A patient in their 60s presented to the emergency department with approximately 20 minutes of acute, severe precordial chest pain radiating to their left arm at night, accompanied by dyspnea, dizziness, and sweating. The patient’s medical history was notable for hypertension, cerebral infarction, diabetes, and nicotine addiction. On the patient’s arrival, the vital signs showed blood pressure of 188/101 mm Hg, heart rate at 84 beats/min, and respiratory rate at 20 breaths/min. The initial serum cardiac troponin I level of the patient was lower than 0.05 ng/mL (normal range, <0.16 ng/mL; to convert to μg/L, multiply by 1) and the potassium level was 4.1 mEq/L (normal range, 3.5-5.3 mEq/L; to convert to mmol/L, multiply by 1). The patient’s 12-lead electrocardiogram (ECG) obtained on admission is shown in the Figure, A.
Please finish quiz first before checking answer.
Read the answer below and download your certificate.
Read the discussion below and retake the quiz.
The 12-lead ECG changes are important for the early recognition and diagnosis of acute myocardial infarction (AMI), such as the high peaked T waves before ST elevation representing hyperacute T waves (HATW). In 1975, Schamroth put forward the term HATW,1 which was constantly improved later. Collins and colleagues2 proposed the following diagnostic criteria of HATW after analyzing 13 393 ECGs: (1) J point position/T amplitude greater than 25%, (2) T amplitude/QRS amplitude greater than 75%, (3) J point position greater than 0.3 mV, (4) age older than 45 years, with a specificity of 98% and sensitivity of 61.9%. The pattern of HATW is featured with high amplitude, broad base, and more likely asymmetrical quality, which indicates that subendocardial myocardial ischemia occurs first during AMI, usually lasting from 5 to 30 minutes.3 Without any treatment, HATW can evolve into ST elevation myocardial infarction (STEMI) or uncommon de Winter ECG.4 Notably, there is another ECG pattern, coronary T wave, which is also an ECG sign for ACS. Unlike HATW morphology, the coronary T wave is characterized by an inverted deep tip and symmetrical limbs.5
Sign in to take quiz and track your certificates
JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 Credit(s)™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC
CME Disclosure Statement: Unless noted, all individuals in control of content reported no relevant financial relationships. If applicable, all relevant financial relationships have been mitigated.
Corresponding Author: Tong Liu, MD, PhD, Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, No. 23, Pingjiang Road, Hexi District, Tianjin 300211, People’s Republic of China (email@example.com).
Published Online: November 28, 2022. doi:10.1001/jamainternmed.2022.5057
Conflict of Interest Disclosures: None reported.
Funding/Support: The work was funded by Tianjin Key Medical Discipline (Specialty) Construction Project.
Role of the Funder/Sponsor: The funder had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Contributions: The authors thank Nan Zhang, MD, Second Hospital of Tianjin Medical University, and Chuan-Hai Zhang, MD, The First Affiliated Hospital of Jinzhou Medical University, who were not compensated, for their helpful comments.
Additional Information: Drs Zhao and Jia are co–first authors. They contributed equally to this work.
You currently have no searches saved.
You currently have no courses saved.