Screening
 
 
Population Screening & Risk Assessment
The evidence that autonomic dysfunction is related to prognostically unfavourable outcomes in a community-based population, initially free of clinically apparent heart disease, is based on several large population-based studies. Although the mechanisms for such patterns are yet not satisfactorily delineated, it is generally accepted that reduced HRV, as a correlate of initial autonomic imbalance, plays a decisive role in the predisposition to future cardiovascular disease. Thus, HRV may provide prognostic information beyond that obtained by the evaluation of "traditional" risk factors in a seemingly disease-free community population1.
   
•

 In the Framingham Heart Study with 2501 subjects (mean age of 53), a one standard deviation decrement of total normal RR intervals was associated with a hazard ratio of 1.47 for new cardiac events2.
   
•

 Lower HRV correlates with all-cause mortality risk in a population apparently free of coronary disease or congestive heart failure3.
   
•

 In middle-aged and elderly men, low HRV is predictive of mortality from all causes (indicator of "compromised health" in general population) as shown in the Zutphen-Study in the Netherlands4.
   
•

 Altered cardiac autonomic activity / lower parasympathetic activity is associated with the risk of developing coronary heart disease5.
   
•

 An association between reduced HRV and risk for all-cause mortality was demonstrated in elderly participants in the Framingham Heart Study6.
   
•


 Behavioural and environmental patterns including alimentary influence or smoking play an important role in shaping the HRV of the individual. E.g., hypercholesterolemia is associated with a decreased HRV in men with and without ischemic heart disease7.
   
•

 Smoking cessation is associated with an increase in HRV. Interestingly, a higher HRV was observed in smokers than non-smokers after acute myocardial infarction under the condition of smoking cessation8.
   
•

 Inheritable factors may explain a substantial proportion of the variance in HRV as shown in the Framingham Heart Study9.
 
Occupational health
   
•


 Analysis of HRV also has a clinical role in occupational health: e.g., when exploring elevated cardiovascular risk in shift workers10 or in evaluation of associations between ambient pollution levels and cardiovascular function11 or measurement of cardiac risk in pilots.
 
Home-based monitoring /activities
   
•


 The rapidly growing area of home-based distance monitoring, not only motivates the patients to become more active in their own health care, but also it has the potential to lower health care related costs. This is further enhanced using up-to-date medical & communication technologies12.
   
•

 It has been shown that home-based physical training, in co-operation with a supervising physician, improves exercise capacity and parameters of HRV in chronic heart failure13.
 
References/Screening & Sports:

1. Yap YG, Camm AJ: Clinical perspective, in In Clinical guide to cardiac autonomic tests, Malik M (ed). Dodrecht/Boston/London: Kluwer, 1998.
2. Tsuji H et al: Impact of reduced heart rate variability on risk for cardiac events: The Framingham Heart Study. Circulation 1996; 94/11: 2850-2855.
3. Whitsel EA et al: RR- interval variation, the QT interval index and risk of primary cardiac arrest among patients without clinically recognised heart disease. Eur Heart J 2001; 22: 165-173.
4. Dekker JM et al: Heart rate variability from short electrocardiographic recordings predicts mortality from all causes in middle-aged and elderly men. The Zutphen Study. Am J Epidemiol 1997; 145/10: 899-908.
5. Liao D et al: Cardiac autonomic function and incident coronary heart disease: A population-based case-cohort study: The ARIC study. Am J Epidemiol 1997; 145/8: 696-706.
6. Tsuji H et al: Reduced heart rate variability and mortality risk in an elderly cohort: The Framingham heart study. Circulation 1994; 90/2: 878-883.
7. Christensen JH et al: Heart rate variability and plasma lipids in men with and without ischemic heart disease. Atherosclerosis 1999; 145(1): 181-6.
8. Nishiue T et al: Higher heart rate variability of smokers after acute myocardial infarction. Int J Cardiol 1999; 68(2) : 165-9.
9. Singh JP et al: Heritability of heart rate variability: The Framingham Heart Study. Circulation 1999; 99/17: 2251-2254.
10. Van Amelsvoort LG et al: 24-hour heart rate variability in shift workers: Impact of shift schedule. J Occup Health 2001; 43 (1): 32-38.
11. Gold DR et al: Ambient pollution and heart rate variability. Circulation 2000; 101: 1267-1273.
12. Balas EA et al: Distance technologies for patient monitoring. British Med J 1999; 319:1309.
13. Tygesen H et al: Intensive home-based exercise training in cardiac rehabilitation increases exercise capacity and heart rate variability. Int J Cardiol 2001; 79: 175-82.
 
 
All material contained within this website is copyrighted to Advanced Medical Diagnostic Group Limited.
VariaCardio® and VariaPulse are registered trademarks of AMDG Ltd. This product is protected by patents owned by AMDG Ltd.

Manufactured for AMDG by MIE Medical Research Ltd (an ISO13488 accredited company). AMDG and MIE Research Ltd reserve the right to amend specifications without notice in accordance to their policy of continual product improvement.
 
© 2001-5 Advanced Medical Diagnostics Group Ltd. All Rights Reserved.
 

AMDG Ltd, 6 Wortley Moor Road, Leeds, LS12 4JF
Tel: +44 (0) 113 279 1010 Fax: +44 (0) 113 231 0820