Just a paced rhythm… Or is it?

Ok, so I posted a 12 Lead ECG on Facebook this past Monday, June 2nd, 2014, which  generated some interesting comments and thoughts… https://www.facebook.com/photo.php?fbid=10152417488161049&set=a.436337931048.217588.216914116048&type=1&theater  This ECG was obtained from a 67 year old male, complaining of difficulty breathing for the past 2 hours, and presented diaphoretic, with no other signs of hypoperfusion. Past medical history: Hypertension Congestive Heart Failure (CHF) Hypothyroidism Vital signs: Blood Pressure: 110/88 mmHg Heart Rate: Between 80 -94 beats/min and regular Respiratory Rate: 18 breaths/min SpO2: 97% Now to the fun part… As most noticed, it is indeed a paced rhythm, with unipolar leads which cause a bigger and more noticeable “pacer spike”, preceding every QRS. The QRS  are wide in appearance, with an arrow on the bottom of the ECG pointing to the pacing origin. Some interpreted this as a RBBB due to the dominant R wave in V1, however, this finding in the presence of a pacemaker, suggest LV pacing, with a superior axis, moving away from the inferior leads, as well as the lateral leads, due to impulses originating and moving away from the apex, which causes the axis to shift towards the right upper quadrant of the Hexaxial Reference System, at approximately -118 degrees. But there is more to it than just a paced rhythm. Some suggested that since the rhythm is paced,  no other diagnosis could be made, but this i...
Source: EMS 12-Lead - Category: Cardiology Authors: Tags: 12 lead ecg MI Paced Rhythm Sgarbossa's Criteria Source Type: research