Ventricular tachycardia is an attack of palpitations ventricles to 180 beats or more. Accuracy of rhythm is usually preserved. If ventricular tachycardia as well as with supraventricular (supraventricular) usually attack begins acutely. Edema hysteria often occurs independently.
Paroxysmal ventricular tachycardia – the most dangerous type of arrhythmias. This is due to the fact that, first, this type of arrhythmia is accompanied by breach of the pumping function of the heart, resulting in circulation failure. And, secondly, the high probability of a transition in the atrial or ventricular fibrillation. When such complications stops coordinated work of the myocardium, and, therefore, there is a complete cardiac arrest. If in this case does not provide resuscitation, then followed by asystole (cardiac arrest) and death.
Classification of ventricular tachycardias
According to the clinical classification allocate 2 types of tachycardias:
- duration for more than 30 seconds;
- pronounced hemodynamic disturbances;
- higher risk of developing heart failure.
Paroxysmal unstable ventricular tachycardia:
- short duration (less than 30 seconds);
- hemodynamic disturbances are absent;
- the risk of developing atrial fibrillation and heart failure is still high.
Particular attention should be paid to so-called special forms of ventricular tachycardia. They have one common feature. In the event of such sharply increased willingness of the heart muscle to the development of ventricular fibrillation. Among them are:
- Recurrent ventricular tachycardia:
- resumption of paroxysm after periods of normal heart rhythm source of the sinus node.
- Polymorphic tachycardia:
- this form can occur at the same time there are multiple lesions rhythm source.
- Bidirectional ventricular tachycardia:
- It is characterized by a variety of ways of nerve impulse from one ectopic foci or regular alternation of the two sources of the nerve impulse.
- Tachycardia type “pirouette”:
- abnormal rhythm;
- in type is bi-directional;
- a very high heart rate (heart rate) to 300 beats per minute;
- the ECG – undulating rise followed by a decrease in the amplitude of the ventricular QRS-complexes;
- tendency to relapse;
- at the onset of the paroxysm determined lengthening the interval Q-T (ECG) and the emergence of early premature beats (premature contractions of the myocardium).
In order to determine the type of paroxysmal tachycardia and ensure that it takes place ventricular shape sufficiently several diagnostic methods. The main of them is the electrocardiogram (ECG).
There are also a number of indirect signs, which can assume the presence of a ventricular tachycardia such as paroxysmal. These include all of the above symptoms plus some simple physical examination and their results:
- while listening to the work of the heart (auscultation) – palpitations with deaf cordial tones that can not be calculated;
- weak pulse in the radial artery (defined on the wrist) or not (if it is impossible to “feel out”);
- a sharp decline in blood pressure (BP). Blood pressure often do not determine, firstly, due to its very low level and, secondly, because the heart rate is too high.
In the absence of ECG signs of ventricular tachycardia, but the presence of these symptoms, it is advisable to conduct Holter monitoring. One of the main objectives of these two instrumental examinations – determining the presence of ventricular tachycardia and its differential diagnosis of supraventricular forms with aberrant conduct (with extended QRS-complex).