Ventricular arrhythmias are heart rhythm disturbances. There are many types of ventricular arrhythmias, ranging from relatively less dangerous premature beats to dangerous tachycardia. Where does ventricular arrhythmia come from? What are its symptoms? How is her treatment going?

Ventricular arrhythmiasare cardiac arrhythmias originating in the chambers of the heart - two chambers which, thanks to their systolic activity, supply blood to the circulation.

The term ventricular arrhythmia covers many types of arrhythmias, which differ in terms of both the appearance of the ECG waveform and the prognosis.

A thorough understanding of arrhythmias requires knowledge of the physiology of the heart and the basics of electrocardiographic examination, i.e. the popular ECG, which is a standard in diagnostics.

Ventricular arrhythmia: causes

The causes of ventricular arrhythmias are complex and complicated abnormalities at the level of the heart muscle cells. They result from improper generation and conduction of electrical impulses within the ventricular mucosa, i.e. myocardium.

Therefore, all conditions associated with damage to the heart muscle or its abnormal remodeling predispose to ventricular arrhythmias. They mainly include:

  • myocardial ischemia - people after a heart attack and suffering from ischemic heart disease are predisposed to arrhythmias
  • left ventricular hypertrophy - often secondary to hypertension
  • primary cardiomyopathies - a group of diseases with anatomical and functional abnormalities within the ventricles, including: hypertrophic cardiomyopathy, dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy or dilated cardiomyopathy
  • heart defects - reconstruction of the heart cavities secondary to heart defects may also contribute to arrhythmia

It is worth remembering that ventricular arrhythmias can also occur in patients without organic heart disease.

Severe and life-threatening ventricular arrhythmias can be the result of rare genetic heart diseases associated with abnormalities in ion channels that play a role in triggering and conducting a depolarization wave.

In the most often structurally sound heart it happens"electrical" disturbances. The group of heart diseases called channelopathies includes:

  • congenital long or short QT syndrome
  • Brugada team
  • catecholaminergic polymorphic ventricular tachycardia

The occurrence or intensification of ventricular arymias is also favored by non-cardiac conditions such as:

  • electrolyte disturbances e.g. potassium deficiency, magnesium deficiency
  • metabolic disorders
  • hormonal disorders, e.g. hyperthyroidism
  • medications (including some anti-arrhythmic drugs)
  • systemic diseases

Ventricular arrhythmia: types and division of ventricular arrhythmias

Below is a simplified division and a short description of selected arrhythmias.

  • Additional ventricular beats- most often they are of the so-called premature ventricular beats (PVC).
    These are spontaneous excitations of the ventricular muscle that occur earlier than a properly conducted excitation wave resulting in a synchronized contraction. They are most common, even in he althy people. Their number usually does not exceed 200 stimulations a day. Most often they are asymptomatic.
    Occasionally, additional stimulations may appear with a certain regularity and occur, for example, after the second or third sinus beat. Then they arrange themselves in a rhythm called, respectively, bigeminy or ventricular trigeminia.
    They can also appear in pairs. When they occur frequently (especially in heart-damaged patients) and appear too early, they are a risk factor for more serious, life-threatening arrhythmias.
  • Ventricular tachycardia(VT-ventricular tachycardia) - This is an abnormal but regular, fast heart rhythm originating in the ventricles of the heart consisting of consecutive beats at a rate greater than 100 / min .

There are several divisions that classify ventricular tachycardias, e.g.

  • due to the shape of the beats in the ECG trace:

- polymorphic
- polymorphic

  • or for the duration

- unstable tachycardia (consisting of at least 3 beats and lasting less than 30 s)
- permanent tachycardia (lasting 30 s or longer)
- continual tachycardia (lasting more than 50% days)

  • Ventricular fibrillation - very fast (more than 300 / minute) irregular ventricular rhythm causing sudden cardiac arrest and resuscitation with immediate shock delivery

Ventricular arrhythmia: symptoms

Symptoms of ventricular arrhythmias arevery varied. From the most common asymptomatic single extrasystoles, through severe, symptomatic tachycardia, to ventricular fibrillation - one of the mechanisms of cardiac arrest.

Symptoms of arrhythmias are non-specific and do not allow for unambiguous determination of its type or duration. The most common symptoms suggesting an arrhythmic cause are:

  • palpitations - a feeling of beating hard or hard
  • the feeling of "your heart running down your throat"
  • stabbing or angina chest pains
  • shortness of breath
  • dizziness
  • fainting or fainting

Ventricular arrhythmia: diagnosis

The basis for the diagnosis of ventricular arrhythmias, as in all other arrhythmias is an EKG that records the electrical activity of the heart.

Distinctive features of ventricular heartbeats in the ECG record are primarily wide QRS complexes (>120ms) and the ST-T complex deflection opposite to the QRS.

Taking a standard electrocardiogram is insufficient if testing is not performed at the time of an arrhythmic episode. When the arrhythmia is less frequent, prolonged ECG monitoring methods are used to detect it and document the relationship to symptoms.

The basis is a 24-hour (or longer) Holter ECG recording. Prolonged examination can increase the probability of detecting arrhythmias, assess its frequency and estimate the prognosis.

Nowadays we also have other methods of long-term monitoring of the heart rhythm. This may prove especially useful in the setting of very rare arrhythmia attacks. Although the availability of such devices is not yet widespread, in practice, external event recorders, telephone monitoring and implantable loop recorders are used.

People with known ventricular arrhythmia must undergo echocardiography (ECHO) to diagnose possible organic heart disease that may be the underlying cause.

Ventricular arrhythmia: treatment

The treatment of arrhythmias has developed significantly in recent years. The main reason is the introduction and improvement of invasive treatment. However, one should not forget about still important first-rate methods of therapy.

The basic principle of the chronic treatment of ventricular arrhythmias is to eliminate the factors that may contribute to its occurrence. An example is the correction of electrolyte disturbances, such as e.g. potassium or magnesium deficiency.

Treatment occurs through proper supplementation. Lifestyle modification may also turn out to be important - reducing stress, improving the quantity and quality of sleep, excluding nicotine and other stimulants.

Pharmacotherapy is also used in the preventive treatment of arrhythmias. The most widely used drugs are beta-blockers and amiodarone.

In the case of ventricular arrhythmias due to ischemic disease, especially frequent after myocardial infarction, revascularization procedures aimed at improving the coronary circulation - angioplasty of the coronary arteries, as well as cardiac aortic-coronary bypass surgery, or colloquially "bypass", play a significant role.

In case of ineffectiveness of antiarrhythmic pharmacotherapy, invasive treatment - percutaneous ablation - can be used. Ablation is a procedure to destroy the focus of the arrhythmia. Thus, it heals it permanently.

Ablation is immediately preceded by an electrophysiological test (EPS), which aims to accurately diagnose the type of arrhythmia and locate the focus responsible for maintaining it.

The entire procedure is usually performed under local anesthesia, under X-ray control.

Special diagnostic electrodes and the actual ablation electrode are inserted into the heart through peripheral venous and arterial vessels. The tip of the latter is heated (by means of a radio frequency current), which leads to the destruction of the area causing a specific rhythm disturbance. A cooled electrode can also be used for this purpose. Then we are talking about the so-called cryoablation.

Ablation is highly effective, but sometimes the procedure must be repeated several times to obtain a lasting effect.

The above methods are primarily the prevention of arrhythmias. Stopping a ventricular tachycardia attack is a completely different matter.

If tachycardia is haemodynamically unstable, i.e. with pulmonary edema, a significant drop in blood pressure, chest pain or impaired consciousness, it is necessary to perform electrical cardioversion - delivering an electrical impulse discharge to the patient's body surface in order to restore normal heart rhythm .

If there are no symptoms of haemodynamic instability, pharmacological treatment can be used, e.g. amiodarone infusion.

Cardiac arrest (in the course of VF or VT in the absence of a pulse) is an indication for immediate CPR with the fastest possible defibrillation. All extensionssymptoms that may lead to suspicion of arrhythmia require an urgent call for help.

A component of the treatment of ventricular arrhythmias, especially ventricular fibrillation and tachycardia, is an implantable cardiac defibrillator (ICD).

It is a device consisting of a special "box" containing a battery and an electronic circuit, and electrodes placed inside the heart cavities. The task of the ICD is to detect life-threatening arrhythmias and terminate them by means of cardioversion, defibrillation, or rapid pacing.

The classic indications for implanting a cardioverter-defibrillator in patients include: a previous episode of ventricular fibrillation or haemodynamically unstable ventricular tachycardia and symptomatic heart failure with reduced ejection fraction persisting after myocardial infarction<=35%.

Category:

Cardiology