Memory T-Waves, a Rare Cause of T-Wave Inversion in the Emergency Department

Area of Science:

• Cardiology
• Electrocardiography
• Emergency Medicine

Background:

• Diffuse T-wave inversion (TWI) on an electrocardiogram (ECG) can mimic ischemia, necessitating careful differential diagnosis.
• Memory T-waves represent a rare, benign etiology of diffuse TWI.

Observation:

• This case series presents three patients with diffuse TWI attributed to memory T-waves.
• Two cases exhibited TWI following ventricular tachycardia (VT) reversion, while one patient had TWI during normal sinus rhythm with a VVI pacemaker.
• ECG findings included TWI in inferior and precordial leads, with specific criteria for diagnosis.

Findings:

• Memory T-waves are a rare cause of diffuse TWI, particularly in patients with a history of VT or pacemaker implantation.
• Established ECG criteria (positive T wave in aVL, positive/isoelectric T wave in lead I, and precordial TWI > inferior TWI) demonstrate high sensitivity (92%) and specificity (100%) for diagnosing memory T-waves.
• These T-wave inversions are benign and do not require treatment.

Implications:

• Emergency physicians must consider memory T-waves in the differential diagnosis of diffuse TWI to avoid misattributing them to acute cardiac ischemia.
• Accurate differentiation can prevent unnecessary interventions and patient anxiety.
• An algorithmic approach is proposed to aid in the diagnosis of suspected memory T-waves in the emergency department setting.