Life-Threatening Cardiac Toxicity After Chewing Inverted Nut (Pinang-Wang)

A 51-year-old man collapsed after chewing a pinang-wang due to curiosity. He was transported to our emergency department (ED) presenting with out-of-hospital cardiac arrest. Quick paddle look showed ventricular fibrillation and the patient received repetitive defibrillation, epinephrine, vasopressin, amiodarone, lidocaine and magnesium sulphate. After 20 minutes, it changed to wide QRS complex tachycardia. Intravenous sodium bicarbonate (1 mEq/kg, total dose: 70 mEq) was administered and the arrhythmia was successfully terminated. His blood pressure increased to 126/71 mmHg. Electrocardiogram showed ST segment elevation over precordial leads (V1-V6). Primary percutaneous coronary intervention revealed normal coronary arteries. However, the electrocardiogram remained ST elevation post-percutaneous coronary intervention. General blood laboratory tests, except for cardiac enzyme, revealed normal results. Cardiac enzyme results showed myocardial injury with a maximal troponin I of 151.2 ng/ml. He was then admitted to the intensive care unit. Two days later, ST segment elevation returned to the baseline level. His plasma concentrations of arecolin and arecaidine measured by liquid chromatography tandem mass spectrometry revealed 10.1 ng/ml and 183 ng/ml, respectively. Both of these levels also decreased to undetectable after 2 weeks. He did not have any arrhythmia attack during the period.

Betel nut is commonly used in East Africa, Far East Asia, India, and the South Pacific. It has been brought to the Western Hemisphere by immigrants, but its use has not spread to the general population.1 Chewing betel nut independently contributes to the risk of oropharyngeal cancer, oral mucosal lesions, oral leukoplakia, etc.2 Betel nut contains several alkaloids. Arecolin and arecaidine have the properties of acetylcholine at central ganglionic, peripheral nicotinic and muscarinic receptors. Acute effects of betel nut cause cardiac arrhythmia, bronchospasm, psychosis, etc.3 Pinang-wang and betel nut are from the same betel nut tree (Figure). There are 0-4 pinang-wang on each spadix of a betel nut tree. Pinang-wang growing in the different direction on the same spadix have higher alkaloid concentrations and severe clinical effects. In our patient, collapse occurred immediately after chewing a pinang-wang and high concentrations of arecolin and arecaidine were also noted. Those were decreased gradually and no more arrhythmia was noted thereafter. This suggests that arecolin and arecaidine may be related to the development of malignant arrhythmia. We treated the arrhythmia of the patient according to ventricular fibrillation algorithm initially, but in vain. Later on, wide QRS tachycardia was noted and converted by the injection of intravenous sodium bicarbonate. Therefore we assume that the constituents of pinang-wang may possess sodium channel blocker properties. In addition, coronary spasm induced by arecoline might be the cause of acute myocardial infarction.4 The cause of prolonged ST-segment elevation in our patient may not be due to acute myocardial infarction because of normal coronary angiogram. It may be related to transthoracic defibrillation.5

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Figure. Pinang-wang.

In conclusion, high arecoline and arecaidine concentrations after chewing pinang-wang may result in ventricular fibrillation. If this arrhythmia has no response to the standard algorithm treatment, sodium bicarbonate may be used.