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Premature Ventricular Contraction
Aka: Premature Ventricular Contraction, PVC
- See Also
- Extrasystole
- Physiology
- PVCs have been historically thought to be benign
- More recently, data suggests increased risk
- In underlying cardiac disease, PVCs increase Arrhythmia risk
- In otherwise normal hearts, PVCs are still typically benign
- However, longstanding frequent PVCs, increase risk of Cardiomyopathy
- Definitions
- Bigeminy
- Extrasystole follows every sinus beat
- Trigeminy
- Extrasystole follows every other sinus beat
- Every third beat is ectopic
- Couplet
- Extrasystole and preceding beat
- Causes
- Occasional PVCs are normal finding in healthy patient
- Cardiac causes
- Ischemic Heart Disease
- Cardiomyopathy
- Valvular heart disease
- Mitral Valve Prolapse
- Stimulants
- Caffeine
- Cocaine
- Alcohol
- Ephedrine or Pseudoephedrine
- Electrolyte Abnormalities
- Metabolic Acidosis
- Hypoxemia
- Hyperkalemia
- Hypokalemia
- Hypomagnesemia
- Medications
- Digoxin
- Theophylline
- Antipsychotic Medications
- Tricyclic Antidepressants
- Antiarrhythmics (Flecainide, Sotalol, Quinidine)
- Signs: EKG Findings
- Unusual and Wide QRS with bizarre axis
- Large T Wave with opposite polarity as QRS
- Full compensatory pause
- No P Wave included in Extrasystole
- Associated with left bundle branch pattern
- Evaluation: Lown Criteria to distinguish pathologic PVCs
- Low risk of degenerating into ventricular Dysrhythmia
- Class 0: No PVCs
- Class 1: <30 PVCs per hour
- Intermediate risk of degeneration
- Class 2: 30 or more PVCs per hour
- High risk of degeneration
- Class 3: Multifocal PVCs
- Class 4a: Two consecutive PVCs
- Class 4b: Three consecutive PVCs
- Class 5: R on T Phenomena
- Management
- No heart disease (normal left ventricular function)
- Avoid provocative factors
- Mild asymptomatic PVCs
- No management required
- Symptomatic PVCs accounting for <20% of total beats
- Consider Beta Blocker for disabling symptoms
- PVCs account for >20% of total beats
- Consider Cardiac Catheter Ablation
- Associated with increased risk of developing a Cardiomyopathy
- See physiology above regarding risk
- Heart disease (with Left Ventricular Dysfunction)
- PVCs increase risk of morbidity and mortality
- Consider management for Lown Class 3-5
- Consider Cardiac Catheter Ablation
- References
- Baman (2010) Heart Rhythm 7(7): 865-9 [PubMed]