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Old 23-04-2008, 16:17   #5
Salu
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Re: VLF HF LF LF/HF Ratio

Well, there's a lot of background physiology to appreciate before one can fully interpret this data but I'll try to give an overview.

This data is about giving an indication of sympathovagal balance using spectral analysis of the ECG (Electrocardiogram). The R-R interval is a measurement of heart rate. Each beat on an ECG has a PQRST wave. The P wave represents the contraction (depolarisation) of the Atria pushing blood into the ventricles. The R wave represents the depolarisation of the ventricles emptying the heart of blood to pump round the body. The heart rate is calculated by measuring the R-R interval in milliseconds.
A “normal” heart rhythm is called NSR or normal sinus rhythm. However there is a variation of this rhythm called sinus arrhythmia which is purported to be a sign of fitness but may also be suggestive of other diseases.
The HRV (heart rate variability) is a measurement of the variations in the R-R interval.
The HF, LF, VLF and ULF are representative of the processes involved in the symbiosis of the heart beating. It measures the cardiovagal and sympathetic activity and the delay in baroceptor measurement.
The LF/HF ratio is used as an index to measure the sympathovagal balance between these.
However unless you have a good understanding of these figures then you probably aren’t going to find these measurements that useful.

The spikes will probably cause the data to be measured incorrectly. It depends on the error correction that the monitor has built it and for how long you measure it.


Quote:
Data Value Unit
Duration 0:48:54
Sampling Rate R-R Intervals

Energy Expenditure 851 kcal
Number of Heart Beats 7763 beats
Minimum R-R Interval 271 ms (221 bpm)
Average R-R Interval 378 ms (159 bpm)
Maximum R-R Interval 648 ms (93 bpm)
RLX baseline 8 ms
Standard Deviation 31.2 ms
Max/min ratio 2.39
Weighted RR Average 381 ms
SD1 5.4 ms
SD2 43.9 ms
RMSSD 3.4 ms
pNN50 0.0 %

Total power (0.00 - 0.40 Hz) 3260.81 msē
VLF (0.00 - 0.04 Hz) 3247.58 msē (99.6 %)
LF (0.04 - 0.15 Hz) 11.67 msē (0.4 %)
HF (0.15 - 0.40 Hz) 1.56 msē (0.0 %)
LF/HF ratio 746.1 %
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