Understanding an ecg ecg interpretation geeky medics. Ecg is a recording of the electrical activity of the heart over a period of time detected by electrodes attached to the surface of the skin and recorded and displayed by a device external to the body changes in electrical activity may indicate arrhythmias, cardiac ischemia, or electrolyte imbalances 12 lead ecg or ekg 2 dos course 2017. General introduction to ecg reading assignment p216 in pdf. Basic cardiac rhythms identification and response utmc.
The pr interval is measured from the beginning of the p wave to the beginning of the r portion of the qrs complex. The j point is the the junction between the termination of the qrs complex and the beginning of the st segment. Ecg basics including rate, rhythm, axis calculations and interpretation of p, q, r, s. Qt interval this intervalqt interval this interval. If the wave of electrical activity is moving toward the electrode, the wave will be positive.
Nov 10, 2016 in our ninth video of our series ecg basics, we go over the different segments of cardiac repolarization. Sep 25, 2012 hyperkalaemianarrow and tall peaked t wave a is an early signpr interval becomes longerp wave loses its amplitude and may disappearqrs complex widens bwhen hyperkalemia is very severe, the widened qrs complexes merge with theircorresponding t waves and the resultant ecg looks like a series of sine waves c. Apr 17, 2019 in our quest to understanding ecg, let us first try to understand the first wave, that is p wave. Farther to the right is the interpretation of the ecg written this may be missing in a fresh ecg, but later the interpretation of the cardiologist or computer will be added down left is the paper speed 25 mms on the horizontal axis, the sensitivity 10mmmv and the filters frequency 40hz, filters noise from eg. At the beginning or end of the ecg, you may see a square wave, machine induced, that is. The following is a summary of the ecg wave morphologies and parameters that users can use as a guide to understand more about their ecg recordings. Specifically, a 12lead ecg tracing shows how the depolarization wave, which is a wave of positive charge, moves during each heartbeat, by. T wave ventricular repolarization begins at apex, causing t wave. The t wave usually deflects in the same direction as the qrs complex, and should be smooth and rounded. The electrical flow is translated to the ecg as the p wave.
Ecg criteria for lvh has very poor sensitivity but high. Characterized by hyperacute stt wave changes in ecg leads that correlate to specific areas of the heart without adequate oxygenation higher the stt wave changes indicates more tissue involved more proximal occlusion may take several days to resolve. Basics of ekg interpretation sonoma state university. The basics of ecg the information contained within a single 12lead electrocardiogram can be extensive. Learning how to interpret the subtle differences in characteristic changes that can arise is a specialized skill that can take years to learn. The t waves are also raised in contrast to a stemi where the t wave remains the same size and the st segment is raised. Ecg basics including rate, rhythm, axis calculations and interpretation of p, q, r, s, t u waves, segments and basic ecg calculations.
A deviation either above or below the isoelectric line represents myocardial injury or ischemia. Lvh with strain pattern seen in lv pressure overload conditions like aortic stenosis, hypertensive heart disease, ihss see p61 in the 2018 pdf outline for various lvh criteria. T wave usually same directiont wave usually same direction as qrs ventricular repolarisation. Our swan boxes give us a continuous cardiac output reading. Waveform abnormalities beginning with p waves, qrs complexes, stt, and u waves. It is a tool used to visualize, or gram, the electricity, or electro, that flows through the heart, or cardio. Poor r wave progression v14 st depression, t inversion in i, avl, v56 abnormal ecg 1. Basic ecg interpretations the first course in the series is to advance the learners understanding of the electrocardiogram and develop their skills at reading a basic electrocardiogram rhythm strip.
Free online ultrasound lessons this website is intended for. After this there is a gradual dip only to take a very sharp rise to form. Fortunately, basic ecg interpretation can be rather straightforward, as long as you know the basics. Ecg interpretation usually starts with an assessment of the p wave. Ventricular repolarization is complete, after which new wave follows with atrial depolarization p wave leads. Nov 09, 20 poor progression r wave left ventricular hypertrophy, anteroseptal mi j point. Ekg interpretation should be performed using a standard procedure. Pr interval impulse from atria to ventriclesto ventricles.
T wave the t wave is the wave of ventricular repolarization. The t wave axisis much neglected, and may be of value. Ecg is a recording of the electrical activity of the heart over a period of time. The st segment is an isoelectric line that represents the time between depolarisation and repolarisation of the ventricles i. The larger and wider a q wave is as in the qrpattern in the lower row of figure3,compared to the qrpattern in the upper row the more likely it is that myocardial infarction heart attack has occurred at some point in the patients history.
Assessment of stt wave changes can then be used to provide insight as to whether infarction is new or old. Basic ecg interpretations the first course in the series is to advance the learners understanding of the electrocardiogram and develop their skills. Ecg basics 910 st interval, t wave and u wave youtube. Posted by by admin october 29, 2018 november 1, 2018 12lead ecg 12lead ecg device abnormal heart rhythms atrial fibrillation blood blood pressure bundle branch block cardiac chest leads ecg ecg an ecg ecg basics pdf ecg basics pdf by dr. For practical purposes, we often refer to the amplitude, or height, of an ecg complex in millimeters of paper rather than in millivolts. Free online ultrasound lessons this website is intended for use by medical professionals for educational purposes only. For this course, we are using an eight step procedure. Hard to interpret an ecg with lbbb lead v1 q wave and an s wave lead v6 an r wave followed by another r wave. Wellens syndrome, deep anterolateral twave inversion, critical lad stenosis. It is small because the atria make a relatively small muscle mass. How to read an ecg ecg interpretation geeky medics.
The st segment starts at the end of the s wave and ends at the beginning of the t wave. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Ecg rhythm study guide normal sinus rhythm looking at the ecg youll see that. Clinical pediatrics simplified pediatric electrocardiogram. Explain the common errors practitioners make with ecg. This is conventional because the q portion of the complex is so frequently. Poor progression r wave left ventricular hypertrophy, anteroseptal mi j point. Top 100 ecg litfl clinical cases ekg electrocardiography. In other words, a normal ecg does not rule out chf. How to read an ecg ecg from basics to essentials wiley.
Analyses of p wave, q wave, and t wave are also presented in the chapter. In our quest to understanding ecg, let us first try to understand the first wave, that is p wave. Our aim is to familiarise you with the layout of the 12lead ecg, and to. On a normal ecg of good quality, the p waves, qrs complexes, and t waves are visible the tachometer is triggered by the r wave but not the t wave. It appears as three closely related waves on the ecg the q, r and s wave. Hyperkalaemianarrow and tall peaked t wave a is an early signpr interval becomes longerp wave loses its amplitude and may disappearqrs complex widens bwhen hyperkalemia is very severe, the widened qrs complexes merge with theircorresponding t waves and the resultant ecg looks like a series of sine waves c. Normal t axes 61 52 97 abnormal ecg when compared with ecg of 17may2006 st elevation now present in inferior leads st now depressed in anterolateral leads t wave inversion now evident in anterolateral leads qt interval prolongation normal is considered less than half of the rr when the heart rate is 70. The ecg impulse is conducted from the patient to the cardiac monitor through cables attached to the patient with disposable adhesive monitoring pads or metal electrodes and straps. We are not going in details of them, rather name them out as follows.
The basics and beyond cindy weston, dnp, rn, ccrn, cns. Following depolarization, ventricular muscle repolarizes, and this event is great enough in amplitude to generate the t wave on the ecg tracing. Ecg diagnosis of st elevation of myocardial infarction mi stemi is also provided. Lead i, lead ii, lead iii, lead avl, lead avr, lead avf. Abnormal j slurring elevation is seen in hypothermia osborne wave. Advanced cardiovascular life support provider manual. P wave is generally about 1 box wide or 1 box tall. Characteristic ecg changes would be large qrs complex associated with giant t wave inversion in lateral leads i, avl, v5, and v6, together with st segment depression in left ventricular thickening. Wellens syndrome, deep anterolateral t wave inversion, critical lad stenosis. Ventricular repolarization pr and qt intervalsconduction problems. Observe that p wave of this ecg graph forms a plateau and is shorter in height than q. Describe the process for interpretation of a 12 lead ecg.
Q wave first negative or downward deflection of this large complex r wave first upward or positive deflection following the p wave tallest waveform s wave the sharp, negative or downward deflection that follows the r wave normal interval is 0. If the t wave axis is more than about 45 to 60 o different from the qrs axis, this is abnormal. Produced by ventricular repolarization or relaxation. The causes of pathologic t wave inversion include myocardial ischemia and infarction, ventricular strain, and treatment with digoxin. Sep 17, 2016 here we have described about the normal physiology of t wave,u wave,osborne wave, epsilone wave and delta wave. The st segment starts at the end of the qrs and ends at the start of the t wave. The vertical, or y axis, on the ecg is voltage, with each millimeter mm of paper equal to 0. Pr interval impulse from atria to ventricles to ventricles.
T wave memory, preexcitation, wolffparkinsonwhite, wpw, ecg quiz library 1. It represents end of repolarization of the ventricles. Sah, stemi, subarachnoid haemorrhage, inferior stemi with lead reversal with sah. As congestive heart failure chf is the outcome of many pathophysiologic disorders, the ecg may show a large variety of abnormalities. Normally, no voltage is apparent between the end of the qrs and the t wave. T waves are normally positive, but negative t waves are normal findings in leads avr and v 1 and in young people, in v 2. Ecg basics an electrocardiogram is also known as an ecg. Anas yasin md ecg interpretation ecg or ekg electrical electrical activity electrocardiogram. Pdf in this second article, we take a more detailed look at the 12lead ecg.
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