12 Lead EKG Basics PDF

12 Lead EKG Basics Lead Morphology and Placement © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle Ri...

12 Lead EKG Basics Lead Morphology and Placement © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Electrocardiography The recording of the heart’s electrical impulses by way of electrodes on the skin. Willem Einthoven: “Father of electrocardiography” and the inventor of the EKG machine. © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  EKG Paper One small block is 0.04 seconds. Five small blocks = one big block. © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis One big block = 0.20 seconds. Upper Saddle River, NJ 07458  Placement of Electrodes The placement of the positive electrode is critical in understanding the upward or downward pointing of QRS complexes. Simply stated, the ECG machine is “looking at” how current flows from the negative to the positive electrode © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Bipolar Leads Figure 3-1: The Bipolar Leads © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Bipolar Are Also Called: Frontal leads, as they are all located on the front of the body. Standard leads. Limb leads. © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Precordial Leads Six unipolar leads that see the heart from the horizontal plane. All are positive electrodes. V1 V2 V3 V4 V5 V6 Figure 3-8: The Precordial Leads © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Continuous Monitoring Allows monitoring of rhythm for a prolonged time vs “snap shot” view offered by 12-lead. Requires altered electrode placement to minimize artifact. Bedside monitoring: Patient attached to an EKG machine by a cable. Telemetry: Remote cardiac monitoring of ambulatory patients. © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Bedside Monitor © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Lead Placement for Continuous Monitoring This configuration can be achieved with both 3 wire and 5 wire ECG cabling © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Electrocardiographic Truths Positive QRS written by impulse travelling toward positive electrode. Negative QRS from impulse travelling away from positive electrode. Isoelectric QRS from impulse travelling perpendicular to positive electrode. Flat line “written” when there is no impulse at all. © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Electrocardiographic Truths(cont’d) Figure 3-11: Electrocardiographic Truths © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Normal Vector (cont’d) Figure 3-12: Normal Vector © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Normal QRS Deflection in Lead I Figure 3-13: QRS Deflection in Lead I : POSITIVE DIRECTION © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Normal QRS Deflection in Lead II Figure 3-14: QRS Deflection in Lead II : POSITIVE DIRECTION © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Normal QRS Deflection in Lead III Figure 3-15: QRS Deflection in Lead III :MOSTLY POSITIVE DIRECTION © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Normal QRS Deflection in V1 Figure 3-19: QRS Deflection in V1:MOSTLY NEGATIVE © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Normal QRS Deflection in V6 Figure 3-20: QRS Deflection in V6 :MOSTLY POSITIVE © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Progression of R wave from negative to positive as the + electrode moves across precordium © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  10 electrodes are placed on the body. So why is it a 12-Lead ECG? We have seen 3 Limb leads (I, II, III) and 6 precordial leads (V1-V6)for a total of 9 views produced by the 4 limb electrodes + 6 precordial electrodes. The computer inside the ECG machine uses this data to calculate 3 more views called the augmented leads. © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Augmented Leads aVR: + electrode on right arm aVL: + electrode on left arm aVF: + electrode on left foot Which of these leads would have a predominately negative deflection? Why? © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458  Standard Format of 12 Lead © 2007 Pearson Education, Inc. EKG Plain and Simple, 2e Pearson Prentice Hall By Karen M. Ellis Upper Saddle River, NJ 07458