Therapeutic measures for atrial flutter are aimed at stopping paroxysms, restoring normal sinus rhythm, preventing future episodes of disorder. Beta blockers (for example, metoprolol, etc.), calcium channel blockers (verapamil, diltiazem), potassium preparations, cardiac glycosides, antiarrhythmic drugs (amiodarone, ibutilide, sotalol hydrochloride) are used for drug therapy of atrial flutter. To reduce thromboembolic risk, anticoagulant therapy is indicated (heparin intravenously, subcutaneously; warfarin).
To relieve typical paroxysms of atrial flutter, the method of choice is transesophageal pacing. In acute vascular collapse, angina pectoris, cerebral ischemia, and an increase in heart failure, electrical cardioversion with low-power discharges (from 20–25 J) is shown. The effectiveness of electropulse therapy increases with the holding of antiarrhythmic drug therapy.
Recurrent and persistent atrial flutter are indications for radiofrequency ablation or cryoablation of a macro-re-entry focus. The efficiency of catheter ablation during atrial flutter exceeds 95%, the risk of developing complications is less than 1.5%. Patients with SSS and paroxysmal atrial flutter are shown to have RFA of the AV node and EX implantation.
Atrial flutter – supraventricular tachycardia, characterized by an excessively frequent, but regular atrial rhythm. Along with atrial fibrillation (fibrillation) (frequent, but irregular, disordered atrial activity), flutter refers to varieties of atrial fibrillation. Atrial flicker and flutter are closely intertwined and can alternate, mutually replacing each other. In cardiology, atrial flutter is much less common than flicker (0.09% versus 2-4% in the general population) and usually occurs in the form of paroxysms. Atrial flutter often develops in men over 60 years of age.
Atrial flutter – tachyarrhythmia with the correct frequent (up to 200-400 in 1 min.) Atrial rhythm. Atrial flutter is manifested by paroxysmal palpitations lasting from several seconds to several days, arterial hypotension, dizziness, loss of consciousness. To detect atrial flutter, a clinical examination, 12-lead ECG, Holter monitoring, transesophageal electrocardiography, rhythmography, heart ultrasound, EFI are performed. For the treatment of atrial flutter, medical therapy, radiofrequency ablation and atrial EX is used.
Causes of Atrial Flutter
In most cases, atrial flutter occurs against the background of organic heart disease. The causes of this type of arrhythmia can be rheumatic heart defects, IHD (atherosclerotic cardiosclerosis, acute myocardial infarction), cardiomyopathy, myocardial dystrophy, myocarditis, pericarditis, hypertension, SSS, WPW-syndrome.
Atrial flutter can complicate the course of the early postoperative period after cardiac surgery for congenital heart disease, coronary artery bypass surgery.
Atrial flutter is also found in patients with COPD, pulmonary emphysema, and pulmonary thromboembolism. In pulmonary heart, atrial flutter is sometimes accompanied by end-stage heart failure. Risk factors for atrial flutter, not associated with heart disease, may be diabetes, thyrotoxicosis, sleep apnea syndrome, alcohol, drug and other intoxications, hypokalemia.
If atrial tachyarrhythmia develops in a practically healthy person for no apparent reason, they speak of idiopathic atrial flutter. The role of a genetic predisposition to the occurrence of atrial fibrillation and flutter is not excluded.
Pathogenesis of atrial flutter
The basis of the pathogenesis of atrial flutter is the macro-re-entry mechanism – multiple repeated excitation of the myocardium. A typical paroxysm of atrial flutter is caused by the circulation of a large right atrial circle of re-entry, which is in front limited by the tricuspid valve ring, and behind by the Eustachian crest and hollow veins.
Trigger factors necessary for the induction of arrhythmias may be short episodes of atrial fibrillation or atrial extrasystoles. At the same time, a high frequency of atrial depolarization is noted (about 300 beats per minute).
Since the AV node is unable to transmit pulses of such a frequency, only half of the atrial impulses (block 2: 1) are usually carried out into the ventricle, so the ventricles contract with a frequency of about 150 beats. per minute. Much less often blocks arise in the ratio 3: 1, 4: 1 or 5: 1. If the conduction coefficient changes, the ventricular rhythm becomes irregular, which is accompanied by an abrupt increase or decrease in heart rate. Extremely dangerous ratio of atrioventricular conduction is a 1: 1 ratio, manifested by a sharp increase in heart rate to 250-300 beats. per minute, decreased cardiac output and loss of consciousness.
Atrial Flutter Classification
Allocate typical (classic) and atypical options for atrial flutter. In the classic variant of atrial flutter, the excitation wave circulates in the right atrium in a typical circle; at the same time, a flutter frequency of 240-340 per minute develops. Typical atrial flutter is isthmus-dependent, i.e., susceptible to stopping and restoring sinus rhythm using cryoablation, radiofrequency ablation, transesophageal pacing in the area of the caval-tricuspid isthmus (isthmus) as the most vulnerable part of the loop.
Depending on the direction of circulation of the excitation wave, there are two types of classical atrial flutter: counterclockwise – the excitation wave circulates around the tricuspid valve counterclockwise (90% of cases) and clockwise – the excitation wave circulates in a clockwise macro-re-entry loop (10% of cases ).
Atypical (isthmus-independent) atrial flutter is characterized by the circulation of an excitation wave in the left or right atrium, but not in a typical circle, which is accompanied by the appearance of waves with a flutter frequency of 340-440 per minute. Taking into account the place of formation of the macro-re-entry circle, right atrial (multiple-cycle and upper-loop) and left atrial and atrial independent atrial flutter are distinguished. Atypical atrial flutter cannot be stopped by CPEX due to the absence of a zone of slow conduction.
From the point of view of the clinical course, there is a first atrial flutter, paroxysmal, persistent and permanent form. The paroxysmal form lasts less than 7 days and is stopped independently. The persistent form of atrial flutter has a duration of more than 7 days, while the independent restoration of sinus rhythm is impossible. A constant form of atrial flutter is indicated if drug or electrical therapy did not bring the desired effect or was not performed.
The pathogenetic significance of atrial flutter is determined by heart rate, on which the severity of clinical symptoms depends. Tachysystole leads to diastolic, and then systolic contractile myocardial dysfunction of the left ventricle and the development of chronic heart failure. In atrial flutter, there is a decrease in coronary blood flow, which can reach 60%.
Symptoms of atrial flutter
The clinic was first developed or paroxysmal atrial flutter is characterized by sudden attacks of heartbeat, which are accompanied by general weakness, decreased physical endurance, discomfort and pressure in the chest, angina, shortness of breath, arterial hypotension, dizziness. The frequency of paroxysmal atrial flutter varies from one per year to several per day.
Attacks can occur under the influence of physical exertion, hot weather, emotional stress, heavy drinking, drinking alcohol and intestinal upset. With a high pulse rate, pre-syncope or syncopal states often occur.
Even asymptomatic atrial flutter is accompanied by a high risk of developing complications: ventricular tachyarrhythmias, ventricular fibrillation, systemic thromboembolism (stroke, renal infarction, pulmonary embolism, acute occlusion of mesenteric vessels, occlusion of extremity vessels), heart failure, cardiac arrest.
Diagnosis of atrial flutter
Clinical examination of a patient with atrial flutter reveals a quickened, but rhythmic pulse. However, when the coefficient of 4: 1 pulse can be 75-85 beats. in minutes, and with a constant change of the coefficient, the heart rhythm becomes wrong. Pathognomonic sign of atrial flutter is a rhythmic and frequent pulsation of the cervical veins, corresponding to the rhythm of the atria and exceeding the arterial pulse by 2 or more times.
The 12-lead ECG recording detects frequent (up to 200-450 min.) Regular, atrial F waves that have a saw-tooth shape; lack of P teeth; correct ventricular rhythm; unchanged ventricular complexes, preceded by a certain number of atrial waves (4: 1, 3: 1, 2: 1, etc.). A sample with carotid sinus massage enhances AV block, resulting in atrial waves becoming more pronounced.
Using daily ECG monitoring, the pulse rate is assessed at different times of the day, and paroxysmal atrial flutter is recorded. During ultrasound of the heart (transthoracic echocardiography), the dimensions of the heart cavities, the contractile function of the myocardium, and the condition of the heart valves are examined. Performing transesophageal echocardiography reveals blood clots in the atria.
Biochemical blood tests are used to detect the causes of atrial flutter and may include the determination of electrolytes, thyroid hormones, rheumatologic tests, etc. To clarify the diagnosis of atrial flutter and differential diagnosis with other types of tachyarrhythmias, an electrophysiological study of the heart may be required.
Atrial flutter prediction and prevention
Atrial flutter is characterized by resistance to anti-arrhythmic drug treatment, persistence of paroxysms, a tendency to recurrence. Recurrences of flutter may turn into atrial fibrillation. The long course of atrial flutter predisposes to the development of thromboembolic complications and heart failure.
Patients with atrial flutter need to be monitored by a cardiologist-arrhythmologist, consult a cardiac surgeon to decide on the feasibility of surgical destruction of the arrhythmogenic focus.
Prevention of atrial flutter requires the treatment of primary diseases, reduction of stress and anxiety, cessation of caffeine, nicotine, alcohol, and some drugs.