Gaby Plimmer Cardiology Nurse Practitioner Imperial College NHS Trust St Mary’s Hospital 2008 Each small square is 0.04 secs (300 large squares in a minute) PR interval - 0.12 - 0.2 secs (3-5 small squares) QRS complex- < 0.12 secs (< 3 small squares) ST segment = isoelectric T wave = usually positive, except AVR (possibly V1) Is there any electrical activity? Is the QRS rhythm regular or irregular? What is the ventricular (QRS) rate? Is the QRS complex width normal or prolonged? If the QRS width is prolonged, why? Is atrial activity present? How is atrial activity related to ventricular activity? • ST segment elevation represents myocardial tissue injury and occurs in the leads overlying the area of infarction • Accompanied by reciprocal ST depression • Chest pain and new left bundle branch block = acute MI V1-V4 – Anterior I, AVL, V5-V6 – Lateral V1-V3 – Antero-septal II, III, AVF – Inferior Q wave is at least 1 small square wide (0.04 secs) Q wave is greater than 25% in depth compared to the height of the R wave in the same complex Asa Q wave forms the height of the R wave diminishes Pathological Q waves occur in a territory, not in an isolated lead, eg II, III, AVF. Is aVR Negative Are there any signs of ST elevation, ST depression or T wave inversion If ST elevation is present is there any reciprocal ST depression Are there any pathological Q waves Are there any tall R waves or deep S waves, meeting criteria for LVH Any questions?
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