Updated: Jan 25, 2021
The heart is comprised of 4 chambers; 2 atria, which sit on 2 ventricles. An electrical “timekeeper”, called the sino-atrial node, is located at the top of the right atrium. This is the heart’s natural pacemaker, sending out regular electrical impulses that travel through pathways which run down the atria, through the ‘junction box’ of the heart (known as the AV node) and into the ventricles, allowing the heart to contract and relax regularly and pump blood around the body.
Normal Sinus Rhythm
Atrial flutter arises commonly owing to an abnormal ‘circuit’ in the right atrium and can be relatively easily cured by ablating (‘burning’) a small area/region/loci of tissue (termed the "Isthmus") in the heart between the tricuspid valve (TV) and the inferior vena cava (IVC).
Atrial flutter can occur with a variety of conditions, but it also often exists on its own in patients with no other apparent problem. It can be present with atrial fibrillation as well, and it is important to investigate and treat any underlying causes. Like atrial fibrillation, atrial flutter carries a risk of developing life-threatening blood clots and stroke. In at least 50% of patients, no underlying cause is found. Treatment can be by with medication,cardioversion, occasionally a pacemaker and increasingly with catheter ablation. Typical Atrial Flutter Catheter Ablation procedures have high procedural success rates with low concomitant complication rates.
The Figure below depicts the area of interest in the right side of the heart created using 3D Mapping within the heart. The yellow dots depict the normal conduction area of the heart close to the AV node which is marked to know where to avoid ablation energy delivery. The red dots and salmon pink dots depict a straight line delivered in sequential lesions (each dot is one lesion) to create a line of block and disconnect the Right Atrial Flutter circuit.
This figure depicts a 3D map of the heart using a different mapping system. The signals below in the white colour depict the final lesion delivery that led to the quietening of electrical activity within the area of interest and resumption of the regular heart electrical conductivity through normal heart circuit between the atria and the ventricle (turquoise coloured signals at the bottom).