Assessment of Diastolic Function in Single-Ventricle Patients After the Fontan Procedure.
Patients with functional single ventricles after the Fontan procedure have abnormal cardiac mechanics. The aims of this study were to determine factors that influence diastolic function and to describe associations of diastolic function with current clinical status.



Echocardiograms were obtained as part of the Pediatric Heart Network Fontan Cross-Sectional Study. Diastolic function grade (DFG) was assessed as normal (grade 0), impaired relaxation (grade 1), pseudonymization (grade 2), or restrictive (grade 3). Studies were also classified dichotomously (restrictive pattern present or absent). Relationships between DFG and pre-Fontan variables (e.g., ventricular morphology, age at Fontan, history of volume-unloading surgery) and current status (e.g., systolic function, valvar regurgitation, exercise performance) were explored.



DFG was calculable in 326 of 546 subjects (60%) (mean age, 11.7 ± 3.3 years). Overall, 32% of patients had grade 0, 9% grade 1, 37% grade 2, and 22% grade 3 diastolic function. Although there was no association between ventricular morphology and DFG, there was an association between ventricular morphology and E', which was lowest in those with right ventricular morphology (P < .001); this association remained significant when using Z scores adjusted for age (P < .001). DFG was associated with achieving maximal effort on exercise testing (P = .004); the majority (64%) of those not achieving maximal effort had DFG 2 or 3. No additional significant associations of DFG with laboratory or clinical measures were identified.



Assessment of diastolic function by current algorithms results in a high percentage of patients with abnormal DFG, but few clinically or statistically significant associations were found. This may imply a lack of impact of abnormal diastolic function on clinical outcomes in this cohort, or it may indicate that the methodology may not be applicable to pediatric patients with functional single ventricles.
Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts. Electronic address: renee.margossian@cardio.chboston.org.
Renee
R
Margossian
New England Research Institutes, Watertown, Massachusetts.
Lynn A
LA
Sleeper
National Heart, Lung, and Blood Institute, Bethesda, Maryland.
Gail D
GD
Pearson
Duke University Medical Center, Durham, North Carolina.
Piers C
PC
Barker
The Hospital for Sick Children, Toronto, Ontario, Canada.
Luc
L
Mertens
The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania.
Michael D
MD
Quartermain
University of Utah, Salt Lake City, Utah.
Jason T
JT
Su
Medical University of South Carolina, Charleston, South Carolina.
Girish
G
Shirali
New England Research Institutes, Watertown, Massachusetts.
Shan
S
Chen
Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts.
Steven D
SD
Colan
D000293:Adolescent; D015984:Causality; D002648:Child; D004452:Echocardiography / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D018729:Fontan Procedure / Q000706:statistics & numerical data*; D006330:Heart Defects, Congenital / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D006801:Humans; D015994:Incidence; D008297:Male; D009656:North America / Q000453:epidemiology; D011183:Postoperative Complications; D012307:Risk Factors; D013318:Stroke Volume; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000517:prevention & control
Congenital heart disease; Diastolic function; Fontan; Single ventricle