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Ventricular Arrhythmias

• Wide QRS complex
• No preceding P wave

Premature Ventricular Contractions (PVC)

• Extra beat originating in one of the ventricles
• No p wave
• Wide QRS

Terminology

• Bigeminy – PVC is every other beat. One normal beat followed by a PVC repeated continuously
• Trigeminy – PVC is every third beat. Two normal beats followed by a PVC repeated continuously
• Unifocal PVC – all PVCs originate at the same place within the ventricles and therefore all PVC QRS complexes look the same.
• Multifocal PVC – PVCs originate at different places within the ventricles and therefore PVC QRS complexes will appear different.

Clinical Presentation

• “Skipped heart beats”
• Palpitations

Labs & Studies

• ECG
  • Wide QRS complex without preceding p wave
  • Compensatory pause before the next beat
• Holter monitor
• Electrolyte panel

Treatment

• No treatment necessary for most asymptomatic cases
• Correct electrolyte imbalance if present
• Beta blockers are first line if the patient is symptomatic

Ventricular Tachycardia

• Wide QRS waves with no p wave.
• A run of three or more PVCs is considered Vtach
• Polymorphic vs Unifocal
• Sustained V Tach lasts for more than 30 seconds
• Unsustained V Tach lasts for less than 30 seconds
• Pulseless V Tach – ECG shows a V Tach however cardiac output has fallen so low it does not create a palpable pulse

Risk factors

• Previous MI

Clinical presentation

• May be asymptomatic
• Palpitations
• Chest pain
• Syncope
• Dizziness
• Symptoms of poor cerebral perfusion

Labs & Studies

• ECG
  • Rate of 160–240
  • Wide QRS complex
  •  No visible P waves

Treatment

Is the patient stable?
How well do they tolerate an episode?
How often are they having episodes?

• Defibrillation – used for pulseless V Tach
• Synchronized cardioversion – Used for V Tach when a pulse is present
• Medications
  • Beta blockers
    • Sotalol
  • Antiarrhythmics
    • Lidocaine
    • Procainamide
    • Amiodarone

Torsades de Pointes

• “Turning of the spikes”
• Can lead to sudden cardiac death
• The QRS complexes appear to twist around the isoelectric line because they are polymorphic.
• Treatment is with a bolus of magnesium.
• Cardioversion is also an option but may be difficult

Ventricular Fibrillation

• Ventricular myocytes contracting without any coordination.
• There is NO effective movement of blood at this point.

Risk factors

• Coronary artery disease
• History of MI
• Valve disease
• Cardiomyopathy

Physical Exam findings

• NO PULSE
• Unresponsive
• No normal breathing

Labs & Studies

• ECG
  • No p waves
  • Irregular unformed QRS complexes

Treatment

• Immediate intervention is necessary to prevent sudden death.
• DEFIBRILLATION
• Lidocaine, procainamide, amiodarone
• Vasopressin