Once a person has been returned to sinus rhythm, can efforts be made to keep the person ‘on track’ in normal rhythm, remembering that currently atrial fibrillation can’t be cured?

The short answer is, “Yes”.

However, there are several factors that drive our decision:

•    unacceptable symptoms,
•    age (the younger the person is the more likelihood of success), and
•    the structure of the heart, in particular the left atrium.

There are also a number of considerations that need to be kept in mind when making the decision:

1)    We want to keep people in normal rhythm to reduce symptom load so that they feel better.
2)    We understand that our rhythm control treatments are moderately
effective most of the time, but we rarely have a perfect result.
3)    We accept that, as there is no cure, we are looking to reduce the rate
of recurrence and the time people are in atrial fibrillation.
4)    If we are dealing with one agent, then it is possible that we may need to add in another therapy or we may need to swap therapies to achieve some reduction in the time the person is in atrial fibrillation.
5)    Our medications can generate rhythms of their own (be proarrhythmic) and this can be a problem.
6)    We need, always, to try to ensure that we are balancing therapy
safety with effectiveness.

With this in mind then, what are the steps we can undertake to try to maintain sinus rhythm in a person who has atrial fibrillation?

reversible factors

The first important thing to do is to address the reversible factors.
If the patient is significantly overweight, we want to improve that immediately. We know that weight has an impact on the way atrial fibrillation will recur. Very importantly, weight also has a very big impact on obstructive sleep apnoea or paused breathing while asleep at night. If obstructive sleep apnoea is present this needs to be addressed as the heart comes under a significant load if oxygen is not getting around the body properly.

If alcohol is central to triggering atrial fibrillation, we would encourage the patient to understand how alcohol intake can impact on the recurrence of AF. We would also check blood pressure and thyroid function and, encourage the patient to exercise and to manage diabetes or other medical conditions.

medications

Having addressed these reversible lifestyle factors, we then consider medications.

My practice is to use beta-blockers as a first-line therapy. These are broadly available and, on the whole, they seem to be well-tolerated for their effectiveness. A number of guidelines do not necessarily support the use of beta-blockers for maintaining sinus rhythm but, clinically, I repeatedly see patients who achieve long, symptom-free periods while using beta blockade. They are relatively safe, and my clinical experience suggests they are effective in a wide range of people, particularly those whose atrial fibrillation can be brought on by emotional triggers.

For those people for whom beta-blockers are not ideal, I will often use a calcium channel blocker, particularly in patients whose ECG monitoring shows extra atrial beats. For some reason, they seem to respond very well to verapamil. Again, current guidelines do not necessarily support this as a therapy for the maintenance of sinus rhythm. However, I observe that these agents can be beneficial for certain individuals. I know cardiologist colleagues who have had similar experiences.

If beta-blockers and calcium channel blockers are not working, or are not particularly well-tolerated, I might prescribe flecainide. Generally, I will use flecainide with a little bit of beta blockade, hoping for some effectiveness from both agents without pushing either agent too hard. Keeping doses as low as possible can reduce the possibility of side-effects while receiving benefit from two agents with two different actions.

If I use flecainide without a beta-blocker or without a calcium channel blocker, I will often use it with a small amount of digoxin. This is because we know that flecainide can increase the conduction of electricity through the AV node17 which may increase the rate responsiveness of the atrial fibrillation for the individual should that person go back into AF.

Agents such as amiodarone, dronedarone and sotalol can also be used. They are more powerful agents, the next step up. These agents need to be closely monitored and regular ECGs are an important part of management.

electrophysiological ablation

Lastly, in very specific cases, for example for younger patients who
•    are quite symptomatic with atrial fibrillation,
•    have a fairly normal looking heart, structurally,
•    fail control on a beta-blocker and, say, flecainide, or
•    are now progressing to using a next line agent such as amiodarone or sotalol in the longer term,

I would next consider an ablation of atrial fibrillation using electrophysiological technologies. This modifies the atria in such a way that we alter the threshold of atrial fibrillation. My experience is that it is a really good way of achieving ongoing management and maintenance of sinus rhythm in the longer term.

It is really important, however, to understand that EP ablation is not a cure, nor is it for everyone. Used for the right patient, AF is less likely to redevelop quickly and it can provide up to several years of symptom-free sinus rhythm. I tend to combine it with a small dose of the beta-blocker or calcium channel blocker.

what is electrophysiological ablation?

Electrophysiological ablation is another method used to restore and maintain sinus rhythm. Electrophysiological simply means pertaining to the electrical function of the heart; ablation means destruction or removal.

Highly-trained cardiology specialists, electrophysiologists, who have a very detailed understanding of the electrics of the heart, perform the procedure.

As we have seen, electrophysiological ablation becomes a possible treatment when lifestyle modifications, together with a drug regime, do not effectively control symptomatic AF.

There are muscle cells that make up the left atrium called atrial myocytes. It would seem that protrusions of these myocytes can be found in the pulmonary veins as a consequence of embryological development during the formation of the atrium while in the womb. The problem is that these extensions of muscle cells into the vein are not meant to be there. As these cells are out of their usual location, in the veins, they are not subject to the same regulatory factors. This means that they can fire off intermittently and create a disturbance within the electrical milieu of the left atrium, thus creating a focus for the development of atrial fibrillation.

Electrophysiological ablation separates those cells in the veins from the cells within the left atrium.

Imagine one of the pulmonary veins coming into the left atrium. We ‘ring-bark’ it, literally separating the cells within the pulmonary vein which may be exciting the cells in the left atrium causing erratic and chaotic activity.

This ‘ring-barking’ is called pulmonary vein isolation.

There are increasingly more clever techniques becoming available but essentially pulmonary vein isolation is a catheter technique. A long tube, or catheter, is used, along with radiofrequency, freezing or burning techniques, to damage the pulmonary vein tissue in a ring-like formation. The resultant scarring separates the misbehaving cells in the vein from the cells that are in the left atrium, leaving these cells, hopefully, to move together in an orchestrated way.

Of my patients, about 70 to 80 percent have a very successful result so that in the long-term they do well. Maybe five to 10 percent of patients will require a repeat procedure. Who goes for a second visit, the time frame and in what circumstances, are dependent on the patient’s specific situation and the experience of the doctor. The person’s symptoms must be weighed against the risk of the procedure and the risk associated with the underlying condition.

Electrophysiological ablation is a tremendous technology.

We tend to use it only for patients who are younger and/or who are symptomatic of atrial fibrillation, as well as those whose hearts are relatively structurally sound. If the heart is significantly unsound structurally, the chance of success is markedly reduced.

As with every procedure, there are risks. Major complications of EP ablation are quoted at between 1-in-5000 to 1-in-10,000. So this is an important conversation to have with your doctor to ensure it is right for you.

A CLOSER LOOK
EP ABLATION PROCEDURE

The left atrium is quite deep in the body. The proceduralist generally gains access to the venous system in the leg and then passes a special catheter up to the right side of the heart. That catheter will cross between the atria, through the atrial septum from the right side to the left side and then, by rather impressive manipulation, the catheter is placed into each of the four pulmonary veins. A circumferential derangement of the cells, burning or freezing, or ablation, is performed. The procedure can take several hours.

The electrophysiologist has some tools for guidance. A CT scan of the left atrium gives a visual of exactly the shape and placement of those pulmonary veins. Generally, the patient will be on an anticoagulant at that time because if we are deranging those cells we are creating ‘rough spots’ in the veins, and those ‘rough spots’ could be a focus for the formation of a clot.

Although it sounds complicated, the patient often leaves hospital the day after the procedure. Its specialist nature, however, means that it is not performed in all cardiac units. For example, patients in Tasmania where I practise currently travel to Melbourne to have the procedure.

CASE STUDY – TONY
athlete who progresses to EP ablation

When I first met him, Tony was a very fit and very active 58-year-old man who had spent his life in the pursuit of fitness. He was an endurance athlete, a very high-level swimmer, runner, cyclist and a rower. He had participated at the top levels of his sports for many years. He still trained every day, often for several different events. Tony had quite a lot of stress at work and was having a difficult time with ‘restructuring’.

I first saw him a number of years ago when he was having episodes of atrial fibrillation between six and 12 months apart. When there was more stress at work, his atrial fibrillation was more frequent. This is a recurring story, not just for Tony.

With regard to the management of his overt, paroxysmal atrial fibrillation, when we looked at his predicted risk of stroke based on his CHA₂DS₂-VASc score, he scored zero, which is a low risk. This measurement considers cardiac failure, hypertension, age, diabetes and other factors that could increase a person’s risk of an AF-related stroke. As Tony’s score was zero and his symptoms waxed and waned with changes with his work, I put him on low dose aspirin. I also prescribed him a ‘pill in the pocket’ which was a number of tablets that he could take when an episode occurred so that his heart would slow, giving it a chance to return to normal rhythm. It worked well for him.

Over the next year or two, the work situation settled, and his atrial fibrillation episodes became less frequent.

Several years later, however, having established an alternate career, and with all things going well in his life, Tony presented with the recurrence of episodes of atrial fibrillation. This time, the occurrences were more frequent, more intense and clearly interrupting his daily living, particularly his exercise. These episodes were not related to stress. They represented the progression to an increased propensity to develop atrial fibrillation with time and age.

A decision was taken that he should have an EP ablation of his atrial fibrillation, to maintain normal rhythm. Using special catheters placed in the heart, a highly-trained specialist in a major hospital performed a pulmonary vein isolation procedure, a way to ‘ablate’ atrial fibrillation. This went very well.

Since then, he’s been essentially free of atrial fibrillation.

We chose that particular approach because he had had intolerances or difficulties with different drugs and as an athlete, he was keen to remain drug free if possible.

Although Tony presented some challenges to management, he is doing well. His work situation is good and, for the moment, his atrial fibrillation is only a memory. I keep an eye on him because we know there is a reasonable chance that, as he ages, the condition will return. For the moment, though, it’s a matter of time and a matter of surveillance.

ANSWERING AN IMPORTANT QUESTION
CAN I USE SUPPLEMENTS OR COMPLEMENTARY PRACTICES?

SUPPLEMENTS

Many of my patients are interested in using supplements. Is this wise?

When it comes to atrial fibrillation, there is not much data available. Some studies have looked at magnesium and others at fish oil in the setting of post-operative cardiac surgery and found no benefit.

Having said that, I do not have a problem with my patients using magnesium as it seems to dampen atrial and ventricular ectopic beats for some and has also been shown to help keep blood pressure down.

Fish oil is fairly commonly used for joints and general health. Currently, there are no good studies to suggest it has an impact on AF. However, research tells us that omega 3 oils can stabilise the membrane of heart cells, so it should help.

Can fish oil help reduce heart attacks and death?

Although the fairly recently released ASCEND18 trial suggested, in a fairly low risk group of individuals, that fish oil made no difference, there have been a number of studies that suggest it is beneficial. These include the recently published REDUCE-IT19 trial in which good doses of fish oil were given to high risk patients who had high triglyceride levels. Chat with your doctor about this situation.

Does fish oil increase bleeding?

In my hospital, many of the surgeons caution their patients not to take fish oil before surgery, although for doses of up to three or four grams per day studies have not shown any increase in the risk of bleeding or an impact on bleeding even if on warfarin. However, if my surgeon asked me to stop a supplement before surgery, I’d take the advice.

For daily living, I am happy with my patients eating oily fish or taking fish oil. I take some fish oil daily and eat oily fish once a week for my joints, with the feeling that it is probably a good thing for my heart.

As for any other supplements, I tell my patients to check with someone who has expertise and experience using supplements to ensure that they are not taking something that may interfere with their mainstream medications.

COMPLEMENTARY PRACTICES

Exercise regularly. Modest regular exercise will alter cardiovascular risk and with that, the likelihood of developing AF. So, please, try to keep active.

An interesting study has been undertaken by the University of Kansas Hospital. The researchers investigated the impact of yoga on atrial fibrillation20. They took a group of patients and followed them for three months as a baseline, and then started a twice weekly yoga regime with home practice. Comparing the before and after, yoga reduced the rates of AF by nearly 40 percent. Isn’t that fantastic!

So, if you have AF, don’t be surprised if your doctor tells you to take a deep breath and relax. Your medical practitioner is quoting evidenced- based medicine.

IMPORTANT POINTS    
STAYING IN SINUS RHYTHM

•    Although there is no cure for atrial fibrillation, some patients can be kept in sinus rhythm for years.
•    Factors contributing to the decision to keep the patient in normal rhythm include
-    the unacceptable nature of the symptoms
-    the age of the person
-    the soundness of the heart’s structure.
•    Keeping a person in sinus rhythm is achieved by
-    addressing reversible factors such as weight, obstructive sleep apnoea, alcohol consumption, high blood pressure,    thyroid function and control of other diseases
-    medication
-    EP ablation.