"HANG ON. HELP IS ON THE WAY. " >Page 1, 2, 3, 4
Coming advances in cardiac arrhythmias
Ablation
for atrial fibrillation
Radiofrequency ablation has made a huge impact in the treatment for most forms
of supraventricular tachycardia (SVT). With
the ablation technique, the cardiac electrical system is mapped during an
electrophysiology study, the “abnormal” portion of the electrical system
that is responsible for the SVT is carefully mapped, and the offending area is
cauterized (i.e., ablated) through the catheter.
The procedure cures the SVT.
Unfortunately, atrial fibrillation, the most common and the most difficult-to-treat of the SVTs, has proven extremely difficult to ablate. This is because atrial fibrillation is not caused by a single, abnormal area within the electrical system – an area that can then be ablated. Instead, atrial fibrillation is caused by a more general – and impossible to localize – electrical abnormality. However, a new form of ablation (in which a series of linear cauterizations are made instead of one “pinpoint” cauterization) has shown significant promise in ablating atrial fibrillation. This new, “linear” ablation technique is technically very difficult, and initially was not feasible in most electrophysiology laboratories.
Advances in technology, however, are bringing us ever closer to the day when curing atrial fibrillation with ablation procedures is effective and safe. Several ablation systems for atrial fibrillation are now undergoing clinical trials, and it is likely that ablating atrial fibrillation will become routine within the next 2 – 3 years. (Click here for a review of atrial fibrillation.)
Broader
application of the implantable defibrillator
Sudden death from ventricular arrhythmias remains one of the most common causes
of death in developed countries. In
the U.S. alone, approximately 300,000 people die suddenly each year from these
arrhythmias.
The means for preventing these deaths is available – the implantable cardioverter defibrillator, or ICD – but its use has been limited due to its expense. Both the federal government and insurance carriers have refused to pay for ICDs except for those few groups of patients for whom rigorous clinical trials have been conducted showing a significant improvement in overall survival. These trials have been difficult and expensive to perform (at least partly because of the reluctance of doctors to randomize high-risk patients to therapy without the ICD.) Consequently, ICDs are officially “indicated” for only a small minority of patients who have an increased risk of sudden death.
However, several clinical trials are now underway that have the potential of drastically changing the equation. These trials are examining the use of the ICD in broad populations of patients who have coronary artery disease and/or heart failure (these groups of patients account for most of the sudden deaths). Over the next 2 years, the results of these trials will be reported. Most cardiologists predict that when this happens, the ICD will become available for hundreds of thousands of patients who clearly have an increased risk for sudden death but, so far, do not meet the restrictive criteria for ICD implantation.What do you think? Enter the Heart Disease Forum:
