Tachyarrhythmias

Question 1

Classification

Answer 1

• Supraventricular and ventricular

- HR greater than 100bpm for 3 beats or more

Question 2

Sinus tachycardia

Answer 2

• narrow QRS complex

- HR 150-180/min

Question 3

Tachyarrhythmias result from:

Answer 3

Enhanced automaticity

Reentry or trigged activity

Question 4

Supraventricular tachycardia

-reentry tachycardia and WPW symptoms

Answer 4

• palpitations
• pounding sensations in neck
• fatigue
• chest pain
• dyspnea
• dizziness
• sweating

Question 5

Supraventricular tachycardia

1. narrow QRS tachycardia
2. wide QRS tachycardia

Answer 5

1. if not hemodynamic stable –> vagal manouevers –> if not effective –> adenosine –> if not effective –> verapamil or diltiazem or beta blockers –> if ineffective –> synchronized cardioversion

if hemodynamic stable –> synchronized cardioversion

2. if not hemodynamic stable –> vagal manouevers –> if not effective –> adenosine (if not evidence of pre-exictation on resting ECG) –> if not effective –> procanamide (?) and ? –> if not effective –>synchronized cardioversion

if hemodynamic stable –> synchronized cardioversion

Question 6

Ventricular premature beat

Answer 6

• Common among healthy people, often asymptomatic and benign
• Avoid caffeine, stress, hypoxia…
• Reassurance, B blocker, ICD (implantable cardiac device)

Question 7

Ventricular tachycardia

Answer 7

• Three or more consecutive PVC
• Sustained VT: persists >30s, severe symptoms such as syncope, required cardioversion, degenerates to VF
• Non-sustained: shorter and self-terminated
• Monomorphic vs polymorphic

Question 8

Ventricular tachycardia

-symptoms

Answer 8

• palpitations
• chest pain/pressure
• dyspnea
• dizziness, hypotension, syncope, cardiogenic shock signs of reduced cardiac output
• cardiac arrest

Question 9

Ventricular tachycardia

-treatment of sustained VT

Answer 9

hemodynamically unstable

• pulseless: PCR
• with pulse: polymorphic (defibrillate), monomorphic (cardioversion)

hemodynamically stable 
-Pharmacological conversion with antiarrhythmics: 
QT prolongation present: amiodarone
No QT prolongation: procainamide
Refractors VT: electrical cardioversion

Question 10

Ventricular tachycardia

-Treatment of unsustained VT or resolved sustained VT

Answer 10

Identifiable reversible cause

• Correct any electrolyte imbalances
• Stop drugs that prolong QT
• Consider digoxin immune fab for digoxin toxicity

No identifiable cause
-Long term management with antiarrhythmics (b blockers), device therapy or ablation

Question 11

Torsade de pointes

-treatment:

Answer 11

Type of polymorphic VT, can progress to VF

• Hemodynamically unstable: defibrillation plus CPR
• Hemodynamically stable: IV magnesium sulfate
• Identify and treat underlying etiology

Question 12

Ventricular flutter

Answer 12

cardioversion

Question 13

Ventricular fibrillation

Answer 13

electrical defibrillation

survivors: ICD