Determining a new electrode configuration for a hand held ECG device when compared to the 12 lead ECG.

Transcription

1 Determining a new electrode configuration for a hand held ECG device when compared to the 12 lead ECG. AMY FAIRHURST STP TRAINEE CARDIAC SCIENCE CENTRAL MANCHESTER UNIVERSITY HOSPITALS

2 Life Threatening Arrhythmia s. Cardiac arrhythmia s account for around 100,000 sudden death s per year. Most common arrhythmia s include; Atrial Fibrillation Ventricular Fibrillation Arrhythmia s are either inherited or due to structural heart disease. Many individuals are asymptomatic and unaware of risks. Inherited cardiac disorders are the most common cause of death in the young aged under 30 years of age. No national screening programme

3 RISKS OF AF Stroke Heart failure Death

4 Ricks of cardiac genetic disorders Long QT Syndrome Brugada Syndrome Ventricular Fibrillation

5 How to detect life threatening arrhythmia s? A variety of ways to detect arrhythmia s particularly AF some are better than others. Pulse checks opportunistic screening predominantly in primary care. Electrocardiogram (ECG) NICE (2006) ECG screening of young people is not well supported due to cost and low sensitivity and specificity. Research in Italy shows the benefits of pre-participation ECG screening in reducing the risk sudden cardiac death.

6 The 12 lead ECG Universally considered the Gold Standard diagnostic tool of several cardiac arrhythmias. First developed over 100 years ago by Willem Einthoven. To date the principles by Einthoven remain unchanged. Development of the augmented leads by Wilson et al (1934) and Goldberger (1942) lead to the 12 lead ECG used in clinical practice today. The 12 lead ECG consists of; 6 limb leads I, II, III, avl, avr, avf 6 precordial (chest) leads V1 to V6

7 Issues with recording 12 lead ECG s Although simple can be difficult to perform in primary care and community settings. Lack of training in acquiring ECG s Lack of training in ECG interpretation The ECG can be time consuming SCST allow 12 minutes to complete obtaining an ECG This does not include time to interpret recordings GP s have between minutes pre patient consultation

8 Modifying ECG limb electrodes Historically limb electrodes should be proximal to the wrists and ankles (SCST 2010). This cannot always be done; Patient habitus, i.e. amputation. Emergency settings Exercise testing Documented that more distal placement of electrodes DOES alter ECG waveform; QRS amplitudes ST-segments Axis deviation

9 MSc Project Aims To examine the effect of 4 modified limb electrodes positions on a pre-prototype 6-electrode (8-lead) ECG system, in order to determine which provides the best match to the conventional 10 electrode (12 lead) ECG measurements. To analyse the diagnostic accuracy to enable use of a quick ECG screening tool for arrhythmias and inherited cardiac genetic disorders

10 MSc Study Assessing 4 modified positions and 12 lead ECG Hand-held device against subjects chest 30 second ECG recorded Software overlays modified ECG and 12 lead ECG

11 Results Largest arm dimensions correlated best Lead I and V1 most significantly affected by all modifications Significant alterations to QRS complex amplitudes Possible misdiagnosis of myocardial infarction Right axis deviation Which position best matches the 12 lead? r)( n o it al 0.3 er ro C A supine B supine C supine D supine A seated B seated C seated D seated

12 Conclusion Simplification of the ECG is vital to improve diagnosis of arrhythmia s. Novel techniques provide improved opportunistic screening of AF. The new device provides an easier and quicker way of obtaining a modified ECG that could provide diagnosis. What s next; Several prototypes have been made Study set up in the community to assess the efficiency and diagnostic capabilities of the device.

13 Thank you for your time.