Antoine Egbe^1,, Agyingi Chris², Hussein Gaith¹, Khurram Arshad¹

Pulmonary embolism (PE) is also known as the great faker. It is difficult to diagnose and entails a lot of suspicion from a clinician. Our case talks about the appearance of a complete heart block in a patient with PE who had a pre-existing left bundle branch block. We present the case of a 75-year-old lady with a pre-existing left bundle branch block, diabetes and hypertension presented to the emergency department because of shortness of breath which had been ongoing for 4 days. She was tachycardic and hemodynamically stable initially on arrival. Computed tomography pulmonary angiogram done in the emergency department showed an embolus in the distal right main pulmonary artery, which was extending to and involving the proximal right lower lobe of the pulmonary arterial tree. Follow-up cardiac echography showed an enlarged right ventricle with decreased right ventricular systolic function. Initial electrocardiogram (EKG) only showed a left bundle branch block. However later during the day, the patient became hemodynamically unstable before thrombectomy. The thrombectomy was planned for the following day. Repeat electrocardiogram at this point in time showed a third-degree heart block. The patient received atropine and a transvenous pacemaker was placed. She later on underwent thrombectomy. Electrocardiogram post-thrombectomy repeatedly showed complete heart block, hence the decision was made to place a permanent pacemaker. Pulmonary embolism can present in a variety of ways. It could possibly present as a complete heart block. In patients with a pre-existing left heart block, a PE could easily cause a complete heart block especially in the scenario where we have a right ventricular strain evident on a transthoracic echocardiogram (TTE). The presence of right ventricular strain on EKG, be it T wave inversion in V1 like in my patient or new onset complete right bundle branch block could be used as an indicator of massive/sub-massive(severe) pulmonary embolism.

pulmonary embolism, cardiology, complete heart block