A case of rate dependent bundle branch block presented with atypical course of the disease

A 83 years old woman with past medical history of coronary artery disease, had four stents nine years ago, colon cancer, finished the chemotherapy course and resection fourteen years ago, iron deficiency anemia, diverticulosis of large intestine, fibromyalgia, osteopenia, presented with an episode of syncope.Patient stated she has been in her usual health when she woke up that morning.Patient took her medications which were amlodipine 10mg daily, Aspirin 81mg daily, HCTZ 25mg Daily, Metoprolol succinate 50 daily, Rosuvastatin 20mg Daily, then was doing her daily activities when she felt weak and nauseated then went to her bed and fell next to it.Syncope was witnessed by daughter who stated that patient lost consciousness for about three minutes, covered in cold sweat, no shaking, no bladder or bowel incontinence were noted.Patient did not remember any of these events.Patient's vitals were within normal limits except the heart rate was 50bpm.Basal metabolic panel and complete blood count were normal.Troponin was negative.EKG (Figure 1) demonstrated HR of 50bpm.Repeated EKG with Sinus bradycardia, HR 60bpm with 1st degree block and new LBBB.(Figure 2) Echocardiography: ejection fraction 60-65%, non significant for any changes.