Abstract 2453: Reversible Left Ventricular Dysfunction in the Presence of Frequent of Idiopathic Premature Ventricular Complexes - Is There a Critical PVC Burden?
Background: Frequent idiopathic premature ventricular complexes (PVCs) can result in a reversible form of left ventricular dysfunction. The factors resulting in impaired left ventricular function are unclear. Whether a critical burden of PVCs can result in cardiomyopathy has not been determined. The objective of this study was to determine a cut-off PVC burden that can result in PVC-induced cardiomyopathy.
Methods: In a consecutive group of 167 patients referred for ablation of frequent, idiopathic PVCs, the burden was determined by 24 hour Holter monitoring. Transthoracic echocardiograms were used to assess LV function. Frequent PVCs were defined as >10 PVCs/hour, a reduced ejection fraction was defined as <0.50, the PVC burden was defined as the percentage of PVCs based on all QRS complexes on a 24 hour Holter monitor. Receiver operator characteristics curves were constructed based on the PVC burden and on the presence or absence of reversible left ventricular dysfunction in order to determine a cut-off PVC burden that is associated with left ventricular dysfunction.
Results: A reduced left ventricular ejection fraction (mean 0.37±0.10) was present in 59 (35%) patients. Patients with a decreased ejection fraction had a mean PVC burden of 33±13% as compared to those with normal left ventricular function 13±12% (p<0.0001). A PVC burden of >24% best separated the patient population with impaired as compared to preserved left ventricular function. The sensitivity was 85% and the specificity was 82%. The lowest PVC burden resulting in a reversible cardiomyopathy was 10%. Nineteen percent of patients with reversible left ventricular dysfunction had a PVC burden <24%.
Conclusion: A PVC burden of >24% best separated patients with PVC-induced cardiomyopathy from patients without cardiomyopathy.