amphetamine and 3,4 methylenedioxymethamphetamine (MDMA) (ecstasy). The patient was intubated, sedated, and ventilated. Within 1 h after the return of spontaneous circulation and hemodynamic stabilization, therapeutic hypothermia was initiated for neurologic protection. An external-cooling device was used for cooling. He was maintained at 33oC for 72 h. The patient was weaned from the ventilator and extubated on day 5. He was discharged from the hospital on the day 10 with good cerebral performance. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Initiation of early therapeutic hypothermia within 1 h after return of spontaneous circulation might contribute to better neurologic outcome in patients who suffer VF cardiac arrest. We suggest that early therapeutic hypothermia may be considered in patients who suffer out-of-hospital cardiac arrest due to MDMA and amphetamine intoxications.

Risk of sudden cardiac arrest and ventricular arrhythmia with sulfonylureas: An experience with conceptual replication in two independent populations.

Sulfonylureas are commonly used to treat type 2 diabetes mellitus. Despite awareness of their effects on cardiac physiology, a knowledge gap exists regarding their effects on cardiovascular events in real-world populations. Prior studies reported sulfonylurea-associated cardiovascular death but not serious arrhythmogenic endpoints like sudden cardiac arrest (SCA) or ventricular arrhythmia (VA). We assessed the comparative real-world risk of SCA/VA among users of second-generation sulfonylureas: glimepiride, glyburide, and glipizide. We conducted two incident user cohort studies using five-state Medicaid claims (1999-2012) and Optum Clinformatics commercial claims (2000-2016). Outcomes were SCA/VA events precipitating hospital presentation. We used Cox proportional hazards models, adjusted for high-dimensional propensity scores, to generate adjusted hazard ratios (aHR). We identified 624,406 and 491,940 sulfonylurea users, and 714 and 385 SCA/VA events, in Medicaid and Optum, respectively. Dataset-specific associations with SCA/VA for both glimepiride and glyburide (vs. glipizide) were on opposite sides of and could not exclude the null (glimepiride: aHRMedicaid 1.17, 95% CI 0.96-1.42; aHROptum 0.84, 0.65-1.08; glyburide: aHRMedicaid 0.87, 0.74-1.03; aHROptum 1.11, 0.86-1.42). Database differences in data availability, populations, and documentation completeness may have contributed to the incongruous results. Emphasis should be placed on assessing potential causes of discrepancies between conflicting studies evaluating the same research question.

Various Manifestations of 5-Fluorouracil Cardiotoxicity: A Multicenter Case Series and Review of Literature.

5-Fluorouracil is a key element to the treatment of colon cancer. But it is also one of the most cardiotoxic chemotherapies, and the management of those that experience cardiotoxicity can be challenging. We present three cases of 5-FU cardiac toxicity that manifested as myocardial infarction, cardiogenic shock, and ventricular fibrillation. Additionally, we discuss the current literature regarding 5-fluorouracil cardiotoxicity mechanisms as well as management.