Atrial fibrillation

What is AF?

Atrial fibrillation is often referred to as AF or A-Fib. It is the most common abnormal rhythm worldwide. It frequently manifests as a rapid, irregular heartbeat and can lead to serious consequences such as stroke, heart failure, reduced quality of life, energy levels, and exercise capacity.

How does AF start and manifest?

Atrial fibrillation (AF) is an electrical issue that primarily affects the upper chambers of the heart, known as the atria. The onset of AF occurs when abnormal electrical signals are emitted, leading to disordered and chaotic electrical activity in these chambers. The pulmonary veins are frequently responsible for generating these abnormal impulses. Subsequently, the irregular rhythm is conducted through the AV node to the ventricles, causing a fast and/or irregular heartbeat.

What are the risk factors for atrial fibrillation?

AF can be influenced by various factors, some of which are modifiable while others are not. Among the modifiable risk factors are hypertension or high blood pressure, obesity, excessive alcohol consumption (more than 3 standard drinks per week), and sleep apnoea. If you experience night-time snoring or excessive daytime sleepiness, undergoing a sleep study might be beneficial. Addressing these factors by losing excess weight, abstaining from alcohol, and treating sleep apnoea can significantly improve AF management. Additionally, maintaining good control over blood pressure is crucial in managing AF effectively.

HEAD 2 TOES is a good approach to AF risk factor optimisation.

H: Heart failure optimisation – Including use of medications such as ACE inhibitors or Angiotensin receptor blockers (ARB).

E: Exercise >200mins / week. Moderate intensity

A: Arterial hypertension (Aim BP <140/80 mmHg at rest and <200/100mmHg with exercise)

D2: HBA1c <7% and Dietary changes

T: Tobacco – Complete Cessation.

O: Obesity. >10% reduction and BMI <27 Kg/m²

E: Ethanol <3 std drinks per week

S: Sleep apnoea. AHI < 15 without CPAP. CPAP for AHI > 30 (different in Hypertensive Pts)

(Adapted from 2024 CSANZ AF guidelines)

On the other hand, there are non-modifiable risk factors that include advancing age, being male, and genetics. These factors contribute to the likelihood of developing AF but cannot be altered. Moreover, AF can sometimes be triggered by other conditions such as an overactive thyroid, imbalances in salt levels, certain medical illnesses, or even surgery. These situations imply that your heart has a predisposition to experience AF under specific circumstances.

Why is AF a problem? What are potential consequences of AF?

AF has the potential to lead to debilitating strokes. The irregular and chaotic rhythm associated with AF can cause sluggish blood flow in various regions, particularly in the left atrial appendage. This can create an environment conducive to blood clot formation. These clots have the ability to travel throughout the body, including the brain, where they can cause blockages in the blood vessels, resulting in compromised blood supply to specific areas of the brain.

In addition to stroke, AF can also give rise to other complications. One such complication is heart failure, which occurs when the pumping function of the heart becomes inefficient. Another potential consequence is the weakening of the heart muscle, known as cardiomyopathy. These complications can significantly impact the overall functioning and health of the heart.

Common symptoms related to AF include palpitations, decreased energy, shortness of breath, fatigue, decreased exercise capacity, weakness, swelling of the legs, chest discomfort, intermittent dizziness and rarely loss of consciousness.

Are there different types / patterns of AF?

Indeed, the pattern of AF can vary among individuals. It can manifest as either intermittent or continuous episodes. To describe different patterns of AF, terms such as paroxysmal AF, persistent AF, and long-standing persistent AF are commonly used. Paroxysmal AF refers to the occurrence of AF in an intermittent manner, with episodes that come and go. On the other hand, persistent AF is characterized by continuous AF episodes that last for more than 7 days.

It’s important to note that AF is typically a progressive condition. It can evolve from a paroxysmal pattern to persistent AF and, eventually, to chronic AF. This means that over time, AF may become more frequent and sustained in nature. Regular monitoring and appropriate management are crucial to address the progression of AF and its associated complications.

What is the long-term prognosis with AF?

The natural progression of AF exhibits significant variability among individuals. It is not uncommon for people to experience clusters of AF episodes followed by periods of stability. Identifying specific triggers for these episodes is not always possible.

People diagnosed with AF face an elevated risk of stroke, heart failure, and the potential need for hospitalization. However, modern treatment approaches, including medications and, if necessary, ablation procedures, have proven effective in adequately managing these risks. With the implementation of appropriate management strategies and treatment, many individuals with AF can expect to lead a normal life.

It is crucial to work closely with healthcare professionals to find the most suitable treatment plan and to ensure that proper management strategies are in place. By doing so, individuals with AF can minimize the impact of the condition on their daily lives and maintain a good quality of life.

What is Atrial flutter and how is it different to AF?

Atrial flutter and AF are both types of cardiac arrhythmias, which involve abnormal irregular (or regular in case of atrial flutters) heartbeats. While they share some similarities, they are distinct in terms of their underlying mechanisms and characteristics.

In the majority of people who are diagnosed with atrial flutter as their initial abnormal rhythm, AF is eventually diagnosed.

Both atrial flutter and atrial fibrillation are associated with an increased risk of stroke and other complications due to the potential formation of blood clots in the atria. Treatment approaches may include medications to control heart rate and rhythm, anticoagulants to prevent blood clots, and in some cases, procedures such as cardioversion or catheter ablation.

It’s important to note that these are generalizations, and individual cases can vary. The specific diagnosis and treatment plan should be determined by a healthcare professional based on a thorough evaluation of your condition.

What treatment options are available for AF?

Increasing treatment efficacy:

• Simple beta blockers / Calcium channel blocker / Digoxin.
  • Note: these medications are not designed to regulate your rhythm. They are used to slow racing heart and reduce severity of symptoms.
• Anti-arrhythmic drugs (AAD) – Sotalol / Flecainide + another medication / Amiodarone
  • Pill in pocket
  • Regular AAD
• AF ablation
• AF ablation + AAD
• Repeat AF ablation (If ongoing AF)
• Repeat AF ablation + AAD (If ongoing AF)

Medications:

In the majority of cases, the primary and fundamental approach to treatment involves the use of medications. Medications serve two key purposes in the management of AF. Firstly, they are utilised to prevent strokes. These medications, collectively known as anticoagulants, are designed to reduce the risk of blood clot formation. Secondly, medications are employed to control heart rhythm. They can be used to restore a normal heart rhythm or regulate the heart rate.

For individuals who continue to experience AF episodes despite medication usage, or for those who have intolerances to prescribed medications or prefer not to be on long-term medications, procedural options can be considered. In certain cases, the use of a pacemaker may be necessary to safely administer medications.

There are various medications and combinations available for AF treatment, and finding the most effective one often involves a process of trial and adjustment of dosage and medication type. Regular monitoring is typically required when using medications that target abnormal heart rhythms. Medications can be used in a “pill-in-pocket” approach for acute episodes or taken regularly as part of a long-term treatment plan.

What is pill-in-pocket approach?

The “pill-in-the-pocket” approach involves the as-needed use of specific antiarrhythmic medications, such as flecainide or sotalol, which are prescribed by a healthcare professional. This strategy is typically employed for individuals who experience relatively infrequent episodes of AF. The goal is to terminate AF episodes without requiring an emergency department visit or hospitalization.

In this approach, the prescribed medication is taken when an AF episode is suspected to last longer than 15 minutes. It’s important to note that these medications may take several hours to take effect. If you feel significantly unwell or if the episode persists for more than 24 hours, it is advised to seek medical attention. It is crucial not to drive if you are experiencing AF symptoms or are taking the medication for this purpose.

Procedural options:

Cardioversion is a straightforward non-invasive procedure utilised for some individuals who continue to experience persistent AF despite medication use. Its purpose is to restore the heart’s normal sinus rhythm, similar to rebooting a slow-running computer. The procedure involves a brief deep anaesthesia administered by an anaesthetist. A cardioversion by itself is a temporary relief. We rely on medications and / or and ablation to maintain rhythm.

Catheter ablation

for AF is an effective method to control heart rhythm. This procedure often leads to symptomatic improvement, with success rates estimated to be up to 80% depending on factors such as AF duration, cardiac chamber size, and comorbidities. Over time, approximately 30-50% of individuals may require additional procedures as the heart may heal at previously treated sites or new areas may arise. Following successful ablation, it is often possible to discontinue medications used to control heart rhythm. The majority of individuals experience a significant reduction in AF occurrence and better control of the condition after undergoing ablation.

What are the reasons for an AF ablation?

Deciding whether to undergo an ablation is a decision you and your clinician will make together, based on your individual circumstances. In some cases—such as when atrial fibrillation (AF) is leading to serious complications like heart failure—an ablation may offer significant benefits. You always have a choice.

Broadly, there are three main reasons to consider AF ablation:

1. Persistent or recurrent AF despite treatment with anti-arrhythmic medication and/or previous cardioversions.
2. Avoiding current or potential medication side effects or addressing intolerance to drugs used to maintain normal rhythm.
3. Reducing or simplifying ongoing medication for heart rhythm control, based on patient preference.

Pacemaker implantation and AV node ablation are considered as a final treatment option when medications and/or previous ablation procedures prove ineffective in managing rapid heart rhythms associated with AF. This two-step process begins with the placement of a pacemaker, followed by an AV node ablation procedure several weeks later. This combination stops the heart from beating irregularly and allows the pacemaker to take over the heart’s rhythm. While AF may still be present in the background, it no longer accelerates the heart rate. Long-term use of anticoagulants is necessary to prevent stroke in these cases.

Is there more than one way to perform AF ablation?

Yes, AF ablation can be performed from the inside of heart chambers (Endocardial) or from the outside (Epicardial).

Standard AF ablation is performed from the inside and could use one of 3 modalities that are currently available. These are heat (radiofrequency / RF), cold (Cryoablation / Cryo) or electrical (Pulsed Field Ablation – also called PFA). PFA is the most recent modality. These modalities have their individual strengths and weaknesses but largely considered equivalent to one another. There are many types of PFA systems with their individual characteristics and advantages that might be more suited to your specific condition / situation.

Epicardial / Surgical AF ablations are performed by cardiac surgeons which is considered in people undergoing concomitant cardiac surgery if there is history of AF. Standalone surgical AF is considered in select circumstances.

What are the distinctions between initial and repeat / redo AF ablation?

Achieving better control of arrhythmia often necessitates multiple procedures for each individual. The need for repeat procedures may arise shortly after the initial AF ablation or years later. The approach to a repeat procedure depends on the specific rhythm issue and the findings during the procedure; it’s not predetermined. In addition to AF, individuals might also present with other types of arrhythmias, such as atrial flutter (typical or atypical) and atrial tachycardia, which can be addressed concurrently during the ablation.

During each ablation procedure, there are several possible steps that can be taken. Below is an example of an escalating series of ablations.

EXAMPLE:

• Step 1: Isolation of Pulmonary Veins
• Step 2: Isolation of Posterior Wall
• Step 3: Isolation of Superior Vena Cava (SVC)
• Step 4: Creation of Anterior or Mitral Line
• Step 5: (CFE)

Each individual may undergo any combination of these steps during their ablation procedure. Typically, Procedures 1 and 2 focus on achieving Step 1.

For instance:

What are the risks of having an AF ablation?

They include but are not limited to the following.

Common risks and complications (more than 5%) include:

• Bruising bleeding at the puncture site. Bruising can extend beyond the puncture site and can take a few weeks to improve in some cases.

Uncommon risks and complications (1- 5%) include:

• Development of another arrhyth
• Bleeding related to the groin puncture site or injury to an artery in the groin. This (rarely) may need surgery and or blood transfusion
• Chest pain / Pericarditis. This is an inflammation of the heart sack that can cause chest pain for some weeks after the procedure and is easily managed with anti-inflammatory medications

Rare risks and complications (less than 1%) include:

• Fluid around the heart called a “pericardial effusion” which may need to be drained thru a tube under the breast bone or “sternum”
• A stroke. This may cause long term disability (0.5%)
• Requirement for a pacemaker following the procedure
• Injury to the food pipe related to the ultrasound or temperature probe used during the procedure.
• Injury to the urinary tract if a urinary catheter is required for the procedure.
• Damage to the phrenic nerve that controls the diaphragm (breathing muscle) called phrenic nerve palsy.
• Atrial oesophageal fistula. A hole forms between the gullet and heart. This can cause vomiting of blood and a stroke. This may be life threatening.
• Narrowing of the veins from the lungs to the heart called pulmonary vein stenosis.
• Damage to normal electrical system requiring a permanent pacemaker
• Renal failure due to haemolysis requiring haemodialysis and ICU care (PFA)
• Death because of this procedure is rare

What are the costs involved with an ablation?

If you undergo this procedure as a public patient in a public hospital, Medicare will cover the expenses. If you choose to have this procedure in a private hospital, the standard hospital excess will still apply. It is common for anaesthetists to have additional costs that we recommend you address before your scheduled procedure.

How do I prepare for an ablation?

Before your procedure, you will receive a letter containing instructions and necessary steps to follow. This will include the date of admission, fasting guidelines, medications to discontinue, and items to bring along. Typically, you will need to have recent kidney and blood count tests before the procedure. As a general rule, refrain from eating or drinking anything for at least 6 hours prior to the procedure. It is important to consult your doctor regarding your regular medications. In most cases, blood thinners are continued for AF ablation procedures. However, if you are taking SGLT2 medicine for heart failure or diabetes, you will need to discontinue them at least 3 days before the surgery. Lastly, it is advisable to leave any valuable personal belongings such as jewellery at home.

What happens when you arrive at the hospital?

Upon your arrival at the hospital for the procedure, you will typically be directed to the admission area of the cardiac catheter laboratory, where you will be officially admitted as a hospital patient. You will be asked to change into a hospital gown and securely store any valuable belongings. Some basic tests will be conducted, such as an ECG, recording of vital signs, shaving of the groin area, and insertion of a cannula in your arm to aid the procedure. Technologists will apply special stickers and wires to your chest and back. In most cases, a pre-ablation cardiac CT scan of the heart is performed to assist in guiding the ablation procedure. If you have this scan done externally, make sure to request a copy of the CD and bring it to the hospital with you.

The ablation itself will be conducted under general anaesthesia, which requires the presence of an anaesthetist. The anaesthetist will discuss their role with you. Additionally, you will need an arterial line to monitor your blood pressure throughout the ablation, which carries a certain level of risk for complications.