ECG Flashcards
1
Q
What is the origin of the cardiac impulse?
A
The SA node
The SA node is considered the normal cardiac pacemaker.
2
Q
Where is the SA node located?
A
At the junction of the superior vena cava with the right atria.
3
Q
What are the three bundles of atrial fibers that connect the SA node with the AV node?
A
- Anterior tract
- Middle tract
- Posterior tract
4
Q
Where is the AV node located?
A
In the right posterior portion of the interatrial septum next to the tricuspid valve.
5
Q
What does the AV node connect to?
A
The bundle of His.
6
Q
What branches from the bundle of His?
A
- Left bundle branch
- Right bundle branch
7
Q
What does the left bundle branch divide into?
A
- Left anterior fascicle
- Left posterior fascicle
8
Q
What do the Purkinje system fibers do?
A
They separate to all parts of the ventricular myocardium.
9
Q
What does an ECG record?
A
The electrical activity of the heart from the body surface.
10
Q
What does the P wave represent in an ECG?
A
Atrial depolarization.
11
Q
What does the QRS complex represent in an ECG?
A
Ventricular depolarization.
12
Q
What does the T wave represent in an ECG?
A
Ventricular repolarization.
13
Q
What is the PR interval?
A
The time between the onset of the P wave and the onset of the QRS complex.
14
Q
What is the QT interval?
A
The duration from the beginning of ventricular depolarization to the end of ventricular repolarization.
15
Q
What does the RR interval represent?
A
The duration of a single cardiac cycle.
16
Q
What is the normal amplitude of a P wave?
A
2-3 mm.
17
Q
What is the normal duration of a PR interval?
A
120 to 200 milliseconds.
18
Q
What is the amplitude range of a QRS complex?
A
5 to 30 mm.
19
Q
What is the normal duration of a QRS complex?
A
Less than 100 milliseconds.
20
Q
What is the normal variation of the ST segment?
A
Less than 0.5 mm negative to 1 mm positive.
21
Q
What is the amplitude range of a T wave?
A
0.5 mm to 10 mm.
22
Q
What is the normal duration of the QT interval?
A
360 to 440 milliseconds.
23
Q
What does the U wave represent?
A
The recovery period of Purkinje fibers.
24
Q
How many leads does an ECG have?
A
12 leads.
25
What are the two types of limb leads?
* Unipolar (AVR, AVL, AVF)
* Bipolar (lead 1, 2, 3)
26
How is the electrical axis of the heart determined?
Using the QRS complex.
27
What is the normal cardiac axis range?
Around +60 degrees, ranging from -30 to +90 degrees.
28
What is ECG Rhythm Determination?
The process of determining the rhythm of an ECG by measuring the intervals between waves.
## Footnote
Key points include measuring the distance between two adjacent P waves (PP intervals) and assessing regularity to identify sinus rhythm or arrhythmia.
29
How do you calculate heart rate from an ECG strip?
Using the 1500 method: count small squares between two P waves and divide 1500 by this number.
## Footnote
Standard ECG speed is 5 large squares per second, where 1 large square = 200 milliseconds.
30
What should be evaluated when assessing P waves?
Presence, configuration, and relationship to QRS complexes.
## Footnote
A P wave followed by a QRS complex indicates sinus rhythm.
31
What is the normal range for the PR interval?
120 to 200 milliseconds (3 to 5 small squares).
## Footnote
PR interval measurement is done by counting small squares from the start of the P wave to the start of the QRS complex.
32
What defines a normal heart axis?
Normal axis: -30 to +90 degrees.
## Footnote
Left axis deviation: -30 to -150 degrees; Right axis deviation: +90 to -150 degrees.
33
What is the normal duration of a QRS complex?
60 to 100 milliseconds (less than 3 small squares).
## Footnote
Measure by counting small squares for QRS duration.
34
What indicates myocardial ischemia in an ST segment evaluation?
Elevation or depression >1mm.
## Footnote
The normal ST segment is isoelectric with minimal changes.
35
What should be assessed regarding T waves?
Shape and amplitude, ensuring they have the same deflection as QRS complexes.
## Footnote
Abnormal T waves may indicate potential abnormalities.
36
What is the normal QT interval duration?
360 to 440 milliseconds.
## Footnote
Count small squares from the start of QRS to the end of T wave; expect 9 to 11 small squares for a normal interval.
37
What characterizes Sinus Bradycardia?
Heart rate < 60 beats per minute.
## Footnote
It can occur during sleep or in well-conditioned individuals and may be caused by various conditions or medications.
38
What is Sinus Tachycardia?
A condition where the heart rate exceeds 100 beats per minute.
## Footnote
It can be a normal response to exercise, stress, or pain, or due to underlying conditions.
39
What ECG changes occur during a myocardial infarction?
ST elevation, pathologic Q wave, and T wave inversion.
## Footnote
These changes help localize the infarction site.
40
How do you determine the heart rate in a regular rhythm?
Count the number of large squares between consecutive R waves and use the formula: Rate (bpm) = 300 / number of large squares between R-R intervals.
41
How do you determine the heart rate in an irregular rhythm?
Count the number of R waves in a 6-second strip and multiply by 10.
42
What indicates that the rhythm is likely originating from the atria?
Presence of P waves before each QRS complex.
43
What is the normal range for the PR interval?
0.12 to 0.20 seconds.
44
What does a prolonged or shortened PR interval indicate?
Specific conduction issues.
45
What is the normal duration for a QRS complex?
Less than 0.12 seconds.
46
What does a wider QRS complex suggest?
A bundle branch block or ventricular rhythm.
47
What should you analyze to determine if the rhythm is regular or irregular?
The regularity of the R-R intervals.
48
What indicates a normal cardiac axis using limb leads?
Positive in both lead I and aVF (approximately -30° to +90°).
49
What indicates left axis deviation?
Positive in lead I, negative in lead aVF (approximately -30° to -90°).
50
What indicates right axis deviation?
Negative in lead I, positive in lead aVF (approximately +90° to +180°).
51
What should lead II show for a normal cardiac axis?
It should be positive.
52
What indicates left ventricular hypertrophy (LVH)?
Tall R waves in V5/V6 and deep S waves in V1/V2 with a sum greater than 35 mm.
53
What indicates right ventricular hypertrophy (RVH)?
Right axis deviation and tall R waves in V1 with S waves in V5/V6.
54
What ST segment change may indicate myocardial infarction?
ST segment elevation (typically ≥ 1 mm in two contiguous leads).
55
What does ST segment depression (≥ 1 mm) suggest?
Ischemia.
56
What does an inverted T wave indicate?
Ischemia or myocardial injury.
57
What are peaked T waves often associated with?
Hyperkalaemia or early ischemia.
58
What do pathological Q waves indicate?
Previous myocardial infarction.
59
What can prolonged QT intervals increase the risk for?
Arrhythmias.
60
What indicates a normal cardiac axis on an ECG?
The QRS complexes in leads I and aVF both have positive deflections.
## Footnote
Normal axis range is typically between -30° and +90°.
61
What is the definition of Left Axis Deviation (LAD)?
Left axis deviation occurs when the electrical impulse moves more towards the left side of the body.
## Footnote
Criteria for LAD include a positive QRS complex in Lead I and a negative QRS complex in aVF.
62
What is the axis range for Left Axis Deviation (LAD)?
The axis typically falls between -30° and -90°.
## Footnote
LAD is often associated with left ventricular hypertrophy (LVH), left bundle branch block (LBBB), or inferior wall myocardial infarction.
63
What is the definition of Right Axis Deviation (RAD)?
Right axis deviation occurs when the electrical impulse moves towards the right side of the body.
## Footnote
Criteria for RAD include a negative QRS complex in Lead I and a positive QRS complex in aVF.
64
What is the axis range for Right Axis Deviation (RAD)?
The axis typically falls between +90° and +180°.
## Footnote
RAD is associated with right ventricular hypertrophy (RVH), chronic obstructive pulmonary disease (COPD), and lateral wall myocardial infarction.
65
What are the steps to determine the cardiac axis on an ECG?
1. Look at Lead I: Determine if the QRS complex is positive or negative.
2. Look at Lead aVF: Determine if the QRS complex is positive or negative.
3. Combine Findings: Classify the axis based on the results.
## Footnote
Combinations include normal axis, LAD, RAD, and extreme axis deviation.
66
What does a positive QRS complex in Lead I and a positive QRS complex in aVF indicate?
Normal Axis
## Footnote
This indicates the electrical impulse is directed normally.
67
What does a positive QRS complex in Lead I and a negative QRS complex in aVF indicate?
Left Axis Deviation (LAD)
## Footnote
This suggests the electrical impulse is deviating towards the left.
68
What does a negative QRS complex in Lead I and a positive QRS complex in aVF indicate?
Right Axis Deviation (RAD)
## Footnote
This indicates the electrical impulse is deviating towards the right.
69
What does a negative QRS complex in both Lead I and aVF indicate?
Extreme Axis Deviation
## Footnote
This is often not clinically useful.
70
What is the standard 12-lead ECG used for?
Evaluating the heart's electrical activity from multiple perspectives
## Footnote
It provides crucial information for diagnosing various cardiac conditions.
71
What does Lead I of the limb leads view?
The lateral wall of the heart
## Footnote
Lead I is placed from the right arm to the left arm.
72
Which limb lead views the inferior wall of the heart?
Lead II and Lead III
## Footnote
Lead II is from the right arm to the left leg; Lead III is from the left arm to the left leg.
73
What does aVR represent in the limb leads?
Provides a view from the right shoulder
## Footnote
aVR averages signals from the left arm and foot to the right arm.
74
What is the primary view of Lead V1?
The right ventricle and septum
## Footnote
Lead V1 is placed in the fourth intercostal space to the right of the sternum.
75
Which lead focuses on the anterior wall of the heart?
Lead V3
## Footnote
V3 is located midway between V2 and V4.
76
What does a positive deflection in an ECG indicate?
The electrical impulse moves towards a lead
## Footnote
This is crucial for interpreting the heart's electrical activity.
77
What is represented by the isoelectric line in an ECG?
No net deflection, representing baseline electrical balance
## Footnote
It indicates a stable electrical state in the heart.
78
What defines the normal cardiac axis?
Typically between -30° and +90°; positive QRS deflections in lead I and lead aVF
## Footnote
This axis is important for assessing heart orientation.
79
What indicates left axis deviation in an ECG?
Between -30° and -90°; positive QRS in lead I and negative in lead aVF
## Footnote
This can indicate various cardiac issues.
80
What is the view provided by precordial leads (V1-V6)?
A horizontal plane view of the heart
## Footnote
They capture anterior, septal, and lateral structures.
81
What is the significance of integrating data from all 12 leads?
Allows interpretation of various potential abnormalities
## Footnote
This includes arrhythmias and myocardial infarctions.
82
True or False: The cardiac axis refers to the direction of the heart's electrical activity in the horizontal plane.
False
## Footnote
The cardiac axis is assessed in the frontal plane.
83
Fill in the blank: The limb leads provide a _______ view around the heart.
360-degree
## Footnote
This view includes inferior, superior, and lateral surface perspectives.
84
What does lead aVF view?
Looks at the heart from below
## Footnote
aVF averages signals from both arms to the left leg.
85
What is tachyarrhythmia?
An abnormal heart rhythm characterized by a heart rate exceeding 100 beats per minute (bpm) due to disturbance in the electrical conduction system of the heart.
86
List the mechanisms that can lead to tachyarrhythmias.
* Increased automaticity
* Triggered activity
* Re-entry circuits
87
What are the two types of tachyarrhythmias based on duration?
* Sustained (lasting more than 30 seconds)
* Non-sustained
88
Define palpitations.
A sensation of an abnormal awareness of the heartbeat, which may feel like fluttering, pounding, or racing.
89
What is the clinical significance of palpitations?
Palpitations are a common symptom of tachyarrhythmias and can be benign or signify more serious underlying conditions.
90
What does presyncope refer to?
A feeling of light-headedness, dizziness, or impending fainting due to reduced blood flow to the brain.
91
How can tachyarrhythmias lead to presyncope?
They can lead to a decrease in cardiac output and, consequently, perfusion to vital organs.
92
What is chest pain associated with tachyarrhythmias often related to?
Myocardial ischemia or increased myocardial oxygen demand due to a rapid heart rate.
93
What is dyspnoea?
Difficulty in breathing or a sensation of being unable to catch one’s breath.
94
What causes dyspnoea in the context of tachyarrhythmias?
Decreased cardiac output leading to reduced oxygen delivery or pulmonary congestion.
95
What additional symptoms may patients experience with tachyarrhythmias?
* Fatigue
* Hypotension
* Anxiety and Fear
96
True or False: Tachyarrhythmias can lead to low blood pressure.
True
97
Fill in the blank: Tachyarrhythmias can result in a sensation of _______ due to anxiety.
fear
98
What is ventricular tachycardia (VT)?
A potentially life-threatening arrhythmia characterized by a rapid heartbeat originating from the ventricles.
99
What is the most common cause of VT?
Coronary Artery Disease (CAD)
100
What leads to scar tissue formation in the myocardium?
Prior myocardial infarction (heart attack)
101
List the types of cardiomyopathies associated with VT.
* Dilated Cardiomyopathy
* Hypertrophic Cardiomyopathy
* Arrhythmogenic Right Ventricular Cardiomyopathy
102
How does dilated cardiomyopathy affect the heart?
Impacts the heart’s ability to pump effectively, leading to electrical instability.
103
What is a characteristic of hypertrophic cardiomyopathy?
Thickened heart muscle can obstruct blood flow and create arrhythmogenic foci.
104
What is the effect of heart failure on the likelihood of arrhythmias?
Increases the likelihood due to structural and electrical changes.
105
What electrolyte imbalances can promote arrhythmias?
Abnormal levels of potassium, magnesium, or calcium.
106
True or False: A history of previous arrhythmias decreases the risk of recurrent episodes.
False
107
What types of structural heart disease can predispose patients to VT?
* Valvular heart disease
* Congenital heart defects
108
What are ischemic changes in relation to VT?
Ischemia from myocardial oxygen deprivation can create areas of reentry circuits in the ventricles.
109
What genetic factors can predispose individuals to VT?
Genetic syndromes, such as Long QT syndrome.
110
What types of drug use can induce VT?
* Certain medications (e.g., antiarrhythmics, stimulants)
* Illicit drugs (e.g., cocaine, amphetamines)
111
What are reentry circuits?
Electrical impulses traveling in a circular path around a scarred or ischemic area of the myocardium.
112
What is increased automaticity in the context of VT?
Areas of myocardial tissue developing increased automaticity, leading to rapid, ectopic foci firing independently.
113
What role does scar tissue play in VT?
Disrupts normal electrical conduction, creating a substrate conducive to arrhythmias.
114
What are the electrophysiological properties affecting VT?
* Action Potential Duration
* Refractoriness Alteration
115
How does ventricular ischemia affect action potential duration?
May prolong the action potential duration, contributing to early or delayed afterdepolarizations.
116
What is the consequence of reduced cardiac output during VT?
Can lead to hypotension and inadequate perfusion.
117
What complications can arise from prolonged VT?
* Ventricular fibrillation (VF)
* Syncope
* Heart failure
* Sudden cardiac death
118
What is ventricular fibrillation (VF)?
A critical and life-threatening arrhythmia characterized by disorganized electrical activity in the ventricles, leading to ineffective twitching rather than coordinated contraction.
119
What is the most common cause of ventricular fibrillation?
Coronary Artery Disease (CAD).
120
How can myocardial infarction lead to ventricular fibrillation?
Damage to the heart muscle from lack of blood flow may create areas of scarring that can lead to reentrant circuits.
121
What are the two types of cardiomyopathies associated with VF?
* Dilated Cardiomyopathy
* Hypertrophic Cardiomyopathy
122
What effect do electrolyte imbalances have on the heart?
They can alter cardiac action potentials and induce arrhythmias.
123
Name a structural heart disease that can predispose patients to VF.
Valvular heart disease, congenital defects, or prior heart surgery.
124
True or False: A history of ventricular tachycardia increases the risk of VF.
True
125
What types of drug use can induce ventricular fibrillation?
* Illicit drugs like cocaine and methamphetamine
* Certain medications, including antiarrhythmics or psychotropic drugs.
126
Which genetic syndromes can predispose individuals to ventricular fibrillation?
* Long QT syndrome
* Brugada syndrome
127
What types of severe physical stress can precipitate VF?
* Intense exercise
* Electrical injuries
* Blunt trauma
128
What is meant by disorganized electrical activity in VF?
Multiple ectopic foci in the ventricles fire rapidly and chaotically, disrupting normal electrical conduction.
129
What is the consequence of loss of coherent contraction in VF?
It leads to the cessation of any meaningful cardiac output.
130
What role does scarred myocardium play in ventricular fibrillation?
It creates a substrate for reentrant circuits, facilitating electrical disarray.
131
How does myocardial ischemia contribute to ventricular fibrillation?
* Oxygen deprivation can lead to cell death and fibrosis
* An acute myocardial infarction can create regions of ischemic and non-ischemic tissue.
132
What changes in ion channels can lead to arrhythmias?
Dysfunction in sodium, potassium, and calcium ion channels can lead to abnormal depolarization and repolarization.
133
What happens to cardiac output during ventricular fibrillation?
There is a complete loss of effective pumping action, resulting in rapid hemodynamic collapse.
134
What are the immediate consequences of VF if not treated promptly?
* Loss of consciousness
* Brain hypoxia
* Death
135
Fill in the blank: Ventricular fibrillation is a severe medical emergency often precipitated by underlying _______.
[cardiac conditions, electrolyte imbalances, and structural heart changes]
136
What are the critical components of the pathophysiological mechanism of VF?
* Electrical instability
* Myocardial ischemia
* Structural heart changes
137
What does supraventricular tachycardia (SVT) refer to?
A group of arrhythmias that originate above the ventricles, typically in the atria or AV node.
138
At what age is SVT more prevalent?
In younger individuals.
139
Name a condition that can predispose individuals to SVT.
* Hypertrophic cardiomyopathy
* Dilated cardiomyopathy
* Valvular heart disease
140
How does ischemic heart disease contribute to SVT?
Previous myocardial infarction can create scar tissue that disrupts normal electrical pathways.
141
What effect does heart failure have on the risk of SVT?
Increases the risk due to reduced cardiac function and structural changes.
142
What types of electrolyte imbalances can lead to SVT?
* Potassium
* Magnesium
* Calcium
143
Which substances can trigger episodes of SVT?
* Caffeine
* Nicotine
* Alcohol
144
What role do medications play in SVT?
Certain medications, especially decongestants and some antiarrhythmics, can precipitate SVT.
145
What is a genetic predisposition in the context of SVT?
Inherited conditions or gene mutations that predispose individuals to arrhythmias.
146
How does hyperthyroidism affect heart rate?
Increased thyroid hormone levels can lead to an increase in heart rate and arrhythmias.
147
What autonomic nervous system factors can trigger SVT?
Stress, anxiety, or physical activity can activate the sympathetic nervous system.
148
What is the significance of previous episodes of arrhythmia?
A history of SVT increases the likelihood of future episodes.
149
What are reentrant circuits in relation to SVT?
Electrical impulses travel in a circular path in areas of scar or structural abnormality.
150
What is increased automaticity in the context of SVT?
Ectopic foci within the atria or AV node fire at abnormally high rates.
151
What is triggered activity?
Early or delayed afterdepolarizations that initiate abnormal impulses in cardiomyocytes.
152
Name a type of SVT.
* Atrial Fibrillation
* Atrial Flutter
* AV Nodal Reentrant Tachycardia (AVRT)
* Paroxysmal Supraventricular Tachycardia (PSVT)
153
What are the hemodynamic consequences of SVT?
Increased heart rate can decrease diastolic filling time and potentially lead to reduced cardiac output.
154
What symptoms might patients experience due to SVT?
* Palpitations
* Shortness of breath
* Dizziness
* Syncope
155
How can understanding the risk factors of SVT aid in management?
Essential for effective diagnosis and management.
156
What treatment options can improve patient outcomes in SVT?
* Vagal maneuvers
* Medications
* Catheter ablation
157
What is Atrial Fibrillation (AF)?
A common arrhythmia characterized by disorganized electrical activity in the atria, leading to an irregular and often rapid heart rate.
158
How does age impact the risk of Atrial Fibrillation?
The risk of AF increases significantly with age, especially in individuals over 65.
159
What role does hypertension play in Atrial Fibrillation?
High blood pressure can lead to atrial enlargement and remodeling, which predisposes to AF.
160
What is the connection between coronary artery disease and Atrial Fibrillation?
Ischemic changes and myocardial infarction can disrupt normal electrical conduction, leading to AF.
161
How does valvular heart disease contribute to Atrial Fibrillation?
Particularly mitral valve stenosis or regurgitation can lead to atrial enlargement and fibrosis.
162
What is the impact of heart failure on Atrial Fibrillation?
Heart failure leads to structural and functional changes in the heart, which can promote AF.
163
How does hyperthyroidism affect Atrial Fibrillation risk?
Excess thyroid hormone increases heart rate and excitability, increasing AF risk.
164
What is the relationship between diabetes and Atrial Fibrillation?
Diabetes is associated with changes in cardiac structure and function, contributing to AF.
165
How does obesity contribute to Atrial Fibrillation?
Contributes to atrial enlargement and increased sympathetic activity, which can precipitate AF.
166
What is the effect of sleep apnea on Atrial Fibrillation?
Episodes of hypoxia and increased intrathoracic pressure can lead to atrial remodeling.
167
How can alcohol and stimulants trigger Atrial Fibrillation?
Excessive alcohol intake (often termed 'holiday heart syndrome') and use of stimulants can trigger AF episodes.
168
What is the genetic aspect of Atrial Fibrillation?
Some individuals may have a genetic predisposition to AF, although the specific genes involved are complex.
169
What is meant by disorganized electrical activity in Atrial Fibrillation?
Multiple ectopic foci or reentrant circuits within the atria cause rapid and uncoordinated electrical impulses.
170
What are the structural changes associated with atrial remodeling?
Fibrosis, dilation, and hypertrophy can occur in response to pressure or volume overload.
171
What is electrical remodeling in the context of Atrial Fibrillation?
Changes in ion channel expression and function can lead to increased atrial excitability.
172
What role do pulmonary veins play in Atrial Fibrillation?
Often the initial site of ectopic activity that triggers AF; isolation of these veins is a common therapeutic target.
173
How does the autonomic nervous system affect Atrial Fibrillation?
Both sympathetic and parasympathetic influences can modulate AF initiation and maintenance.
174
What is the significance of the loss of atrial kick in Atrial Fibrillation?
Reduces ventricular filling efficiency, decreasing cardiac output and potentially leading to symptoms like fatigue and heart failure.
175
What is the mechanism behind the risk of thromboembolism in Atrial Fibrillation?
Stagnant blood flow in the atria, particularly the left atrial appendage, increases the risk of clot formation.
176
What are the key components of effective management for Atrial Fibrillation?
Addressing underlying risk factors, controlling heart rate or rhythm, and preventing stroke with anticoagulation therapy.
177
True or False: Early detection and appropriate intervention can significantly improve patient quality of life in Atrial Fibrillation.
True
178
What is atrial flutter?
A type of supraventricular tachycardia characterized by a rapid but regular atrial rhythm.
179
What is one common risk factor for atrial flutter related to heart disease?
Coronary Artery Disease
## Footnote
Ischemia can lead to atrial remodeling, promoting arrhythmias.
180
How does heart failure contribute to atrial flutter?
Structural changes in the heart increase susceptibility to arrhythmias.
181
Which valvular heart disease is particularly associated with atrial flutter?
Mitral valve disorders that lead to atrial enlargement.
182
What effect does hypertension have on the atria?
Leads to increased atrial pressure and size, contributing to atrial flutter.
183
True or False: Individuals with prior atrial fibrillation may also experience atrial flutter.
True
184
Name two types of cardiomyopathy that can predispose individuals to atrial flutter.
* Dilated cardiomyopathy
* Hypertrophic cardiomyopathy
185
How can surgical history contribute to atrial flutter?
CABG or valve surgery can cause post-surgical scarring that disrupts normal conduction pathways.
186
What pulmonary disease is linked to atrial flutter and how?
Chronic Obstructive Pulmonary Disease (COPD): Pulmonary hypertension and right atrial enlargement can induce atrial flutter.
187
What thyroid disorder is known to trigger arrhythmias, including atrial flutter?
Hyperthyroidism, which increases cardiac excitability.
188
Fill in the blank: Excessive use of _______ can initiate atrial arrhythmias, including flutter.
[stimulants]
189
What is the mechanism behind atrial flutter?
Typically due to a large, macro-reentrant circuit within the right atrium, often around the tricuspid valve.
190
What is the typical atrial rate during atrial flutter?
Usually around 240-350 beats per minute.
191
What are some symptomatic consequences of rapid atrial rates?
* Palpitations
* Fatigue
* Shortness of breath
192
How does atrial flutter increase the risk of thromboembolism?
Increases risk of blood clot formation due to stagnant blood flow, particularly if it persists.
193
What structural changes in the atria can sustain the reentrant circuit leading to flutter?
Changes due to underlying conditions such as hypertension or valve disease.
194
What are the main treatment options for atrial flutter?
* Rate control
* Rhythm conversion
* Anticoagulation to prevent thromboembolic events
195
What interventional procedure can provide a long-term solution for atrial flutter?
Catheter ablation, which disrupts the reentrant circuit.
196
What is the overall conclusion about atrial flutter?
Characterized by specific structural and electrical abnormalities in the heart; understanding risk factors and pathophysiology is crucial for effective diagnosis and management.
197
What are Bradyarrhythmias?
A group of cardiac arrhythmias characterized by a slower-than-normal heart rate, typically defined as fewer than 60 beats per minute (bpm).
## Footnote
Bradyarrhythmias can result from various factors, including issues with the heart's electrical conduction system, increased vagal tone, or underlying health conditions such as ischemic heart disease or electrolyte imbalances.
198
What heart rate defines Bradyarrhythmias?
Fewer than 60 beats per minute (bpm).
199
What are palpitations in the context of Bradyarrhythmias?
An awareness of the heart beating, which can feel like a pause or fluttering in the chest.
## Footnote
In bradyarrhythmias, palpitations may occur intermittently, especially when the heart rate fluctuates.
200
What is syncope?
A temporary loss of consciousness due to insufficient blood flow to the brain.
201
How can syncope occur in patients with Bradyarrhythmias?
When the heart rate drops significantly, leading to reduced cardiac output and inadequate cerebral perfusion.
202
What symptoms may patients experience with syncope?
Lightheadedness, dizziness, or fainting spells, particularly during exertion or if standing up quickly.
203
How can Bradyarrhythmias affect heart failure?
They can lead to decreased cardiac output, which may precipitate or exacerbate heart failure symptoms.
204
What symptoms may indicate heart failure in patients with Bradyarrhythmias?
Shortness of breath, fatigue, swelling in the legs or abdomen, and decreased exercise tolerance.
205
What is lethargy?
A feeling of persistent tiredness or lack of energy.
206
How does a reduced heart rate contribute to lethargy?
It can decrease overall blood flow, leading to inadequate oxygen delivery to the tissues.
207
What challenges may patients with Bradyarrhythmias face due to lethargy?
Difficulty engaging in daily activities and a general sense of malaise.
208
What are heart blocks?
Disturbances in the heart's electrical conduction system, leading to a delay or complete blockage of electrical impulses.
209
What are the main types of heart block?
* First-degree
* Second-degree (Mobitz Type I and Type II)
* Third-degree
210
What are the risk factors for First-Degree Heart Block?
* Age
* Coronary Artery Disease (CAD)
* Myocardial Infarction
* Increased Vagal Tone
* Certain Medications
211
What characterizes the pathophysiology of First-Degree Heart Block?
Prolonged PR interval (>200 ms) on ECG with no dropped beats.
212
What is the significance of the PR interval in First-Degree Heart Block?
It indicates a delay in conduction through the AV node while all impulses are conducted.
213
What are the risk factors for Second-Degree Heart Block Type I (Mobitz Type I)?
* Vagal Tone
* Ischemic Heart Disease
* Medications
214
What is the pathophysiology of Second-Degree Heart Block Type I?
Progressive PR interval lengthening until a ventricular beat is dropped.
215
What are the risk factors for Second-Degree Heart Block Type II (Mobitz Type II)?
* Structural Heart Disease
* Myocardial Infarction
* Inflammation or Fibrosis
216
How does Second-Degree Heart Block Type II differ in pathophysiology from Type I?
Consistent PR interval before a dropped beat occurs, with a higher risk of progression.
217
What are the risk factors for Third-Degree Heart Block?
* Age
* Ischemic Heart Disease
* Structural Heart Disease
* Electrophysiological Disorders
* Medications
218
What characterizes the pathophysiology of Third-Degree Heart Block?
Dissociation of atrial and ventricular activity with escape rhythms.
219
What are the potential severe symptoms of Third-Degree Heart Block?
* Bradycardia
* Syncope
* Hemodynamic instability
220
What urgent intervention may be necessary for Third-Degree Heart Block?
Pacemaker
221
True or False: First-degree heart blocks are typically benign.
True
222
Fill in the blank: Second-degree blocks show varying patterns of ________.
conduction failure
223
What is a key conclusion regarding heart blocks?
Understanding risk factors and pathophysiology is crucial for diagnosis and management.
224
What is an Electrocardiogram (ECG or EKG)?
A standard test that records the electrical activity of the heart over a short period, typically a few seconds.
225
What are the uses of an Electrocardiogram (ECG)?
Identifying arrhythmias, heart size, and various cardiac conditions.
226
What findings can an ECG detect?
Irregular rhythms, heart rate, atrial and ventricular hypertrophy, signs of ischemia.
227
What is a Holter Monitor?
A portable ECG device worn continuously for 24-48 hours to record heart rhythms.
228
What are the uses of a Holter Monitor?
Monitoring for intermittent arrhythmias that may not be captured during a standard ECG.
229
What findings does a Holter Monitor provide?
Comprehensive data on heart rates, rhythm changes, episodes of arrhythmia, correlations with symptoms.
230
What is an Event Recorder (Loop Recorder)?
A device that monitors heart rhythms and records events when activated by the patient.
231
What are the uses of an Event Recorder?
Capturing infrequent or transient arrhythmias, especially in unexplained syncope or palpitations.
232
What findings does an Event Recorder capture?
Arrhythmia data when the patient activates the device, allowing correlation with symptoms.
233
What is Pacemaker Interrogation?
A process using a programmer device to communicate with implanted pacemakers or ICDs to retrieve stored data.
234
What are the uses of Pacemaker Interrogation?
Assessing device function, heart rates, and detected arrhythmias.
235
What findings does Pacemaker Interrogation provide?
Information on frequency of pacing, detected arrhythmias, effectiveness of the device.
236
What is a Cardiac Electrophysiology Study (EPS)?
An invasive procedure that maps electrical activity of the heart to induce arrhythmias.
237
What are the uses of Cardiac Electrophysiology Study (EPS)?
Identifying specific mechanisms of arrhythmias for targeted treatment or ablation.
238
What findings can a Cardiac Electrophysiology Study (EPS) pinpoint?
Location and mechanism of arrhythmias.
239
What is a Tilt Table Test?
A test that evaluates autonomic nervous system responses and can induce syncope.
240
What are the uses of a Tilt Table Test?
Diagnosing vasovagal syncope.
241
What findings may a Tilt Table Test reveal?
Abnormal heart responses due to changes in position.
242
What is a significant complication of Atrial Fibrillation (AF)?
Stroke due to thrombus formation from stagnant blood flow in the atria.
243
What complications can arise from Atrial Flutter?
* Stroke
* Heart Failure
* Transition to Atrial Fibrillation.
244
What is a major complication of Ventricular Tachycardia (VT)?
Cardiac Arrest due to degeneration into ventricular fibrillation.
245
What are the complications of Ventricular Fibrillation (VF)?
* Sudden Cardiac Death
* Cerebral Anoxia.
246
What complications can result from Bradyarrhythmias?
* Syncope
* Heart Failure
* Increased Risk of Sudden Cardiac Events.
247
What are complications associated with Sick Sinus Syndrome?
* Bradycardia
* Tachyarrhythmias
* Syncope and Falls.
248
What potential complications can arise from Premature Atrial Contractions (PACs) and Premature Ventricular Contractions (PVCs)?
* Potential for More Serious Arrhythmias
* Symptoms like palpitations.
249
What is a complication of Vasovagal Syncope?
Fainting or syncope, which can cause injuries from falls.
250
True or False: Atrial Fibrillation can lead to a decline in quality of life.
True.
251
Fill in the blank: The __________ is a test that records the electrical activity of the heart over a short period.
Electrocardiogram (ECG or EKG)
252
Fill in the blank: A __________ is a device that can be worn for weeks to continuously monitor heart rhythms.
Event Recorder (Loop Recorder)
253
What are the pharmacological management options for the treatment of arrhythmias?
* Na+ channel blockers
* β-blockers
* K+ blockers
* Ca2+ channel blockers
## Footnote
These are the main classes of drugs used in managing arrhythmias.
254
What is the mechanism of action for Class Ia sodium channel blockers?
They block sodium channels during the depolarization phase of the action potential, prolonging action potential duration and refractory period.
## Footnote
Examples include Quinidine and Procainamide.
255
What is the effect of Class Ib sodium channel blockers?
They shorten action potential duration and decrease refractory period, particularly in ischemic cardiac tissue.
## Footnote
Examples include Lidocaine and Mexiletine.
256
How do Class Ic sodium channel blockers affect conduction velocity?
They markedly slow conduction velocity in His-Purkinje and myocardial tissue without significantly affecting action potential duration.
## Footnote
Examples include Flecainide and Propafenone.
257
What is the primary mechanism of action for beta-blockers?
They block beta-adrenergic receptors (specifically β1 receptors in the heart).
## Footnote
Examples include Metoprolol, Atenolol, and Propranolol.
258
What is the effect of potassium channel blockers on the action potential?
They prolong action potential duration and refractory period, preventing premature excitations.
## Footnote
Examples include Amiodarone, Sotalol, and Dofetilide.
259
What is the mechanism of action for calcium channel blockers?
They block L-type calcium channels, inhibiting calcium influx during depolarization.
## Footnote
Examples include Verapamil and Diltiazem.
260
What is the role of digoxin in the management of arrhythmias?
It inhibits the Na+/K+ ATPase pump, increasing intracellular sodium and promoting calcium influx.
## Footnote
Commonly used for rate control in atrial fibrillation.
261
How does adenosine work in treating certain arrhythmias?
It activates adenosine receptors (A1 receptors) in the AV node, leading to hyperpolarization and decreased conduction.
## Footnote
Rapidly terminates certain types of supraventricular tachycardia.
262
What is defibrillation?
A procedure that delivers an electric shock to the heart to restore normal rhythm.
## Footnote
Primarily used for Ventricular Fibrillation and Pulseless Ventricular Tachycardia.
263
What is transcutaneous pacing?
A temporary and non-invasive method delivering electrical impulses through the skin to stimulate heartbeats.
## Footnote
Used for symptomatic bradycardia or heart block in emergency situations.
264
What is the purpose of a permanent pacemaker?
To provide regular electrical stimulation to maintain an adequate heart rate.
## Footnote
Used for chronic bradyarrhythmias and high-degree AV block.
265
What is the process of ablation in arrhythmia treatment?
It uses energy to destroy small areas of heart tissue responsible for abnormal electrical signals.
## Footnote
Targets areas for conditions like atrial fibrillation and ventricular tachycardia.
266
What dietary changes are recommended for secondary prevention of arrhythmias?
* Incorporate fruits, vegetables, whole grains, lean proteins, and healthy fats
* Limit salt intake
* Reduce saturated and trans fats
* Moderate alcohol consumption
## Footnote
A heart-healthy diet can help manage risk factors.
267
What type of physical activity is encouraged for managing arrhythmias?
* Regular moderate aerobic exercise
* Strength training
## Footnote
Consult a healthcare provider before starting new exercise routines.
268
What is a key aspect of weight management for arrhythmia prevention?
Achieve and maintain a healthy weight to decrease the burden on the heart.
## Footnote
This can improve control of hypertension and diabetes.
269
What techniques can be used for stress reduction in arrhythmia management?
* Mindfulness
* Relaxation techniques
* Adequate sleep
## Footnote
Practices like meditation and yoga can lower the incidence of arrhythmias.
270
What stimulants should be avoided to help manage arrhythmias?
* Caffeine
* Nicotine
## Footnote
Excessive caffeine can trigger arrhythmias, and nicotine increases heart rate.
271
What is important for medical compliance in arrhythmia management?
* Medication adherence
* Regular medical check-ups
## Footnote
Monitoring heart health is essential for treatment effectiveness.
272
What health conditions should be monitored and managed for arrhythmia prevention?
* Hypertension
* Diabetes
## Footnote
Keeping blood pressure and glucose levels controlled reduces cardiovascular risk.
