Differential Diagnosis for Wide Complex Tachycardia
Single Most Likely Diagnosis
- Ventricular Tachycardia (VT): This is the most common cause of wide complex tachycardia, especially in patients with a history of heart disease. VT originates from a ventricular focus and can be life-threatening, requiring immediate intervention.
Other Likely Diagnoses
- Supraventricular Tachycardia (SVT) with Aberrancy: This occurs when a supraventricular rhythm is conducted to the ventricles with an abnormal pathway, resulting in a wide QRS complex. Conditions like Wolff-Parkinson-White syndrome can cause this.
- Antidromic AVRT: A type of reentrant tachycardia involving an accessory electrical pathway in the heart, leading to a wide complex tachycardia due to the anterograde conduction down the accessory pathway.
Do Not Miss Diagnoses
- Torsades de Pointes: A specific type of VT characterized by a polymorphic QRS complex that twists around the baseline. It is often associated with a long QT interval and can degenerate into ventricular fibrillation, making it critical not to miss.
- Hyperkalemia-induced Wide Complex Tachycardia: Severe hyperkalemia can cause wide complex tachycardia due to its effects on cardiac conduction. This condition requires immediate treatment to prevent cardiac arrest.
Rare Diagnoses
- Bundle Branch Reentrant Tachycardia: A rare form of VT that uses the bundle branches as part of the reentrant circuit, typically seen in patients with dilated cardiomyopathy or other structural heart diseases.
- Orthodromic AVRT with Bundle Branch Block: While not as rare as some other conditions, this can present as a wide complex tachycardia if there is a coexisting bundle branch block, making the diagnosis slightly more challenging.
- Cardiac Sarcoidosis or Other Infiltrative Cardiomyopathies: These conditions can lead to various arrhythmias, including wide complex tachycardia, due to the disruption of normal cardiac tissue by the disease process.