Key Points Pacemaker syndrome is a hemodynamic problem caused by loss of proper atrioventricular (AV) synchrony. Most commonly occurs with ventricular pacing that produces retrograde atrial activation, but can also…
Key Points Pacemakers treat bradyarrhythmias by delivering timed atrial, ventricular, or dual-chamber pacing when intrinsic activity is slow or absent. Know the major device types encountered in the ED: single-chamber,…
Key Points: Three primary pacemaker malfunctions: Failure to pace – no pacing spike when one is needed. Failure to capture – pacing spike appears but no depolarization follows. Failure to…
Key Points Ventricular pacing changes depolarization, so ST–T segments often look “abnormal.” Expect appropriate discordance: ST/T deflect opposite the main QRS polarity. RV pacing (most common) ≈ LBBB pattern: wide…
Key Points Continuous-flow LVADs can mask shock: patients may talk through VT/VF because pump flow maintains some perfusion. Treat the rhythm, not the appearance. First steps in any unstable LVAD…
Key Points Wide QRS & Repolarization Abnormalities: Bundle branch blocks (BBBs) and ventricular-paced rhythms (RV, LV, BiV) cause abnormal ventricular depolarization, leading to secondary ST segment and T wave changes—even…
Key Points 1. Paced Rhythms and Acute MI Detection: Ventricular paced rhythms significantly alter ST segment and T wave morphology, complicating acute myocardial infarction (MI) recognition. Accurate ECG interpretation in…