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Atrial fibrillation triggered by left foci and atrial flutter

Short summary

p68-year-old male with recurrent asymptomatic paroxysmal atrial fibrillation underwent ablation of the cavo-tricuspidal isthmus. Holter exams showed sinus rhythm with brief and isolated episodes of atrial fibrillation, again with focal trigger. The choices of therapy are rate control, rhythm control, catheter ablation or antithrombotic therapy.

Patient's questions
  1. What are the risks and success percentages of the ablation treatment (some tell the patient 85% and others 70%)?
  2. What instead are the risks of pursuing long-term pharmacological treatment?
  3. Which solution is more indicated in this case?


Medical Background

68 year old male

The patient is a 68-year old man in good health. Family medical history negative for heart disease; never a smoker, plays sports regularly in accordance with his doctor's instructions, and is a member of CAI.
In 2004 with recurring asymptomatic atrial fibrillation. Requested opinion on the pharmacological treatment and whether or not indication exists regarding ablation. The specialist who assessed the case advised anticoagulant treatment and beta blockers if needed, excluding further pharmacological or other remedies at that point.
Currently the patient has provided us with documentation about the tests run in October 2006.
These results show that in October 2005 the patient underwent ablation of the cavo-tricuspidal isthmus. Previous documentation of bilateral dilation with normal left ventricular function. After the procedure the patient continued the treatment with flecainide and anticoagulant, suspended following various dynamic ECGs within the norm. In July 2006 the dynamic ECG detected brief episodes of atrial fibrillation lasting a maximum of two hours with documentation of trigger most likely from right superior pulmonary vein. Well-being and resumption of normal recreational activity since July. Two Holter exams show sinus rhythm with brief and isolated episodes (<5 minutes, one per recording) of atrial fibrillation, again with focal trigger. One echocardiogram within normal limits with left atrium at upper limit of normal. In October 2006 the treatment was flecainide (dosages unknown) and anticoagulant with INR of 2.07, the physical exam was within the norm. The specialist did not suggest pharmacological solutions.
In December 2007 the specialist detected an evolution of the arrhythmia and suggested that a non-pharmacological option of pulmonary vein ablation be considered. In August 2007 a Holter exam documented iterative atrial fibrillation triggered by left foci with brief periods of organization in atypical atrial flutter after the reduction in treatment (flecainide 50 mgx2). After resuming the full dose of flecainide (200 mg/day?) further dynamic ECG showed a reduction in arrhythmic phenomena with sustained atrial fibrillation lasting two hours. Physical exam within the norm, ECG in rhythm (Dec 07).
In January 2008 he visited another cardiologist who advised anticoagulant treatment, Almarytm 1 tab x 2 but excludes indication of antiarrhythmic treatment with Cordarone/Amiodarone and excluded indication for ablation of the atrial fibrillation, considering that the patient is asymptomatic and enjoys a good quality of life (the patient pursues mountaineering with the CAI). Prescribes Holter exam in six months.


Medical opinion

The patient's clinical problem is typical of recurrent paroxysmal atrial fibrillation which is in fact a very common arrhythmia affecting people of different ages, with or without heart problems or otherwise healthy.

In recent years different modalities of treatment have become available allowing better treatment for this affected population, while at the same time has created confusion regarding the best treatment option for them.
The confusion stems from the fact that all these options are considered effective and are accepted by the medical profession (guidlines) ,therefore making difficult for the treating physician and patient himself to choose the right treatment.
In other words, the patient has the right and possibility to choose one of these treatment options according to his needs or preferences.
In this particular case of the patient there are 3 alternative choices of therapy:
1) RATE CONTROL: this mode of therapy has become very popular following the publication of several research medical publications demonstrating the effectiveness of this line of therapy. This modality of therapy implies using (if necessary) medications such as beta-blockers, calcium channel blockers or digoxin in order to control (slow) the heart rate during the paroxysm of atrial fibrillation. This line of therapy is usually chosen for patients who feel well on this treatment and are satisfied with their quality of life.
2) RHYTHM CONTROL: In this line of treatment antiarrhythmic drugs are used in order to prevent further episodes of atrial fibrillation, the patient is presently taken flecainide for this purpose, flecainide apparently decreases the number of episodes of atrial fibrillation but has not been able to completely prevent it (partial success?). Sotalol has been used by the patient in the past without success. Amiodarone is considered the most effective drug against atrial fibrillation, however, we have to consider that amiodarone has a higher incidence of side effects compared to the previously mentioned drugs.
3) CATHETER ABLATION: catheter ablation of atrial fibrillation is also an option, but we have to take into account several facts; first of all, it is an invasive and not a simple procedure and secondly and most importantly the success rate of this procedure is in debate. The success rate depends significantly on the type of atrial fibrillation and also on the experience of the physician performing the procedure. Success rates may vary from below 50% and up to 90% depending on which institution or physician is performing the procedure. If you decide to go ahead with this procedure I strongly suggest that you investigate the results of the group performing the ablation. You also have to consider that there are some potentially serious complications when performing the ablation which can also be life threatening; the incidence of these complications are very low but still present.
4) ANTITHROMBOTIC THERAPY: the continuous use of anticoagulants such as warfarin in the patient's case is also debatable. Recent guidelines suggest that in patients without significant risks factors for embolization (absence of previous thromboembolism, hypertension, heart failure, diabetes, coronary artery disease and age less than 75), treatment with aspirin is sufficient.
In this particular case of the patient we have to consider and emphasize the fact that he is ASYMPTOMATIC, in other words he is not aware of his episodes of atrial fibrillation.
He apparently enjoys a good quality of life.
Considering this fact my opinion and recommendation is to continue his present medical treatment. I believe that flecainide prevents (up to certain extent) further episodes of atrial fibrillation and may prevent the conversion to chronic atrial fibrillation. I am not against stopping the flecainide and pursuing the "rate control" strategy, however, I believe that flecainide is actually preventing some episodes of atrial fibrillation. I am against the use of amiodarone due to his side effects and I strongly recommend not to consider the strategy of catheter ablation, specially in an asymptomatic patient.
Regarding anticoagulation I would continue warfarin (coumadin) since he has been taken it for a long time and apparently tolerates it well.
In my opinion if he is satisfied with his present quality of life I would continue his present medical therapy without further intervention. I would leave the possibility of ablation as the final resort and I would make sure that the procedure is performed in a medical center with vast experience ablating atrial fibrillation.