Fast & Easy ECGs – A Self-Paced Learning Program
Transcript of Fast & Easy ECGs – A Self-Paced Learning Program
![Page 1: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/1.jpg)
Q
I
A
6
Fast & Easy ECGs – A Self-Paced Learning Program
QRS Complexes
![Page 2: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/2.jpg)
ECG Waveforms • Normally the heart beats in a regular, rhythmic
fashion producing a P wave, QRS complex and T wave
I
![Page 3: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/3.jpg)
Step 4 of ECG Analysis • Examining the QRS complexes
Q
I
![Page 4: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/4.jpg)
QRS Complex • Q wave
– first negative deflection from the baseline following the P wave
• R wave – first positive deflection
following the Q wave
• S wave – first negative deflection that
extends below the baseline following the R wave
I
![Page 5: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/5.jpg)
Common QRS Complex Configurations
• Usually the QRS complex consists of positive (upright) deflections called R waves and negative (inverted) deflections called Q and S waves
• If there is no R wave, the complex is called a QS complex
• If there is no Q wave, the complex is called an RS complex
I
![Page 6: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/6.jpg)
Common QRS Complex Configurations
![Page 7: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/7.jpg)
Variations in the QRS Complex
• While there is only one Q wave there can be more than one R and S wave
I
![Page 8: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/8.jpg)
Examining QRS Complexes
• Look closely at their characteristics, especially their location, configuration, and deflection
![Page 9: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/9.jpg)
Measuring QRS Complexes • Starting point is
where first wave of complex starts to move away from baseline
• Ending point is where last wave of complex begins to level out (flatten) at, above, or below the baseline
![Page 10: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/10.jpg)
Measuring the QRS Complex
• Determining where the QRS complex ends can be difficult as sometimes there isn’t a clear transition
• Measurement of the QRS complex should include the entire S wave but it shouldn’t overlap into the ST segment or the T wave
Q
I
![Page 11: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/11.jpg)
Measuring the QRS Complex
![Page 12: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/12.jpg)
Evaluating QRS Complexes
• Identifying the QRS complexes and determining whether they are normal or abnormal helps determine what rhythm the patient may be experiencing
I
![Page 13: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/13.jpg)
![Page 14: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/14.jpg)
Normal QRS Complexes • QRS complexes should appear normal
(upright and narrow) if: – the rhythm is initiated from a site above the
ventricles – conduction has progressed normally from the
bundle of His, through the right and left bundle branches, and through the Purkinje network
– normal depolarization of the ventricles has occurred
![Page 15: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/15.jpg)
Normal QRS Complexes • Seen with normal sinus rhythm and
dysrhythmias that arise from above the ventricles – Unless there is a conduction delay through the
ventricles or other type of abnormality
![Page 16: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/16.jpg)
Abnormal QRS Complexes
• Produced by abnormal depolarization of the ventricles
• Pacemaker site in these abnormal QRS complexes can be the SA node, or an ectopic pacemaker in the atria, AV junction, bundle branches, Purkinje network, or ventricular myocardium
![Page 17: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/17.jpg)
Abnormal QRS Complexes • The shape of an
abnormal QRS complex can vary from normal to wide and bizarre and/or slurred and notched
I
![Page 18: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/18.jpg)
Abnormal QRS Complexes • Caused by a number of factors including:
– Ventricular hypertrophy – Intraventricular conduction disturbance – Aberrant ventricular conduction – Ventricular preexcitation – Ventricular ectopic or escape pacemaker – Ventricular pacing by cardiac pacemaker
![Page 19: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/19.jpg)
Tall QRS Complexes • Usually caused by:
– hypertrophy of one or both ventricles
– an abnormal pacemaker
– aberrantly conducted beat
![Page 20: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/20.jpg)
Low-Voltage QRS Complexes
• Seen in: – obese patients – hyperthyroid patients – pleural effusion
![Page 21: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/21.jpg)
Wide-Bizarre QRS Complexes (of Supraventricular Origin)
• Often result from intraventricular conduction defect • Typically a result of right or left bundle branch block
![Page 22: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/22.jpg)
Aberrant Conduction • Occurs when electrical impulses reach the
bundle branch while it is still refractory after conducting a previous electrical impulse
• Results in the impulse traveling down the unaffected bundle branch followed by the stimulation of the other bundle branch
• Causes QRS complex to appear slightly wider than normal
![Page 23: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/23.jpg)
Aberrant Conduction
![Page 24: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/24.jpg)
Ventricular Preexcitation • Premature depolarization of the ventricles • Occurs when an impulse arising from a
supraventricular site travels through abnormal accessory conduction pathways to the ventricles
• May produce: – Wider than normal QRS complexes – Abnormal slurring at its onset (called the
delta wave)
![Page 25: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/25.jpg)
Ventricular Preexcitation
![Page 26: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/26.jpg)
Cardiac Pacemaker-Induced QRS Complexes
• Generally ≥ 0.12 seconds in width and appear bizarre
• Preceding each pacemaker-induced QRS complex is a pacemaker spike
![Page 27: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/27.jpg)
Cardiac Pacemaker-Induced QRS Complexes
![Page 28: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/28.jpg)
Ventricular Dysrhythmias • Originate from the ventricular tissue
![Page 29: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/29.jpg)
Wide QRS Complexes
• Key characteristic of ventricular dysrhythmias
• Bizarre-looking • T wave that
takes an opposite direction to R waves
![Page 30: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/30.jpg)
Wide QRS Complexes • Premature Ventricular Complexes (PVCs) are early
beats that arise from the ventricles before SA node can fire
![Page 31: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/31.jpg)
Wide QRS Complexes • Seen with idioventricular rhythm
– A sustained escape rhythm having a rate of 20 to 40 beats per minute (may be slower)
I
![Page 32: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/32.jpg)
Wide QRS Complexes
• Seen with ventricular tachycardia (VT) – Three or more PVCs in a row are considered
ventricular tachycardia – May come in bursts of 6 to10 complexes or be
sustained – In sustained VT the heart rate is between 100
and 250 BPM
I
![Page 33: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/33.jpg)
Wide QRS Complexes
![Page 34: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/34.jpg)
Changing Ventricular Waveforms
• Seen with torsades de pointes – Appears as a series of QRS complexes that rotate about the
baseline between upright deflections and downward deflections – This produces a “spindle-like” appearance of the ECG rhythm
![Page 35: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/35.jpg)
Wide QRS Complexes
• Seen in 3rd-degree AV heart block – Location of the ventricular escape pacemaker site
determines appearance of the QRS complex
I
![Page 36: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/36.jpg)
Chaotic Wavy Line • Called ventricular fibrillation • Represents erratic firing of multiple sites in the ventricles • On ECG monitor it looks like a chaotic, wavy line with no
discernible waveforms
I
![Page 37: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/37.jpg)
Flat (or Nearly Flat) Line • Called asystole • Represents lack of any cardiac activity in the ventricles • Complete cessation of cardiac output
![Page 38: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/38.jpg)
Practice Makes Perfect • Determine the type of ventricular waveforms
I
![Page 39: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/39.jpg)
Practice Makes Perfect • Determine the type of ventricular waveforms
I
![Page 40: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/40.jpg)
Practice Makes Perfect • Determine the type of ventricular waveforms
I
![Page 41: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/41.jpg)
Practice Makes Perfect • Determine the type of ventricular waveforms
I
![Page 42: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/42.jpg)
Practice Makes Perfect • Determine the type of ventricular waveforms
I
![Page 43: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/43.jpg)
Summary • Fourth step of analyzing an ECG rhythm is examining
the QRS complexes.
• QRS complex starts where first wave of complex starts to move away from the baseline. It ends at the point where the last wave of the complex transitions into the ST segment.
• QRS complex is larger than the P wave because ventricular depolarization involves a considerably larger muscle mass than atrial depolarization.
![Page 44: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/44.jpg)
Summary • Amplitude of a normal QRS is 5 to 30 mm and the
duration is 0.06 to 0.12 seconds.
• Q wave is first negative deflection from baseline following the P wave.
• R wave is the first positive deflection following the Q wave (the P wave if Q wave is absent).
• S wave is first negative deflection that extends below the baseline in the QRS complex following the R wave.
![Page 45: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/45.jpg)
Summary • Normal sinus rhythm and dysrhythmias that arise from
above the ventricles will usually have normal QRS complexes.
• Abnormal QRS complexes are produced by abnormal depolarization of the ventricles.
• Duration of an abnormal QRS complex is greater than 0.12 seconds.
![Page 46: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/46.jpg)
Summary • Shape of an abnormal QRS complex varies from almost
normal to wide and bizarre and/or slurred and notched.
• Tall QRS complexes are usually caused by hypertrophy of one or both ventricles, or by an abnormal pacemaker or aberrantly conducted beat.
• Low voltage or abnormally small QRS complexes may be seen in obese patients, hyperthyroid patients and pleural effusion.
![Page 47: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/47.jpg)
Summary • Wide, bizarre QRS complexes of supraventricular origin
are often the result of intraventricular conduction defect which usually occurs due to right or left bundle branch block.
• Wide QRS complexes may be seen in aberrant conduction, ventricular preexcitation and with a cardiac pacemaker.
![Page 48: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/48.jpg)
Summary • Wide, greater than 0.12 seconds in duration, QRS
complexes are the key characteristic seen with ventricular dysrhythmias.
• With torsades de pointes the shape of the ventricular waveforms changes. It has a “spindle-like” appearance of the ECG rhythm.
I
![Page 49: Fast & Easy ECGs – A Self-Paced Learning Program](https://reader031.fdocuments.in/reader031/viewer/2022012100/6169d8ee11a7b741a34c0862/html5/thumbnails/49.jpg)
Summary • 3rd-degree AV heart block is another dysrhythmia where
there may be abnormal QRS complexes.
• Ventricular fibrillation appears on ECG monitor as a chaotic wavy line, with no discernible waveforms.