Int J Cardiol. 2009 Jan 26. [Epub ahead of print]
Lammers
AE, Munnery
E, Hislop
AA, Haworth
SG.
INTRODUCTION: Objective risk stratifiers are required to assess need for escalation of
medical therapy or listing for transplantation in children with pulmonary
arterial hypertension (PAH). We aimed to assess whether heart rate variability
(HRV) predicts outcome in children with severe PAH. PATIENTS AND METHODS:
Parameters of HRV [SDNN = standard deviation of normal-to-normal intervals,
SDANN = standard deviation of mean values for normal-to-normal intervals over 5
min, and RMSSD = square root of the mean square differences of successive RR
intervals] were determined from Holter electrocardiograms of 47 patients (27
male; mean age 11.4+/-5.5 years) with PAH (idiopathic PAH n=21; associated PAH
n=26). HRV was assessed in relation to WHO Functional Class,
six-minute-walk-test, echocardiographic and haemodynamic data, and as a predictor of death or lung transplantation.
RESULTS: The mean follow-up period was 19+/-11.5 months (1.8-49.1 months). Ten
patients died and 7 underwent transplantation and these children had
significantly lower values of HRV [SDANN (70.7+/-30.9 vs. 119.2+/-57.2), SDNN
(79.5+/-30.5 vs. 129.9+/-63.6), and RMSSD (22.+/-11.7
vs. 47.7+/-34.5); p<0.001 for all]. On univariate
Cox-proportional-hazards analysis all parameters of HRV predicted death or
transplantation (p<0.05). SDANN and SDNN were also predictive of mortality
alone (p<0.05). On bivariate analysis SDANN and
SDNN predicted outcome independently of functional status, syncope, right
ventricular function, and haemodynamic parameters.
CONCLUSIONS: HRV is a useful, non-invasive means of predicting a poor outcome
and hence need to escalate therapy in children with PAH.
PMID: 19176261 [PubMed - as supplied by publisher]