Objectives. Coronary Artery Anatomy What the Leads See Lead Placement Skin Preparation

Transcription

1 12 Lead Basics

2 Objectives Coronary Artery Anatomy What the Leads See Lead Placement Skin Preparation

3 Coronary Artery Anatomy The 12 lead shows which area of the heart is ischemic or damaged This corresponds to the artery that is occluded

4 Coronary Artery Anatomy Right Coronary Artery Right Ventricle Right Coronary Artery Supplies Right ventricle, inferior and posterior wall SA and AV node Inferior Wall

5 Coronary Artery Anatomy Left Main Coronary Artery Left Anterior Descending Left Main Coronary Artery Left Anterior Descending and Circumflex arteries branch off the Left Main Occlusion of the left main has very poor prognosis

6 Coronary Artery Anatomy Left Anterior Descending Supplies Anterior and Septal wall of the left ventricle Anteroseptal Left Anterior Descending

7 Coronary Artery Anatomy Posterior view of heart and arteries Left Circumflex Artery Supplies Posterior wall Lateral wall Inferior wall in 10% of the population Lateral wall Posterior wall

8 Normal 12 Lead This an example of a 12 lead that the Zoll E series will generate The 12 lead only provides a view of the left ventricle, the right ventricle and posterior wall is not seen with a 12 lead To view the right ventricle or posterior wall a 15 lead ECG would need to be done we are not covering this or doing this in the field at this time

9 12 Lead ECG Limb Leads (I, II, III, avr, avl, avf) 3 bipolar leads (I, II, III) 3 unipolar leads (avr, avl, avf) Place electrodes on the limbs if there is a 12 lead in the patient s future highly preferable to torso placement I avr V1 V4 II avl V2 V5 III avf V3 V6

10 12 Lead ECG Chest Leads (V1, V2, V3, V4, V5, V6) 6 unipolar electrodes Electrodes are placed on the chest Preparing the skin improves tracing (more about that later) I avr V1 V4 II avl V2 V5 III avf V3 V6

11 Limb Lead Placement Place leads on limbs Away from major muscles or arteries Have patient remain still during 12 lead acquisition (to reduce artifact)

12 Chest Lead Placement V1 is placed in the 4 th intercostal space to the right of the sternal boarder To find the 4 th intercostal space feel for the clavicle Just below the clavicle is the 2 nd rib, then the 3 rd and 4 th rib Between the 4 th rib and the 5 th rib is the 4 th intercostal space V2 is placed to the left of the sternal boarder in the 4 th intercostal space

13 Chest Lead Placement V4 is placed next in the 5 th intercostal space in the mid-clavicular line Find the half way mark on the left clavicle and move down one rib so V4 is between the 5 th and 6 th ribs V3 is placed after V4 and is simply placed in between V2 and V4 either on the 5 th rib or in the 5 th intercostal space

14 Chest Lead Placement V5 is placed in the 5 th intercostal space and the anterior axillary line To find the anterior axillary line lay the patient s left arm at their side and follow the crease line in their armpit down the front of their chest V6 is placed in the 5 th intercostal space in the mid-axillary line

15 Chest Lead Placement V1 V2 V3 V4 V5 V6 V1: 4 th intercostal space to the right of the sternum V2: 4 th intercostal space to the left of the sternum V3: directly between V2 and V4 V4: 5 th intercostal space at the left mid-clavicular line V5: level with V4 at the anterior axillary line V6: level with V5 at the mid-axillary line

16 Skin Prep Dry moist skin Clip or shave excess hair Abrade dead skin with skin prep tape or dry 4x4 gauze These measures improve the 12 lead tracing

17 Inferior Wall II, III, avf View from Left Leg inferior wall of left ventricle I avr V1 V4 II avl V2 V5 III avf V3 V6

18 Inferior Wall Posterior View portion resting on diaphragm ST elevation in leads II, III, avf suspect inferior injury I avr V1 V4 II avl V2 V5 Inferior Wall III avf V3 V6

19 Lateral Wall I and avl View from Left Arm lateral wall of left ventricle I avr V1 V4 II avl V2 V5 III avf V3 V6

20 Lateral Wall V5 and V6 Left lateral chest lateral wall of left ventricle I avr V1 V4 II avl V2 V5 III avf V3 V6

21 Lateral Wall I, avl, V5, V6 ST elevation suspect lateral wall injury Lateral Wall I avr V1 V4 II avl V2 V5 III avf V3 V6

22 Anterior Wall V3, V4 Left anterior chest electrode on anterior chest I avr V1 V4 II avl V2 V5 III avf V3 V6

23 Anterior Wall V3, V4 ST segment elevation suspect anterior wall injury I avr V1 V4 II avl V2 V5 Anterior Wall III avf V3 V6

24 Septal Wall V1, V2 Along sternal borders Look through right ventricle & see septal wall I avr V1 V4 II avl V2 V5 III avf V3 V6

25 Septal V1, V2 ST segment elevation suspect septal wall injury septum is left ventricular tissue I avr V1 V4 II avl V2 V5 Septal Wall III avf V3 V6

26 Remember to SAIL through it! Septal leads: V1 and V2 Anterior leads: V3 and V4 Inferior leads: II, III, avf Lateral leads: I, avl, V5 and V6

27 What about avr? avr does not face the epicardial surface so it does not provide information regarding ischemia avr is therefore not used for identification of STEMI I avr V1 V4 II avl V2 V5 III avf V3 V6

28 Thank You for participating in Sunnybrook Osler Centre for Prehospital Care online education! If you have any questions please bring them with you to class!