The ECG is one of the oldest and most important methods of assessing people with cardiac issues. Its significance stems from the fact that cardiac illnesses frequently deteriorate rapidly, necessitating prompt diagnosis and treatment if survival is to be predicted.
This paper discusses electrocardiography developments, particularly the use of the 12-lead EKG in advanced cardiac life support. In prehospital electrocardiography, the 12 lead ECG is now the gold standard. The research contrasts the advanced characteristics of the 12 lead EKG monitor with those of the older, but still popular, 3 lead electrocardiogram monitor. The advantages of the 12-lead EKG are highlighted, along with supporting research. The 12 lead electrocardiogram is currently the gold standard in prehospital electrocardiography. The paper highlights the advanced features of the 12 lead electrocardiogram, which are contrasted to those of the older, but popular, 3 lead electrocardiogram monitor. Benefits of the 12 lead electrocardiogram are discussed with reference to supporting evidence. The 12 lead electrocardiogram, which is more accurate and thorough than its predecessors, facilitates faster diagnosis of heart problems by paramedics. This aids in hospitalization and in treatment, as it reduces the door to balloon and door to drug times.
Key words: 12 lead ECG, electrocardiography, myocardial infarction
Implementation of the 12 Lead Electrocardiogram in Prehospital Advanced Life Support
According to statistics from the Centre for Disease Control (2015), over 700,000 people experience a myocardial infarction (MI) annually, with cardiovascular diseases listed as one of the leading causes of mortality in the country. Rapid assessment and diagnosis of MI can have a significant impact on patients’ recovery rate, hence the interest in prehospital electrocardiograms (PHECG) in literature and in practice. The underlying premise is that swift and accurate identification of persons suffering from MI, conducted by paramedics, can greatly facilitate hospitalization and treatment (Beebe and Myers, 2012). This essay discusses changes in prehospital electrocardiography particularly the implementation of the 12 lead electrocardiogram (ECG) for patients who require advanced life support.
An electrocardiogram is one of the most useful measures in assessing patients who present with cardiac symptoms, and involves readings of heart activity taken through electrodes placed on the skin, referred to as leads (Beebe and Myers, 2012). For decades, the 3 lead ECG has been in use in PHECG, and comprises of three color-coded electrodes placed on the patient’s right arm (RA), left arm (LA), left leg (LL). While this monitor enabled paramedics to assess the patient’s cardiac rate and rhythm, its lack of non-diagnostic properties, among other challenges, has led to the adoption of the 12 lead electrocardiogram. The 12 lead ECG uses 10 electrodes; four placed on limbs and six on the chest, and gives a three-dimensional view of the electrical activity of the heart (Beebe and Myers, 2012).
In addition to monitoring the heart’s rate and rhythm, the 12 lead ECG also allows for an assessment of the direction of electrical activity during depolarization, referred to as the axis (Beebe and Myers, 2012). The 12 lead ECG has a number of benefits over its predecessors, first and foremost that its measurements are more reliable owing to more points of reference. Secondly, it facilitates a more thorough assessment, as the specific areas of the heart involved in the MI can be easily identified. Additionally, it is useful in identifying tachycardias and unstable anginas, and arrhythmias owing to the monitor’s QRS complex and P wave morphology (Beebe and Myers, 2012).
One of the most crucial benefits of the 12 lead ECG is that it saves on time. Studies have associated its use with a reduction in the amount of time between identification of MI and treatment. Earlier studies such as Mercer (1993) found that use of the 12 lead ECG by paramedics resulted in diagnoses generated three times faster than those by hospital emergency departments. Newer studies such as Ting et al. (2008) report that PHECG reduces the time interval between the patient’s hospital arrival and thrombolytic therapy (door-to-drug time) by 10 minutes, and between arrival and balloon angioplasty (door-to-balloon time) by 15 to 20 minutes.
This is unsurprising considering that modern 12 lead electrocardiographs are capable of recording, storing and transmitting data to emergency rooms, providing hospitals with sufficient time to activate catheterization laboratories as the patient is in transit (Quinn et al., 2014). Consequently, Quinn et al. (2014) report that failure to perform a PHECG has been associated with delayed treatment. It is perhaps for these reasons that the 12 lead ECG is currently the recommended first step in the prehospital pathway for persons who present with coronary symptoms (American College of Emergency Physicians, 2013).
Conclusion
In summary, it should be noted that for any intervention aimed at assessment and diagnosis of persons who present with symptoms of MI to be effective, it has to be time-sensitive. The implementation of the 12 lead ECG for advanced life support by paramedics is informed by evidence of its accuracy, reliability and speed of diagnosis.
References
American College of Emergency Physicians. (2013). 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction: executive summary: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Journal of the American College of Cardiology, 61(4), 485.
Beebe, R., & Myers, J. C. (2012). Professional Paramedic, Volume II: Medical Emergencies, Maternal Health & Pediatrics. New York: Delmar, Cengage Learning.
Centre for Disease Control (2015). Heart Disease Facts. Retrieved from: https://www.cdc.gov/heartdisease/facts.htm#hdus
Quinn, T., Johnsen, S., Gale, C. P., Snooks, H., McLean, S., Woollard, M., Weston, C. and Myocardial Ischaemia National Audit Project (MINAP) Steering Group (2014). Effects of prehospital 12-lead ECG on processes of care and mortality in acute coronary syndrome: a linked cohort study from the Myocardial Ischaemia National Audit Project. Heart, heartjnl-2013.
Mercer, S. (1993). 12-lead ECGs: Ready to hit the streets? Emergency, 25, 46-49.
Ting, H. H., Krumholz, H. M., Bradley, E. H., Cone, D. C., Curtis, J. P., Drew, B. J., Field, J. M., French, W. J., Gibler, W. B., Goff, D. C. and Jacobs, A. K. (2008). Implementation and integration of prehospital ECGs into systems of care for acute coronary syndrome. Circulation, 118(10), 1066-1079.
