remature ventricular contractions (PVCs) lead to irregular heart rhythm and decreasing of left ventricular ejection fraction (LVEF), which may be accompanied with undesirable hemodynamic effects and the development of LV dysfunction. Purpose. The aim of the study is to estimate effects of PVCs on echocardiographic (EchoCG) parameters in children without structural and inflammatory heart diseases.Material and methods. 32 children aged 11.6 ± 5.1 years with idiopathic PVCs (13.4 ± 9.8% per day) were examined. Standard echocardiographic parameters were assessed on normal contraction (NC) of the heart, on extrasystolic contraction (EC) and on the first post-extrasystolic contraction (PEC).Results: Left ventricular end-diastolic diameter (LVEDD) decreased in 71.9% of children and left ventricular end-systolic diameter LVESD increased in 62.5% of children on the EC, which determined decreasing LVEF and LV stroke volume (LVSV) among most of children (96.8%). LVEDD decreased in 62.5% of children and LVESD decreased in 65.6% of children, LVEF increased in 81.3% of children on the PEC, while values of LVSV were less in half of children (46.9%) than the initial parameters, including all children with left ventricular PVCs.Values of LVEF were higher than the initial parameters in the other half of the children (53.1%).LV ejection fraction in children with epicardial localization PVCs was lower than in children with endocardial localization during the EC (53.8 ± 6.7% versus 62.0 ± 10.7%; p = 0.01), which was also noted on PEC (69.8 ± 7.5% on average 75.6 ± 7.0%; p = 0.05). Conclusion.PVCs lead to decreasing of LVEF in children by reducing of LVEDD and by increasing of LVESD. LVEF increased in most children during of postectopic LV contraction, but LV stroke volume did not exceed initial values in children with left ventricular PVCs. LVEF of patients with epicardial PVCs was significantly less than in children with endocardial PVCs on extrasystolic and post-extrasystolic contractions.
Aim. To evaluate the effectiveness of beta-blockers (BB) in the treatment of idiopathic premature ventricular contractions (PVCs) in children.Material and methods. BBs were prescribed to 27 children with idiopathic PVCs. In 3 (11,1%) patients, side effects (hypotension, bronchial obstruction) was revealed at the beginning of therapy. A total of 24 children were included in the further study (15 boys (62,5%), 9 girls (37,5%). The mean age was 8,3±5,4 years. Data from anamnesis, electrocardiography (ECG), 24-hour ECG monitoring, and echocardiography were analyzed.Results. The 24-hour PVC rate was 33,2±17,7 thousand/day or 26,6±13,2%. In 14 (58,3%) children, we recorded paired PVCs, in 3 (12,5%) — multiform, in 10 (41,7%) — runs of non-sustained VT. There were complaints in 7 (29,2%) children. The follow-up period lasted 369,8±119,1 days. Propranolol was received by 17 (70,8%) patients, metoprolol — by 7 (29,2%). The therapy was effective in 11 (45,8%) patients, while ineffective in 13 (54,2%), among which 5 (20,8%) had an increase in the number of PVCs. The effectiveness of BBs was higher in children under the age of 1 year (p=0,043). Propranolol showed greater efficacy than metoprolol (p=0,047). Less efficiency was observed in female patients and those with pathological heart rate turbulence parameters (p=0,04).Conclusion. The effectiveness of BBs in children with idiopathic PVCs is 45,8%, higher in children aged <1 year and declines with age, decreasing in adolescents to 25%. The use of BBs is limited by non-cardiac side effects in 11,1% of children. Propranolol is more effective than metoprolol.
Background Premature ventricular contractions (PVCs) is the one of the most frequent arrhythmias in children. There is no clear understanding regarding the causes of PVCs in children without structural heart diseases. There is also little information about the state of the conduction system (CS) of the heart in children with PVCs. Purpose:The aims of the study were to estimate the electrophysiological properties of the sinus node (SN) and atrioventricular node (AVN) in children with PVCs, and to evaluate the effect of atropine test on the frequency and nature of the PVCs. Methods: 167 children(54(32,3%) girls and 113(67,7%) boys with PVCs without structural heart disease were examined. Mean age at the time of the first examination was 14,5 ± 5,3years (6-18 years). Examination included: ECG, 24-hour Holter monitor (HM), echocardiogram, treadmill test, transesophageal pacing study (TEPS), atropine test.Results:The duration of the PVCs was 3,3 ± 1,5years (6-14 years). The burden of the PVCs was 7-29% according to HM data. 5(3%) children had syncope. Frequent PVCs were recorded in 43(25,7%) patients, single PVC in 59 (35,3%), and the rest of children did not have PVCs during TEPS. SN recovery time (SNRT) was 1118,1 ± 292,4ms (541-2300ms) which exceeded the age-dependent limit in 23(13,7%) children. Corrected SNRT was 350,1 ± 171,1ms (41-1317ms), which exceeded the age-dependent limit in 15(8,9%) children. Max.rate of 1:1 conduction through AVN was 166,7 ± 39,1 imp/min (90-220 imp/min); in 16(9,6%) children it was less than 120 imp/min, while 8 (4,8%) children had enhanced AV nodal conduction (more than 200imp/min). The effective refractory period (ERP) of AVN was 325,1 ± 91,7ms (190-650ms), exceeding the age norm in 18(10,7%) children. 16(9,6%) children had a discontinuous AV nodal conduction. The frequency of stimulation which suppressed PVCs was 100-160imp/min. Atropine test was performed in 100(59,9%) children (0,1% sol. Atropini sulfatis 0,02 mg/kg IV). After administration of atropine the increase in heart rate constituted 7-131%, with an average of 57%. The SNRT was 665,5 ± 154,4 ms (406-1512ms), maximal rate of 1:1 conduction through AVN was 213,2 ± 31,9 imp/min (150-270 imp/min). Among patients who initially had PVCs during TEPS, after atropine test PVCs disappeared in 61(59,8%) children, in 16(15,7%) children there was a significant decrease, and 4(3,9%) patients had an increase in the number of PVCs and episodes of stable ventricular bigeminy, and in 1(0.9%) child there were short runs of ventricular tachycardia (up to 8 QRS complexes).Conclusions: In children with PVCs normal electrophysiological parameters of cardiac CS were noted in most cases. In 35% of children there was a hypervagotonic influence on SN or AVN, and in 75,5% cases there was a disappearance or decrease in PVCs after atropine test. This suggests that the preferential nature of PVCs in children without structural heart diseases is autonomic system dependent
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