Atrial flutter is a cardiac arrhythmia (alteration of the beat ) that involves the atria. Or the upper chambers of the heart, which is characterized by the presence of an irregular and high-frequency heartbeat that often arises suddenly.
The most common causes that can trigger atrial flutter are:
- Disorder of a heart valve ( mitral or tricuspid)
- Congestive heart failure
- Ischemic heart disease (any condition that results in an insufficient supply of blood and oxygen to the heart muscle)
- Pericarditis
- Hypertensive heart disease
- Hyperthyroidism and respiratory disease (among non-cardiac causes)
The clinical picture of atrial flutter is characterized by a set of symptoms that includes:
- Palpitations, related to high heart rate, and a feeling of “heart in the throat”
- Chest pain
- Asthenia and generalized malaise
- Breathing difficulties (dyspnoea)
- Syncope or loss of consciousness with falling to the ground
The diagnosis of certainty requires, in addition to anamnesis and cardiological physical examination, the execution of diagnostic investigations such as:
- Ecg and ECG Holter
- Echocardiogram
- Electrophysiological study with possible radio ablation
The treatment uses drug therapy based on the use of antiarrhythmic drugs and beta-blockers; in the absence of a satisfactory response, interventional procedures such as electrical cardioversion or catheter radiofrequency ablation become necessary.
Being part of the cardiac arrhythmias group, atrial flutter has a highly variable prognosis based on the causes that caused this arrhythmia and its therapeutic responsiveness. Even in the event of resolution of the episode of atrial flutter, it is always necessary to indicate to these subjects the need to perform periodic cardiological checks during their life. In order to be ready to intervene in the event of a change in the present condition.
REVIEW OF ANATOMY AND PHYSIOLOGY
The heart is made up of 4 different chambers:
- 2 atria, above
- 2 ventricles, inferiorly
Each atrium is directly connected to its respective ventricle, while normally there are no blood passages between the chambers placed at the same level.
From an electrophysiological point of view, the heart rhythm is triggered in an anatomical structure called a “sinus node” (or sinoatrial node) and located on the wall of the right atrium of the heart, where there are specialized cells that are able to spontaneously generate electrical impulses (pacemaker cells). Each impulse then crosses the specific conduction pathways, which include the atrioventricular node, the bundle of His, and the right and left branches. And finally reaches all the heart cells, thus allowing the heart to contract. erotic massage nyc
In case of the onset of atrial flutter, the cardiac atria depolarize at a very high rate, often reaching a range between 250 and 300 beats per minute; however, this speed of contraction cannot be transmitted to the ventricles since the atrioventricular node is unable to conduct impulses at this very high speed. The consequence is that the passage to the ventricles will settle on a conduction ratio of 2: 1 (in most cases), that is
- An atrial rate of 300 beats per minute,
- But with a true ventricular (and therefore heart) rate of approximately 150 beats per minute (half).
This is because of the 2 impulses that reach the atrioventricular node. It will be able to conduct only 1 (thus respecting the ratio of 2 to 1).
The conduction ratio can also change and settle on values of 3: 1, 4: 1, or 5: 1, causing a very variable and irregular heart rhythm.
CAUSES
It is a not very frequent cardiac arrhythmic pathology, which has a higher prevalence in the elderly population that already has some form of heart disease; however, the real incidence is not easily calculated, since in most cases it tends to evolve into the more frequent form of atrial fibrillation.
The main causes of the onset of atrial flutter substantially include some heart diseases that involve a dilation beyond the normal of the atrial chambers, a phenomenon that is more frequently found in the case of:
- Mitral valve disease (the valve between the left atrium and left ventricle) of rheumatic origin or not
- Valvular pathology of the tricuspid (the valve between the right atrium and right ventricle) of the rheumatic origin or not
- Congestive heart failure (heart failure)
- Ischemic heart disease ( myocardial infarction )
- Pericarditis (inflammation or infection of the pericardium, the thin membrane that surrounds the pericardium)
- Hypertensive heart disease (the heart consequences of persistent and not effectively treated high blood pressure )
Among the non-cardiac causes stand out in importance
- Hyperthyroidism (first non-cardiac cause)
- Severe respiratory diseases
There are several risk factors that can become a contributing cause to the onset of atrial flutter, the most important are:
- Anxiety condition
- Severe psychophysical stress
- Beverages containing caffeine or other exciting substances
- Narcotic substances and alcohol
- Smoke
- Sympathetic-mimetic drugs
- Severe obesity
Taking into account the sex, flutter occurs with an approximately 3 times higher incidence in male subjects compared to their female counterpart.
CLASSIFICATION
Following the classification according to Scheinman, atrial flutter can be distinguished, depending on the atrium from which it originates:
- Left atrial flutter (if it originates from the left atrium)
- Right atrial flutter (if it originates from the right atrium)
- Isthmus-dependent atrial flutter also called typically
- Common or type I counterclockwise flutter: this is by far the most frequent form of flutter, accounting for over 80% of cases. It is a regular atrial rhythm that is formed following the presence of a reentry circuit that occupies a large part of the right atrium. In turn, caused by a slowdown in the conduction of impulses at the level of the hollow-tricuspid isthmus, or at the functional block of impulses along with the so-called crista terminals and eustachian crista. This form of atrial flutter represents the most responsive to a possible treatment with catheter ablation. As well as being easily recognizable by the typical sawtooth f wave pattern on the electrocardiogram.
- Uncommon or type ii clockwise flutter: This represents less than 10% of cases and is caused by the same circuit as type I, but with the pulses running through it in the opposite direction and therefore clockwise. On the electrocardiogram, what emerges, in this case, is a pattern with positive reverse sawtooth f waves (i.e. facing downwards) together with other peculiar electrocardiographic characteristics.
- Isthmus-independent atrial flutter also called atypical: Presents as a regular atrial tachycardia that is based on a circuit (different from that found in the previous forms) that can occur both in the right atrium and, more rarely, in the left atrium.
On the basis of the mode of onset, two forms of atrial flutter are distinguished:
Paroxysmal form: it is characterized by an abrupt and sudden onset. With a high frequency that can reach 180 beats per minute and a conduction ratio of 2: 1 in most cases. This form of flutter typically occurs in healthy individuals and can last from a few hours to a few days. It often tends to self-resolution even without the use of drugs or other therapeutic procedures.
Permanent form: it has a less sudden onset with a frequency that remains below 100 beats per minute for a conduction ratio of impulses between the atria and ventricles of 3: 1, 4: 1 or 5: 1. This form, being more clinically silent, can go unnoticed for several years or in most cases is associated with some cardiac pathology. For its resolution, it often requires targeted and effective therapy.
SYMPTOMS
The clinical picture of a person with atrial flutter can predict the presence of various symptoms, such as:
- Feeling of palpitations
- Feeling of “heart in the throat”
- Chest pain
- Asthenia and generalized malaise
- Stress intolerance
- Dyspnea: Difficulty in breathing with a feeling of air hunger
- Hypotension (i.e. reduction in normal blood pressure)
- Syncope with fall to the ground
- Vertigo with risk of falling
- Loss of consciousness (up to coma in case of supervening complications)
Since atrial flutter is often concomitant with other diseases, both cardiac and extra-cardiac, symptoms can directly overlap the underlying disease:
- Myocardial infarction: the death of heart cells due to blockage of the blood supply from the coronary arteries can lead to the onset of various cardiac arrhythmias, including atrial flutter, with the presence of:
- Retrosternal chest pain
- Pain in the left arm and jaw
- Difficulty breathing and a feeling of air hunger (dyspnoea)
- Hyperthyroidism: the high levels of thyroid hormones in circulation cause an increase in heart rate. In predisposed subjects, can trigger atrial flutter or other arrhythmias such as ventricular extrasystoles
- Infectious diseases: infections by some bacteria create systemic inflammatory conditions ( brucellosis, Lyme disease, typhoid fever, syphilis, …) Which can also compromise the normal function of the heart, with an increased risk of causing abnormalities in the heart rate.
COMPLICATIONS
In the event of an excessively rapid heartbeat for a long time, especially when undiagnosed or neglected. The patient may progressively develop a weakening of the heart.
Alongside this risk, it is then necessary to remember that it is an embolic arrhythmia. That is capable of causing the formation of dangerous blood clots capable of causing an embolic stroke (for emboli that from the heart are released into the circulation reaching the brain) or myocardial infarction.
Finally, in the case of atrial flutter, symptoms associated with a dynamic impairment of the cardiovascular system may sometimes occur. Especially in subjects who already have some heart disease, these rare adverse events such as:
- Atrial fibrillation
- Ventricular tachycardic arrhythmias up to very severe ventricular fibrillation.
TREATMENT
Treatment of atrial flutter relies on heart rate control, which can be pursued with
- PHARMACOLOGICAL THERAPY
- INTERVENTIONAL PROCEDURES SUCH AS ABLATION OR ELECTRICAL CARDIOVERSION, ARE LIMITED TO SELECTED AND REFRACTORY CASES.
Together with this main treatment, it is also advisable to prevent the possible serious complication of thrombo-embolism by means of a permanent therapy that includes the use of oral anticoagulants; especially in the case of chronic atrial flutter or after evolution to chronic atrial fibrillation, oral anticoagulant therapy is necessary, based on the use of vitamin K inhibitors (such as Warfarin ) or direct inhibitors of thrombin, factor II or X of coagulation (the so-called NAO, an acronym for New Oral Anticoagulants).
From a medical-pharmacological point of view, the treatment consists of the use of antiarrhythmic and bradycardic drugs. Such as beta-blockers and calcium channel blockers. Less frequent is the use of digitalis drugs.
These drugs are particularly useful in cases where there is heart disease such as heart failure or after myocardial infarction.
If it is not possible to obtain effective control of the heart rate values and therefore to correct the atrial flutter. It is possible to propose synchronized electrical cardioversion, which is indicated above all in the case of:
- VERY RECENT-ONSET ATRIAL FLUTTER
- ATRIAL FLUTTER ASSOCIATED WITH HEMODYNAMIC IMPAIRMENT
- ATRIAL FLUTTER IN THE CASE OF ATRIOVENTRICULAR CONDUCTION 1: 1 (VERY DANGEROUS AS IT CAN LEAD TO DIZZYING INCREASES IN THE VENTRICULAR HEART RATE)
Cardioversion is usually performed with a biphasic shock at approximately 50 Joules
In the case of refractory to drug therapy, even the most invasive ablation treatment can be undertaken, after an electrophysiological study.
Catheter ablation has the objective of making the macro-orientation circuit responsible for the onset of flutter inactive. This circuit usually occurs in the right atrium and is typical of the typical isthmus-dependent form of atrial flutter.
During a short hospital stay that can last 1 or 2 days, a special catheter is introduced under local anesthesia which reaches the heart chambers through an arterial or venous entrance.
At this level, electrical impulses are induced that allow an electrophysiological study. So as to precisely identify the area responsible for the arrhythmia. At this point, we proceed with the radio ablation of that area through the emission of heat that causes a small scar at the level of the circuit responsible for the flutter
