Differential Diagnosis for 78-year-old Male with Dementia

Single Most Likely Diagnosis

• Atrial Fibrillation with Rapid Ventricular Response (AFib with RVR): The patient's ECG showing atrial fibrillation one day prior to the wide QRS rhythm suggests that the wide QRS rhythm could be a result of AFib with RVR, which is a common cause of wide QRS complexes in the setting of atrial fibrillation.

Other Likely Diagnoses

• Multifocal Atrial Tachycardia (MAT): This condition can cause a wide QRS rhythm and is often seen in older adults with underlying lung disease or other comorbidities.
• Ventricular Tachycardia (VT): Although less likely than AFib with RVR, VT is a possible cause of wide QRS rhythm, especially in patients with underlying heart disease.
• Supraventricular Tachycardia (SVT) with Aberrancy: This condition can cause a wide QRS rhythm due to aberrant conduction.

Do Not Miss Diagnoses

• Torsades de Pointes: A life-threatening condition that can cause a wide QRS rhythm and is often associated with QT interval prolongation.
• Ventricular Fibrillation (VF): A fatal arrhythmia that requires immediate recognition and treatment.
• Pulmonary Embolism (PE): Although not directly related to the ECG findings, PE can cause syncope and should be considered in the differential diagnosis of any patient with sudden loss of consciousness.

Rare Diagnoses

• Wolff-Parkinson-White (WPW) Syndrome: A rare condition that can cause a wide QRS rhythm due to pre-excitation of the ventricles.
• Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC): A rare genetic disorder that can cause ventricular arrhythmias and wide QRS complexes.
• Brugada Syndrome: A rare genetic disorder that can cause wide QRS complexes and ventricular arrhythmias.