5 How to Conduct an ECG Patient lies flat on back Electrodes are placed on the bodySites may need to be shaved or cleaned to ensure the leads will stick properly.Patient will lie as still as possible, hold breath, or put hands under bottom to keep from moving.The results are then printed out on paper for MD to review.
7 Lead Placements V1 - Junction of the 4th ICS, Right sternal border V2 - Junction of the 4th ICS, Left sternal borderV3 - Midway between V2 and V4V4 - Junction of 5th ICS, Mid clavicleV5 - Anterior aspect of axilla, same line as V4V6 - Mid axilla, same line a V44 limb leads (for grounding etc)
17 Understanding the Waves Baseline (what is it?)P waveLength of time it takes the impulse to pass from the SA node to the AV nodeShould precede every QRS wavePR intervalShould be no longer than 0.12 – 0.2
18 Understanding the Waves QRSShould be no longer than 0.12If energy is going towards a positive electrode (camera), the picture will show a positive QRS complexIf energy is going away from positive electrode, the picture will show a negative QRS complexIf energy is toward the positive electrode and then passes by it, the QRS will be biphasicVentricle contracting
19 Understanding the Waves T waveShould always start from baselineWill indicate ischemia
20 Understanding an ECG Is as easy as… 1. 2. 3. = rate = intervals = rhythm
21 Step 1 = Rate Different ways to calculate a rate: a) ECG usually tells youb) Locate a QRS that is close to a big line and count to next big line: 300, 150, 100, 75, 60, 50c) take a 6 second strip, count QRS and multiply by 10 (hint: the middle of V3 on the lead II strip is 6 seconds)One small box = 0.04 sec.One large box = 0.2 sec.5 large boxes = 1 sec.300, 150, 100, 75, 60, 50, 45, 37…
22 Step 1 = Rate (cont’)Checking the regularity:map out QRS’s
23 Step 2 = IntervalsWe assess intervals to see where the impulse is coming from (pacemaker beat)Remember:PR interval: normal isQRS interval: normal is less than or equal to 0.12One small box = 0.04 sec.One large box = 0.2 sec.5 large boxes = 1 sec.
24 Step 3 = RhythmThe biggest question in relation to rhythm is…
28 Other Sinus Rhythms Sinus bradycardia a sinus rhythm with a rate <60 bpmWhat do we want to do for this patient?
29 Other Sinus Rhythms Sinus tachycardia a sinus rhythm with a rate >80 bpmWhat do we want to do for this patient?
30 Atrial Arrhythmias Atrial fibrillation (A-fib) irregular rate no discernable P wavesincreased risk of strokes due to clots that might form due to fibrillation (patients are usually on anticoagulation therapy)What do we want to do for this patient?
48 MI’s How else can you tell that your patient has had an MI? Cardiac MarkersCK will show in 4-6 hours (starts to come back down after 1 day)Troponin will show in 4-6 hours (may stay elevated for weeks)Others are: LDH, CK-MB, myoglobin, AST
50 I Lateral (circumflex) aVR V1 Anterior (Lt ant desc) V4 Anterior II Inferior (Rt coronary)aVL LateralV2 AnteriorV5 LateralIII InferioraVF InferiorV3 AnteriorV6 LateralYour paper should look like this now…