Electrical and mechanical dyssynchrony in pediatric pulmonary hypertension.
BACKGROUND
Electrical and mechanical dyssynchrony are often seen in patients with left ventricular failure. In pediatric pulmonary hypertension (PH), right ventricular failure predominates; however, the prevalence of electrical and/or mechanical dyssynchrony in these patients is unknown. We examined the prevalence of electrical and mechanical dyssynchrony in pediatric PH patients.


METHODS
Medical records (including, functional status, electrocardiograms and echocardiograms) of pediatric PH patients were reviewed. QRS duration z-scores were calculated to determine electrical dyssynchrony. Echo vector velocity imaging was used to calculate the mechanical dyssynchrony index (DI).


RESULTS
Seventy-seven PH patients (idiopathic pulmonary arterial hypertension [IPAH]: n = 26; congenital heart disease: n = 41; other: n = 10) were studied. Electrical dyssynchrony was seen in 84% (p < 0.01 vs historic controls), with a mean z-score of 4.3 (95% CI 3.5 to 5.1). There was no difference between those with IPAH, z = 3.6 (95% CI 2.5 to 4.6), and those without, z = 4.7 (95% CI 3.6 to 5.8). Mechanical dyssynchrony was seen in 76% of patients (mean DI = 66 ± 47 vs 18 ± 8 milliseconds in historic controls, p < 0.01) in both IPAH and non-IPAH patients. Post-operative congenital heart disease patients had the largest dyssynchrony index. No correlation was found among electrical or mechanical dyssynchrony, hemodynamics or disease severity.


CONCLUSIONS
Significant electrical and mechanical dyssynchrony is present in pediatric PH patients, regardless of etiology. The overall effect of electrical and mechanical dyssynchrony on outcomes in this patient population is still unknown. Select patients may benefit from resynchronization therapy.
Department of Pediatrics, Division of Cardiology, Stanford University Medical School, Palo Alto, CA, USA.
Allison C
AC
Hill
Dawn M
DM
Maxey
David N
DN
Rosenthal
Stephanie L
SL
Siehr
Seth A
SA
Hollander
Jeffrey A
JA
Feinstein
Anne M
AM
Dubin
D000293:Adolescent; D001696:Biomechanical Phenomena; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006330:Heart Defects, Congenital / Q000503:physiopathology; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology*; D007223:Infant; D008297:Male; D012189:Retrospective Studies; D012720:Severity of Illness Index; D018497:Ventricular Dysfunction, Right / Q000503:physiopathology*