ABSTRACT
CLINICAL INTRODUCTION: An 88-year-old man, admitted to the emergency room (ER) after three episodes of syncope within 1â day, reported a precursory of syndrome of light-headedness with rapid palpitations that led to an abrupt loss of consciousness. After undergoing percutaneous and surgical revascularisation, he started complaining of chest and back discomfort for the past 20â years and searching for help from Chinese medicine, Fuzi. He had history of chronic renal failure and heart failure, but denied neither taking digitalis nor having family history related to sudden death.On arrival, heart rate was 150â bpm and blood pressure (BP) by cuff was 91/81â mmâ Hg (non-invasive BP could not be accurately obtained during tachycardia) plus oedema on both lower extremities. There were diffuse crackles and indistinct heart sounds on auscultation.The admission ECG was performed in the ER (figure 1). His serum creatinine was 139.7â mmol/L, serum K(+) was 4.7â mmol/L, N-terminal of the prohormone brain natriuretic peptide was highly elevated (12â 000â pg/mL) and troponin I was negative. QUESTION: What is the most likely diagnosis suggested based on the patient's ECG and history? Aconite poisoningDigitalis toxicityCatecholaminergic polymorphic ventricular tachycardia (CPVT)Andersen-Tawil syndrome (ATS).