Dual Sinus Nodes - Heart Transplant ECG

ECG Findings:

1. Normal Sinus Rhythm

2. Normal Sinus Rhythm

3. Left Atrial Enlargement

4. Left Anterior Fascicular Block

5. ST-T Wave Abnormality - Consider Ischemia

When the patient's heart was removed, a portion of the right atrium was left behind including the native sinoatrial node (SA node). A new heart was implanted which also included a SA node. The end result is two P waves both of sinus morphology, however at different rates. Interestingly, only the transplanted SA nodal activity is able to conduct to the ventricles since the surgical anastomotic site creates an electrical block not allowing the native SA node to depolarize the transplanted atrium and thus it is not able to conduct to the transplanted ventricles.