Electrocardiographic Pauses: Not Always What They Initially Seem
Harsh Goel, MD
Department of Internal Medicine, The University of Texas Health Science Center, Houston, TX, USA
Disclosure: The author has no conflict of interests to declare.
A 63-year-old female with a past medical history of Type 2 Diabetes Mellitus (T2DM), End Stage Renal Disease (ESRD) on dialysis, paroxysmal atrial fibrillation, sick sinus syndrome with a history of a permanent pacemaker presents to the emergency department for shortness of breath, nausea, and vomiting after missing dialysis. The patient was admitted to the hospital for dialysis. While obtaining dialysis in the dialysis unit, a rapid response was called for bradycardia with heart rates between 30-40 beats per minute. All other vitals were within normal limits. At bedside, patient complained of feeling anxious however denied chest pain or palpitations. Cardiopulmonary exam revealed bradycardia with an irregular pulse but was otherwise unremarkable. Bedside telemetry showed evidence of fluctuating heart rates between 30-60 beats per minute with evidence of frequent pauses. Laboratory studies, including electrolytes, hemoglobin, and troponin were unremarkable. Of note, the patient was recently hospitalized for tricuspid valve endocarditis secondary to S. aureus bacteremia from her tunneled dialysis catheter, with subsequent pacemaker removal and completion of an IV antibiotic course. Home medications included apixaban, sevelamer, levothyroxine, nifedipine, gabapentin, and linagliptin. ECG obtained during the rapid response is shown below (Figure 1a).
Figure 1a: 12 lead ECG obtained during the rapid response