Inappropriate tachycardia affects more than 1% of the population. However, it is not considered an arrhythmia, but is rather a condition where the heart rate at rest is faster than normal and where there is an inappropriate acceleration of the heart rate when a minimal effort is done.
Let's review some basics to better understand.
The heart has an electrical system of its own.
Its function is to synchronize its contraction effectively.
An electrical system managed by a conductor
The conductor of this electrical system is located at the top of the heart, in the right atrium.
It is a cluster of cells called the sino-auricular node which is in fact the heart's natural “pacemaker”. It initiates all heartbeats and determines the frequency of the heartbeat.
An organized electric transmission
The electricity generated by the heart is transmitted to the auricles and ventricles by the different stages of the electrical system, the electrical customs officer and the fast conduction network in the ventricles.
Factors influence the heart rate
Various factors, like nerves or hormones, influence the heart rate to meet the needs of the body.
These factors accelerate the heart when you hear bad news, when you do physical activity or when you have a fever.
The heart rate continuously adapts to life situations.
Inappropriate tachycardia occurs when the heart rate remains above 100 beats per minute for no apparent reason. There is no beginning or abrupt end to this tachycardia. The heartrate is almost constant, sometimes faster or slower. The heart rate also accelerates very quickly as soon as there is even a slight effort and the heart rate is abnormally high even at night.
Typically, young woman, often with an anxiety disorder but otherwise healthy, suffer from inappropriate sinus tachycardia
The symptoms often described are:
· Chest pain
· Easily out of breath
The diagnosis should first consider and ensure that there are no other causes for this faster heartrate;
· Heart failure with fractioned ejection of the lowered left ventricular
To name only a few.
The electrocardiogram often shows sinus tachycardia of more than 100 beats per minute.
The Holter monitors a heart rate that remains fast without any significant slowing down during periods of rest, even at night. Physical activity quickly increases this frequency to over 130 beats per minute.
People with this problem should avoid stimulants such as caffeine, chocolate and alcohol.
What is the cause?
The cause remains obscure.
The sinoatrial node, or the conductor of the heart rate, is influenced by the sympathetic nervous system that makes it accelerate and the parasympathetic nervous system that slows it down. Under normal conditions, at rest, these two systems are in equilibrium with each other.
Some believe that a disorder of the parasympathetic nerve fibers leads to an imbalance and the sympathetic nervous system increases the base of the frequency to a higher level. It's somewhat like the "thermostat" of the normal heart rate was out of order.
Not dangerous and without consequences
Although inappropriate tachycardia may seem worrisome, this condition is benign. It does not cause heart muscle fatigue and no deterioration of the heart’s contraction force is noted. It is therefore not a cause of tachyarrhythmia cardiomyopathy.
The treatment is adapted to each person depending on the symptoms present. Beta-blockers or calcium channel blockers are the most commonly used. Ivrabadine can also be used.
Since the sinoatrial node is the conductor of the heart rate, ablation through a catheter is excluded. Cauterization of this area is associated with a high risk of bradycardia and the need for a pacemaker.