Ventricular Flutter And Ventricular Fibrillation – Causes, Diagnosis And Treatment
Ventricular flutter is a rapid ventricular tachycardia, with a rate of 180-250 beats / minute, which degenerates, most frequently, into ventricular fibrillation. Ventricular flutter occurs most often in severe organic heart disease, the most common cause is acute myocardial infarction. Some drugs (digoxin, quinidine, tricyclic antidepressants) may be triggers of ventricular flutter. From a clinically point of view, a patient with ventricular flutter presents secondary signs of hemodynamic deterioration, loss of consciousness, the absence of peripheral pulse and collapsed blood pressure.
ECG shows the following:
- Electrocardiographic waves with large amplitude, with continues ongoing and sinusoidal aspect, the components of the QRS complex can not be individualized (electrical activity is impossible to identify), a characters that allow the differentiation from a ventricular tachycardia,Â in which is possible the distinguish between individual components of the the QRS complex .
- Flutter wave frequency is 180-250 beats / minute.
Ventricular flutter is a major cardiovascular emergency and therefore the treatment should be done as quickly as possible. This consists in CPR measures and the administration of external electric shock of 200-400 joules, as soon as possible.
Ventricular fibrillation represents the disappearance of organized ventricular electrical activity. It is the most serious cardiac arrhythmia, due to serious hemodynamic consequences which are inducing: loss of pump function of the heart, collapse of cardiac output and of blood pressure. Most of the times, ventricular fibrillation is irreversible, fatal if the measures of CPRÂ and external electric shock are not quickly applied, to obtain a efficiently heart rate, from haemodynamically point of view.
- Myocardial infarction;
- Atrial fibrillation in the presence of Wolf-Parkinson-White syndrome;
- Long QT syndrome;
- Brugada syndrome;
- Drug intoxication (digoxin, quinidine, procainamide, tricyclic antidepressants);
- Heart failure, in terminal phase.
In terms of conditions of appearance, ventricular fibrillation may be primary, in the absence of cardiogenic shockÂ and heart failure, and secondary, which occurs in patients with cardiogenic shock or heart failure.
Triggering factors of ventricular fibrillation are, most often, a ventricular extrasystole with R / TÂ phenomena,or can occur the degeneration of ventricular tachycardia or torsades de pointes into ventricular fibrillation.
Clinically, patients experience loss of awareness, convulsive movements, respiratory arrest, peripheral pulse and blood pressure are absent. In situations in which the intervention dose not occur quickly, will appear death.
ECG shows the following:
- Chaotic undulations of isoelectric line, with variable amplitude, morphology and duration;
- Ventricular rate is between 150-250 beats / minute.
In terms of the ECG, there are two types of ventricular fibrillation:
- Tonic ventricular fibrillation with large waves, which usually respond to external electric shock.
- Atonic ventricular fibrillation, with small waves, hard reducible.
Ventricular fibrillation is a major cardiovascular emergency, so the treatment should be instituted as quickly as possible and is aiming measures of CPR and application of external electric shock of 200-400 joules. If the measures of treatment are not quickly applied, the patient may die.
Prevention of ventricular fibrillation recurrences is achieved by intravenous administration of amiodarone (5-20 mg / kg intravenous infusion for 30-120 minutes, followed by intravenous infusion to a total dose of 1200 mg/24 hours, then is given an oral dose of amiodarone of 100-600 mg / 24 hours), procainamide, lidocaine or tosylate of bretilium. Some patients require implantation of a cardioverter defibrillator.