Arrhythmias Flashcards
1
Q
Sinus Bradycardia
Type, Etiology
A
- Bradyarrhythmias and conduction abnormalities
- Normal response to cardiovascular conditioning; also can result from sinus node dysfunction or beta-blocker or calcium channel blocker (CCB) excess
2
Q
First degree AV block
Type, Etiology
A
- Bradyarrhythmias and conduction abnormalities
- Can occur in normal individuals; associated with increased vagal tone and with beta-blocker and CCB use
3
Q
Second degree AV block (Mobitz I/Wenckebach)
Type, Etiology
A
- Bradyarrhythmias and conduction abnormalities
- Due to drug effects (digoxin, beta-blocker, CCBs) or increased vagal tone; right coronary ischemia or infarction
4
Q
Second degree AV block (Mobitz II)
Type, Etiology
A
- Bradyarrhythmias and conduction abnormalities
- Results from fibrotic disease of the conduction system or from acute, subacute, or prior MI
5
Q
Third degree AV block (Complete)
Type, Etiology
A
- Bradyarrhythmias and conduction abnormalities
- No electrical communication between the atria and ventricles
6
Q
Sick Sinus syndrome/Tachycardia-bradycardia syndrome
Type, Etiology
A
- Bradyarrhythmias and conduction abnormalities
- A heterogeneous disorder that leads to intermittent supraventricular tachy- and bradyarrhythmias
7
Q
Sinus Tachycardia
Type, Etiology
A
- Supraventricular tachyarrhythmias
- Normal physiologic response to fear, pain, and exercise. Can be secondary to hyperthyroidism, volume contraction, infection or pulmonary embolism
8
Q
Atrial Fibrillation (AF) (Type, Etiology)
A
- Supraventricular tachyarrhythmias
- Acute AF: pulmonary disease, ischemia, rheumatic heart disease, anemia, atrial myxoma, thyrotoxicosis, ethanol and sepsis. Chronic AF: hypertension and congestive heart failure
9
Q
Atrial Flutter
Type, Etiology
A
- Supraventricular tachyarrhythmias
- Circular movement of electrical activity around the atrium at a rate of about 300 times per minute
10
Q
Multifocal Atrial Tachycardia
Type, Etiology
A
- Supraventricular tachyarrhythmias
- Multiple atrial pacemakers or reentrant pathways; COPD and hypoxemia
11
Q
Atrioventricular Nodal Reentry Tachycardia (AVNRT)
Type, Etiology
A
- Supraventricular tachyarrhythymias
- A reentry circuit in the AV node depolarizes the atrium and ventricle nearly simultaneously
12
Q
Atrioventricular Reciprocating Tachycardia (AVRT)
Type, Etiology
A
- Supraventricular tachyarrhythmias
- An ectopic connection between atrium and ventricle that causes a reentry circuit. Seen in Wolff-Parkinson-White syndrome (WPW) [Bundle of Kent (Atria to ventricles)] and Lown-Ganong-Levine syndrome (LGL) [Bundle of James (atria to bundle of His)]
13
Q
Paroxysmal Atrial Tachycardia
Type, Etiology
A
- Supraventricular tachyarrhythmias
- Rapid ectopic pacemaker in the atrium (not sinus node)
14
Q
Premature Ventricular Contraction (PVC)
Type, Etiology
A
- Ventricular tachyarrhythmias
- Ectopic beats arise from ventricular foci. Associated with hypoxia, electrolyte abnormalities, and hyperthyroidism
15
Q
Ventricular Tachycardia (VT) (Type, Etiology)
A
- Ventricular tachyarrhythmias
- Can be associated with CAD, MI, and structural heart disease
16
Q
Ventricular Fibrillation (VF) (Type, Etiology)
A
- Ventricular tachyarrhythmias
- Associated with CAD and structural heart disease. Also associated with cardiac arrest (together with asystole)
17
Q
Torsades de Pointes
Type, Etiology
A
- Ventricular tachyarrhythmias
- Associated with long QT syndrome, proarrhythmic response to medications (AntiArrhythmics [Class IA, III], AntiBiotics [e.g., macrolides], Anti”C”ychotics [e.g., haloperidol], AntiDepressants [e.g., TCAs], AntiEmetics [e.g., ondanserton]), hypokalemia, hypomagnesemia, congenital deafness and alcoholism
18
Q
Long QT Syndrome (LQTS)
Etiology
A
- Either congenital disorder of myocardial repolarization, typically due to ion channel defects; which increase the risk of sudden cardiac death due to torsade de pointes (either Romano-Ward syndrome [AD] which is pure cardiac phenotype or Jervell and Lange-Nielsen syndrome [AR] which is associated with sensorineural deafness) or acquired as in Anorexia nervosa
19
Q
Brugada Syndrome
Etiology
A
- Autosomal dominant disease, most common in Asian males, due to myocytes sodium channel defects
- Associated with increased risk of ventricular tachyarrhythmias and sudden cardiac death
20
Q
Right Bundle Branch Block (RBBB)
Etiology
A
- It can be due to ASD, Brugada syndrome, right ventricular hypertrophy, pulmonary embolism, IHD, rheumatic heart disease, cardiomyopathy, myocarditis and hypertension
21
Q
Left Bundle Branch Block (LBBB)
Etiology
A
- It can be due to aortic stenosis, dilated cardiomyopathy, acute MI, hypertension with aortic root dilatation and Lyme disease
22
Q
Sinus Bradycardia
Presentation, ECG findings
A
- May be asymptomatic, but may also present with lightheadedness, syncope, chest pain or hypotension
- ECG: Sinus rhythm and ventricular rate < 60 bpm
23
Q
First degree AV block
Presentation, ECG findings
A
- Asymptomatic
- ECG: PR interval > 200 msec
24
Q
Second degree AV block (Mobitz I/Wenckebach)
Presentation, ECG findings
A
- Usually asymptomatic
- ECG: progressive PR lengthening until a dropped beat occur; the PR interval then resets
25
Second degree AV block (Mobitz II)
| Presentation, ECG findings
- Occasionally syncope; frequent progression to third degree AV block
- ECG: unexpected dropped beat(s) without a change in PR interval
26
Third degree AV block (Complete)
| Presentation, ECG findings
- Syncope, dizziness, acute heart failure, hypotension and "cannon" a waves
- ECG: no relationship between p waves and QRS complexes
27
Sick Sinus syndrome/Tachycardia-bradycardia syndrome
| Presentation, ECG findings
- Secondary to tachycardia or bradycardia; may include syncope, palpitations, dyspnea, chest pain, TIA, and stroke
- ECG: transient non-specific tachycardia or bradycardia
28
Sinus Tachycardia
| Presentation, ECG findings
- Palpitations and shortness of breath
| - ECG: sinus rhythm. Ventricular rate > 100 bpm
29
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Atrial Fibrillation (AF)
(Presentation, ECG findings)
```
- Often asymptomatic, but may present with shortness of breath, chest pain, or palpitations. P/E: reveals irregularly irregular pulse
- ECG: no discernible p waves, with variable and irregular QRS response
30
Atrial Flutter
| Presentation, ECG findings
- Usually asymptomatic, but can present with palpitations, syncope, and lightheadedness
- ECG: regular rhythm. "sawtooth" appearance of p waves. Atrial rate is usually 240-320 bpm and the ventricular rate is about 150 bpm
31
Multifocal Atrial Tachycardia
| Presentation, ECG findings
- May be asymptomatic
| - ECG: three or more unique p wave morphologies; rate > 100 bpm
32
Atrioventricular Nodal Reentry Tachycardia (AVNRT)
| Presentation, ECG findings
- Palpitations, shortness of breath, angina, syncope, and lightheadedness
- ECG: rate 150-250 bpm; p wave is often buried in QRS or shortly after
33
Atrioventricular Reciprocating Tachycardia (AVRT)
| Presentation, ECG findings
- Palpitations, shortness of breath, angina, syncope, and lightheadedness
- ECG: a retrograde p wave is often seen after a normal QRS. A preexcitation delta wave with wide QRS and shortened PR interval is characteristically seen in WPW, while in LGL shortened PR interval with normal QRS and no delta wave is seen
34
Paroxysmal Atrial Tachycardia
| Presentation, ECG findings
- Palpitations, shortness of breath, angina, syncope, and lightheadedness
- ECG: rate > 100 bpm; p wave with unusual axis before each normal QRS
35
Premature Ventricular Contraction (PVC)
| Presentation, ECG findings
- Usually asymptomatic, but may lead to palpitations
| - ECG: early, wide QRS not preceded by a p wave. PVCs are usually followed by a compensatory pause
36
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Ventricular Tachycardia (VT)
(Presentation, ECG findings)
```
- Non-sustained VT is often asymptomatic; sustained VT can lead to palpitations, hypotension, angina, syncope. Can progress to VF and death
- ECG: three or more consecutive PVCs; wide QRS complexes in regular rapid rhythm; may see AV dissociation
37
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Ventricular Fibrillation (VF)
(Presentation, ECG findings)
```
- Syncope, absence of blood pressure and pulselessness
| - ECG: totally erratic wide complex tracing
38
Torsades de Pointes
| Presentation, ECG findings
- Can present with sudden cardiac death; typically associated with palpitations, dizziness, and syncope
- ECG: Polymorphous QRS; VT with rates between 150 and 250 bpm
39
Long QT Syndrome (LQTS)
| Presentation, Diagnosis
- Usually asymptomatic, but can presents as syncope (stress induced), seizures or sudden cardiac death
- Dx: is complex and depends on a scoring system
40
Brugada Syndrome
| Presentation, ECG findings
- Asymptomatic
- ECG: persistent ST elevation in leads V1-V3 with pseudo RBBB appearance (J point elevation with inverted T wave or saddle back T wave) which either seen in a routine ECG or after giving antiarrhythmics with sodium channel blocking activity
41
Right Bundle Branch Block (RBBB)
| Presentation, ECG findings
- Asymptomatic or presents with syncope, chest pain and dypnea
- ECG: MaRRoW; wide QRS with M shape in V1 (V1-V3) and W shape in V6 (V4-V6) with appropriate T wave discordance
42
Left Bundle Branch Block (LBBB)
| Presentation, ECG findings
- Asymptomatic or presents with syncope, chest pain and dyspnea
- ECG: WiLLiaM; wide QRS with W shape in V1 (V1-V3) and M shape in V6 (V4-V6) with appropriate T wave discordance
43
Sinus Bradycardia
| Treatment
None if asymptomatic; atropine may used to increase heart rate. Pacemaker placement is the definitive treatment in severe cases
44
First degree AV block
| Treatment
None
45
Second degree AV block (Mobitz I/Wenckebach)
| Treatment
Stop the offending drug. Atropine as clinically indicated
46
Second degree AV block (Mobitz II)
| Treatment
Pacemaker placement
47
Third degree AV block (Complete)
| Treatment
Pacemaker placement
48
Sick Sinus syndrome/Tachycardia-bradycardia syndrome
| Treatment
The most common indication for pacemaker placement
49
Sinus Tachycardia
| Treatment
Treat the underlying cause
50
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Atrial Fibrillation (AF)
(Treatment)
```
- Estimate risk of stroke using CHADS2 score. Anticoagulation therapy if equal or more than 2
- If more than 48 hrs passed give anticoagulants to prevent CVA and give beta-blockers, CCBs and digoxin (for rate control)
- If less than 48 hrs passed, or transesophageal echo (TEE) shows no left atrial clot or after 3-6 weeks of warfarin treatment with satisfactory INR (2-3) initiate cardioversion
51
Atrial Flutter
| Treatment
- Estimate risk of stroke using CHADS2 score. Anticoagulation therapy if equal or more than 2
- If more than 48 hrs passed give anticoagulants to prevent CVA and give beta-blockers, CCBs and digoxin (for rate control)
- If less than 48 hrs passed, or transesophageal echo (TEE) shows no left atrial clot or after 3-6 weeks of warfarin treatment with satisfactory INR (2-3) initiate cardioversion
52
Multifocal Atrial Tachycardia
| Treatment
Treat underlying cause; verapamil or beta-blockers for rate control and suppression of atrial pacemakers (not very effective)
53
Atrioventricular Nodal Reentry Tachycardia (AVNRT)
| Treatment
Cardioversion if hemodynamically unstable. Carotid massage, Valsalva, or adenosine can stop the arrhythmia
54
Atrioventricular Reciprocating Tachycardia (AVRT)
| Treatment
Cardioversion if hemodynamically unstable. Carotid massage, Valsalva, or adenosine can stop the arrhythmia
55
Paroxysmal Atrial Tachycardia
| Treatment
Adenosine can be used to unmask underlying atrial activity
56
Premature Ventricular Contraction (PVC)
| Treatment
Treat the underlying cause. If asymptomatic, give beta-blocker or occasionally other antiarrhythmics
57
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Ventricular Tachycardia (VT)
(Treatment)
```
Cardioversion and antiarrhythmics (e.g., amiodarone, lidocaine, procainamide)
58
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Ventricular Fibrillation (VF)
(Treatment)
```
Immediate electrical cardioversion and ACLS protocol
59
Torsades de Pointes
| Treatment
Give magnesium initially and cardioversion if unstable. Correct hypokalemia; withdraw offending drugs
60
Long QT Syndrome (LQTS)
| Treatment
- Advise the patient to avoid drugs that will prolong the QT interval further or lower the threshold of torsade de pointes
- Beta-blockers to prevent stress induced arrhythmias
- Implantable cardioverter defibrillators [ICD] (for prevention and termination) in patients with failed beta-blockers therapy or experienced cardiac arrest
- Cervical sympathetic chain amputation (left stellectomy) for Jervell and Lange-Nielsen syndrome
61
Brugada Syndrome
| Treatment
ICD
62
Right Bundle Branch Block (RBBB)
| Treatment
Treat the underlying cause
63
Left Bundle Branch Block (LBBB)
| Treatment
Pacemaker
64
Atrial Enlargement
| ECG Findings
- Right: P pulmonale which is a peaked p wave in lead II
| - Left: P mitrale which is notched (M-shaped) p wave in lead II
65
Ventricular Enlargement
| ECG Findings
- Right: right axis deviation and an R wave > 7 mm in V1
- Left:
* Amplitude of S in V1 + R in V5 or V6 is > 35 mm
* Alternative criteria: Amplitude of R in aVL + S in V3 is > 28 mm in men or > 20 mm in women
66
Normal Heart Axis
| ECG Findings
- It is 0 to +90 degrees
| - An upright (positive) QRS in leads I and aVF
67
Left Axis Deviation of the heart
| ECG Findings, Causes
- More than -30 degrees
- An upright (positive) QRS in lead I and a downward (negative) QRS in lead aVF
- Causes:
* Left ventricular hypertrophy
* Left anterior fascicular block (hemiblock)
* Inferior MI
* WPW
* Ostium primum ASD
68
Right Axis Deviation of the heart
| ECG findings, Causes
- More than +105 degrees
- A downward (negative) QRS in lead I and an upright (positive) QRS in lead aVF
- Causes:
* Right ventricular hypertrophy
* Left posterior fascicular block
* Lateral MI
* WPW
* Ventricular tachycardia and ventricular ectopy
