A Practical Guide To. ECGs JENNY ESAU

Transcription

1 A Practical Guide To ECGs JENNY ESAU

2 Objectives What is an ECG Indications Patient Preparation Lead Placement Consequences of getting it wrong ECG - PQRST

3 What is an ECG An ECG Represent the heart's electrical activity recorded from electrodes on the body surface. Records changes in magnitude and direction of the electrical activity Detects electrical current generated by depolarisation and repolarisation of the atria and ventricles

4 Indications Chest pain / discomfort atypical presentations / pressure SOB be mindful of new exertional dyspnoea Light-headedness Palpitations SCD arrhythmias, prolong QT, HCM, Brugada Syncope / near syncope Hypertension Murmurs Upper abdominal pain Any suspected drug overdose / metabolic derangement

5 Indications Pain/discomfort often associated with cardiac ischemia are Jaw Neck Shoulder Left arm Back pain

6 Indications Patients with signs & symptoms of? ACS SOB Diaphoresis & Dizziness Nausea & vomiting Feeling of impending doom

7 Patient Preparation Principle Rationale Explain procedure to patient Place patient in a supine or semi Fowler s position with arms on the side, relaxing the shoulders & uncrossing the legs Allay anxiety, ensures concurrence & relaxation Minimises artefact from muscle tremor

8 Patient Preparation Principle Skin preparation: Clean and dry if moist /diaphoretic Shave chest hair if necessary Rub alcohol prep pad to remove oils Exfoliation may be required Rationale Maximum adhesion of the electrodes reduces potential interference on the ECG tracing Electrode Application: Electrode gel must be moist Do not place electrodes where there is a lot of muscle movement Maximises adhesion & minimises artefact

9 Lead Placement

10 Lead Placement

11 ECG faxed to AHG All ECGs must be correctly labelled with patient s identification and relevant clinical details especially: Pt s name & surname DOB Date & time of recording Name of referrer Name of institution Reason for ECG (Indication)

12 Consequences of getting it wrong Errors in lead placement can create: Artefacts, Mimic pathologies, Hinder proper ECG interpretation Improper positioning of praecordial leads may result in a pseudo infarction pattern Unstable baseline is due to artefact

13 Consequences of getting it wrong Can alter the ECG appearance dramatically resulting in: Unnecessary investigations Admissions to hospital Treatment Lead misplacement can result Harm to the patient if essential treatment is withheld Incorrect treatment is delivered solely on the basis of ECG findings

14 Approx. 20% of ECGs faxed to AHG are difficult to interpret

15 Poor Quality ECG faxed to AHG for Interpretation

16 AVR is positive indicating crossed limb leads AVR should be predominantly negative

17 Maximum Diagnostic Value ECGs must be recorded correctly paying attention to: Patient preparation Electrode positioning It is a diagnostic tool that is used in conjunction with: Patient s history Observations Appearance Remember! The patient is the gold standard not the recording

18 Voltage ECG -PQRST Iso-electric line Time

19 ECG SQUARES Every 3 seconds (15 large boxes) is marked by a vertical line

20 In Summary We discussed What is an ECG Indications Patient Preparation Lead Placement Consequences of getting it wrong ECG - PQRST

21 References Evans-Murray, A. (2006) ECG s Simply (1 st Ed.) Health Ed Professionals Perez-Riera AR, Barbosa-Barros R, Baranchuk A. Current value of electrocardiogram in the 21 st century. Austin J Clinical Cardiology.2014 Feb 24;(2):1-3. Richard A. Harrigan,MD; Theodore C.et al.electrocardiographic Electrode Misplacement, Misconnection, and Artifact. J Emerg Med. 2012;4(6) Rosen AV,Koppikar S, Shaw C, Baranchuk A. Common ECG Lead Placement Errors.Part 11: Precordial Misplacements. Int J Med Students Jul- Oct;2(3): SCST (February 2010) Clinical Guidelines by Consensus Recording a standard 12 lead ECG,

22 Questions