What a trouble it is!
As a disease that associates with wear and tear, aging, obesity, sleep disorders, high blood pressure and inflammation, it’s no wonder the incidence of atrial fibrillation continues to rise.
AF represents a huge health problem. For the individual patient, it can cause life-altering symptoms, increase the risk of stroke or weakened heart muscle and perhaps most troublesome: AF exposes patients to perilous treatments. It brings patients closer to doctors–which is always a risky proposition. For the healthcare system, AF treatment has grown more complex and expensive. There is both under-treatment, which leads to excessive disability from stroke and heart failure, as well as over-treatment, which leads to therapeutic misadventures too numerous to list here. There is a huge knowledge gap on how best to treat this disease.
Over the last decade, catheter ablation has offered patients with AF that won’t go away with medicines or lifestyle changes an opportunity for symptom relief. I’ve written many times about ablating AF. In brief, catheter ablation of AF entails electrically isolating areas of the atria (most often the muscle sleeves surrounding the pulmonary veins). The energy source most often used is radiofrequency energy–a burn. The problem with using RF energy to make electrical lines of block in the atria is that it’s hard to draw a line with dots. An electric fence made with dots tends to have gaps. And these gaps lead to reconnection of the veins and the need for redo ablation procedures.
So investigators, in Europe first, began experimenting with the use of freezing tissue rather than burning. Cryoballoons were developed that could be placed in the orifice of a pulmonary vein. Then, with a single freeze, an entire ring of ablation isolates the vein. Rather than making 20-30 encircling point RF lesions, a single freeze electrically isolates the vein.
Small observational trials and then one big randomized controlled trial (STOP-AF) reveal cryoballoon ablation compares favorably (in safety and efficacy) to RF ablation in patients with intermittent AF. (Though there have been no large trials comparing the technologies head-to-head.) The FDA approved the cryoballoon system and the technique has taken off in the US.
But with any procedure comes risk. Recently, you may have seen Dr Wes’ report on procedural deaths from cryoballoon ablation.
About 6 months ago, after an extensive (and I mean extensive) learning process, I began doing cryoballoon ablation. Why would I change a perfectly well-practiced RF ablation procedure? What are the safety issues? What about efficacy? How does the new generation cryoballoon compare with the first generation? What’s the take home on freezing versus burning?
I hope you want to read more over at theHeart.org. Here is the link:
How safe is cryoballoon ablation of atrial fibrillation?
JMM