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117 Cards in this Set
- Front
- Back
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Which region of ventricle do leads V1-V2 correspond to?
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Septal and right ventricle
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Which region of ventricle do leads V2-V4 correspond to?
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Anterior part of ventricles
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Which region of ventricle do leads V1-V4 correspond to?
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Anteroseptral part of the ventricles
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Which region of ventricle do leads V5-V6 correspond to?
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Apical part of the heart |
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Which region of ventricle do leads II, III and aVF correspond to?
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Inferior part of the heart |
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Which region of ventricle do leads I, aVL, V6 correspond to?
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Anterolateral part of the ventricles |
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Which region of ventricle do leads I, aVL, V1, V6 correspond to?
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Extensive anterior part |
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How wide and tall is one big square? |
200 ms wide 0,5 mV tall |
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How wide and tall is one small square? |
40 ms wide 0,1 mV tall |
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How can we see if a ECG is rhythmic? |
The distance between R-R waves stays the same- 2 mm deviation is considered normal |
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What are the criteria for sinus rhythm? |
- Every P-wave is followed by an QRS and every QRS is proceeded by a P-wave. - PQ time is normal (120-200 ms) - P-P and R-R intervals should be constant. - Frequency should be 60-100/min |
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How can we measure the frequency of arrhythmic ECGs? |
Number of QRS-complexes in a 15 big square section multiplied by 20 |
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What is the normal axis of the heart? |
Between 0 and +90 degrees |
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When do we have left deviation? |
When the heart axis is between 0 and -30 degrees |
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When do we have right deviation? |
Between +90 and +110 degrees |
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How can you determinate the QRS axis? |
By comparing the amplitude of the R-wave in leads I, II and III. Normal axis: II > I > III Left axis deviation: I > II > III Right axis deviation: III > II > I |
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In which lead can we see a physiological biphasic P-wave? |
V1 |
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How wide and tall is a normal P-wave? |
Should not be wider than 100 ms and not taller than 0,25 mV (2,5 small squares) |
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Where can we find a negative P-wave? |
aVR |
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How long is a normal PQ interval? |
120-200 msec |
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What can a PQ interval longer than 200 ms be? |
AV-blocks. If only long PQ in ECG: 1st degree AV block. |
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What can a PQ interval shorter than 120 ms be? |
Preexcitation syndromes. |
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What does the Q-wave in QRS represent? How wide and tall should it be? |
- Septal depolarisation - Should be 25 % of the corresponding R-wave and the width should be less than 40 ms. |
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What can a pathological Q-wave tell us? |
It's a sign of myocardial necrosis. |
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Where can we find physiological QS complexes? |
aVR and V1 |
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What does the R-wave represent? |
Depolarisation of the bulk of the muscle in the left ventricle |
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How should the R-wave be evaluated? |
- The amplitude is between 0,5-1,5 mV (1-3 big squares) - Amplitude increases from V1 to V5 (R progression) - May be absent in V1 because of the QS complex. |
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What can a large R wave in V1-V3 be a sign of? (Remember that in these leads, S is bigger than R) |
- Posterior AMI - RV hypertrophy - Acute load on the right ventricle |
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What does the S wave represent? |
Depolarisation of the posterobasal region. |
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Physiological properties of S-wave? |
Decreases between V1-V5 Absent in V6 |
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How wide is a QRS complex normally? |
Less than 100 ms. This is called a narrow QRS |
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What are the causes of a wide QRS? (more than 100 ms) |
1. Complete bundle branch blocks 2. Stimuli of ventricular origin 3. WPW syndrome 4. Hyperkalemia 5. Left ventricular hypertrophy |
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Definition of VAT? (ventricular activation time) |
Time elapsing from the beginning of the QRS until the peak of the last positive wave in the QRS. |
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What can be the reason for prolonged VAT in V5 and V6? |
- Left bundle branch block - LV hypertrophy |
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What can be the reason for prolonged VAT in V1 and V2? |
- Right bundle branch block - RV hypertrophy |
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What can cause low voltage? (amplitude of QRS lower than 0,5 mV in extremity leads, less than 0,7 mV in chest leads) |
- Primary reason: damage of myocardium like extensive myocardial infarct - Secondary reason: pericarditis, obesity |
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What can cause high voltage? |
LV hypertrophy |
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What is PAPA? |
The conditions that can cause ST-elevation. Pericarditis AMI Pinzmetals angina Aneurysm |
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What can cause horizontal ST-depression? |
Myocardial ischemia, angina pectoris |
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What can cause descending ST depression? |
Severe myocardial ischemia, left ventricular stretch |
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How does the digitalis effect look like on the ECG? |
Scooped type ST depression |
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What do we mean with secondary ST deviations and what can cause this? |
- If the depolarisation is abnormal, and the repolarisation cannot be evaluated. - Bundle branch blocks - WPW syndrome - Ventricular hypertrophy - Beats of ventricular origin - Ventricular pacemaker |
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What is the width of a normal T wave? |
100-250 ms |
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The order of ventricular repolarization? |
Opposite from depolarization. From subendocardial region of the ventricular muscle till the subepinardial region. |
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How does the T-wave look in case of an infarct? |
Coronary T: negative, pointed T-wave |
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Where can a high, pointed T-wave be seen? (higher than 9 mm) |
Primary causes: Sunbendocardial ischemia, hyperacute phase of infection, mirror sign of posterior AMI. Secondary causes: Bundle branch blocks, increased sympathetic activity, hyperkalemia |
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How long is the normal QTc value? |
0,38-0,42 s |
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What can cause the QT interval to shorten? |
Hypercalcemia Hyperkalemia Digitalis effect |
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What are the causes for right atrial enlargement? |
Pressure load of atria, like - stenosis of tricuspid or pulmonary valve - COPD - Chronic respiratory failure - Right ventricular hypertrophy Volume load of atria - Insufficiency of tricuspid or pulmonary valve - Left to right shunts - Left-sided heart failure |
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What are the signs of right atrial enlargement in ECG? |
A pulmonary P. Peaked and high, but not wide. Typically in inferior leads, II, III and aVF. In V1, the first part of biphasic P is widened. |
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What are the signs of left atrial enlargement? |
Mitral P: Broad (longer than 100 ms) split P wave in leads I, II, V5 and V6 P terminal force: The second component (terminal) in the biphasic P in V1 is broader than 40 ms |
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Signs of biatrial enlargement? |
P-biatriale: Leads II, III, aVF, the P-wave is wide and broad (more than 100 ms) In V1: both components of biphasic P are higher than 0,1 mV and terminal negative wave exceeds 40 ms. |
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Signs of left ventricular hypertrophy? |
- Left axis deviation - High voltage - VAT is longer than 40 ms in V5 and V6 - ST-depression - Negative T waves |
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What can cause hypertrophy of left ventricle? |
Hypertension, aortic stenosis |
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Signs of acute load of right ventricle? |
- Large S in I - Large Q and negative T in III - Large R wave in V1 - Sinus Tachycardia |
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What are the signs of subendocardial ischemia/hypoxia? |
High, peaked, positive T |
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What are the signs of subepicardial-transmural ischemia? |
Coronary T. (negative, peaked, symmetric T) |
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What is the current of injury? |
The decreased function of Na/K ATPase due to ischemia causes hypopolarization of muscle cells, making their surface more electronegative. This produces a potential difference between the injured cells and the intact cells. |
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What is the sign of myocardial necrosis? |
The pathological Q |
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Characteristrics of the pathological Q? |
- at least one small square wide (40 ms) - Amplitude is at least 25 % of the corresponding R wave - Appears 6-8 hours after the occlusion of the coronary |
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In which pathologies can we see a QS complex? |
- Transmural necrosis |
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Symptoms of acute myocardial infaction? |
- Dull, pressing chest pain on the left side that radiates to left arm/neck. - Nitrate don't alleviate it - Shortness of breath - Weakness - Palpitation |
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Signs of hyperacute phase of AMI? (30 mins - 8 hours) |
- High, pointed, positive T-waves - ST-elevation = T en dome - ST depression in the opposite leads. |
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Signs of acute phase of AMI? (8-72 hours) |
- Pathological Q-wave - R-reduction in chest leads - ST-elevation is smaller, T turns negative - QS-complex after 24 hours - Coronary T after 24 hours |
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Signs of posterior myocardial infarction? |
Seen in V1-V3 - High R-wave - ST-depression - Peaked T - Often with inferior infarctions. Mirror signs from what would have be seen in dorsal leads. |
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How does a right ventricular infaction look like? |
- ST elevation in lead V1 - Frequently occur with posteroinferior AMI |
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What are the signs of the chronic phase of AMI? |
- Pathological Q - R-reduction - ST segment is usually normalised - T-wave is normal |
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What is NSTEMI? |
Myocardial infarction without ST-elevation. (more common than STEMI) |
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What is the sign of stabile angina in ECG? |
Horizontal or descending ST-depression, but only during exertion! |
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What are the signs of Prinzmetals angina? |
- Occurs during rest - Due to a spasm in the epicardial coronary vessel - Transient ST elevation |
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Why does ST-elevation occur? |
Subepicardial injury shifts the baseline down except for the ST segment. |
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Why does ST-depression occur? |
Subendocardial injury |
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Signs of Pericarditis? |
- Concave ST-elevation in every lead except aVR. - Low voltage - T inversion in chronic cases - No mirror signs! |
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What does nomotopic mean? |
The sinus node operates at an abnormal rhythm or frequency like sinus bradycardia, tachycardia, sinus arrhythmia, sinus arrest and sick sinus syndrome |
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What is heterotopy? |
Disorder of pacemaking, and the stimulus originate from an ectopic focus. |
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Examples of active heterotropy? |
- Extrasystole - Paroxysmal tachycardia |
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Examples of passive heterotopy? |
- Escape beat - Escape rhythm |
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What can be seen in a sinus tachycardia? |
- QT time decreases - Ascending ST depression and flat/biphasic T waves are common. |
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What can be seen in a atrial tachycardia? |
- The frequency rises gradually (warm up phenomenon) - Narrow QRS - P waves differ from sinus P |
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What can be seen in ventricular tachycardia? |
- Wide QRS - Secondary repolarization disorders - |
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What is Torsade de pointes? |
QRS axis changes continuously in ventricular tachycardia, resulting in a spindle-like morphology. |
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What do we mean by coupling time regarding extrasystole? |
The time between the peak of the R wave of the previous beat and the peak of the R wave of the following beat |
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What do we mean by compensatory pause regarding extrasystole? |
Time between the peak of the R wave of the extrasystole and the peak of R of the following beat |
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Which kind of extrasystoles are sub compensated? |
Supraventricular. They reset the P-wave cycle because they affect the SA node |
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What is an interpolated extrasystole? |
A ES that doesn't interfere with sinus frequency. RR interval is constant. Appears in extreme bradycardia. |
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How does an atrial extrasystole differ from sinus rhythm? |
- Negative or positive P wave different from sinus P. - Normal QRS - Normal repolarization |
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Morphology of junctional extrasystole? |
- Negative P waves in II, III and aVF - P wave can percede, follow or coincide with QRS - Normal QRS and repolarization. |
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Morphology of ventricular extrasystole? |
- Not preceded by P wave - Broad and bizarre QRS (> 0,12 s) - Followed by secondary repolarization abnormalities. - Compensated. |
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What can cause ventricular extrasystole? |
- Ischemic heart disease - AMI - Dilative cardiomyopathy - Digitalis intoxication - Hypoxia - Acidosis |
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Definition of an escape beat? |
A single stimulus coming from a locus of lower automatism in case of short-term omission of sinus stimuli as in sinus arrest or AV block. Comes later than expected based on the current rhythm. |
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How does the junctional escape rhythm look like? |
- P wave is negative - P wave can persede, follow or coincide with the QRS. - QRS and repolarisation is normal |
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What can cause junctional escape rhythm? |
- 3rd degree supra-His AV block - Sinus arrest - 3rd degree SA block |
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How does ventricular escape rhythm look like? |
- Broad QRS - Secondary repolarization disorders |
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What is Stokes-Adams syndrome? |
Syndrome that develops in asystole due to absence of blood flow to brain. Leads to death without effective treatment. |
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What can cause Stokes-Adams syndrome? |
- Sinus arrest, - 3rd degree SA block - Severe sinus bradycardia - 3rd degree AV-block (most common) where there is no escape rhythm. |
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What is the sick sinus syndrome? |
It includes several types of arrhythmias: - Sinus tachycardia - Sinus bradycardia - Sino-atrial block (SA block) - Sinus arrest - Tachy-brady syndrome (a combination of those above) |
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What is sinus arrest? |
Total cessation of sinus functions that can be brief og lasting. Must be taken over by a lower pacemaker, or escape rhythm, or else there will be Stokes-Adams syndrome. |
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What is the atrial fibrillation triade? |
3 main causes of atrial fibrillation: - Pressure and/or volume load of atria - Atrial ischemia/hypoxia - Hyperthyroidism |
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Morphology of atrial fibrillation? |
- f-waves instead of P-waves - irregular ventricular contractions - absolute arrhythmia - 400-600/min |
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Morphology of atrial flutter? |
- Saw-tooth F-waves instead of P waves - Varying block ratio (how many F waves are conducted to ventricles), normally 2:1 and 4:1 - Frequency 200-400/min - More dangerous than fibrillation since some of these are effective contractions. |
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What does ventricular flutter look like? |
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What can cause ventricular flutter and what can it develop to? |
Causes: AMI, heat stroke, hypothermia, hypo- and hyperkalemia, low Mg or Ca levels. Can progress into ventricular fibrillation |
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What is ventricular fibrillation? |
- Irregular ventricular impulses with high frequency where cardiac output is 0. - Causes symptoms resembling Stokes-Adams syndrome. |
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What are the types of 2nd degree SA-block? |
Type 1: The sinoatRial conduction time increases with each beat until one stimulus is not conducted to the atria. Type 2: After normal SA conductions, suddenly a P wave and QRS don't appear. |
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How does a 3rd degree SA-block look like? |
No conduction to atrium at all. The ECG curve will be an isoelectric line unless a escape beat develops. |
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How can we see a 1st degree AV-block? |
Conduction from atrial to ventricle is slower than usual. PQ interval is prolonged (more than 5 small squares) |
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How can we see 2nd degree AV-block? |
Not every P is followed by QRS |
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What can we see in Mobitz type-I 2nd degree AV-block? |
- PQ interval increases gradually - After a while, stimulus will not be conducted from atria to ventricles - P waves will suddenly not be followed by QRS - Block ratio |
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What can be causes for Mobitz type-I 2nd degree AV-block? |
Digitalis intoxication Inferior AMI Myocarditis |
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Mobitz type-II second degree AV block? |
- P wave is suddenly not followed by QRS - Commonly progresses into 3rd degree AV block - Caused by anterior ami and cardiomyopathies |
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What is high grade AV block? |
Two or more consecutive P waves are not followed by QRS. Block ratio: 3:1, 4:1 |
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3rd degree AV block? |
- No atrial impulses are conducted to the ventricle. - Stokes-Adam syndrome can develop is no junctional or escape rhythm develops. - If escape rhythm: P waves and QRS complexes are independent, they appear as they want to. |
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What can cause 3rd degree AV block? |
- Myocarditis - Degenerative processes in the AV node - Ischemic heart disease - AMI - Digitalis intoxication - Congenital reasons |
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Signs of right bundle branch block? (RBBB) |
- Wide and split R and R' waves (rsR') in V1 and V2. - Deep S wave in I, II, aVL, V5, V6 - VAT is prolonged in V1 and V2 (<40 ms) - Secondary repolarization abnormalities |
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Signs of left bundle branch block? (LBBB) |
- Wide QRS, > 120 ms - No Q wave in I, aVL, V5, V6 - split R wave in same leads - Prolonged VAT in V5 and V6 (>80ms) - QS and rS in V1 and V2 - Q cannot be evaluated |
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Signs of left anterior hemiblock? |
- Extreme left deviation - qR complex in I, aVL -rS in II, III and aVF - QRS is not wide (just between 80-120 ms) |
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Signs of left posterior hemiblock? |
- Extreme right axis - rS in I and aVL - qR in II, III and aVF - QRS is not wider than 120 ms |
