Chronic Left Ventricular Pacing Preserves Left Ventricular Function in Children

Abstract

Chronic right ventricular (RV) pacing can induce structural and functional cardiac deterioration. Because animal studies showed a benefit of left ventricular (LV) over RV pacing, this study compared the effects of chronic RV and LV pacing in children. Retrospectively, echocardiographic data were evaluated from 18 healthy children (control subjects) and from children undergoing chronic epicardial RV pacing (7 RVP) or LV pacing (7 LVP). Assessment included LV end-diastolic wall thickness (LVEDWT) and end-systolic wall thickness (LVESWT) as well as LV end-diastolic diameter (LVEDD) and end-systolic diameter (LVESD). The shortening fraction and eccentricity index (LV diameter/2 9 LV wall thickness) were calculated as measures of LV function and eccentricity, respectively. Duration of QRS and septal posterior wall motion delay (SPWMD) were used as measures of electrical and mechanical dyssynchrony, respectively. A p value less than 0.05 determined significance. As the findings showed, LVEDD, LVESD, LVEDWT, and LVESWT were not significantly different between the groups. The shortening fraction was significantly lower in the RVP (21.7% ± 6.0%) than in the LVP (32.2% ± 5.2%) or control (29.3% ± 4.3%) children. The systolic LV eccentricity index was significantly larger in the RVP (1.8 ± 0.2) than in the LVP (1.4 ± 0.1) or control (1.4 ± 0.2) children. The SPWMD was significantly larger in the RVP (338 ± 20 ms) than in the LVP (-16 ± 14 ms) or control (-5 ± 35 ms) group, whereas QRS duration was similarly longer in the RVP (157 ± 10 ms) and LVP (158 ± 22 ms) groups compared than in the control group (69 ± 7 ms). The authors conclude that LV function in children is preserved by chronic pacing at the LV lateral wall.Keywords Cardiac function Á Children Á Dyssynchrony Á Pacing Á Site Á Ventricular In children and adults with congenital or acquired atrioventricular (AV) block, the ventricular pacing lead is traditionally positioned at the right ventricle (RV) [16,19]. However, RV apex pacing causes an acute decrease in left ventricular (LV) function in animals [26], adults [6] and children [14,36]. During chronic RV pacing in children, LV function, morphology [30,31], and histology [15] are at risk for deterioration over time (for review see Karpawich [16]). Chronic RV pacing can eventually result in cardiac failure, which occurs in 6% to 7% of children [17,20,38]. Also, in adults, chronic RV apex pacing has deleterious effects (for review see Manolis [19]) and increases the risk of heart failure [1,28].Recognition of the possible harmful effects from RV apex pacing initiated the search for alternative ventricular pacing sites including the RV outflow tract, His bundle, LV wall, and biventricular pacing. Pacing at the His bundle is likely the superior approach [8], but appears to be

Permanent Cardiac Pacing in Children: Choosing the Optimal Pacing Site

“…This study strongly supports previous findings of a retrospective pediatric report 7 showing a decrease in LV function specifically due to RV free wall pacing. Our results also confirm data on preservation of LV function with LV apical or LV lateral wall pacing, [10][11][12][13][14] including a large retrospective pediatric multicenter survey 8 and a recently published experimental study. 22 Our present report does not show any superiority of RV septal over RV apical pacing.…”

“…9 Pediatric pacemaker therapy represents an optimal model for the evaluation of the long-term effects of different pacing sites because, on the basis of surgical preferences and in contrast to adults, various pacing sites are used, including LV epicardial pacing. In small single-center reports [10][11][12][13][14] and a larger retrospective survey, 8 pacing from the LV apex or free wall was associated with better preservation of LV function. The purpose of the present multicenter study was to evaluate the influence of different ventricular pacing sites on long-term LV function in children with nonsurgical atrioventricular block and a structurally normal heart and to search for a mechanism for the difference in pump function between sites by measuring mechanical synchrony and efficiency in a cross-sectional echocardiographic evaluation.…”

Left Ventricular Septal and Left Ventricular Apical Pacing Chronically Maintain Cardiac Contractile Coordination, Pump Function and Efficiency

“…3,4 Experimental and clinical studies indicate that LV pacing sites often render better hemodynamic performance than RV pacing sites. [5][6][7] In a previous acute canine study, we observed hemodynamic benefits by LV septal and LV apical pacing, compared with RV apical pacing, and mixed effects during RV septal pacing. 8 No studies have directly addressed the influence of alternate site pacing on myocardial efficiency.…”

“…However, statistical testing on many variables may lead to Type I errors (falsely positive significant differences), despite correction for multiple comparisons. Despite these potential differences, adverse hemodynamic effects of RV pacing are equally clear in the human 5,7,28 and canine heart. 8,29 Maintaining conduction, contractile coordination, and LV pump function as close as possible to that during normal conduction, as demonstrated for LV septal and LV apical pacing over 4 months, may decrease the long-term risk of developing heart failure.…”

Avaliação da estimulação ventricular direita crônica em crianças e adultos jovens com bloqueio atrioventricular congênito isolado

“…O tratamento desta condição tem sido feito com o uso de medicamentos, pela ressincronização cardíaca e menos comumente por transplante cardíaco 27,50,51 A influência da miocardite intrauterina provocada pelos autoanticorpos maternos, já previamente discutida, é considerada pela literatura como o fator mais importante para a evolução tardia desfavorável dos portadores de bloqueio AV congênito 5,6,71,76,77 . O motivo para a realização deste estudo é porque alguns pacientes portadores de marcapasso cardíaco podem apresentar insuficiência cardíaca (diminuição na força do coração), necessitando de tratamento com medicamentos e até mesmo trocar o tipo de marca-passo.…”