Volume 1 number 1 Summer 2003
Special issue for the abstracts of the 7th Pan Arab Conference on Diabetes
PACD7 , 25 – 28 March 2003 Cairo

Abstract Number : 43
TIME DOMAIN AND POWER SPECTRAL ANALYSIS OF HEART RATE VARIABILITY FOR ASSESSMENT OF DIABETIC CARDIAC AUTONOMIC NEUROPATHY

Fadia Mahmoud M.D., Mona Atteya M.D.,
Ghada Anawar M.D. and Rania Hegazy M.Sc.

Cardiology Unit and Diabetic Endocrine Metabolic Pediatric Unit (DEMPU)
Children's Hospital, Cairo University

OBJECTIVES:
The purpose of the study was to assess relevant information that could be provided by time domain and frequency domain analysis of heart rate variability in diabetic cardiac autonomic neuropathy (DCAN) as well as to compare them to the standard Ewing battery of cardiovascular reflexes. 

RESEARCH DESIGN AND METHODS:
Forty diabetic children and adolescents with a mean age of 13.2+/-4.8 years were selected from DEMPU for assessment of their cardiovascular autonomic impairment. The studied groups were compared to forty aged and sex matched controls. HRV was assessed using time domain analysis, power spectral analysis and phase space plot by computerized analysis of short-term heart rate samples (512-1024) using Schiller Cardiovit at 60. HRV was compared to standard cardiovascular reflexes.

RESULTS:
Diabetics showed significant decrease in the mean value of different parameters of RR tacchogram namely SDRR, MSRR, average dRR, SDdRR, MSDdRR and PNN50 (p>0005).
The studied group showed marked decrease in HF with mild decrease in LF Narrower degree of dispersion of phase plots was present in diabetics. HRV values had significant negative correlation with HBA1c, age of the patients, duration of diabetes and puberty. CVR tests were normal in 25 out of 40 patients (62.5%), 9 out of 40 (225%) patients had early involvement 3 out 40 patients (7.5%) had definitive involvement and 3 out of 40 patients (7.5%) had severe involvement. HRV was significantly lower in-patients with abnormal CVR tests. Moreover these parameters worsened significantly as the severity of autonomic neuropathy increased as assessed by CVR tests.

CONCLUSION:
HRV proved to be the early marker of diabetic autonomic deterioration before its clinical expression. Time domain and frequency domain analysis of HRV can discriminate between different degree of parasympathetic and sympathetic involvement. HRV offers a picture of overall autonomic activity that can be explored only partially by traditional CVR tests.
We recommend the installment of HRV as a routine procedure for early detection and proper follow up of DCAN in our outpatient clinic.

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