EKG Exam Flashcards
1
Q
EKG graph
A
2
Q
EKG graph
A
3
Q
QRS configurations
A
4
Q
PR interval
A
- time from start of atrial depolarization to start of ventricular depolarization
- .12-.2sec
- isoelectric
5
Q
ST segment
*J point
A
end of ventricular depolarization and initiation of ventricular repolarization
6
Q
QT interval
A
time taken for ventricular depolarization and repolarization
7
Q
P wave
A
- atrial depolarization
- less than .12 sec
- 3 small boxes
- amp is less than 2.5 mm in limb leads
- amp is less than 1.5 mm in precordial leads
8
Q
Left Ventricular Hypertrophy
A
9
Q
LVH in AVL
A
10
Q
5 basic types of arrhythmias
A
- Arrhythmias of sinus origin—originate in the SA node, but the rate is too fast, too slow, or irregular
- Ectopic rhythms—originating in a focus other than the SA node
- Re-entrant arrhythmias—an electrical impulse trapped and recirculating somewhere in the heart
- Conduction blocks—a normally originating impulse following a normal track that encounters unexpected delays or blocks
- Pre-excitation syndromes—an impulse following an abnormal or aberrant pathway through the heart, i.e., a shortcut
11
Q
Arrhythmias of sinus origin
A
- Sinus tachycardia (fast rate)—above 100 beats per minute
- Sinus bradycardia (slow rate)—below 60 beats per minute
-
Sinus arrhythmia – slightly irregular sinus rhythm in which the variation in heart rate accompanies respiration
- The heart rate accelerates with inspiration and slows with expiration
- Sinus arrest, Asystole, and Escape beats
- In Sinus Arrest, the SA node does not fire normally and so there is a pause between complexes
- If nothing else happens, the EKG would just be a flat line without any electrical activity—prolonged electrical inactivity is called Asystole
- Thankfully, other natural cardiac pacemakers may take over in sinus arrest and spontaneously depolarize, generating a rescue or “escape beat”
12
Q
Sinus tachycardia
A
13
Q
Sinus bradycardia
A
14
Q
Respiratory Sinus Arrhythmias
A
15
Q
Sinus pause, arrest, escape beat
A
16
Q
Ectopic or Nonsinus Pacemakers
A
¤Atrial pacemakers (other than the SA node, i.e., the P-Wave looks different from a P-wave originating in the SA node)
- AV Nodal or Junctional pacemakers ( usually no P Wave at all- may see a retrograde P wave-, and normal QRS complex)
- Ventricular pacemakers (wide, bizarre QRS complexes)
- Atrial—60-75 beats per minute
- Junctional—40-60 beats per minute
- Ventricular—30-45 beats per minute, generally less than 40
17
Q
Supraventricular Arrhythmias
A
- Paroxysmal supraventricular tachycardia (PSVT)
- Atrial Flutter (Flutter)
- Atrial Fibrillation (AF or A Fib)
- Multifocal Atrial Tachycardia (MAT)
- Paroxysmal Atrial Tachycardia (PAT)
18
Q
Paroxysmal supraventricular tachycardia (PSVT)
A
19
Q
Atrial Fibrillation (AF or A Fib)
A
20
Q
Atrial Flutter (Flutter)
A
21
Q
Multifocal Atrial Tachycardia (MAT)
A
22
Q
Wandering Atrial Pacemaker
A
23
Q
Paroxysmal Atrial Tachycardia (PAT)
A
24
Q
Ventricular Arrhythmias
A
*rhythm disturbances arising below the AV node*
- Premature Ventricular Contractions (PVCs)
- Ventricular Tachycardia (VT or V tach)
- Ventricular Fibrillation (V fib)
- Accelerated Idioventricular Rhythm
- Torsade de Points (a unique form of VT)
25
Premature Ventricular Contractions (PVCs)
26
Ventricular Tachycardia (VT or V tach)
27
Ventricular Fibrillation (V fib)
28
Accelerated Idioventricular Rhythm
29
Torsade de Points (a unique form of VT)
30
Supraventricular vs. Ventricular Arrhythmias
* The main distinction between supraventricular and ventricular arrhythmias is simply that:
* Supraventricular arrhythmias have a narrow QRS complex
* Ventricular arrhythmias have a wide QRS complex
* You can see a wide complex which is preceded by a P Wave which comes from above the ventricles but it must be conducted aberrantly (and it will usually come with a pulse) due to a block in the conduction system - this is known as “SVT with aberrancy”
31
Conduction Blocks
¤Any obstruction or delay in the flow of the electrical current through the normal conduction pathways of the heart is considered a Conduction Block, i.e., a blockage in time.
* A conduction block can occur anywhere in the system but typically appears in one of three areas:
* **Sinus Node Block**—it appears as a delay or pause in the cardiac cycle
* **Atrio-ventricular Block**—a block anywhere between the SA node and the Purkinje fibers, including the AV node and Bundle of His
* **Bundle Branch Block**—a block in part or all of the ventricular bundle branches
32
1st degree AV block
33
2nd degree AV block (Mobitz 1/Wenckebach)
34
2nd degree AV block (Mobitz 2)
35
Mobitz 1 vs. Mobitz 2
36
3rd degree AV block
37
RBBB
38
LBBB
39
Hemiblocks
* When we talk about hemiblocks, we are talking about the left bundle only and either anterior or posterior fascicle pathology
* Hemiblocks cause axis deviation
* A **Left Anterior Hemiblock** causes a left axis deviation (Lead 1 is positive and aVF is negative) and it is more common of the two types of blocks
* A **Left Posterior Hemiblock** causes a right axis deviation (Lead 1 is negative and aVF is positive)
* Hemiblocks do not prolong the QRS complex
* Hemiblocks do not cause any ST segment or T Wave changes
* These axis deviations are NOT due to ventricular hypertrophy
40
Left Anterior Hemiblock
41
Left Posterior Hemiblock
42
Preexcitation Syndromes
* There are two major pre-excitation syndromes:
* **Wolff-Parkinson-White (WPW) syndrome**
* **Lown-Ganong-Levine (LGL) syndrome**
* These two conditions are actually the opposite of cardiac blocks, that is the electrical current is conducted to the ventricles more rapidly than usual
* In order for pre-excitation syndromes to exist there must first be accessory pathways in the patient (i.e., congenital abnormalities)
* Less than 1% of individuals possess accessory pathways; males predominate. The accessory pathway may be an isolated finding, or occasionally noted in patients with mitral valve prolapse, hypertrophic cardiomyopathies, and other congenital disorders
43
Wolff-Parkinson-White (WPW) syndrome
44
Lown-Ganong-Levine (LGL) syndrome
