12 Lead ECG Vs Single lead ECG

Cardiac emergencies are the leading cause of mortality worldwide. In a cardiac emergency, the two pillars that facilitate the right diagnosis and treatment are; the time and accuracy of every verbal or diagnostic information. Both of these have a critical effect on the outcomes of the cardiac patient.

In terms of diagnosis, ECG measurements are most important for the initial assessment of the patient. ECG not only helps in establishing the diagnosis, but it also evaluates the changes in cardiac status from time to time. It also helps in the prediction of future events to make appropriate treatment decisions. Above all, time is precious, and every minute is accountable in a cardiac emergency.

ECG / EKG

An ECG or electrocardiogram records the electrical activity of the heart by placing electrodes over skin. There are different types of ECG, depending upon the number of electrodes like 1-lead, 2-Lead, 6-Lead, and 12-Lead.

1-lead ECG is used for basic heart monitoring. On the other hand, 12-Lead ECG provides a complete picture of heart activity and is a very important tool in making clinical decisions related to heart disorders. It uses 10 different electrodes placed over predetermined positions on the body to record 3-dimensional electrical activity of the heart.

Use of Single lead ECG/EKG recorder for 12-lead ECG/EKG

Though a one-lead ECG recording machine is widely used to get 12-lead recording in a sequential way, it is not appropriate to follow this manner. As mentioned before, 12-Lead ECG uses different leads placed over different body parts, but when a single lead machine is used to get a 12-Lead ECG reading, the same electrode is placed at different places one by one.

This procedure has many shortcomings like:

Application of single-lead electrodes to the torso to get 12-lead ECG readings takes time that can cause major ECG changes.

The movement of an electrode from one part to another can affect ECG readings.

Its precision is operator-dependent, thus raising clinician’s concerns about the accuracy and reliability of reading.

This setting has the potential for false‐negative test results that can lead to potentially fatal missed diagnosis.

So, using a single-Lead ECG machine to get 12-Lead ECG reading is not an appropriate way in cardiac emergencies. To authenticate this even more, let’s discuss:

The demonstrated advantages of 12-Lead ECG/EKG:

• Accurately reproduces QRS, ST and T waveforms.
• Provides evidence of P wave and QRS complex morphology that cannot be determined by single-Lead ECG.
• ST elevation cannot be identified without a 12- lead ECG.
• ST segment elevation is very important to localize the myocardial injury and the corresponding culprit coronary artery.
• The changes in the ST segment are best observed in 12 leads.
• Establishes early diagnosis by rapid identification of infarction/injury and its extent.
• Facilitates decreased time of MI to reperfusion by quickly identifying the MI, and getting the patient the reperfusion as fast as possible.
• Detects and localizes potentially life-threatening arrhythmias that can be missed in other ECGs.
• Able to track long term effects of sustained hypertension.
• Enables evaluation of acute effects of a pulmonary embolus.
• Increases the index of suspicion.
• Assists clinicians in deciding for any modification required in the therapy.
• Changing patterns of ST segment as observed by 12-Lead ECG after angioplasty are reliable to identify restenosis of the involved coronary artery.

Finally, it can be concluded that 12-Lead ECG recording is a unified method of signal acquisition that can be used to diagnose almost all the possible cardiac pathologies in bedside monitoring, ambulatory recording and as standard electrocardiography also.

References:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2536187/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5891427/
https://centegra.org/wp-content/uploads/2013/06/12-Lead-ECG-Introductions-10.pdf
https://www.researchgate.net/publication/267193112_Value_and_limitationsof_12-lead_ECG_monitoring

This post was originally posted on www.tricog.com