Influence of atrial flutter ablation on right to left inter-atrial conduction

Abstract

Aims Ablation of the atrial isthmus between the tricuspid annulus and the inferior vena cava changes P-wave morphology during low lateral right atrial pacing. For better understanding of the mechanism of this alteration, the sequence of activation of the inter-atrial septum and the left atrium were compared before and after ablation of the isthmus between the inferior vena cava and the tricuspid annulus. Methods and ResultsIn 13 patients, left atrial mapping was performed using a duodecapolar electrode catheter advanced to the far distal coronary sinus. The inter-atrial septum was mapped using a right atrial duodecapolar electrode catheter. Conduction times were measured during low lateral right atrial pacing from the pacing artefact and during sinus rhythm from the earliest right atrial electrogram to every intra-cardiac electrogram before and after the ablation. During low lateral right atrial pacing, isthmus ablation resulted in a significant delay in every left atrial lead. Changes were maximal at the posterior aspect of the left atrium and minimal at its anterior aspect. No significant change was discernible on the inter-atrial septum. During sinus rhythm, atrial activations remained unchanged.Conclusion Electrocardiographic changes of P-wave morphology result from alteration in the sequence of left atrial activation rather than that of the inter-atrial septum.

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

“…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.…”