Cardiac memory during rather than after termination of left bundle branch block
Laszlo Littmann1, Patrick A Proctor1, Priscilla M Givens1
1Department of Internal Medicine, Carolinas Medical Center, Charlotte, NC, USA.
Journal of Electrocardiology
|August 31, 2014
Summary
This study highlights cardiac memory, an electrocardiogram phenomenon, observed during left bundle branch block. It demonstrates that T-wave changes can occur even with alternating wide complex rhythms, expanding our understanding of this condition.
Area of Science:
- Cardiology
- Electrophysiology
- Medical Diagnostics
Background:
- An 83-year-old female patient presented with fatigue and leg swelling.
- She had a history of chronic left bundle branch block and intermittent atrioventricular block requiring pacemaker implantation.
Observation:
- Routine electrocardiogram revealed sinus rhythm with left bundle branch block.
- Diffuse negative T waves were noted in inferior and anterolateral leads, concordant with QRS complexes.
- These T-wave changes mirrored deep negative QRS complexes seen during previous ventricular pacing.
Findings:
- Electrocardiographic findings were consistent with cardiac memory.
- This case is unique as cardiac memory typically manifests after QRS normalization, not during left bundle branch block.
- The study observed cardiac memory with alternating wide complex rhythms (ventricular pacing followed by left bundle branch block).
Implications:
- Cardiac memory T-waves can develop following normalization of wide complex rhythms.
- This phenomenon can also occur with alternating wide complex rhythms, as seen in this patient.
- The findings expand the understanding of cardiac memory manifestation in patients with intermittent conduction abnormalities.
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