I suggest you start by reading the 'Task Force paper':

URL of task force paper: http://circ.ahajournals.org/content/93/5/1043.full

Heart Rate Variability

Standards of Measurement, Physiological Interpretation, and Clinical Use

Task Force of the European Society of Cardiology the North American Society of Pacing Electrophysiology

Correspondence to Marek Malik, PhD, MD, Chairman, Writing Committee of the Task Force, Department of Cardiological Sciences, St George’s Hospital Medical School, Cranmer Terrace, London SW17 0RE, UK.

This link is the article mentionned above: http://eurheartj.oxfordjournals.org/content/17/3/354.long

So far it is the most complete and perhaps comprehensive review about the subject. As far as I know there have been no other efforts to standarise measurements. In the appendix you will find some "normal" values, mostly useful for time-domain variability.

You can read some of my papers :)

There is an interesting and useful i phone app called "ithlete" which combines a heart rate belt with a very useful algorothm which analyses Heart rate variability. The authors use this as an index of fitness and overtraining but it has considerable potential for use in cardiology.

If you are interested also in the HRV methods generally there are many useful reviews like:

ACHARYA, U. R., K. P. JOSEPH, N. KANNATHAL, Ch. M. LIM a J. S. SURI. Heart rate variability: a review. Medical. 2006, vol. 44, issue 12, p. 1031-1051. DOI: 10.1007/s11517-006-0119-0. Dostupné z: http://link.springer.com/10.1007/s11517-006-0119-0

It contains also some reference values for linear time domain methods and frequency domain methods. And it is a really good review.

For some values you can try to look also on this study about age dependence in HRV:

VOSS, A., A. HEITMANN, R. SCHROEDER, A. PETERS a S. PERZ. Short-term heart rate variability—age dependence in healthy subjects. Physiological Measurement. 2012, vol. 33, issue 8, p. 1289-1311. DOI: 10.1088/0967-3334/33/8/1289. Dostupné z: http://stacks.iop.org/0967-3334/33/i=8/a=1289?key=crossref.219a8d67b4ce4cf0bb323795b1dc6e03

It also has some overview on the methods.

We have linear and non linear methods for analysis of HRV. Before of all we have to start with a good recording of the signal. Time and frequency indexes mauy be applied soon after.

Note that R-R is a non linear , non stationary and non periodic signa. Also non linear methodlogies are required for its analysis

Please visit the site www.saistmp.com to have details

Sorry colleagues if I insert you considerationas that apparently do not link the posed question. I retain it may be of interest.

I am not here to outline you the importance of the HRV current studies and I have not to remember you that the current linear or non linear methodologies are not completely satisfactory. Of course every day we find papers published also in valuable international journals that continue to use standard linear indexes and FFT or DFT for their clinical investigations and conclusions. Non linear methodologies have their valuable content also if currently they still do not find a continuous clinical appreciation. Usually three bands are considered in the frequency domain , as you well know, the VLF, the LF , and the HF for short 5-6 minutes recording. We need to remain in this framework, we need to use such bands for our estimations but my modest opinion is that the basic methodology as well as the physiological setting need to be advanced. This is the reason because we have studied for several years a new method, called the CZF method. We have verified, however, that such method, although of great interest, results of difficult interpretation for some clinicians. Consequently we have elaborated a new method, the new CZF version , that , in addition to the rigour of the previous formulation , gives results that give immediate clinical interpretation.

The method as well the software for your experimentation are given in our site www.saistmp.com Consequently I invite all you to visit the site and go to use such new method in your experimental as well as clinical conditions and verify directly its interest. The present software is the primary elaboration. Within a brief time we will give the complete version responding to all the formulation of the method. All the researchers that , at this time, will result using currently such new CZF method will receive obviously automatically the updates.

A final question. We have experienced the method on a large number of subjects and in some different pathological conditions. Consequently don’t hesitate to contact me if you need help, suggestions, questions, previous results that may help you in your use of the method.