Post Operative PVC’s, When to Worry?DefinitionPVC’s are premature ventricular contractions, also known as Ventricular premature beats (VPBs) or Ventricular Premature Depolarization(VPDs).PVC’s are ectopic impulses originating from a focus distal to the His Purkinje system. PVC’s are the most common ventricular arrhythmia with variable prognostic importance.PathophysiologyEnhanced Automaticity-new site of depolarization in non-nodal ventricular tissue. Associated with electrolyte abnormalities, ischemia, or increased catecholamines.Triggered Activity-early or late afterdepolarizations that can be associated with electrolyte abnormalities, ischemia, or drug toxicity (digoxin, prolonged QT)Reentry-occurswith unidirectional block (slow conducting myocardium next to normal conducting tissue). Occurs in the setting of damaged myocardium.CausesCardiac-Acute MI, Valvular disease (MVP), Cardiomyopathy (ischemia, dilated, hypertrophic), Cardiac Contusion,LVH, CHF (EF<40%), and Tachycardia (associated w/ high catecholamine state), Previous Cardiac Surgery, Congenital Heart Disease (h/o tetrology of fallot)NonCardiac-electrolyte abnormalities (hypokalemia, hypomagnesemia, hypercalcemia), medications (digoxin, TCA, amitriptyline, pseudophedrine, flouoxetine), drugs (cocaine, amphetamines, caffeine, alcohol),stress response (surgery, infection), anesthestics (sevoflurane, droperidol, ondansetron, etc...)EvaluationSymptomatic-palpitations, skipped beat, dizzinessPast Medical/Surgical History/PhysicalExam-high risk patientidentification as well as possible identification of underlying causes (renal failure, acute MI, etc...)Frequency-greater then 10/hr, bigeminy, trigeminyCharacter-multifocal vs.unifocal Work-Up-look for underlying/reversible causesEKG-evaluate for ischemia, prolonged QTElectrolyte Panel-chem. 10 as well as Ca and MgTreatment-only needed for symptomatic pt’s, high risk pt’s (CHF, cardiomyopathy or previous MI and EF<40%), or frequent PVC’sBeta-Blockers-1stline treatmentAmniodarone, Sotalol
Bottom LineWorry If:Pt is high risk: previous MI, CHF, Cardiomyopathy w/ EF<40%PVCs are frequent >10/hr, mutifocal, or bigeminy/trigeminyIf there is any evidence of Acute Ischemia, hemodynamic instability, or altered mental statusReferences:1.Curry T., Gaver R., & White R. Acquired Long QT syndrome and Anesthesia. Pediatric Anesthesia.Feb 2006;16,471-478.2.Clinical Significance and Treatment of VPBs. www.uptodate.com3.Ventricular Premature Complexes. www.emedicine.comKim Howard-Quijano M.D. 9/17/2008