Differential Diagnosis for PVC vs Aberrantly Conducted Complex
- Single most likely diagnosis:
- Premature Ventricular Contraction (PVC) - This is the most likely diagnosis because PVCs are common and can mimic aberrantly conducted complexes on an electrocardiogram (ECG). PVCs originate from a ventricular focus and can have a wide QRS complex, similar to an aberrantly conducted supraventricular beat.
- Other Likely diagnoses:
- Aberrantly Conducted Supraventricular Beat - This is another likely diagnosis, as supraventricular beats can be conducted aberrantly, resulting in a wide QRS complex that resembles a PVC. The key to differentiating this from a PVC is the presence of a P wave preceding the QRS complex.
- Ventricular Escape Beat - This can also present with a wide QRS complex and may be mistaken for a PVC or an aberrantly conducted complex. However, escape beats typically occur in the setting of a slow heart rate or atrioventricular block.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Ventricular Tachycardia (VT) - Although less common, VT is a life-threatening condition that can present with wide QRS complexes and must be differentiated from PVCs and aberrantly conducted complexes. The key to diagnosing VT is the presence of three or more consecutive premature ventricular beats at a rate greater than 100 beats per minute.
- Wolff-Parkinson-White (WPW) Syndrome - This condition can cause wide QRS complexes due to pre-excitation of the ventricles via an accessory electrical pathway. WPW syndrome can lead to life-threatening arrhythmias, such as atrial fibrillation with rapid ventricular response, and must be considered in the differential diagnosis.
- Rare diagnoses:
- Bundle Branch Re-entry Tachycardia - This is a rare condition that can cause wide QRS complexes and may be mistaken for PVCs or aberrantly conducted complexes. It typically occurs in patients with underlying heart disease and can be diagnosed with electrophysiological testing.
- Mahaim Fiber Tachycardia - This is another rare condition that can cause wide QRS complexes due to pre-excitation of the ventricles via a Mahaim fiber. It can be diagnosed with electrophysiological testing and is typically treated with catheter ablation.