Repetitive Monomorphic Ventricular Tachycardia (RMVT)

Repetitive monomorphic ventricular tachycardia (RMVT) is a type of ventricular tachycardia that tends to occur in young people whose hearts are otherwise normal. This is in stark contrast to the usual kind of ventricular tachycardia, which is most often seen in older people who have coronary artery disease or heart failure.

What Is Ventricular Tachycardia?

Ventricular tachycardia is a sudden, rapid, often dangerous cardiac arrhythmia that originates in the cardiac ventricles. While sometimes a person having ventricular tachycardia will experience only minimal symptoms, much more typically this arrhythmia causes immediate problems which may include significant palpitations, severe lightheadedness, syncope (loss of consciousness), or even cardiac arrest and sudden death.

These symptoms occur because ventricular tachycardia disrupts the heart's ability to pump effectively. The pumping action of the heart deteriorates during ventricular tachycardia for two reasons. First, the heart rate during this arrhythmia tends to be very rapid (often, greater than 180 or 200 beats per minute), rapid enough to reduce the volume of blood the heart can pump. Second, ventricular tachycardia can disrupt the normal, orderly, coordinated contraction of the heart muscle — so much of the work the heart is able to do becomes wasted. These two factors together often make ventricular tachycardia a particularly dangerous cardiac arrhythmia.

What Makes RMVT Distinctive

Three things make RMVT and other idiopathic ventricular tachycardias different from "typical" ventricular tachycardia: who gets is, what causes it, and how it is treated.

Typical ventricular tachycardia is an arrhythmia that occurs in older people who have underlying heart disease. The diseased cardiac muscle creates a localized environment in which ventricular tachycardia occurs.

In contrast, RMVT is seen almost exclusively in people under 40 or 45 years of age who have structurally normal hearts, and it seems to be somewhat more prominent in females. While an underlying genetic cause seems likely, this has not been proven.

Typical ventricular tachycardia is a reentrant arrhythmia. RMVT, on the other hand, is not a reentrant arrhythmia but is caused by an entirely different mechanism (so-called "triggered" activity), that is related to an abnormal flow of ions across the cardiac cell membrane.

Because of the differences in who gets these arrhythmias and how they occur, the treatment of RMVT is much different from the treatment of typical ventricular tachycardia. More on the treatment below.

Symptoms

RMVT usually produces frequent, brief, non-sustained "bursts" of ventricular tachycardia, though it is also common for people with this condition to have occasional longer episodes.

The most common symptoms caused by RMVT are palpitations and dizziness. More rarely, syncope (loss of consciousness) can also occur. Fortunately, the risk of cardiac arrest and sudden death with RMVT appears to be quite low.

The ventricular tachycardia associated with RMVT can be triggered by situations in which adrenaline levels are elevated. So, people with RMVT are more likely to experience symptoms with exercise (in particular, during the warm-down period immediately following exercise), or during periods of severe emotional stress.

Treatment

Fortunately, RMVT can often be controlled with a calcium blocker (verapamil) or with beta blockers (such as propranolol) — drugs that tend to produce relatively few side effects.

If these drugs do not provide sufficient suppression of ventricular tachycardia, the use of more powerful antiarrhythmic drugs can be considered, although these drugs tend to cause much more toxicity.

In most patients with RMVT, the ventricular tachycardia originates in a localized area in the upper portion of the right ventricle, just below the pulmonic valve. In a few patients who have RMVT, the arrhythmia comes from a similar location in the left ventricle — that is, just below the aortic valve.

In either case, the fact that the arrhythmia's origin can be isolated to a particular location makes RMVT amenable to ablation therapy. Successful ablation of RMVT can be achieved in 80-95% of patients with this condition.

Given these treatment options, most experts will first attempt to treat a patient with RMVT using verapamil and/or a beta blocker. If that is not successful, ablation therapy is usually considered to be the next step. One way or the other, with good medical care the arrhythmias associated with RMVT can usually be controlled or eliminated.

A Word From Verywell

RMVT is a particular type of ventricular tachycardia seen in otherwise healthy young people. While the risk of death from RMVT appears to be quite low, this arrhythmia can be disruptive to a person’s life. Fortunately, with appropriate therapy, it can be controlled or eliminated.