Differential Diagnosis for Wide Complex Regular Tachycardia with Pacemaker Vpacing at a Rate of 120
- Single most likely diagnosis:
- Pacemaker-mediated tachycardia (PMT): This condition occurs when a pacemaker inappropriately senses electrical activity and triggers a pacing response, leading to a rapid heart rate. The regular wide complex tachycardia with a pacemaker vpacing at a rate of 120 is highly suggestive of PMT, as it indicates the pacemaker is directly contributing to the tachycardia.
- Other Likely diagnoses:
- Ventricular tachycardia (VT): Although less likely given the direct involvement of the pacemaker, VT could present similarly, especially if the pacemaker is not functioning correctly or if there's an underlying cardiac condition predisposing to VT.
- Paced rhythm with aberrancy: In this scenario, the pacemaker is pacing the ventricle at a rate of 120, but the wide complex morphology could be due to aberrant conduction rather than a true ventricular arrhythmia.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Torsades de Pointes: Although typically characterized by a polymorphic VT, in rare cases, it could present with a wide complex regular tachycardia. Given its potential for rapid deterioration into ventricular fibrillation, it's crucial not to miss this diagnosis.
- Ventricular fibrillation (VF) precursor: Any wide complex tachycardia could potentially degenerate into VF, a lethal arrhythmia requiring immediate intervention.
- Rare diagnoses:
- Supraventricular tachycardia (SVT) with anterograde conduction over an accessory pathway: This would be an unusual presentation for SVT but could result in a wide complex tachycardia if the accessory pathway is involved.
- Junctional tachycardia with aberrancy: Though less common, a junctional tachycardia could present with a wide complex morphology if there's aberrant conduction, and the pacemaker is somehow interacting with this rhythm.