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Posts Tagged ‘Interpretation’

Patients undergoing Percutaneous Transluminal Coronary Angioplasty (PTCA) are at an increased risk of coronary artery occlusion related to clot formation (thrombosis) or plaque rupture, especially in the acute period after procedure. It is imperative that individuals providing care for this patient population are knowledgeable in reading EKG’s and are able to correlate EKG changes with acute coronary artery occlusions and / or spasms.

When a patient presents with chest pain, pressure, tightness, shortness of breath or other related symptoms status post PTCA, a STAT EKG should be ordered. When caring for a patient post PTCA, is important to know which coronary artery was ballooned and/or stented and be able to identify the EKG leads which reflect those coronary arteries.

The best way to learn how the EKG reflects the coronary anatomy is to take a systematic approach.  Think about where the EKG leads are placed on the patient’s chest and visualize the heart within the chest.  This article assumes that the reader already knows how to read an EKG strip and understands what the P, Q, R, S and T represent on the EKG.

The limb leads are I, II and III. Lead I is between the right arm and left arm; Lead II is between the right arm and left leg; Lead III is between the left arm and left leg.

            The precordial leads are V1- V6. V1 is the fourth intercostal space to the right of the septum; V2 is the fourth intercostal space to the left of the sternum; V3 is directly between leads V2 and V4; V4 is the fifth intercostal space at midclavicular line; V5 is at the same level as V4 but at the left anterior axillary line; V6 is level with V5 but is at the midaxillary line.

The right coronary artery (RCA) provides oxygen supply to the inferior portion of the heart. Therefore, it is leads II, III, and aVf that reflect this artery.

            Next let’s look at the anterior and septal leads. These are V1 , V2, V3 and V4. These leads lay directly over the anterior and anterioseptal area of the heart.  The left anterior descending artery (LAD) lies down the front of the heart, providing the septal and anterior walls with oxygen. Leads V1 and V2 reflect the LAD and septum. The LAD and diagonal branches are reflected in the EKG leads V3 and V4.

            The lateral wall is exactly that. The part of the heart that faces the lateral part of the chest wall. This area is reflected in the leads V5 and V6, I and aVL. These leads reflect the circumflex artery.

            Myocardial ischemia and injury are reversible (2). This is due to an increase in demand, or a decrease in supply of oxygen (2).  An acute MI will have the following progression: Tall T waves in the first few minutes; ST elevation or T wave inversion in the first hour(s); possibly pathologic Q waves in the hours after onset; Q waves remain and ST and T waves return to normal in the days following acute myocardial infarction (AMI) (2).

            Acute myocardial infarction (AMI) must be 1 mm in the inferior leads and 2 mm in the anterior leads (2).  There MUST always be a presence of ST elevation in 2 or more contiguous leads (2).

By definition, a myocardial injury has ST segment elevation of at least one mm above the baseline (1). Other signs may be: straightening of the ST segment that slopes up to the peak of the T wave without any time spent at baseline; tall, peaked T waves; or symmetric T wave inversion (1).

            Myocardial ischemia has a classic pattern of T-wave inversion (1). The ST segment may be depressed 0.5 mm or more below baseline, or the ST segment may remain at baseline longer than 0.12 seconds, or from a sharp angle with the upright T wave (1). The EKG may also present tall, wide-based T waves and inverted U waves.

            A myocardial infarction (MI) may present with the development of Q waves on the EKG in the leads reflecting the affected coronary artery (1). Decreased R-wave amplitude, ST segment depression and T-wave inversion are also sometimes noted on the EKG (1).

References

1        Microsoft Power Point – The NEW 12-Lead ECG. Retrieved from www.wccems.com/Files/12_Lead_ECGs.pdf on June 15, 2010.

2        www.ambulancetechnicianstudy.co.uk/ecgbasics.html Ambulance Technician Study : ECG Basics. Retrieved June 15, 2010.

Understanding and interpreting a standard 12-lead ecg can prove to be a quite difficult task, especially for students and practicing nurses at their first contact with clinical cases requiring an accurate interpretation of an ecg. Basic knowledge of the ecg is usually the most difficult to assimilate, as it implies learning the basis of interpretation. Every student, nurse or even resident doctor must be aware of the importance of correlating clinical findings after a complete examination with the ecg findings. A good basic ecg interpretation may rely on the ability to combine clinical skills with basic ecg interpretation.

A systematic approach in course of a basic ecg interpretation might appear as highly recommended for students having their first experiences with an ecg in practice. An essential step towards a good basic ecg interpretation is understanding how and why the electrodes are placed in certain locations on the patient’s body. Identifying errors in the positioning of the electrodes can sometimes be vital for a further accurate interpretation of the resulting ecg.

When the electrodes are successfully placed at the right spots, the student may begin to analyze the 12-lead EKG starting with heart rate, identification of the sinus rhythm or an abnormal electrical conduction, the heart axis calculated in function of the QRS complex, duration and amplitude of the different waves and intervals. The commonly used ecg paper is divided into 1mm squares and the speed of the registration is usually 25 mm per second.

Besides ecg training in school and in hospitals and ekg books, an also well accepted and received method of understanding and learning how to read an ecg are the interactive web-based applications meant to offer necessary knowledge and skills to any student or nurse with access to the Internet.

The e-learning ecg method is an innovative way of learning the interpretation of a standard ecg and also a way to practice the accumulated practical skills. The e-learning ecg programs are designed to match every student’s personal needs by monitoring the progress and adapting the teaching method according to the student’s capacity of being receptive.

Online e-learning ecg, training courses and accessible exercise methods are becoming more solicitant by students and nurses all over the world every day. The e-learning ecg courses are designed by licensed healthcare and IT training companies. The teaching ways are specialized on different learning steps and made to match the personal needs of the person that accesses online ecg training courses.

E-learning ecg is in general based on the same learning steps as the other ekg teaching methods like live courses and ekg books. Students are taught to recognize a 12-lead standard ecg and be able to interpret at first most simple ecg-related knowledge like heart rate, rhythm, QRS axis. Further steps in e-learning ekg are to recognize and interpret different abnormalities of frequency, arrhythmias, dysrhythmias, electrophysical conduction of the impulse.

In order to be an active participant to an e-learning ecg course you must subscript to one of the available open training courses. After joining the e-learning program, the student or nurse can participate to online live courses, take tests and exercise the practical ecg skills accumulated during the training.

Basic ekg interpretation can prove to be quite difficult for both student and teacher. All methods, ecg books, e-learning and other similar courses must be planned according to every student’s special needs. It might be hard at first but by no means is it impossible.

For more resources about Basic ecg interpretation or especially about e-learning ecg please review http://www.cardiocollege.com

In order to be able to correctly understand and interpret a standards 12-lead ekg, medical students, practicing nurses as well as more experienced young doctors must attend different types of ecg training courses. These courses can be held in universities, hospitals, but the most common method of fast accumulating basic ecg knowledge is the multitude of offers of online ecg courses.

Most ecg courses, both on the Internet and he ones attended by other means, must and usually follow a certain pattern, a systematic learning of the ecg interpretation. Ecg courses are therefore structured on lessons teaching the heart anatomy and physiology as well as the functioning of the conduction system of the electrical impulse generated in the sinus node. The next more practical step would be learning how to record a 12-lead ecg, how to correctly position the electrodes on the patient;S body in order to register a correct ekg ride.

A systematic approach during the ecg courses will certainly ease the understanding of the role of each of the 12 leads of the ecg. A basic as well as important step of the ecg courses is teaching the students how to calculate most practical the heart rate and the QRS axis and to identify the particular rhythm on a given ecg.

When the basic knowledge of ecg interpretation have been fully understood by the students, the ecg course may proceed with explaining the pathology of the heart as shown by a standard ecg lead. Atrial and ventricular abnormalities, disrhythmia, conduction abnormalities, traces of ischemia and infraction on an ecg.

All kinds of ecg teaching methods including the online ecg courses must be finalized with practical exercises and clinical case studies provided by practicing clinicians. When taught in hospitals, theoretical ecg courses should be combined with live clinical observation of cardiovascular patients. A good clinician must be able to combine clinical skills in examining patients with well implemented knowledge of the ecg.

Ecg courses can actually be attended by anyone with basic medical knowledge and interest in developing more soffisticated ecg information. Most frequently, online ecg courses are being attended by nurses, junior doctors, workers in the healthcare support department, physiotherapists, general practitioners, radiographers, ambulance technicians and paramedics.

When looking for an ecg course you should be aware of what you must look for. Best ecg training courses inclusive the online ecg courses are taught by cardiologists and other ekg specialists. A good ecg course must instruct the attending students how to face cardiological emergencies, identify the patients with high cardio-vascular risk and prevent major events.

An also important criteria when choosing to attend an ecg course are prices. This type of courses, held live in universities or hospitals in a specified amount of time usually include in the price attendance, an instruction manual and lunch during the training hours. The price may vary from 150 Euro to 200-250 Euro. An online ecg course’s price lies in most cases around 200-250 Euro including login information, access to the site’s Inernet materials and written materials required for the course.

The offer of ecg training courses has much increased with the development of Internet access. Therefore, students applying for a fast and specialized method to accumulate basic and advanced ekg skills must always know exactly what they are looking for.

For more resources about ecg course or especially about online ecg course please review http://www.cardiocollege.com