Ventricular tachycardia is characterized by increased heart rate arising in the ventricles. It is a life threatening condition, indicating immediate medical intervention.
In the condition of ventricular tachycardia, the heartbeat is increased causing a sudden drop in the blood pressure, resulting in inability of the heart to pump blood to other body organs. Such sequence of events gives rises to the following symptoms:
Prognosis of ventricular tachycardia depends on the functioning of left ventricles. The underlying disease conditions and severity of the symptoms also affect the prognosis. However, left ventricular functioning may not always be the determining factor for prognosis of ventricular tachycardia. Studies have shown that individuals with good left ventricular functioning, but having long QT syndrome, and hypertrophic cardiomyopathy are at an increased risk of sudden death. It has been estimated that, about 30% individuals with non-sustained ventricular tachycardia and ischemic cardiomyopathy are more likely to suffer sudden death within 2 years of onset of disease. Prognosis is excellent in individuals with idiopathic ventricular tachycardia .
Heart diseases are the most common cause of ventricular tachycardia. Individuals with cardiomyopathy, myocarditis, heart failure, or valvular heart disease are at an increased risk of developing this condition. Ventricular tachycardia often is a common accompaniment in patients, who have undergone heart surgery.
In addition to underlying heart disorders the following factors can predispose an individual to develop ventricular tachycardia:
The incidence rate of ventricular tachycardia is higher in the developed nations. In developing countries, the prevalence of these diseases is relatively low. It has been estimated that, in the US, ventricular tachycardia was the major cause of sudden death in about 300,000 cases each year .
Statistics have revealed that ventricular tachycardia accounts for 5.6% of all mortality. Men are more prone to develop the disease condition, mainly because of higher incidence of ischemic heart diseases in them. Females, who have long QT syndrome, are more prone to develop ventricular tachycardia .
Under normal physiological conditions, the heart rate is effectively controlled by the electrical signals, which are transmitted across the heart muscles. Various conditions may cause the signals to be sent too rapidly, leading to development of ventricular tachycardia. Rapid heartbeats in turn lead to decreased cardiac output which results from decreased ventricular filling. In conditions of ischemic heart disease and mitral valve insufficiency, there is also significant decrease in ventricular stroke output as well as reduced hemodynamic tolerance .
Majority of the cases of ventricular tachycardia cannot be prevented. However, individuals with underlying heart diseases should get it treated in order to prevent the onset of ventricular tachycardia.
Ventricular tachycardia (VT) is a dangerous form of arrhythmia, which can call for development of debilitating complications. Individuals affected by ventricular tachycardia, have heart rate of more than 100 beats/minute, accompanied by 3 or more irregular beats. Underlying disease condition, heart diseases, myocardial infarction and heart surgery, all can cause ventricular tachycardia to develop .