An unusual case of cardiac glycoside toxicity

摘要: Cardiac glycosides are naturally occurring toxins that reversiblyinhibit the sodium–potassium adenosine triphosphatase (Na–K–ATPase) exchanger in myocardial cells. They found various plantspecies, such as foxglove (Digitalis purpurea, Digitalis lanata), ouabain(Strophanthus gratus), common oleander (Nerium oleander), yellowoleander (Thevetia peruviana), and sea mango (Cerbera manghas) [1].Self-poisoningwith seeds or fruits of theseplantsisa major clinicalprobleminpartsofthedevelopingworldcausingasignificantnumberofdeaths each year [2]. In particular though, from Cerberaodollamtree (also known asthe“Suicide tree” “Pong-pongtree”)areexcessively toxic, containing cerberin main active cardiacglycoside, often used for suicide homicide certain rural areasof South Asia [3]. countries far natural habitat theseextremely toxic plants, poisonings relatively unknown to Westernphysicians rarely reported. We present an unusual case acutecardiacglycosidetoxicityduetosuicidalingestionof“Pong-pong”seedspurchased online website.A 51-year-old womanwith a history depression prior suicideattempts with drug overdoses presented EmergencyDepartment complaining nausea, vomiting, diarrhea, chesttightness since awakening morning. On physical examination,she was lethargic profoundly bradycardic irregular pulse.Her heart rate 30 beats per minute (bpm) blood pressure90/60 mm Hg. An electrocardiogram (ECG) demonstrated atrialflutter(AFl) variable atrioventricular (AV) block slowventricular response, diffuse ST-segment depressions, shortened QTinterval, peaked T-waves (Fig. 1A). Laboratory studies weresignificant serum potassium level 7.5 mmol/L (normal: 3.5 –5.1),calcium 10.9 mg/dL (normal 8.6 –10.2), creatinine 2.6 mg/dL(normal:0.7–1.2).CardiacenzymesweremildlyelevatedwithatroponinT 0.07 ng/mL b0.03). Comprehensive urinetoxicologyscreenswereunremarkable.Adigoxinconcentrationlevelwasundetectable (b0.3 ng/mL).The patient administered atropine her symptomaticbradycardia, which improved 91 bpm. Calciumgluconate, sodium bicarbonate, glucose, insulin therapy weregiven severe hyperkalemia setting acute kidney injury.A repeat ECG showed continuedAFlwithvariable AV block, shortenedQT interval, deeper, downsloping depressions(Fig.1B). A 5.5 mmol/L, correlatingwithresolutionofthepeakedT-wavesonECG.Arepeatserumcalciumlevel 10.3 mg/dL, though QT interval remained onECG. She transferred Intensive Care Unit (ICU) forcontinued supportive therapy.Upon further questioning ICU, admitted theintentionalingestionofanunknownquantityofseedsobtainedfroma“Pong-pong” tree she purchased several weeks onlinewebsite. The Poison Control Center immediately called, thepatientsubsequentlyreceived10vialsofempiricdigoxinimmuneFab.The following revealed return normal sinus rhythm,continued shortening, persistent depres-sions biphasic T waves, compared priorECGwithresolutionofdysrhythmias(Fig.1C).Furtherevaluationwithan echocardiogram cardiac catheterization normal. wasadministered another 10 vials digoxin immune Fab ultimatenormalization resolution ST-segmentdepressions within 24 h (Fig.1D). recovered uneventfullyand later discharged stable condition.To best our knowledge, this is first reported themedical literature Cerbera odollam poisoning United States.Although parts Asia, non-pharmacologiccardiac glycoside toxicity rare States. Of more than2.3 million human exposures 2011 National PoisonData System, only 569 calls were received plant glycosides(excluding drugs) [4].