A Patient with Ischemic symptoms and a Biventricular Pacemaker

This case was sent by Gary Giorgio from Summa Health Emergency Medicine Residency in Akron, Ohio.  He frequently sends very interesting cases.Background:There are many who say that STEMI cannot be diagnosed in the setting of a ventricular paced rhythm.  In a recent survey, as part of a case posted on Medscape by my mentor, K. Wang, 48% of respondants answered that "One cannot diagnose an infarction from ventricularly paced complexes."CaseAn elderly woman presented with 6 hours of arm, back, jaw pain, diaphoresis, and dyspnea (no chest pain!).  There was an unclear history of CAD as previous care was at another hospital.Here was her initial ED ECG:There is clearly a ventricular paced rhythm (VPR).  What else (ok, it's obvious)?In right ventricular pacing, which was formerly by far the most common, the pacing lead was usually in the apex of the RV and, therefore, the depolarization vector was usually away from the apex, resulting in a negative QRS in all of V1-V6 Here, the QRS is positive in V1, which suggests left to right ventricular activation, at least of the septum.Biventricular pacing (especially "cardiac resynchronization therapy") is common now because it has been shown to improve cardiac function in patients with heart failure who also have a QRS duration greater than 130 ms.   A biventricular pacer has a lead in the RV and a lead that goes through the coronary sinus (the large vein that drains myocardial blood supply ...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs