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Normalization of P-wave Axis After CTI Ablation
  • Parth Makker,
  • Eric Dulmovits,
  • Stuart Beldner
Parth Makker
Lenox Hill Hospital
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Eric Dulmovits
North Shore University Hospital
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Stuart Beldner
Northwell Health
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Abstract

We report a case of superiorly directed sinus p-waves in a young patient who had extensive right atrial scarring due to prior right atriotomies. This sinus p-wave axis then changed to inferiorly directed after catheter ablation of the cavo-tricuspid isthmus (CTI). Normal p-wave morphology during sinus rhythm has been described as having an axis between 0 to +75 degrees. However, this is contingent upon an otherwise healthy atrium without conduction abnormalities. Our case highlights a young patient who has undergone two mitral valve surgeries, and as a result, two right atriotomies for cardiopulmonary bypass. During follow-up after the second surgery, his unusual p-wave axis was noted and it was unclear whether it was due to an atrial escape rhythm that had overtaken the sinus node or abnormal conduction of sinus rhythm. Electroanatomic activation mapping proved that he indeed had a sinus rhythm with conduction abnormality along the sites of his previous atriotomies. Additional ablation on the other side of the sinus node exit resulted in pseudo-normalization of his p-wave axis morphology. Four week follow up showed persistent inferiorly directed P wave, a finding in this patient consistent with persistent block across the caval tricuspid isthmus.