‘Icosa-’ instead of ‘duodeca-’: the meaning of words matters

We have read with great interest the article by Knecht et al.,¹ recently published in the Journal, in which the Authors investigate the relationship between the bipolar voltage amplitude of the left atrium, using four catheters with different electrode design, in order to identify their specific cut-offs for scar and healthy tissue, in patients with atrial fibrillation.

In the paper, one of the catheters used has 20 poles and is described, in the Methods section, as ‘a duo-decapolar variable circular mapping catheter (Lasso 2515 variable mapping catheter, electrode size 1 mm, interelectrode spacing 2–6–2 mm, Biosense Webster, Diamond Bar, USA)’; in the text, there are also other occurrences of the term ‘duo-decapolar’, to refer to another catheter with 20 electrodes, the Pentaray from Biosense Webster.¹

It is quite common to read the adjective ‘duo-decapolar’ (or ‘duodecapolar’) in electrophysiological publications, to indicate 20-pole diagnostic catheters. In addition, several diagnostic catheters from different brands are named ‘duo-decapolar’ in some official catalogues, when having 20 electrodes.

It is worth noticing that ‘duo-deca’ represents a variant for ‘dodeca’, a prefix of greek origin meaning ‘12’.

It is possible that the prefix ‘duo-deca’ to indicate ‘20’ has become so widespread in scientific papers^2,3 and also in marketing because it can resemble ‘two-times-deca’, evoking in this way the quantity of 20. It is also possible that this inappropriate use of the prefix is favoured by the fact that often the poles are paired in dipoles, so that ‘duo-deca’ could be misinterpreted as ‘ten dipoles’.

However, in our opinion, as it is standard the use of a numerical prefix to indicate the precise number of electrodes of a catheter (e.g. octapolar, hexapolar, etc.), it would be more appropriate to use the term ‘icosapolar’ (or ‘eicosapolar’) to designate catheters with 20 poles. The greek prefix for 20, in fact, is ‘icosa-’(a variant being ‘eicosa-’), and it is also indicated in this way in the International Union of Pure and Applied Chemistry nomenclature for multiplying affixes.⁴ Moreover, there are few papers in the literature that correctly refer to 12-pole catheters as to ‘duodecapolar’⁵ and to 20-pole catheters as to ‘eicosapolar’⁶ catheters.

We believe that this issue does not represent a sterile argument, nor a futile classicists’ debate, but should be part of a required effort for science to be clear, precise, and unambiguous at every level. Manufacturers should pay more attention when giving names to the products and also scientists should not passively replicate those errors, making them become commonly used.

References

Author notes