Atrial flutter (AFL) is a discomforting cardiac condition that can occur at any stage of life, including infancy. Read and know about the symptoms, causes, diagnosis and treatment of this disorder.
Atrial flutter Definition
It is an abnormality of the heart rhythm that is characterized by rapid or irregular heartbeat. It generally occurs in the atria- entry chambers on both sides of the heart that lead to the ventricles. It belongs to a group of supra-ventricular tachycardias or any fast heart rhythm originating above the ventricular tissue. In this condition, electrical impulses that normally control the heartbeat take an abnormal path through the atria and start circulating around the tricuspid valve in the right atrium. Owing to the rapid contraction of the atria, the heart rate increases to 250-350 beats per minute.
Picture 1 – Atrial flutter
AFL was first recognized in the year 1920 as a separate medical disorder by the British physician Sir Thomas Lewis British and his colleagues. The condition is found to be more frequent in males than in females.
Atrial flutter versus Atrial fibrillation
The irregular rhythms of the heart are rarely stable and may lead to atrial fibrillation (AF) – a severe form of abnormal heartbeat associated with congestive heart failure. Sometimes, AFL and AF can co-exist together. However, AF is usually much faster and severe, unlike AFL.
Atrial flutter Types
AFL is usually classified into two forms, of which affected patients normally acquire only one. Only few of the patients may exhibit both the forms, where each type occurs only one at a time.
Type 1
It is also known as common AFL or typical AFL and is characterized by a heart rate of 240-340 beats per minute. In this form, the electrical impulses repeatedly travel in a cyclic pattern within the right atrium. It later passes through the cavo-tricuspid isthmus, which is a mass of fibrous tissue in the lower right atrium situated between the inferior vena cava, and the tricuspid valve. It can be further sub-classified into:
Counterclockwise atrial flutter
It is the most commonly diagnosed sub-type of AFL. It shows an inverted electrocardiogram (ECG or EKG) pattern.
Clockwise atrial flutter
It displays an upright ECG pattern.
Type 2
It is completely in contrast to type 1 and has a different pathway of re-entry into the atria and is comparatively faster. It shows a variable atrioventricular (AV) block that leads to impairment of conduction between the atria and ventricles of the heart. The ECG pattern also appears irregular. In this form, the heart rate is around 340-440 beats per minute.
AFL is also categorized on the basis of the persistence of its symptoms. If the symptoms generally persist for a few hours or days, as is generally observed, the condition is known as Paroxysmal Atrial flutter. On the other hand, AFL that results in permanent symptoms is known as Persistent Atrial flutter.
Atrial flutter Symptoms
In most cases, patients of AFL do not exhibit any major signs and are able to tolerate the accelerated heart rate. However, individuals who are already suffering from other forms of cardiac issues may feel uncomfortable and exhibit symptoms like:
- Palpitations
- Shortness of breath
- Anxiety
- Difficulty while exercising or carrying out routine activities
- Discomfort and pain in the chest
- Dizziness or lightheadedness
- Depression
- Nausea
Atrial flutter Causes
Cardiac patients are more prone to AFL than individuals with normal hearts. Sometimes, intake of substances such as alcohol, cocaine, caffeine, and amphetamines may lead to a change in the path of transmission of the electrical impulses through the heart. Open heart surgery is also considered to be an important attribute for this form of irregular heart rate. In majority of the cases, possible causes include presence of cardiovascular abnormalities as well as occurrence of disorders elsewhere in the body such as:
- Cardiomyopathy
- Hypertrophy
- Hypertension
- Atherosclerosis
- Defective mitral valve
- Coronary artery disease
- Diabetes
- Hyperthyroidism
- Pulmonary embolism
- Chronic pulmonary disorders
Atrial flutter Pathophysiology
AF occurs when the electrical impulses starts circulating within the right or left atrium. This leads to electrical activity that starts moving in a loop at a faster pace. This generates an electrical impulse that propagates through the atria.
Atrial flutter Diagnosis
Following a thorough physical examination, health care providers may suspect Arrhythmia or irregular heart beat as the primary cause of the condition. Further tests may aid in identification of the exact cause and type of the condition based on which the appropriate treatment is suggested. Some of the general diagnostic methods for this condition include:
Blood test
It is significantly done to detect the amount of potassium and thyroid levels in the blood. Individuals with AFL normally show elevated levels of the hormone as a consequence of hyperthyroidism.
Chest Radiograph
An X-ray of the chest may assist in determining the size and structure of the heart that generally appears enlarged in patients with AFL.
Electrocardiogram (ECG)
In this process, electrodes are attached to the outer surface of the skin in order to measure the electrical activity of the heart using a device placed external to the body. It is a highly recommended diagnostic test to measure the rate of heartbeat as well as the size and position of the chambers.
Echocardiogram (Doppler echocardiogram)
It is a form of ultrasound test that involves transmission of high-frequency sound waves through a device called Transducer. The technique is used to observe how the heart is beating and pumping blood. The images produced on completion of the test provide detailed information about the functioning of the cardiac valves and chambers.
Holter monitor
This is a portable ECG device that constantly monitors the electrical activity of the heart for nearly 24 hours. It can be easily carried in a pocket or a small pouch worn around the neck or waist. In this way, physicians can determine any irregular heart rhythms while patients carry out their routine activities.
Stress test
Affected patients are generally asked to perform some exercises such as walking on a treadmill or cycling while their heart rate and blood pressure is being monitored using an ECG. The major goal of this test is to determine the amount of stress that the heart can handle before developing an abnormal rhythm. Patients who are unable to exercise are administered with a drug. The alternate method helps in stimulating the heart in a similar way as done during exercise.
Event recorder
It is a pager-sized box that can record the heart rhythm for few minutes when affected patients are actually experiencing the symptoms.
Atrial flutter Treatment
Anticoagulation drugs are mandatorily administered to patients with AFL to control the heart rate and maintain a normal rhythm. A wide variety of treatment options are available to restore normalcy to heart rate and to prevent future episodes of cardiac abnormalities. These include:
Medications
Anti-arrhythmia drugs including amiodarone, sotalol, propafenone are used to reduce the frequency and duration of AFL episodes. Digoxin is recommended for decreasing the conductivity of the electrical impulses to slow down the heart rate. Beta-blockers are also used to reduce the irregular events of heartbeats.
Cardioversion
In this method, an electrical shock is given to patients with AFL by placing electrode pads on their chest and back. This helps in converting the rapid heart rate to a normal rhythm. Several anti-arrhythmic agents may also be used to produce the same effect. This is usually found to be more effective than the former procedure.
Catheter radiofrequency ablation
In this process, several thin, flexible tubes (catheters) are inserted into the blood vessels of a patient, particularly the subclavian or femoral vein. High-frequency electrical impulses are used to generate irregular rhythms. This is followed by ablation or removal of the abnormal tissue that is responsible for the actual problem. The method is quite safe and generally requires less recovery time.
Artificial pacemakers
It is a small device that is implanted in the chest with the help of a minor surgery for regulating the beating of the heart. The primary purpose of this technique is to maintain a normal heart rate.
Surgery
Maze procedure is a common heart surgery that may aid in treating AFL by interrupting the electrical impulses, causing the abnormal heart rhythm. Incisions are made in the atria that later heal to form scar tissues. This in turn blocks the abnormal electrical impulses from passing through the heart. There is a good chance of recovery as the normal rhythm of the heart is gradually restored.
Atrial flutter Treatment Guidelines
The clinical guidelines on AFL from the National Institute for Health and Clinical Excellence (NICE) basically involve:
- The various tests required for diagnosis of AFL
- The therapeutic procedures that patients are given depending on the type of AFL, including the permanent and paroxysmal forms
- The treatment options available to individuals who have encountered a stroke after an AFL
Atrial flutter Complications
The condition normally does not lead to any major health issues. However, prolonged existence of AFL may lead to certain cardiac anomalies like:
Picture 2 – Atrial flutter Image
- Stroke
- Congestive heart failure
- Heart attack
Atrial flutter and exercises
It is very important as well as mandatory for the affected patients to have a detailed discussion with their health care providers before resuming to vigorous exercises. Physicians may suggest patients to start off at a low level and then slowly increase the intensity and duration as tolerated.
Atrial flutter does not have any dangerous consequences and it is possible for patients of the condition to lead a healthy and normal life. With a varied range of treatment options being now available for the condition, its prognosis is considerably good. If the symptoms are severe or alarming, medical aid should be sought immediately.