Differential Diagnosis of Biphasic EKG

The presence of a biphasic EKG pattern can be indicative of various cardiac conditions. Here's a categorized differential diagnosis to consider:

• Single Most Likely Diagnosis

  • Pericarditis: This condition is characterized by inflammation of the pericardium, the sac surrounding the heart. A biphasic EKG pattern, particularly with ST-segment elevation in multiple leads, is a common finding. The biphasic nature can reflect the evolution of the pericardial inflammation.

• Other Likely Diagnoses

  • Myocardial Infarction (MI): Certain types of MI, especially those involving the right ventricle or posterior wall, can present with biphasic EKG patterns. The biphasic pattern may be seen in leads that are adjacent to the area of infarction.
  • Cardiac Contusion: Trauma to the chest can cause a cardiac contusion, which may result in a biphasic EKG due to the injury of the heart muscle.
  • Early Repolarization: This is a benign condition that can mimic more serious cardiac issues on an EKG. It often presents with a biphasic or notched J-point in the leads, particularly in the precordial leads.

• Do Not Miss Diagnoses

  • Pulmonary Embolism (PE): While not typically the first diagnosis that comes to mind with a biphasic EKG, a large PE can cause right ventricular strain, leading to EKG changes that might include a biphasic pattern in certain leads. Missing this diagnosis can be fatal.
  • Cardiac Tamponade: This condition, characterized by fluid accumulation in the pericardial sac leading to cardiac compression, can present with EKG changes including low voltage QRS complexes and, in some cases, biphasic patterns due to the shifting of the heart's electrical axis.

• Rare Diagnoses

  • Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): A rare condition where the muscle in the right ventricle is replaced by fat and scar tissue, leading to abnormal heart rhythms. EKG findings can include a biphasic T-wave in lead V1, among other abnormalities.
  • Brugada Syndrome: Characterized by a specific pattern on the EKG (often described as a "coved" type ST elevation in leads V1-V3), it can sometimes present with biphasic patterns in these leads. This syndrome is associated with an increased risk of sudden cardiac death.

Each of these diagnoses has distinct clinical and EKG features, and a thorough evaluation, including clinical history, physical examination, and additional diagnostic tests (e.g., echocardiography, troponin levels), is necessary to determine the underlying cause of a biphasic EKG pattern.