Exponential distribution of long heart beat intervals during atrial fibrillation and their relevance for white noise behaviour in power spectrum

The statistical properties of heart beat intervals of 130 long-term surface electrocardiogram recordings during atrial fibrillation (AF) are investigated. We find that the distribution of interbeat intervals exhibits a characteristic exponential tail, which is absent during sinus rhythm, as tested in a corresponding control study with 72 healthy persons. The rate of the exponential decay lies in the range 3-12 Hz and shows diurnal variations. It equals, up to statistical uncertainties, the level of the previously uncovered white noise part in the power spectrum, which is also characteristic for AF. The overall statistical features can be described by decomposing the intervals into two statistically independent times, where the first one is associated with a correlated process with 1/f noise characteristics, while the second one belongs to an uncorrelated process and is responsible for the exponential tail. It is suggested to use the rate of the exponential decay as a further parameter for a better classification of AF and for the medical diagnosis. The relevance of the findings with respect to a general understanding of AF is pointed out

[Important changes in the Dutch College of General Practitioners (NHG) practice guideline 'Atrial fibrillation': revised practice guideline issued]

Item does not contain fulltext- A small number of points in the NHG practice guideline 'Atrial fibrillation' have been reviewed; this has important consequences for general practice. - The risk of ischaemic CVA in patients with atrial fibrillation is determined using a new risk score (CHA2DS2-VASc).- The target value of the resting ventricular frequency has been increased from a maximum of 90 to a maximum of 110 beats per minute. - Oral anticoagulants are indicated in almost all patients aged 65 years and older with atrial fibrillation; the only group in whom antithrombotic medication is not indicated is men under the age of 75 with no cardiovascular comorbidity. - Acetylsalicylic acid for the prevention of thrombo-embolism is only indicated if oral anticoagulants are contra-indicated. - The new oral anticoagulants (NOACs) have very limited use in the prevention of a thrombo-embolism in general practice