title: An 88-year-old man with syncope and an alternating axis.
abstract: An 88-year-old man, admitted to the emergency room (ER) after three episodes of syncope within 1 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 20 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 150 bpm and blood pressure (BP) by cuff was 91/81 mm 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 139.7 mmol/L, serum K(+) was 4.7 mmol/L, N-terminal of the prohormone brain natriuretic peptide was highly elevated (12 000 pg/mL) and troponin I was negative.
  
  
  
  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).
authors.affiliation: Department of Cardiology, Aerospace Center Hospital, Beijing, People's Republic of China.
authors.forename: Yun-Tao
authors.initials: YT
authors.lastname: Zhao
authors.affiliation: Peking University Aerospace School of Clinical Medicine, Peking University Health Science Center, Beijing, People's Republic of China.
authors.forename: Yen Shu
authors.initials: YS
authors.lastname: Huang
authors.affiliation: Department of Cardiology, Aerospace Center Hospital, Beijing, People's Republic of China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Yi
mesh_terms: D031841:Aconitum / Q000506:poisoning*; D000200:Action Potentials / Q000187:drug effects; D000369:Aged, 80 and over; D004224:Diterpenes / Q000506:poisoning*; D004365:Drugs, Chinese Herbal / Q000506:poisoning*; D004562:Electrocardiography; D006329:Heart Conduction System / Q000187:drug effects* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D013575:Syncope / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology; D013610:Tachycardia / Q000139:chemically induced* / Q000175:diagnosis / Q000503:physiopathology
chemical_list: D004224:Diterpenes; D004365:Drugs, Chinese Herbal; C575009:fuzi drug herbal