ECG Flashcards
1
Q
Where is the base of the heart located?
A
Level of the second rib
2
Q
Where is the apex of the heart located?
A
Towards the left hip, rest on the diaphragm between the 5th-6th rib
3
Q
What is the right and left atrias separated by?
A
Interatrial septum
4
Q
What blood does the right atrium receive?
A
It receives deoxygenated blood returning from the systemic circulation
5
Q
What blood does the left atrium receive?
A
Receives oxygenated blood returning from the pulmonary circulation
6
Q
What separates the left and right ventricles?
A
Interventricular septum
7
Q
Where does the right ventricle pump blood to?
A
The lungs
8
Q
Where does the left ventricle pump blood to?
A
The rest of the body
9
Q
What does the superior vena cava do?
A
Transports blood from parts of the body superior to the diaphragm to the right atrium
10
Q
What does the inferior vena cava do?
A
Transports blood from parts of the body below the diaphragm to the right atrium
11
Q
What does the coronary sinus do?
A
Transports deoxygenated blood back to the right atrium from coronary circulation
12
Q
What does the pulmonary artery do?
A
Transports deoxygenated blood to the lungs
13
Q
What does the pulmonary vein do?
A
Returns blood from the lungs to the left atrium
14
Q
What does the aorta do?
A
Pumps blood out of the heart, largest artery of the heart
15
Q
Where is the Atrioventricular (AV) valve located?
A
Located between the atria and the ventricles
16
Q
What are the two AV valves?
A
- Tricuspid
- Mitral (bicuspid)
17
Q
What does the semi lunar valve do?
A
Prevents backflow of blood into the ventricles
18
Q
What are the two semi lunar vlaves?
A
- Pulmonary valve
- Aortic valve
19
Q
What is the pericardium?
A
Surrounds the heart and roots of the great vessels
20
Q
What are the two layers of the pericardium?
A
- Parietal layer
- Visceral layer
21
Q
What is the epicardium?
A
A serous membrane that forms the innermost layer of the pericardium and the outer surface of the heart
22
Q
What is the myocardium?
A
Is the muscular middle layer of the wall of the heart
23
Q
What is the endocardium?
A
The thin, smooth membrane which lines the inside of the chambers of the heart and forms the surface of the valves
24
Q
What is pericarditis?
A
Inflammation of the pericardium
25
What is endocarditis?
An inflammation of the inner lining of the heart
26
What is myocarditis?
An inflammation of heart muscle
27
what is cardiac tamponade?
Is compression of the heart produced by the accumulation of fluid or blood in the pericardial sac
28
What is the pulmonary circuit?
1. Blood enters the right atrium through (inferior vena cava, superior vena cava, coronary sinus)
2. Pass down to the right ventricle
3. Than enters the pulmonary arteries
4. Go into the left and right lung
5. Carbon dioxide is unloaded, and oxygen picked up
6. Returns to the left atrium through pulmonary veins
29
What is the systemic circuit?
1. Left atrium to left ventricle to the aorta
2. enters the aorta (the right and left coronary)
3. Goes to the arteries reaching body tissues, branch into small capillaries
4. Oxygen leaves blood to enter body tissue, carbon dioxide from tissue cells is picked up
5. Capillaries join to form veins leading back to the heart
30
What includes the left main coronary artery?
- Left anterior descending (LAD)
| - Left circumflex artery
31
What includes the right coronary artery?
Includes the posterior descending artery
32
What do both the right and left coronary artery do?
Returns blood back to the right atrium through the coronary sinus
33
What is the dominant pacemaker of the heart
SA node
34
What is Polarization?
Depolarization?
Repolarization?
- Polarization=Resting state during which no electrical activity occurs
- Depolarization=When the cardiac cell is stimulated "contraction of the muscle"
- Repolarization=The returning to a resting state
35
What are the major ions that affect cardiac function?
- Sodium
- Potassium
- Calcium
36
What is refractory periods?
When the cell cannot be re-stimulated (it is necessary to allow the ventricles sufficient time to empty)
37
What is automaticity?
Ability to spontaneous initiate an impulse
38
What is excitability?
Ability to respond to an impulse
39
What is conductivity?
Ability to receive and transmit an impulse
40
What is contractility?
Ability to contract in response to an impulse
41
What is the sinus node?
- The hearts natural pacemaker
| - Initiates heart rates between 60-100 bpm at rest
42
What is the atrioventricular Node (AV node)?
- Receives impulses from SA node
- Delivers impulses to the His-Purknje network
- Delivers heart rates between 40-60bpm (if SA node fails to deliver impulses)
43
What is the bundle of His?
Begins conduction to the ventricles
44
What is the Purkinje network?
Moves the impulse through the ventricles for contraction
45
What is called the escape rhythm?
The Purkinje network that initiate heart rates between 20-40 bpm
46
What is the automatic nervous system?
Controls of the heart rate and force of contractility
47
Which leads are the bipolar leads?
I, II, III
48
Which leads are the augmented unipolar leads?
aVR, aVL, aVF
49
Which leads are the precordial or chest leads?
V1, V2, V3, V4, V5 and V6
50
What are the cardiac deflections?
P,Q,R,S,T
51
What is the purpose of an ECG?
- The amount of voltage generated by the heart
| - The time required for the voltage to travel through the heart
52
What will an ECG not reflect?
- Mechanical function of the heart
- Etiology and pathology of the heart disease
- Structural and functional impairment
- Coronary heart disease when related to silent ischemia
53
For the triangle in bipolar leads, where is lead I
Left arm and right arm
54
For the triangle in bipolar leads, where is lead II?
Right arm and left leg
55
For the triangle in bipolar leads, where is lead III?
Left arm and left leg
56
What does the a in aVL stand for?
augmented lead
57
What is the normal paper speed?
25 mm/second
58
What are three clinically acceptable ECG?
Baseline: must be constant, horizontal or flat and free from artifacts, wherever possible
Leads: must be correctly place connect patient cable
Tracing: properly centered, coded and labelled correct leads, patients name, date and time
59
What are two technical errors?
- Reversed arm leads
| - Chest leads hooked up incorrectly
60
What is a wandering baseline?
Weaves up and down rhythmically with a "snakelike" motion
| this artifacts makes it difficult to evalulate ST segment
61
How do you fix a wandering baseline artifact?
- Dry electrodes
- Loose connections
- Patient cable swinging or dangling
62
What is the most common artifact and has no fixed pattern?
Muscle artifact
63
What does an alternating current (AC) artifact look like?
recognized by its uniform and regular saw-tooth appearance. (60 cycle interference)
64
What is the cause of alternating current artifacts?
Leakage of 60 cycle electrical current from: nearby electrical equipment which may not be property grounded, such as a ventilator, electric beds, etc
65
Where are the normal placements for on the arms and legs?
Mid-calf and mid-forearm
66
Which leads should not be compromised where at all possible?
Precordial leads
67
What are 6 types of patients that may need modifications?
- Isolation
- Burns
- Geriatric
- Mastectomy and breast implants
- Pediatric
- Psyhiatric
68
What does the mean QRS axis represent?
The average of instantaneous forces generated during a sequence of ventricular depolarization
69
What does the normal QRS axis range from?
0 degrees to +90 degrees
70
What is the left axis deviation range?
0 degrees to -90 degrees
71
What is the range for right axis deviation?
between +90 up to +180 degrees
72
What is the range for extreme or indeterminate axis?
-90 degrees to +180 degrees
73
What are 4 causes of abnormal axis?
- When right and left ventricle depolarization do not occur together
- When the muscle mass of one ventricle is hypertrophied (enlarged)
- When there is a conduction delay or block in one part of the ventricle
- The heart has physically shifted or is rotated abnormally in the chest cavity
74
What is the order of heart rates?
300-150-100-75-60-50-43-38-30
75
What does the P wave represent?
atrial depolarization or contraction
76
What does the PR interval represent?
The onset of atrial depolarization to onset of ventricular depolarization
(the time required or the impulse to travel from the SA node, through the atria to the AV node)
77
Where is the PR interval measured and what is the normal measurement?
- Measured from the start of the P wave to the start of the QRS
- The normal measurement is between 0.12-0.20 seconds
78
Where is the PR segment measured?
Measures the end of atrial depolarization to start of ventricular depolarization
79
What is the PR segment?
Time required for the delay in conduction from the SA node to the AV node
80
Where is the PR segment measured?
end of P wave to start of QRS
81
Is there any electrical activity in the PR segment?
No
82
What does QRS represent?
represents ventricular depolarization
83
What is the QRS complex?
the time required for the electrical impulse to travel from the AV node through the Purknjie system
84
What is the normal duration for the ORS complex?
0.8-0.12 seconds
85
What is the ST segment?
the time from the end of ventricular depolarization to start of ventricular repolarization
86
what is the T wave?
repolarization of the ventricles
87
What is the QT interval?
start of ventricular depolarization to end of ventricle repolarization
88
what is the interval for QT interval?
0.28-0.44 seconds
89
What is a normal conduction ratio?
1:1
90
What is the conduction ratio?
refers to the number of atrial contractions (P-P) that occur in relation to contraction of ventricles (R-R)
91
What is the normal beats per minute?
60-100 per minute P-P and R-R also regular
92
What do the leads look like in a normal sinus rhythm?
Constant P configuration in any given lead
| -Upright in leads I,II and aVF and inverted (negative) in aVR
93
What is the time for the PR interval?
between 0.12-0.20 seconds
94
What is the normal QRS interval time?
less than 0.12 seconds, with similar morphology
95
What is the normal QT interval?
Between 0.28-0.44 seconds
96
What does a normal sinus rhythm mean?
Means the electrical impulse starts in your sinus node
97
What is the bpm for sinus tachycardia?
greater than 100 bpm (only difference from normal sinus rhythm)
98
What is the causes, symptoms and treatment for sinus tachycardia?
Causes: demand by the body for increased cardiac output
Symptoms: shortness of breathe, fatique
Treatment: hemorrhage, infection
99
What is the bpm for sinus bradycardia?
Less than 60bpm
100
What is the causes, symptoms and treatment for sinus bradycardia?
Causes: Medications, excess vagal tone, MI
Symptoms: may be lightheaded dizzy or lack energy
Treatment: if symptomatic a pacemaker or medication
101
What is sinus arrhythmia?
The rhythm is irregular in both the atria and ventricles
102
What are the causes, symptoms and treatment for sinus arrhythmia?
Causes: usually related to respiration
Symptoms: Usually no symptoms
Treatment: none
103
What is sick sinus syndrome?
Brady/Tachy syndrome= Combined = irregular heart rates bradycardia and tachycardia
104
What are the causes, symptoms and treatment of brady/tachy syndrome?
Causes: something wrong with the SA node or atrial arrhythmia
Symptoms: palpitations, light-headedness, dizziness, fatigue
Treatment: medications if heart rate rapid and if pauses or marked bradycardia a pacemaker may be required
105
What are the rhythms originating in the AV junction?
Escape: 40-60 bpm
Accelerated: 60-100 bpm
106
What is a junctional rhythm?
No P wave or inverted P wave
107
What are rhythms originating in the atria?
- Premature atrial Contraction (PAC)
- Atrial tachycardia
- Atrial fibrillation (most common)
- Atrial flutter (most common)
108
When does atrial rhythms occur?
when an impulse from anywhere in the atrium overrides the SA node by ectopic beats
109
What is Premature Atrial Contraction (PAC)?
- P wave is early
- Makes rhythm appear to be irregular
- QRS is normal size
110
What is Supraventricular Tachycardia (SVT)?
- General name for arrhythmias that start above the ventricles.
- Usually begin and end suddenly
- Can last anywhere from seconds to hours
111
What rhythms are types of SVT?
- Atrial Tachycardia
- Atrial fib
- Atrial Flutter
112
What is Atrial Tachycardia?
- Sudden short bursts of atrial beat
| - More the 3 PACs on a row
113
What is atrial fibrillation?
Multiple ectopic foci in the atria firing causing the atria to depolarize in a chaotic manner (quivering instead of normal contraction)
114
What is the atrial rate for atrial fib?
200-600bpm
115
What is the most common type SVT?
A fib
116
What are fib waves?
Non-measureable P waves
117
Is ventricular rhythm always irregular in A fib?
Yes
118
What is atrial flutter?
A single irritable focus in the atria which repeatedly fires creating a re-entry circuit that depolarizes the atria and gains control
119
Which heart rhythm is the saw-tooth?
Atrial Flutter
120
What are the two rhythms originating in the ventricles?
Active- includes fast rhythms = comes from the foci with one of the ventricles
Passive-includes slow rhythms =Come from Purkinje network
121
What are some characteristics for Premature Ventricular Complex (PVC)?
- Wide bizarre complex usually > 0.12 seconds
- Large T waves generally in the opposite direction as QRS
- P wave if present is unrelated to QRS
122
What do bigeminal PVC's look like?
Every other beat is a PVC
123
What do coupled PVCs look like?
Occur in pairs
124
What do trigeminal PVC's look like?
Every third beat is a PVC
125
What is a potential life threatening arrhythmia?
Ventricular Tachycardia
126
What is monomorphic ventricular tachycardia?
Means that the appearance of all the beats match each other in each lead of a surface electrocardiogram (ECG)
127
What is polymorphic ventricular tachycardia?
Has beat to beat variations in morphology
128
What is ventricular fibrillation?
Is a condition in which there is uncoordinated contraction of the cardiac muscle of the ventricles, making them quiver rather than contact properly
129
What is the heart rate for monomorphic ventricular tachycardia?
140-250 bpm
130
What is the heart rate for ventricular fibrillation?
300-600
131
What is the most common cause of sudden cardiac death?
Ventricular fibrillation or polymorphic VT
132
What has a lethal rhythm?*
Ventricular fibrillation
133
What is ventricular Asystole?
A standstill heart beat (flat line)
134
What are the two heart blocks?
- Bundle branch blocks
| - AV blocks
135
What are bundle branch blocks?
Bundle branch blocks are obstruction in the transmission of the electrical impulse through one of the bundle branches wither the right or left
136
What is the bundle branch block pattern?
- QRS complex is >0.12 seconds
- RR prime either in V! and V2 (right bundle branch block)
- RR prime in V5 and V6 (left bundle branch block) - deep wide S waves V1-V6
137
What is the right bundle branch block ECG diagnostic criteria?
- QRS duration >120ms
- RSR' pattern in V1-3 ("M-shaped" QRS complex)
- Wide, slurred S wave in lateral leads (I, aVL, V5-6)
138
What is the Left bundle branch block ECG diagnostic criteria?
- QRS duration > 120ms
- Dominant S wave in V1
- Broad monophasic R wave in lateral leads (I, aVL, V5-6)
- Absence of Q waves in lateral leads
- Prolonged R wave peak time > 60ms in leads V5-6
139
What are the causes of bundle branch blocks?
Coronary artery disease, cardiac tumors, cardiomyopathy, pericarditis, myocarditus, CHF
140
What are the different types of AV blocks?
- First degree AV block
- Second Degree AV block (type 1, type 2)
- Third degree AV block
141
When do AV blocks occur?
When there is block in conduction of impulses between in atria and ventricles
142
What is a 1st degree AV block?
A sinus impulse is conducted normally to the AV node, but delayed in the AV node longer than usual
143
What is a 2nd degree AV block?
A sinus impulse is conducted normally to the AV node but each impulse has more and more difficulty passing through the AV node. There are two types of 2nd degree AV blocks
144
What is second-degree AV block Mobitz 1
Progressive prolongation of the PR interval until there is failure to conduct and a ventricular beat is dropped
145
What is Mobitz type 2
Every 2nd sinus impulses fails to be conducted to the ventricles
(atrial rate = 75 bpm, ventricular rate = 42 bpm)
146
What is the third degree AV block?
No impulse conduction from the atria to the ventricles
| atrial rate = 130 bpm ventricular rate = 37 bpm
147
What is acute coronary syndrome?
Umbrella term used to cover any group of heart conditions which are cause by the sudden formation of blood clots or fatty deposits within a coronary artery known as artherosclerosis
148
What is Ischemic Heart Disease?
Name given to explain the lack of blood flow and oxygen to the heart muscle (major cause is atherosclerosis and most common symptom is angina)
149
What is CHF?
The inability of the heart to pump blood forward at a sufficient rate to meet the metabolic demands of the body
150
What is cardiomyopathy?
Heart disorder which affects the myocardium
151
What are the three different types of cardiomyopathy?
- Dilated
- Hypertrophic
- Restrictive
152
What will Ischemia look like?
ST segment depression > 1mm and T wave inversion
153
What will myocardial injury look like?
ST segment elevation >1mm
154
What will an MI look like?
ST segment elevation >1mm with or without significant Q wave
155
How long are Q waves normally?
< 0.03 seconds and 1/3 height of the R wave
156
What leads are a inferior MI?
Leads II, III and aVF
157
Which leads are anterior MI?
Leads V1, V2, V3, V4
158
Which leads are lateral MI?
Leads I, aVL, V5 and V6
159
When should 15 and 18 lead ECG be done?
- All acute or recent inferior wall MI's with ST elevation in leads II, III and aVF, perform right sided chest leads RV4, RV5 and RV6
- ST segment depression or elevation >1mm in V1 to V4 perform posterior leads V7, V8, V9
- ST segment elevation >1mm in V5 or V6 perform posterior leads V7, V8 and V9
160
When are right sided chest leads performed?
- Acute inferior and posterior wall MI
| - Positive for right ventricular involvement
161
When are posterior leads used?
Acute posterior wall MI
162
What will low potassium do?
- Prominent U wave
| - Sagging of the ST segment
163
What will high potassium do?
-Tall peaked, symmetrical "tenting" T waves usually in the precordial leads
164
What will low calcium do?
- Prolonged the ST segment
| - Produces a prolonged QT interval
165
What will high calcium levels do?
- A shortened QT interval
| - Wide and round T wave
166
What will high magnesium do?
Flattening of the T wave
167
What will hypothermia do in ECGs?
- Bradycardia
- Low T waves
- Intervals prolonged
- PVC possible
168
What is a pacemaker?
is an electronic device used to treat patients who have symptoms caused by abnormally slow heartbeats
169
Who gets a pacemaker?
- sympotomatic conduction disturbances (2nd and 3rd degree AV blocks)
- Sick sinus syndrome
- Syncope
170
What are the three functions of the pacemaker?
- Sensing
- Pacing
- Capture
171
What is appropriate sensing in pacemakers?
Sensing the ability of the pacemaker to see intrinsic beats and respond by resetting the timing interval
172
What is a implantable cardiac defibrillator (ICD)?
-An implantable cardiac defibrillator (ICD) is a small electronic device installed inside the chest to prevent sudden death from cardiac arrest due to life threatening abnormally fast heart rhythms
173
What can a ICD do?
- Continuously monitor patient rhythm
- Diagnoses rhythm changes
- Treats life threatening arrhythmias
- All have back up pacemaker
