PO-03-146 PREMATURE VENTRICULAR CONTRACTIONS IN CHILDREN AND YOUNG ADULTS: RISK FACTORS FOR LEFT VENTRICULAR DYSFUNCTION

Abstract

Premature ventricular contractions (PVCs) are common in children and are often perceived as benign. However, frequent PVCs can lead to left ventricular (LV) dysfunction. Risk factors for PVC-mediated LV dysfunction are not well defined in children. Characterize the frequency of and risk factors for LV dysfunction in children with frequent PVCs. Retrospective cohort study from 2003-18 including patients aged 1-21 years with frequent PVCs (>0.5% on Holter monitoring), a 12-lead ECG with 1+ PVC, and an echocardiogram. Risk factors for LV dysfunction (LVEF <50%) at time of presentation and during follow up in the subset of patients with echocardiographic follow up were evaluated using logistic regression and Cox proportional hazards analysis, respectively. Exclusion criteria included significant congenital heart disease and known personal or family history of primary arrhythmic or cardiomyopathic disease. We identified 202 patients and four were excluded due to diagnoses made after presentation with PVCs: Andersen-Tawil syndrome (2 siblings), and cardiomyopathy (2), leaving 198 for analysis with a median age 12.3 years. LV dysfunction was present at time of presentation in 4%, developed in an additional 6% during follow up, and was mild in most (LVEF <40% in only 1). Risk factors for LV dysfunction included older age; higher PVC burden; longer PVC duration; couplets, triplets, NSVT, and polymorphic ventricular ectopy (table 1). A PVC burden threshold of ≥15% was 100% sensitive and 76% specific for LV dysfunction at time of presentation (fig. 1) while a PVC duration threshold of ≥151ms was 100% sensitive and 74% specific. No risk factors were identified for developing LV dysfunction during follow up. In children who never received PVC-directed therapy or had serial Holter monitors before therapy was started, PVC burden decreased from a median of 10.2 to 1.8% (p < 0.001) over a median follow up period of 3.2 years. PVC-mediated LV dysfunction is rare in children and is mild in nearly all cases. Younger patients with <15% PVCs, PVC duration <151ms, and without complex ventricular ectopy are at extremely low risk for LV dysfunction. The natural history shows a reduction in PVC burden over time in most, but not all, patients. A minority of children who come to attention due to frequent PVCs have a serious underlying cardiovascular diagnosis.Tabled 1Table 1No LV Dysfunction (n = 191)LV Dysfunction (n = 7)OR [95% CI]p-valueDemographicsMale sex108 (57)6 (86)4.6 [0.5-39.0]0.161Age (years)12.1 (7.8-15.6)17.6 (16.2-17.6)4.5 [1.3-16.1] per 5 year increase0.021CHD8 (4)1 (14)3.8 [0.4-35.5]0.240PresentationPVCs incidentally noted140 (73)6 (86)2.2 [0.3-18.6]0.474Initial Holter Results%PVCs8.6 [3.9-14.9]33.6 [18.5-36.8]1.6 [1.3-2.2] per 5% increase<0.001Sustained VT3 (2)1 (14)10.4 [0.9-115.7]0.056NSVT11 (6)4 (57)21.8 [4.3-109.8]<0.001*Couplets73 (38)7 (100)*0.001Triplets26 (14)4 (57)8.5 [1.8-40.0]0.007Polymorphic ectopy9 (5)2 (29)8.1 [1.4-47.5]0.021ECG PVC CharacteristicsInferior QRS axis156 (82)6 (86)1.3 [0.2-11.5]0.786LBBB morphology141 (74)5 (71)0.9 [0.2-4.7]0.888Outflow tract morphology118 (62)5 (71)1.5 [0.3-8.2]0.608PVC coupling interval (ms)477 (420-531)467 (399-497)0.9 [0.7-1.1] per 25 ms increase0.420PVC duration (ms)135 (119-151)160 (157-168)4.0 [1.5-10.9] per 25 ms increase0.007ETT results (n = 99)PVC suppression during test78 (85)4 (57)0.2 [0.1-1.2]0.080VT during test3 (3)1 (14)4.9 [0.4-55.0]0.194∗Odds ratio cannot be estimated as all patients with dsyfunction are in one group; p-value estimated from Fisher's exact test. CHD = congenital heart disease, VT = ventricular tachycardia, NSVT = non-sustained ventricular tachycardia, LBBB = left bundle branch block, ETT = exercise tolerance test Open table in a new tab