Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 8, 2025 • View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Differential Diagnosis for Biphasic V5 and V6

Single most likely diagnosis

  • Myocardial Infarction (MI): Biphasic QRS complexes in leads V5 and V6 can be indicative of a myocardial infarction, particularly if there are associated ST-segment changes or Q waves. This pattern may suggest ischemia or infarction in the lateral wall of the heart.

Other Likely diagnoses

  • Left Ventricular Hypertrophy (LVH): LVH can cause alterations in the QRS complex, including biphasic patterns in the lateral leads (V5, V6) due to the increased thickness of the left ventricular wall.
  • Bundle Branch Blocks: Both left and right bundle branch blocks can alter the QRS morphology, potentially leading to biphasic patterns in various leads, including V5 and V6, due to the abnormal ventricular depolarization.
  • Ventricular Arrhythmias: Certain ventricular arrhythmias, such as premature ventricular contractions (PVCs), can exhibit biphasic QRS complexes in leads V5 and V6, depending on the origin of the arrhythmia.

Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)

  • Acute Coronary Syndrome (ACS): While MI is considered under the single most likely diagnosis, ACS encompasses a broader range of conditions (including unstable angina and non-ST elevation MI) that could present with biphasic QRS changes in V5 and V6 and requires immediate attention.
  • Cardiac Sarcoidosis: This condition can cause various ECG abnormalities, including biphasic QRS complexes, due to granulomatous infiltration of the myocardium. It's crucial to consider due to its potential for significant morbidity and mortality if not treated.

Rare diagnoses

  • Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): Although primarily affecting the right ventricle, ARVC can occasionally present with ECG abnormalities in the lateral leads, including biphasic QRS complexes, due to fibrofatty replacement of the myocardium.
  • Myocardial Fibrosis: Focal or diffuse myocardial fibrosis can lead to abnormal depolarization patterns, potentially resulting in biphasic QRS complexes in various leads, including V5 and V6. This condition might be secondary to various causes, including myocarditis, cardiomyopathies, or aging.

Related Questions

Can atenolol (beta blocker) decrease sodium levels, leading to hyponatremia?
What are the side effects of Topamax (topiramate)?
What is the treatment approach for infected tophi in gout?
What do you see in a Left Bundle Branch Block (LBBB)?
What are ostium primum and ostium secundum Atrial Septal Defects (ASDs), their differences, causes, and management strategies?
Is Flagyl (metronidazole) safe to use during pregnancy?

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.

Ask Question