A patient in their 80s with a history of paroxysmal atrial fibrillation presented to the emergency department with palpitation, dizziness, nausea, and vomiting. The patient was treated with propafenone 3 × 150 mg/d and discontinued metoprolol use a week ago due to low blood pressure. The patient remained mentally clear. Physical examination revealed a blood pressure of 82/60 mm Hg and heart rate of 160 beats/min. Serum potassium level was 5.2 mmol/L. A 12-lead electrocardiogram (ECG) was obtained (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.
Questions: What is the ECG diagnosis, and how should this patient’s treatment be managed?
The ECG revealed a regular monomorphic wide QRS complex tachycardia (162 beats/min) with a right bundle-branch block (RBBB) pattern and a reversed (<1.0) R/S ratio in lead V6. The possible differential diagnoses include (1) ventricular tachycardia (VT) from the mid to apical left ventricle or idiopathic fascicular VT, (2) supraventricular tachycardia (SVT)/atrial flutter (AFL) with aberration, (3) SVT with preexcitation, and (4) SVT/AFL with QRS widening due to electrolyte disturbance or antiarrhythmic drugs (AADs). Several features supported the diagnosis of VT: in lead II, the R wave peak time (80 milliseconds) was greater than 50 milliseconds (specificity, 99%; sensitivity, 93%).1 In lead aVR, there was an initial dominant R wave (accuracy, 98.6%).2 In lead V6, the R/S ratio was less than 1.0 (specificity, 78.3%; sensitivity, 82.1%).3 However, several features argue against this: in leads V5 and V6, the R to S interval (80 milliseconds) was not more than 100 milliseconds.4 Atrioventricular (AV) dissociation was not found.
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: Hua Wang, MD, Department of Cardiology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, No. 1, Da Hua Rd, Dongcheng District, Beijing 100730, People’s Republic of China (email@example.com).
Published Online: January 30, 2023. doi:10.1001/jamainternmed.2022.6096
Conflict of Interest Disclosures: None reported.
Funding/Support: This work was supported by grants from the Capital’s Funds for Health Improvement and Research (CFH 2022-1-4052).
Role of the Funder/Sponsor: The funder had no role in the preparation, review, or approval of the manuscript and decision to submit the manuscript for publication.
Credit Designation Statement: The American Medical Association designates this Journal-based CME activity activity for a maximum of 1.00 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to:
It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting MOC credit.
You currently have no searches saved.
You currently have no courses saved.