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117 Cards in this Set

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  • Back
Which region of ventricle do leads V1-V2 correspond to?
Septal and right ventricle
Which region of ventricle do leads V2-V4 correspond to?
Anterior part of ventricles
Which region of ventricle do leads V1-V4 correspond to?
Anteroseptral part of the ventricles
Which region of ventricle do leads V5-V6 correspond to?

Apical part of the heart

Which region of ventricle do leads II, III and aVF correspond to?

Inferior part of the heart

Which region of ventricle do leads I, aVL, V6 correspond to?

Anterolateral part of the ventricles

Which region of ventricle do leads I, aVL, V1, V6 correspond to?

Extensive anterior part

How wide and tall is one big square?

200 ms wide


0,5 mV tall

How wide and tall is one small square?

40 ms wide


0,1 mV tall

How can we see if a ECG is rhythmic?

The distance between R-R waves stays the same-


2 mm deviation is considered normal

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

How can we measure the frequency of arrhythmic ECGs?

Number of QRS-complexes in a 15 big square section multiplied by 20

What is the normal axis of the heart?

Between 0 and +90 degrees

When do we have left deviation?

When the heart axis is between 0 and -30 degrees

When do we have right deviation?

Between +90 and +110 degrees

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

In which lead can we see a physiological biphasic P-wave?

V1

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)

Where can we find a negative P-wave?

aVR

How long is a normal PQ interval?

120-200 msec

What can a PQ interval longer than 200 ms be?

AV-blocks.


If only long PQ in ECG: 1st degree AV block.

What can a PQ interval shorter than 120 ms be?

Preexcitation syndromes.

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.

What can a pathological Q-wave tell us?

It's a sign of myocardial necrosis.

Where can we find physiological QS complexes?

aVR and V1

What does the R-wave represent?

Depolarisation of the bulk of the muscle in the left ventricle

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.

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



What does the S wave represent?

Depolarisation of the posterobasal region.

Physiological properties of S-wave?

Decreases between V1-V5


Absent in V6

How wide is a QRS complex normally?

Less than 100 ms. This is called a narrow QRS

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



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.

What can be the reason for prolonged VAT in V5 and V6?

- Left bundle branch block


- LV hypertrophy

What can be the reason for prolonged VAT in V1 and V2?

- Right bundle branch block


- RV hypertrophy

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

What can cause high voltage?

LV hypertrophy

What is PAPA?

The conditions that can cause ST-elevation.


Pericarditis


AMI


Pinzmetals angina


Aneurysm

What can cause horizontal ST-depression?

Myocardial ischemia, angina pectoris

What can cause descending ST depression?

Severe myocardial ischemia, left ventricular stretch

How does the digitalis effect look like on the ECG?

Scooped type ST depression

Scooped type ST depression

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

What is the width of a normal T wave?

100-250 ms

The order of ventricular repolarization?

Opposite from depolarization. From subendocardial region of the ventricular muscle till the subepinardial region.

How does the T-wave look in case of an infarct?

Coronary T: negative, pointed T-wave



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

How long is the normal QTc value?

0,38-0,42 s

What can cause the QT interval to shorten?

Hypercalcemia


Hyperkalemia


Digitalis effect

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

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.

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

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.

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

What can cause hypertrophy of left ventricle?

Hypertension, aortic stenosis

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

What are the signs of subendocardial ischemia/hypoxia?

High, peaked, positive T

What are the signs of subepicardial-transmural ischemia?

Coronary T.


(negative, peaked, symmetric T)

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.

What is the sign of myocardial necrosis?

The pathological Q

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

In which pathologies can we see a QS complex?

- Transmural necrosis

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

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.

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

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.

How does a right ventricular infaction look like?

- ST elevation in lead V1


- Frequently occur with posteroinferior AMI

What are the signs of the chronic phase of AMI?

- Pathological Q


- R-reduction


- ST segment is usually normalised


- T-wave is normal



What is NSTEMI?

Myocardial infarction without ST-elevation.


(more common than STEMI)

What is the sign of stabile angina in ECG?

Horizontal or descending ST-depression, but only during exertion!

What are the signs of Prinzmetals angina?

- Occurs during rest


- Due to a spasm in the epicardial coronary vessel


- Transient ST elevation

Why does ST-elevation occur?

Subepicardial injury shifts the baseline down except for the ST segment.

Why does ST-depression occur?

Subendocardial injury

Signs of Pericarditis?

- Concave ST-elevation in every lead except aVR.


- Low voltage


- T inversion in chronic cases


- No mirror signs!

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

What is heterotopy?

Disorder of pacemaking, and the stimulus originate from an ectopic focus.

Examples of active heterotropy?

- Extrasystole


- Paroxysmal tachycardia

Examples of passive heterotopy?

- Escape beat


- Escape rhythm

What can be seen in a sinus tachycardia?

- QT time decreases


- Ascending ST depression and flat/biphasic T waves are common.

What can be seen in a atrial tachycardia?

- The frequency rises gradually (warm up phenomenon)


- Narrow QRS


- P waves differ from sinus P



What can be seen in ventricular tachycardia?

- Wide QRS


- Secondary repolarization disorders


-

What is Torsade de pointes?

QRS axis changes continuously in ventricular tachycardia, resulting in a spindle-like morphology.

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

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

Which kind of extrasystoles are sub compensated?

Supraventricular.


They reset the P-wave cycle because they affect the SA node

What is an interpolated extrasystole?

A ES that doesn't interfere with sinus frequency. RR interval is constant.


Appears in extreme bradycardia.

How does an atrial extrasystole differ from sinus rhythm?

- Negative or positive P wave different from sinus P.


- Normal QRS


- Normal repolarization

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.

Morphology of ventricular extrasystole?

- Not preceded by P wave


- Broad and bizarre QRS (> 0,12 s)


- Followed by secondary repolarization abnormalities.


- Compensated.

What can cause ventricular extrasystole?

- Ischemic heart disease


- AMI


- Dilative cardiomyopathy


- Digitalis intoxication


- Hypoxia


- Acidosis

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.

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

What can cause junctional escape rhythm?

- 3rd degree supra-His AV block


- Sinus arrest


- 3rd degree SA block

How does ventricular escape rhythm look like?

- Broad QRS


- Secondary repolarization disorders



What is Stokes-Adams syndrome?

Syndrome that develops in asystole due to absence of blood flow to brain. Leads to death without effective treatment.

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.

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)



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.

What is the atrial fibrillation triade?

3 main causes of atrial fibrillation:


- Pressure and/or volume load of atria


- Atrial ischemia/hypoxia


- Hyperthyroidism

Morphology of atrial fibrillation?

- f-waves instead of P-waves


- irregular ventricular contractions


- absolute arrhythmia


- 400-600/min



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.

What does ventricular flutter look like?



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

What is ventricular fibrillation?

- Irregular ventricular impulses with high frequency where cardiac output is 0.
 - Causes symptoms resembling Stokes-Adams syndrome.

- Irregular ventricular impulses with high frequency where cardiac output is 0.


- Causes symptoms resembling Stokes-Adams syndrome.

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.

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.

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)

How can we see 2nd degree AV-block?

Not every P is followed by QRS

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

What can be causes for Mobitz type-I 2nd degree AV-block?

Digitalis intoxication


Inferior AMI


Myocarditis

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

What is high grade AV block?

Two or more consecutive P waves are not followed by QRS.


Block ratio: 3:1, 4:1

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.

What can cause 3rd degree AV block?

- Myocarditis


- Degenerative processes in the AV node


- Ischemic heart disease


- AMI


- Digitalis intoxication


- Congenital reasons

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

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

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)



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