title: Left Ventricular Mechanical Property Changes During Acute AV Synchronous Right Ventricular Pacing in Children.
abstract: Prolonged RV pacing is recognized as a cause of LV dysfunction due to dyssynchronous activation. There are no specific longitudinal parameters known to help predict RV pacing-induced LV dysfunction. The aim of the study was to assess the acute effects of AV synchronous RV pacing on LV mechanics using echocardiographic speckle tracking. Nineteen children, aged 6-23 years, underwent echocardiographic evaluation prior to and following elective electrophysiology and ablation studies. The subjects were evaluated in sinus rhythm and later with AV synchronous RV pacing at a cycle length of 550 ms with a short AV delay of 80 ms. The echocardiographic clips were analyzed using speckle tracking methods to calculate LV circumferential and longitudinal strain, rotation and twist in all conditions. Acute RV apical pacing decreased LV longitudinal strain from 16.1 ± 3.7% in sinus rhythm to 14.4 ± 3.3% (p = 0.03) and LV base rotation from -8.4° ± 3.6° to -6.4° ± 4.0° (p = 0.04). The circumferential strain, apical rotation and LV twist were not affected. Separate analysis of subjects with no prior preexcitation showed that acute RV pacing caused significant twist reduction, from 15.9° ± 7.6° to 12.1° ± 7.0° (p = 0.02), and decreased longitudinal strain and base rotation. Patients with preexcitation had abnormalities that persisted acutely after ablation. Acute RV apical pacing causes reductions in LV base rotation, longitudinal strain and twist. The recognition of abnormal LV activation patterns may provide longitudinal clues to LV dysfunction in chronically paced patients and potential novel indices of effective CRT interventions to reverse these abnormalities.
authors.affiliation: University of California San Diego, Rady Children's Hospital, San Diego, CA, USA. tegmanya@gmail.com.|The Edmond J. Safra International Congenital Heart Center, Sheba Medical Center, Ramat Gan, Israel. tegmanya@gmail.com.
authors.forename: Shai
authors.initials: S
authors.lastname: Tejman-Yarden
authors.affiliation: University of California San Diego, Rady Children's Hospital, San Diego, CA, USA.
authors.forename: Andras
authors.initials: A
authors.lastname: Bratincsak
authors.affiliation: Department of Biomedical Engineering, The Israeli Institute of Technology - the Technion, Haifa, Israel.
authors.forename: Noa
authors.initials: N
authors.lastname: Bachner-Hinenzon
authors.affiliation: Department of Biomedical Engineering, The Israeli Institute of Technology - the Technion, Haifa, Israel.
authors.forename: Hanan
authors.initials: H
authors.lastname: Khamis
authors.affiliation: University of California San Diego, Rady Children's Hospital, San Diego, CA, USA.
authors.forename: Callie
authors.initials: C
authors.lastname: Rzasa
authors.affiliation: Department of Biomedical Engineering, The Israeli Institute of Technology - the Technion, Haifa, Israel.
authors.forename: Dan
authors.initials: D
authors.lastname: Adam
authors.affiliation: University of California San Diego, Rady Children's Hospital, San Diego, CA, USA.
authors.forename: Beth F
authors.initials: BF
authors.lastname: Printz
authors.affiliation: University of California San Diego, Rady Children's Hospital, San Diego, CA, USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Perry
mesh_terms: D000293:Adolescent; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects / Q000379:methods*; D002648:Child; D004452:Echocardiography / Q000379:methods; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult
keywords: LV mechanics; LV twist; Speckle tracking