Ekg Rhythm

Front 1

Wandering Pacemaker

Back 1

-caused by "wandering" pacemaker activity from SA to atrial foci.
-looks like: varying P' waves and irregular rhythm (due to different AF with different inherent rates being stimulated).
-Atrial rate less than 100

Front 2

Multifocal Atrial Tachycardia

Back 2

Caused by: irritable atrial foci having entrance block do not respond to overdrive surpression. Each AF fires at its own inherent rate but total combined causes tachycardia.
Looks like: varying but repeating P' waves, irregular rhythm, arial rate > 100.

Front 3

Atrial Fibrillation

Back 3

caused by: extreme irritable atrial foci-all firing at once. None achieve atrial depolarization.
Looks like: no P/P' waves, irregular rhythm, chaotic atrial spikes.

Hint 3

Only an occasional atrial impulse reaches the AV node and creates a QRS complex-hence the irregularity in rhythm of both atrial and ventricular depolarization.

Front 4

Types of escape Rhythms/Beats

Back 4

Atrial
Junctional
Ventricular

Hint 4

Escape occurs when a focus escapes overdrive surpression and therefore paces at its own inherent rate.

Front 5

Sinus arrest results in...

Back 5

Escape Rhythm

Front 6

Sinus block results in..

Back 6

Escape Beat

Hint 6

Block-SA node only misses one cycle, versus an arrest in which it stops completely

Front 7

Atrial Escape Rhythm

Back 7

When an Atrial Foci takes over and paces for the SA node.
Looks like: an arrest (short flat line) followed by a different P' wave.

Front 8

Junctional Escape Rhythm

Back 8

Occurs when: SA node and Atrial foci fail OR when there is a conduction block in the proximal end of the AV node (therefore pacemaking cannot reach through).
Looks like: Arrest followed by lone QRS/T complexes (Atrial conduction is not occurring).
Rate: 40 to 60

Hint 8

Retrograde Atrial Depolarization can occur

Front 9

Retrograde Atrial Depolarization

Back 9

When pacing occurs at the junction, depolarization to the atria from below may cause "inverted" P' waves.

Hint 9

AV node conducts slowly which means that junctional focus may delay retrograde atrial depolarization. Therefore, P' waves may be immediately before, within, or after QRS.

Front 10

Ventricular Escape Rhythm

Back 10

Occurs when: Conduction block below the AV node or with total failure of the SA node and all A Foci above the ventricles (this is very dangerous).
Looks like: Rate 20-40, Large QRS/T complexes.
P waves can be present as if it's a block, atrial depolarization could still be occurring. P waves are NOT in regular placement (could appear anywhere on the strip).

Front 11

Atrial Escape Beat

Back 11

occurs when: A sinus block interferes with the SA node-skips a cycle.
Looks like: a pause after a cycle, followed by a P' wave (which differs from the other, normal, P waves generated by the SA node).

Front 12

Premature Beats

Back 12

occur when: an auto foci becomes irritable and fires a stimulus causing a beat.
Looks like: a beat which occurs earlier than expected.

Front 13

Ventricular Foci become irritable when...

Back 13

Low O2!

Front 14

Atrial and Junctional foci become irritable when...

Back 14

-Adrenaline/Epinephrine/
Norepinephrine
-Increased Sympathetic activation
-B1 stimulants (caffeine, coke etc)

Front 15

Premature Atrial Beat (PAB)

Back 15

caused by: an irritable atrial automaticity focus that gets stimulated.
looks like: premature P' wave that does not look like the other P waves.

Hint 15

Sometimes the P' wave can be "hiding" in a T wave-often this can be displayed as a too tall T wave.

Front 16

PAB with aberrant ventricular conduction

Back 16

occurs when: Premature beat occurs. One of the bundle branches is not completely repolarized (still partial +) and not ready for depolarization produced by PAB.
Looks like: P ' followed by widened QRS complex ( one ventricle depolarizes and then the other ).

Hint 16

widened QRS complex results from one ventricle depolarizing and then the other. Therefore non-simultaneous depolarization is occurring.

Front 17

Non-conducted Premature Atrial Beat

Back 17

occurs when: PAB reaches the AV node when it is till refractory, therefore no ventricular depolarization results.
Looks like: P' PAB followed by NOTHING...then normal P wave restarting.

Hint 17

P' still depolarizes the SA node which "resets" rhythm to the P' wave.

Front 18

Atrial Bigeminy

Back 18

occurs when: atrial foci is irritated and a PAB occurs which is coupled to the end of a normal P wave.
Looks like: normal cycle followed by premature P' and corresponding cycle.

Front 19

couplet

Back 19

the cycle containing the premature beat together with the normal cycle/cycles to which it couples.

Front 20

Refractory Period

Back 20

Recovery period-repolarizing -or becoming negative again-so can be depolarized again.

Front 21

Atrial Trigeminy

Back 21

occurs when: irritable atrial foci fires after 2 normal cycles.
Looks like: 2 normal cycles followed by 1 P' wave and it corresponding cycle.

Front 22

Premature Junctional Beat (PJB)

Back 22

Occurs when an irritable focus in the AV junction fires a premature stimulus to the ventricles or retrograde to the Atria.
Looks like: a premature QRS complex that can be wider than the other QRS complexes. Note: the RS portion can become more inverted.

Hint 22

If the AV junction fires a premature stimulus that reaches the Atria, you will see an inverted P' wave right before the premature QRS complex.
OR...the P' wave could be hidden within the QRS complex of come afterwards if it takes longer to reach the atria than the ventricle.

Front 23

AV Junctional Bigeminy

Back 23

Occurs when a PJB is coupled with a normal SA node initiated cycle. An irritable junctional node fires and stimulates a beat AFTER the normal cycle.
Looks like: a normal cycle followed by PJB.

Hint 23

Can also be coupled with inverted P' wave prior to the QRS of the PJB.

Front 24

AV Junctional Trigeminy

Back 24

occurs when: PJB falls after 2 normal SA node initiated cycles.
Looks like: 2 normals cycles followed by a PJB (either w or w/out retrograde P' wave).

Front 25

More causes of ventricular foci irritability...

Back 25

LOW O2! (minimum blood o2 in lungs, reduced cardiac output, poor to absent coronary blood supply)
Hypokalemia
Pathology (MV prolapse, stretch, etc)
B1 adrenergic receptors

Hint 25

In the clinic, most ventricular tachycardias are due to coronary insufficiency or infarction-SO-KNOW THE OTHER CAUSES!

Front 26

Premature Ventricular Contraction (PVC)

Back 26

occurs when: a irritable ventricular automaticity focus fires.
Looks like: a giant ventricular complex and is usually inverted to the other normal QRS complexes.

Hint 26

PVC's occur early in the cycle.

Front 27

Why the shape and amplitude of a PVC?

Back 27

PVC is cause by an irritable foci in the ventricle. Normally, impulse moves from the AV node to both sides of the ventricle simultaneously and there is a counterbalance. With a PVC, the foci generates from one side and SLOWLY passes to the other ventricle-thus causing its wideness (slow pace) and amplitude (no counterbalance between ventricles).

Front 28

Compensatory Pause following PVC

Back 28

SA node is NOT depolarize, so rate and P-P length stay the same. The P occurs on schedule yet the ventricles are still refractory, so there is a PAUSE.
looks like: Large QRS complex (inverted) followed by small p wave and then flatline.

Hint 28

Note: T wave can follow P wave and also be large and inverted.

Front 29

Multiple PVC's

Back 29

Pathological! (more than 6 per minute).
Unifocal (meaning they are all originating from the same VFOCI and their waves are identical).

Front 30

Ventricular Bigeminy/tri/quadi

Back 30

occurs when: PVC is coupled with normal Sinus Rhythm.

Hint 30

HYPOXIA!!!

Front 31

Ventricular Parasystole

Back 31

Occurs when: ventricular foci are NOT irritable, but suffer from entrance block-therefore are NOT overdrive suppressed and continue to pace at their own inherent rate.
Looks like: dual rhythm pacing from 2 sources (SA node and V. Focus).
A PVC coupled to a long run of normal cycle should be considered as possible V Parasystole.

Front 32

Multifocal PVC's

Back 32

occurs when: severe hypoxia-multiple ventricular foci's are irritated and emit PVC's. Each foci produces its own PVC.
Looks like: multiple and varying PVC's occurring at random intervals.

Front 33

Mitral Valve Prolapse

Back 33

physiology: mitral valve billows into the L. Atrium during Ventricular systole.
it causes: PVC's, ventricular Tachycardia, and multifocal PVC's.

Front 34

R on T phenomenon (PVC on a T Wave)

Back 34

PVC usually falls AFTER a T wave of normal cycle-if happens on the T wave (during repolarization) it falls during the vulnerable period.

Front 35

Tachyarrythmia

Back 35

occurs when: very irritable focus paces rapidly. With rate of 350 and over more than one foci pacing stimuli at once.

Hint 35

Tachyarrythmias arise at all 3 ventures of the heart (atrial, junctional, and ventricular).
NOTE: Stimulants tend to make higher level foci irritable while pathology/O2 deprivation effect lower level foci. There is CROSSOVER HERE however!

Front 36

Paroxysmal Tachycardia-rate

Back 36

150-250
paroxysmal=sudden

Front 37

Flutter tachyarrhythmia

Back 37

250-350

Front 38

fibrillation

Back 38

350-450: multiple foci discharging

Front 39

Sinus Tachycardia

Back 39

occurs when: exercise or excitement-NORMAL and GRADUAL response as opposed to paroxysmal which occur immediately and are NOT normal.

Front 40

Paroxysmal Atrial Tachycardia (PAT)

Back 40

occurs when: very irritable atrial foci paces at a rate of 150-250/minute.
Looks like: P' wave followed by QRS-T cycle.

Hint 40

A premature stimulus from another focus can set off the PAT-therefore the initial PAT cycle may look different from the subsequent cycles that follow.

Front 41

PAT with (AV) block

Back 41

occurs when: excess digitalis is taken-an atrial focus is very irritable and the AV node is blocked-therefore 2 P' waves occur before conduction flows to the ventricles.
Looks like: 2 P' waves to every QRS complex. P' waves are spiked and rapid (150-250).

Front 42

Paroxysmal Junctional Tachycardia (PJT)

Back 42

occurs when: very irritable junctional focus initiates pacing or when a premature beat sets off a junctional foci.
Looks like: Tachycardia (150-250) of QRS complexes. Inverted P' Waves may also occur before, inside, or after the QRS complex.

Hint 42

Prone to aberrant ventricular conductions as well (widened QRS complexes) as ventricles recover from refractory periods at different paces.

Front 43

AV Nodal Re-Entry Tachycardia (AVNRT)

Back 43

occurs when: continuous reentry circuit develops (circular through the AV node) which continuously depolarizes the atria and ventricles.
Looks like: PJT!

Front 44

Supraventricular Tachycardia

Back 44

defn: Umbrella name for tachyarrythmia originating in foci above the ventricle: both PAT and PJT.

Hint 44

It can be difficult to distinguish between PAT and PJT as they rhythm is so quick in PAT that the P' wave can be inside the QRS and is therefore indistiguishable from PJT-treatment is the same-hence the umbrella name.

Front 45

Paroxysmal Ventricular Tachycardia (PVT/VT)

Back 45

occurs when: a very irritable ventricular foci fires rapidly.
Ventricular conduction is dissociated from atrial conduction which is still occurring via the SA node-this causes DISSOCIATION between atria and ventricle.
Looks like: 150-250 rate of LARGE QRS complexes (same as PVC-which in reality they are). P waves from the SA node are most likely hidden under the large complexes.

Hint 45

NOTE: occasionally, SA node conduction hits the AV node when it is receptive and depolarization to ventricles occurs. This conductions will "fuse" with the PVC contraction to cause a "fusion beat". This confirms PVT/VT.
Looks like: QRS complex coming off of QRS' complex.

Front 46

SVT vs. VT

Back 46

SVT with widened QRS complex, especially in the case of an AV block, can look like a VT-however-never to be treated the same!
-VT: AV dissociation showing fusions, QRS is usually greater than .14, common in patients with coronary disease/infarction, Extreme RAD.
SVT-QRS less than .14, AV dissociation rare, RAD rare.

Front 47

Torsades de Pointes

Back 47

occurs when: rapid ventricular rhythm (250-350) caused by low K, K channel block, or other abnormalities (Long QT syndrome).
Looks like: upward and downward ventricular complexes that increase and decrease in amplitude causing a "twisted rhythm" effect.

Hint 47

Hypothesized that it is caused by 2 competing irritable ventricular voci.

Front 48

Atrial Flutter

Back 48

occurs when: irritable atrial foci fire at rate of 250-350. AV node refractory period is lengthy, therefore QRS happens per every 2 or 3 flutters.
Looks like: P' waves (identical) followed by QRS complex. Looks like waves/saw tooth.

Hint 48

Understand difference between atrial flutter and PAT with AV block (rate is slower/waves are not identical).
NOTE: inversion or vagal maneuver can help in identifying an atrial flutter. Vagal causes refractory to the AV node, decreasing ventricular contraction and therefore letting atrial flutter shine through the QRS complex:)

Front 49

Ventricular Flutter

Back 49

occurs when: irritable ventricular foci fires at a rate of 250-350.
Looks like: constant and smooth sine rhythm of constant amplitude.

Hint 49

Very dangerous-usually leads to V. Fib. This is because there is insufficient fill of ventricles with blood at such a FAST pace-therefore hypoxia ensues which leads to v. foci becoming very irritable and firing constantly :(

Front 50

parasystolic

Back 50

all pace at once-not overdrive surpressed by the SA normal sinus rhythm

Front 51

fibrillation

Back 51

atrial or ventricular-ALL foci are irritable and suffering from parasystole-therefore all firing at once.
looks like: no complete waves and impossible rates-involved chambers are twitching rapidly

Front 52

Atrial Fibrillation

Back 52

occurs when: many irritable atrial parasystolic atrial foci fire at rapid rates. Rate is 350-450.
looks like: rapid erratic rhythm of ups and down and irregular ventricular rhythm (many a foci firing but limited actually reach AV node to cause ventricular conduction).

Hint 52

may appear without visible P/P' waves as they are so erratic looks like a flat line.

Front 53

Ventricular Fibrillation

Back 53

occurs when: many irritable ventricular foci pace at once-rate is 350-450.
looks like: erratic without identificable waves. NOTHING IDENTIFIABLE!

Hint 53

"bag of worms" refers to how the actual ventricle looks as different sections of ventricle contract.
Death: amplitude of deflections diminish as move towards flatline

Front 54

Assist devices for V-FIb

Back 54

ICD-implantable
AED-external, identifies V fib and delivers de-fibrillation

Front 55

Wolff-Parkinson-White Syndrome

Back 55

occurs when: PT has a "bundle of kent" which is an accessory AV conduction pathway on the right edge of the Atrial/Vent junction. It "pre-excites" ventricular depolarization.
Looks like: delta QRS complex (more swoopy from Q to R).

Hint 55

Can cause Paroxysomal tachycardia via:
1) re-entry (immediate re-stimulation to the atria via retrograde depolar)
2) these bundles contain foci that can initiation tachycardia
3) abnormal conditions can be conducted through this pathway at a 1:1 ratio (where would be 2:1 i.e. atrial flutter) which means even HIGHER ventricular rates.

Front 56

Lown Ganong Levine (LGL) syndrome

Back 56

occurs when: anterior internodal tract has an additional "JAMES" bundle which connects directly to the HIS bundle.
Looks like: P and QRS waves are right next to one another: usually the AV node acts as a filter to transmit to the ventricles, but with this "filter" disabled, all conduction to the ventricles ensue.