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.

A Rare Cause and Management of Ventricular Fibrillation: 5-Fluorouracil Toxicity

Um homem de 65 anos com histórico de carcinoma de língua procurou o pronto-socorro com contrações insensíveis estando em casa. Ele estava em terapia com 5-fluorouracil (5-FU) na época. O paciente foi desfibrilado e intubado porque a fibrilação ventricular (FV) se desenvolveu durante o monitoramento no pronto-socorro. A ecocardiografia mostrou que a fração de ejeção do ventrículo esquerdo (FEVE) era de 70% e a espessura do septo interventricular era de 15 mm. A angiografia coronária não revelou qualquer estenose crítica. A ressonância magnética cardíaca (RMC) não mostrou anormalidade de perfusão, fibrose ou cicatriz sugestiva de envolvimento cardíaco. Foi sugerido que a arritmia do paciente estava relacionada principalmente à cardiotoxicidade induzida pelo 5-FU.

O fato de as causas secundárias terem sido proeminentes em nosso caso, de nenhuma patologia cardíaca óbvia que pudesse causar arritmia ter sido encontrada no exame detalhado e de a arritmia não ter recorrido durante a internação hospitalar, que durou até 15 dias, nos levou a acreditar que esse paciente poderia receber alta sem um cardioversor-desfibrilador implantável. Nosso caso foi apresentado para contribuir com a literatura.

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.

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 33^oC 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.

Melatonin receptor activation protects against low potassium-induced ventricular fibrillation by preserving action potentials and connexin-43 topology in isolated rat hearts

Hypokalemia prolongs the QRS and QT intervals, deteriorates intercellular coupling, and increases the risk for arrhythmia. Melatonin preserves gap junctions and shortens action potential as potential antiarrhythmic mechanisms, but its properties under hypokalemia remain unknown. We hypothesized that melatonin protects against low potassium-induced arrhythmias through the activation of its receptors, resulting in action potential shortening and connexin-43 preservation. After stabilization in Krebs-Henseleit solution (4.5 mEq/L K⁺ ), isolated hearts from Wistar rats underwent perfusion with low-potassium (1 mEq/L) solution and melatonin (100 μmol/L), a melatonin receptor blocker (luzindole, 5 μmol/L), melatonin + luzindole or vehicle. The primary endpoint of the study was the prevention of ventricular fibrillation. Electrocardiography was used, and epicardial action potentials and heart function were measured and analyzed. The ventricular expression, dephosphorylation, and distribution of connexin-43 were examined. Melatonin reduced the incidence of low potassium-induced ventricular fibrillation from 100% to 59%, delayed the occurrence of ventricular fibrillation and induced a faster recovery of sinus rhythm during potassium restitution. Melatonin prevented QRS widening, action potential activation delay, and the prolongation of action potential duration at 50% of repolarization. Other ECG and action potential parameters, the left ventricular developed pressure, and nonsustained ventricular arrhythmias did not differ among groups. Melatonin prevented connexin-43 dephosphorylation and its abnormal topology (lateralization). Luzindole abrogated the protective effects of melatonin on electrophysiological properties and connexin-43 misdistribution. Our results indicate that melatonin receptor activation protects against low potassium-induced ventricular fibrillation, shortens action potential duration, preserves ventricular electrical activation, and prevents acute changes in connexin-43 distribution. All of these properties make melatonin a remarkable antifibrillatory agent.

How much can synthetic cannabinoid damage the heart? A case of cardiogenic shock following resistant ventricular fibrillation after synthetic cannabinoid use

New substances are constantly being added to the content of synthetic cannabinoids (SCs). SCs can affect the cardiovascular system and cause hypotension and bradycardia, myocardial infarction, atrial fibrillation, prolonged QTc, and Mobitz type II atrioventricular block. However, no cases associated with ventricular fibrillation (VF) have been reported to date. We report a case of a 26-year-old male patient admitted to the emergency department due to altered consciousness after SC use and requiring prolonged cardiopulmonary resuscitation due to resistant VF and cardiogenic shock.

Fatal butane toxicity and delayed onset of refractory ventricular fibrillation

A 30-year-old male was presented to the Emergency Department (ED) by the Emergency Medical Services (EMS). He was found unconscious but breathing normally, and had a seizure for more than 30 minutes. He was no previous history of systemic disease, previous operation, medication and any known allergy. According to the witnesses, he was alone in the coffee shop, and besides him was a lighter refill canister containing 250 ml extra purified butane gas, and he suddenly collapsed and had seizure. Six hours later, he developed ventricular fibrillation and he was not responding to amiodarone infusion, and 4 times defibrillation and cardioversion. He died after 45 minutes of resuscitation.

[Intravenous epinephrine for anaphylaxis: Kounis or takotsubo syndrome?]

The presence of an acute coronary syndrome in patients with anaphylaxis is a challenging diagnostic conundrum for the cardiologist. Both Kounis syndrome and takotsubo syndrome must be taken into account. We present here the case of a 46-year-old woman suffering from ventricular fibrillation after adrenaline infusion for an anaphylactic reaction. The case report shows the important role of a clear diagnostic work-up and the role of cardiac magnetic resonance in this clinical scenario to reach the final diagnosis of reverse takotsubo cardiomyopathy.

Unusual complications from amitriptyline intoxication

Althoughtricyclic antidepressants(TCAs) are frequently prescribed to patients with depression, these drugs can also be misused. A 21-year-old comatose patient was referred to our hospital presenting with ventricular tachycardia. Despite initial treatment including intravascular lipid emulsion, ventricular fibrillation occurred soon after arrival. Venoarterial extracorporeal membrane oxygenation and therapeutic hypothermia were administered. Refractory arrhythmia disappeared on the next day. A high concentration of amitriptyline was identified in his blood samples on arrival. Mechanical bowel obstruction followed after abdominal compartment syndrome caused by anticholinergic effects, and refractory seizure occurred due to TCA intoxication. Although seizure was brought under control with anticonvulsant agents, his Glasgow Coma Scale did not recover to the full score. MRI presented irreversible damage to the bilateral frontal lobe and insula. Amitriptyline has the potential to cause unusual serious complications, such as abdominal compartment syndrome, irreversible central nervous system disability and lethal arrhythmia.

[Capecitabine-induced ventricular fibrillation]

BACKGROUND

Capecitabine is an orally-administered chemotherapeutic agent used in the treatment of colorectal, gastric and breast carcinoma. Capecitabine has relatively mild side effects. Less known are its potential severe cardiotoxic effects.

CASE DESCRIPTION

We report a case of a 61-year-old man recently diagnosed with rectal cancer. Six days after starting with capecitabine, he developed a cardiac arrest due to ventricular fibrillation (VF). Extensive additional diagnostics did not explain the cardiac arrest nor VF. Given the observed time relation between initiation of capecitabine administration and the occurrence of VF, combined with the absence of other causes for VF, we suspect that VF is a likely consequence of capecitabine-induced coronary vasospasm.

CONCLUSION

Capecitabine-induced VF is a rare occurrence. With the increasing use of capecitabine for the treatment of various cancers, health professionals should be aware of these potential cardiotoxic side effects.

Synthesis and Structure-Activity Relationships of a Series of Aporphine Derivatives with Antiarrhythmic Activities and Acute Toxicity

Some aporphine alkaloids, such as crebanine, were found to present arrhythmic activity and also higher toxicity. A series of derivatives were synthesized by using three kinds of aporphine alkaloids (crebanine, isocorydine, and stephanine) as lead compounds. Chemical methods, including ring-opening reaction, bromination, methylation, acetylation, quaternization, and dehydrogenation, were adopted. Nineteen target derivatives were evaluated for their antiarrhythmic potential in the mouse model of ventricular fibrillation (VF), induced by CHCl₃, and five of the derivatives were investigated further in the rat model of arrhythmia, induced by BaCl₂. Meanwhile, preliminary structure-activity/toxicity relationship analyses were carried out. Significantly, N-acetamidesecocrebanine (1d), three bromo-substituted products of crebanine (2a, 2b, 2c), N-methylcrebanine (2d), and dehydrostephanine (4a) displayed antiarrhythmic effects in the CHCl₃-induced model. Among them, 7.5 mg/kg of 2b was able to significantly reduce the incidence of VF induced by CHCl₃ (p < 0.05), increase the number of rats that resumed sinus rhythm from arrhythmia, induced by BaCl₂ (p < 0.01), and the number of rats that maintained sinus rhythm for more than 20 min (p < 0.01). Therefore, 2b showed remarkably higher antiarrhythmic activity and a lower toxicity (LD50 = 59.62 mg/kg, mice), simultaneously, indicating that 2b could be considered as a promising candidate in the treatment of arrhythmia. Structural-activity analysis suggested that variationsin antiarrhythmic efficacy and toxicity of aporphines were related to the C-1,C-2-methylenedioxy group on ring A, restricted ring B structural conformation, N-quaternization of ring B, levoduction of 6a in ring C, and the 8-, 9-, 10-methoxy groups on ring D on the skeleton.

Carvedilol Mitigates Adverse Effects of Epinephrine During Cardiopulmonary Resuscitation

Introduction: Earlier studies have implicated the adverse effects of β- and α1-adrenergic receptors during cardiopulmonary resuscitation (CPR). Because carvedilol is both a nonselective β- and α1-selective adrenergic receptor-blocking agent, we hypothesized that pre-treatment with carvedilol would convert the actions of epinephrine to that of a selective a2-agonist.

Methods: Ventricular fibrillation (VF) was induced in Sprague-Dawley rats weighing approximately 500 g. Animals were randomized to 4 groups of 5 animals each: (1) placebo pretreatment and epinephrine treatment, (2) carvedilol pretreatment and placebo treatment, (3) carvedilol pretreatment and epinephrine treatment, and (4) placebo pretreatment and placebo treatment. Carvedilol (50 µg/kg) was injected as a bolus into the right atrium 15 minutes before VF was induced. VF was untreated for 8 minutes, after which CPR (chest compression and mechanical ventilation) was begun. Epinephrine (30 µg/kg) was injected into the right atrium 2 minutes after the start of CPR. Electrical defibrillation was attempted after 14 minutes of VF.

Results: All but 2 animals were successfully resuscitated. Approximately equivalent increases in coronary perfusion pressure from 23 ± 1 mm Hg to 30 ± 3 mm Hg were observed after the injection of epinephrine independently of carvedilol pretreatment. Carvedilol pretreatment followed by epinephrine treatment reduced early postresuscitation ventricular ectopy (116 ± 147 vs 834 ± 380, P < .01) and minimized increases in arterial blood lactate at 5 minutes after resuscitation (10.9 ± 2.1 mmol/L vs 17.4 ± 3.5 mmol/L, P < .01). The postresuscitation cardiac index measured 4 hours later was increased (307 ± 43 mL • min-1• kg-1 vs 210 ±6 mL • min-1• kg-1, P <.05). Left ventricular diastolic pressures were decreased (6 ± 1 vs 14 ± 1 mm Hg, P < .05). Animals pretreated with carvedilol survived longer (71 ± 1 vs 45 ± 22 hours, P < .05) and with less postresuscitation neurologic deficit.

Conclusion: After β- and α1-adrenergic blockade with carvedilol before inducing cardiac arrest, epinephrine administered during CPR yielded better postresuscitation myocardial and neurologic functions and significantly increased postresuscitation survival.

Pentobarbital versus medetomidine-ketamine-fentanyl anaesthesia: effects on haemodynamics and the incidence of ischaemia-induced ventricular fibrillation in swine

The present study was performed to compare haemodynamic variables at baseline and the incidence of ventricular fibrillation during the early phase of ischaemia in swine during pentobarbital or medetomidine-ketamine-fentanyl anaesthesia. Twenty-two swine (mean ± SD: 29± 3 kg) were anaesthetized with sodium pentobarbital (induction with 36 mg/kg intraperitoneally, and maintenance with 5-20 mg/kg/h intravenously [i.v.]) and 6 swine (27± 3 kg) were anaesthetized with ketamine and fentanyl (premedicated with medetomidine 0.1 mg/kg and ketamine 10 mg/kg intramuscularly, induction with ketamine 20 mg/kg and fentanyl 0.025 mg/kg i.v., and maintenance with ketamine 20 mg/kg/h and fentanyl 0.025 mg/kg/h i.v.). After a stabilization period of 30 min, the left anterior descending coronary artery (LAD) was occluded for 10 min. Haemodynamic data and occurrence of ventricular fibrillation were recorded. The ischaemic area was measured by fluorescing microspheres. Swine anaesthetized with medetomidine-ketamine-fentanyl had significantly lower heart rate, myocardial contractility, peak left ventricular pressure, arterial blood pressure, aortic blood flow, myocardial blood flow and cardiac index at baseline, than swine anaesthetized with pentobarbital. Whereas none of the swine anaesthetized with pentobarbital fibrillated during the LAD occlusion, ventricular fibrillation occurred in 83% of the animals anaesthetized with medetomidine-ketamine-fentanyl ( P< 0.001). No significant difference was found in size of ischaemic area between the two groups. Thus, we show a depression in haemodynamic variables at baseline and a higher incidence of ventricular fibrillation during the early phase of ischaemia in swine anaesthetized with medetomidine-ketamine-fentanyl compared to swine anaesthetized with pentobarbital.

Pharmacological treatment of cardiac glycoside poisoning

Cardiac glycosides are an important cause of poisoning, reflecting their widespread clinical usage and presence in natural sources. Poisoning can manifest as varying degrees of toxicity. Predominant clinical features include gastrointestinal signs, bradycardia and heart block. Death occurs from ventricular fibrillation or tachycardia. A wide range of treatments have been used, the more common including activated charcoal, atropine, β-adrenoceptor agonists, temporary pacing, anti-digoxin Fab and magnesium, and more novel agents include fructose-1,6-diphosphate (clinical trial in progress) and anticalin. However, even in the case of those treatments that have been in use for decades, there is debate regarding their efficacy, the indications and dosage that optimizes outcomes. This contributes to variability in use across the world. Another factor influencing usage is access. Barriers to access include the requirement for transfer to a specialized centre (for example, to receive temporary pacing) or financial resources (for example, anti-digoxin Fab in resource poor countries). Recent data suggest that existing methods for calculating the dose of anti-digoxin Fab in digoxin poisoning overstate the dose required, and that its efficacy may be minimal in patients with chronic digoxin poisoning. Cheaper and effective medicines are required, in particular for the treatment of yellow oleander poisoning which is problematic in resource poor countries.

β-Adrenergic stimulation and rapid pacing mutually promote heterogeneous electrical failure and ventricular fibrillation in the globally ischemic heart

Global ischemia, catecholamine surge, and rapid heart rhythm (RHR) due to ventricular tachycardia or ventricular fibrillation (VF) are the three major factors of sudden cardiac arrest (SCA). Loss of excitability culminating in global electrical failure (asystole) is the major adverse outcome of SCA with increasing prevalence worldwide. The roles of catecholamines and RHR in the electrical failure during SCA remain unclear. We hypothesized that both β-adrenergic stimulation (βAS) and RHR accelerate electrical failure in the globally ischemic heart. We performed optical mapping of the action potential (OAP) in the right ventricular (RV) and left (LV) ventricular epicardium of isolated rabbit hearts subjected to 30-min global ischemia. Hearts were paced at a cycle length of either 300 or 200 ms, and either in the presence or in the absence of β-agonist isoproterenol (30 nM). 2,3-Butanedione monoxime (20 mM) was used to reduce motion artifact. We found that RHR and βAS synergistically accelerated the decline of the OAP upstroke velocity and the progressive expansion of inexcitable regions. Under all conditions, inexcitability developed faster in the LV than in the RV. At the same time, both RHR and βAS shortened the time to VF (TVF) during ischemia. Moreover, the time at which 10% of the mapped LV area became inexcitable strongly correlated with TVF (R(2) = 0 .72, P < 0.0001). We conclude that both βAS and RHR are major factors of electrical depression and failure in the globally ischemic heart and may contribute to adverse outcomes of SCA such as asystole and recurrent/persistent VF.

Ventricular fibrillation induction and diffuse abnormal ST-segment response to ajmaline in a patient with apparent pre-existing dynamic right bundle branch block

OBJECTIVE

ST-segment elevation in the right precordial electrocardiography (ECG) leads in Brugada syndrome (BS) can be unmasked by class I anti-arrhythmic drugs (sodium channel blockers) administration. It is still debated whether this ECG pattern is better explained by abnormal repolarization or ventricular conduction and depolarization. Conduction diseases can conceal type 1 BS-like ECG in standard V1-V3 leads. ECG alterations were found also in alternative leads. The role of electrophysiology study (EPS) in sudden cardiac death risk stratification remains controversial, and could depend on the phenotypic expression of the cardiac sodium channels disease.

CASE REPORT

We describe unmasked diffuse J-point and ST-segment anomalies in peripheral and precordial ECG leads and ventricular fibrillation (VF) induction by EPS after ajmaline administration in a patient with pre-existing atypical right bundle branch block (RBBB) concealing subtle anomalies in standard V1-V3 leads. RBBB was influenced by the underlying BS-like ECG associating repolarization anomaly and pre-existing conduction disease. EPS induced VF when RBBB was associated with BS-like ECG, and failed to induce VF when RBBB was present alone.

CONCLUSIONS

BS phenotype heterogeneity requires further studies to improve the knowledge of its pathophysiological mechanisms associated with conduction diseases in order to better identify an individual therapy and prognostic stratification.

Papaverine-induced QT interval prolongation and ventricular fibrillation in a patient with a history of drug-induced QT prolongation

A 64-year-old woman underwent a coronary flow reserve evaluation using intracoronary-administered papaverine into the left anterior descending artery. Her baseline electrocardiogram (ECG) was normal, but toward the end of papaverine administration, the QTU intervals were excessively prolonged and torsade de pointes occurred, leading to ventricular fibrillation. Ten months previously, the patient's ECG showed mildly prolonged QTc (480 ms(1/2)), which normalized after the cessation of bepridil. This case report suggests that a history of drug-induced QT prolongation can be a risk factor for papaverine-induced fatal ventricular arrhythmia.

[Weight loss pills purchased on the internet as the cause of ventricular fibrillation]

We present a case regarding a 25-year-old woman who had been taking unauthorized weight loss pills prior to a sudden cardiac arrest from which she was resuscitated by paramedics. Her initial electrocardiogram revealed a prolonged corrected QT-interval (QTc). During admission she developed torsades de pointes and was treated with magnesium sulphate and temporary pacing. An electrophysiological study, a coronary angiogram and genetic testing for long QT syndrome all revealed normal results. After cessation of the pills the QTc normalized, and two weeks later she was discharged.

Ventricular fibrillation cardiac arrest due to 5-fluorouracil cardiotoxicity

The antimetabolite chemotherapeutic agent 5-fluorouracil is used to treat a variety of cancers. Although 5-fluorouracil is generally well tolerated, its toxicity profile includes potential cardiac ischemia, vasospasm, arrhythmia, and direct myocardial injury. These actual or potential toxicities are thought to resolve upon cessation of the medication; however, information about the long-term cardiovascular effects of therapy is not sufficient. We present the case of a 58-year-old man who had 2 ventricular fibrillation cardiac arrests, with evidence of coronary vasospasm and myocarditis, on his 4th day of continuous infusion with 5-fluorouracil. External defibrillation and cessation of the 5-fluorouracil therapy resolved the patient's electrocardiographic abnormalities. In addition to reporting the clinical manifestations of 5-fluorouracil-associated cardiotoxicity in our patient, we discuss management challenges in patients who develop severe 5-fluorouracil-induced ventricular arrhythmias.

Contrast media injection into right coronary artery caused thrombus extraction to aorta that may have resulted in left main trunk thrombosis

A 59-year-old man with inferior acute myocardial infarction underwent an urgent coronary angiography and as a result a total occlusion of the ostial right coronary artery (RCA) was observed. Interestingly, the thrombus in the RCA clearly shortened within 2.3 s during the contrast media injection. While we prepared for percutaneous coronary intervention (PCI) of the RCA, ventricular fibrillation occurred and pulseless electrical activity continued in spite of repeated cardioversion. Despite no stenosis in the left main trunk (LMT) in the initial coronary angiography, the LMT was totally occluded. Following aspiration therapy on the LMT with percutaneous cardiopulmonary support, PCI of the RCA was performed. A coronary angiography should be carefully performed if a lot of thrombi exist in the coronary ostium because LMT embolism may have been caused by thrombus extraction from the RCA by contrast media injection.

On-chip constructive cell-network study (II): on-chip quasi-in vivo cardiac toxicity assay for ventricular tachycardia/fibrillation measurement using ring-shaped closed circuit microelectrode with lined-up cardiomyocyte cell network

BACKGROUNDS

Conventional in vitro approach using human ether-a-go-go related gene (hERG) assay has been considered worldwide as the first screening assay for cardiac repolarization safety. However, it does not always oredict the potential QT prolongation risk or pro-arrhythmic risk correctly. For adaptable preclinical strategiesto evaluate global cardiac safety, an on-chip quasi-in vivo cardiac toxicity assay for lethal arrhythmia (ventricular tachyarrhythmia) measurement using ring-shaped closed circuit microelectrode chip has been developed.

RESULTS

The ventricular electrocardiogram (ECG)-like field potential data, which includes both the repolarization and the conductance abnormality, was acquired from the self-convolutied extracellular field potentials (FPs) of a lined-up cardiomyocyte network on a circle-shaped microelectrode in an agarose microchamber. When Astemisol applied to the closed-loop cardiomyocyte network, self-convoluted FP profile of normal beating changed into an early afterdepolarization (EAD) like waveform, and then showed ventricular tachyarrhythmias and ventricular fibrilations (VT/Vf). QT-prolongation-like self-convoluted FP duration prolongation and its fluctuation increase was also observed according to the increase of Astemizole concentration.

CONCLUSIONS

The results indicate that the convoluted FPs of the quasi-in vivo cell network assay includes both of the repolarization data and the conductance abnormality of cardiomyocyte networks has the strong potential to prediction lethal arrhythmia.

[Case of ventricular fibrillation in patients with brugada type electrocardiogram during surgery]

We described a case of ventricular fibrillation in patients with Brugada type electrocardiogram (ECG) during surgery. A 63-year-old man underwent lung lobectomy under combined general and epidural anesthesia. His preoperative ECG showed Brugada type, but he was asymptomatic and did not have a family history of sudden death. Anesthesia was induced using propofol, vecuronium and fentanyl, and maintained using propofol and lidocaine via epidural catheter. One hour into operation, ventricular fibrillation developed. After cardiac compression in a few seconds, sinus rhythm was restored and blood pressure was elevated. When the wound was sutured, ventricular fibrillation occurred again. Defibrillation was attempted immediately and sinus rhythm was restored. We diagnosed coronary spastic angina after acetylcholine challenge test. Previous report describes that the incidence of vasospasm in Brugada type ECG cases is relatively higher than those with the normal ECG. In addition, ventricular fibrillation might be induced by local anesthetics because these agents were administrated 10 minutes before the few events and balance of autonomic nervous system was changed. We conclude that strict monitoring and immediate treatment for ventricular fibrillation are important for anesthetic management in asymptomatic patient with Brugada type ECG.

[Massive lamotrigine poisoning--case report]

Lamotrigine is a phenyltriazine derivative used as antiepileptic drug with pharmacological profile similar to phenytoin. It is chemically unrelated to the other antiepileptic drugs and mechanism of anticonvulsant action is that lamotrigine inhibits sodium channels, resulting in neuronal membrane stabilization and block of excitatory neurotransmitter release. Mean therapeutical dose of lamotrigine is 200 - 400 mg/day. Overdose experience with lamotrigine is limited. In severe cases of poisonings there were serious effects such as: coma, respiratory depression, recurrent seizures and intraventricular conduction disturbances. We report massive suicidal poisoning with lamotirigine unknown dose. Clinical course was severe--we observed deep coma, respiratory depression, epileptical state, ventricular disrhytmias, atrio-venticular heart block, cardiovascular shock, rhabdomyolysis and hypokalemia. There was ventricular fibrillation in course of poisoning. The patient was successfully resuscitated and discharged on 18 hospital day.

[Toxicological and medico-legal analyses of sudden deaths resulting from butane inhalation]

Butane is known to be a suffocating gas with narcotic activity, especially at high concentrations. Within the past five years, a few cases of sudden deaths in teenage boys who had inhaled butane, a component of gas for lighters, were investigated in the Forensic Medicine Department, Medical University of Silesia, Katowice. Analyses of biological materials secured at autopsies and evidence from places of deaths was carried out using GC/FID. Butane was found in blood, lung and brain samples of the deceased. Moreover, histopathological examinations were performed. Results of autopsies and additional analyses were appraised from the point of view of their significance and usefulness in giving medico-legal opinions on the cause of death.

[Myocardial infarction in a 16-year old following inhalation of butane gas]

BACKGROUND

Butane gas is inhaled by young people with the aim of getting 'high'. This can cause coronary spasm with myocardial infarction and ventricular fibrillation as a result.

CASE DESCRIPTION

We report on a 16-year-old male who collapsed at home after sniffing butane. His father, together with a paramedical emergency team that had found ventricular fibrillation, started basic and advanced life support. ECG showed exaggerated ST-elevations and an echocardiography showed a hypokinetic anterior ventricular wall and ventricular septum. After treatment with dobutamine, nitroglycerine, acetylsalicylic acid and dalteparine, the ECG and left ventricular function improved. He was admitted to a pediatric intensive care unit where he was artificially ventilated for 4 days and treated for cardiogenic shock. In the following days his cardiovascular condition improved. Magnetic resonance imaging showed no ischaemic damage of the brain. At 6 weeks his general condition was not as before, but ECG and cardiac function had almost recovered.

CONCLUSION

Young people who experiment with inhalation of volatile substances generally do not know how dangerous this is. Provision of information about the possible consequences will have a preventive effect.

Antiarrhythmic and antioxidant activity of novel pyrrolidin-2-one derivatives with adrenolytic properties

A series of novel pyrrolidin-2-one derivatives (17 compounds) with adrenolytic properties was evaluated for antiarrhythmic, electrocardiographic and antioxidant activity. Some of them displayed antiarrhythmic activity in barium chloride-induced arrhythmia and in the rat coronary artery ligation-reperfusion model, and slightly decreased the heart rate, prolonged P–Q, Q–T intervals and QRS complex. Among them, compound EP-40 (1-[2-hydroxy-3-[4-[(2-hydroxyphenyl)piperazin-1-yl]propyl]pyrrolidin-2-one showed excellent antiarrhythmic activity. This compound had significantly antioxidant effect, too. The present results suggest that the antiarrhythmic effect of compound EP-40 is related to their adrenolytic and antioxidant properties. A biological activity prediction using the PASS software shows that compound EP-35 and EP-40 can be characterized by antiischemic activity; whereas, compound EP-68, EP-70, EP-71 could be good tachycardia agents.

A case of fatal caffeine poisoning

Caffeine is a natural alkaloid methylxanthine that is found in various plants such as coffee or tea. Symptoms of a severe overdose may present with hypokalemia, hyponatremia, ventricular arrhythmias, hypertension followed by hypotension, respiratory failure, seizures, rhabdomyolysis, ventricular fibrillation and finally circulatory collapse. A 21-year-old woman called for the ambulance herself soon after the ingestion of about 10,000 mg of caffeine. At the arrival of the ambulance, the patient went into cardiac arrest almost immediately. After a total resuscitation period of 34 min including seven counter-shocks and 2 mg epinephrine, the patient was stable enough to be transferred to the hospital. The patient soon went into VF again and received two more counter-shocks and 1 mg epinephrine and finally an intravenous bolus dose of 300 mg amiodarone. The initial arterial blood gas showed pH at 6.47, lactate at 33 mmol/l and potassium level at 2.3 mmol/l. Unfortunately, no blood samples for caffeine analysis were taken. Three days after hospital admission, the patient developed myoclonus, which did not respond to medical treatment. Excessive intake of caffeine may produce arrhythmias and pronounced hypokalemia and ensuing ventricular fibrillation. In case of counter-shock-resistant VF, it can be necessary to give an early loading dose of amiodarone. Furthermore, it may be beneficial to replace the potassium as early as possible. Epinephrine and buffer solutions used during resuscitation may further decrease blood potassium levels and should be administrated cautiously. Epinephrine can be replaced by other vasopressor drugs, such as vasopressin without effects on beta-receptors.

Brugada syndrome with aborted sudden cardiac death related to liquorice-induced hypokalemia

OBJECTIVE

It was the aim of this study to report an aborted cardiac arrest due to ventricular fibrillation and electrocardiographic changes consistent with Brugada syndrome due to liquorice-induced hypokalemia.

CLINICAL PRESENTATION AND INTERVENTION

Ventricular fibrillation was witnessed in a 50-year-old woman who was admitted to our emergency department with a history of liquorice ingestion, a herbal product. After stopping liquorice ingestion, the Brugada-like electrocardiographic pattern changed progressively with potassium replacement. A diagnosis of Brugada syndrome was made after the ajmaline challenge test. The patient was discharged with an implantable cardioverter defibrillator and had an uneventful follow-up.

CONCLUSION

This report illustrates the importance of the investigation for herbal medications in the detailed history of a patient in the cases of electrolyte disturbances and the potential role of hypokalemia in the induction of malignant arrhythmia in Brugada syndrome.

Prodromal ventricular premature beats preceded by a diastolic wave

In a prospective study of quinidine syncope, 71 patients with atrial fibrillation/flutter were ECG monitored for four days after the start of quinidine therapy. Six patients developed ventricular tachycardia (VT) or ventricular fibrillation (VF) during the first 48 hours in sinus rhythm. Q-T prolongation was seen in most patients with and without VT/VF and was non-predictive in this respect. However, a diastolic wave (DW) of larger amplitude than the preceding T wave usually followed by a ventricular premature beat (VPB) appeared in five of the six VT/VF patients (13-185 min before the first event) and in none of the remaining 63 patients reaching sinus rhythm. For comparison, two of our own cases and nine from the literature with idiopathic long Q-T or alternating T wave syndromes were studied for these DW-VPBs. They were found in all ten cases with a VPB recording, but among 19 patients with acute myocardial infarction and VT/VF no such case was seen. As VT/VF was more common after large and VPB after small amplitude DWs, it is discussed whether the DW not only precedes but also initiates the ventricular tachyarrhythmias.

Ventricular fibrillation after intravenous atropine for treatment of sinus bradycardia

A patient with acute myocardial infarction and sinus bradycardia has been treated with 0.5 mg atropine intravenously. Shortly after the injection he showed a sinus tachycardia, then developed ventricular ectopic beats, ventricular tachycardia and ventricular fibrillation, which was treated successfully with electrical countershock.

Recurrent life-threatening ventricular dysrhythmias associated with acute hydrofluoric acid ingestion: Observations in one case and implications for mechanism of toxicity

INTRODUCTION

Hydrofluoric acid (HF) is a weak inorganic acid used for etching and as rust remover. Systemic toxicity is manifested as ventricular dysrhythmias. The mechanisms for these dysrhythmias are not well elucidated.

CASE REPORT

An 82-year-old woman ingested 8 ounces of 7% HF. Shortly after emergency department (ED) arrival, she became pulseless, developing recurrent ventricular dysrhythmias. She was defibrillated 17 times and received several doses of calcium, magnesium, and lidocaine. After three hours, she returned to sustained NSR. She was discharged home after four days.

DISCUSSION

The electrocardiographic findings in this patient demonstrate hypocalcemia, which has been implicated as the culprit in HF-induced arrhythmias. However, despite correction of the hypocalcemia, the ventricular arrhythmias persisted. The proposed mechanisms of systemic HF toxicity and the relevant literature are discussed.

CONCLUSION

Ventricular dysrhythmias due to HF toxicity seem to be independent of either hypocalcemia or hyperkalemia. Systemic toxicity after ingestions may be delayed and precipitous.

Brugada syndrome whose ST-segment changes were enhanced by antihistamines and antiallergenic drugs

We describe a case of Brugada syndrome, in which a coved type ST-segment elevation was enhanced by antihistamines and antiallergenic drugs. The patient had been treated with four kinds of antihistamines and antiallergenic drugs. The twelve-lead ECG exhibited a coved type ST-segment elevation in leads V(1) and V(2), and their enhancement was induced by pilsicainide. After discontinuing those drugs, the ST segment elevation in leads V(1) and V(2) became reduced. An ICD implantation was selected for the therapy since ventricular fibrillation was induced. Our report discusses the possible contribution of antihistamines and antiallergenic drugs to the Brugada type ST-segment changes.