08 May 2018



The heart has its unique electric system. Its function is to effectively synchronise its contraction, from the bottom to the top.


An electric system managed by a conductor

The conductor of this electric system is situated at the top of the heart, near the right atrium.

It is a cluster of cells called sino-atrial node that is in fact the natural “pacemaker” of the heart. It initiates all the heartbeats and determines their frequency.



An organized electric transmission

The electricity generated is transmitted to the atriums and ventricles by the different elements of the electric system, or the electric customs officer, known as the atrioventricular node, and the rapid conduction network in the ventricles called the Purkinje bundle.



The normal heartbeat frequency


The normal heartbeat frequency is between 60 and 100 beats per minute.






It varies during the day

It is normal that the heart rate varies during the day.

The heart beats slower when we are at rest and must accelerate when doing a physical activity or during stress periods.


An influenced electrical system

The heart’s electrical system may be compared to an electric heating system in a house. There is a difference, however as it is influenced by the brain and certain substances found in the blood.


The bradycardia

Unlike accelerations, arrhythmias may manifest themselves in a slower rhythm than usual.

A heart rate slower than 60 beats per minute is called “bradycardia”.


A possible normal situation

These slowdowns are often normal. When we are inactive, during rest or while sleeping, the heart is also resting; the heart rate may be lower than 60 beats per minute.

This is particularly the case with athletes or with people who regularly practice a sustained cardiovascular activity such as jogging or biking.


Activity causes the heart to accelerate


This bradycardia disappears when the individual begins to walk or starts any given activity.

A heartbeat that slows down at rest is therefore without consequence.





The effects of certain medication

The heart rate may also be slowed by certain medications. It is particularly the case for a specific group of medications called Beta-blockers.

The slower heartbeat is actually the goal in the sense that it can solve certain health problems like angina and some arrhythmias.



Few or no symptoms

Luckily, the bradycardias often cause few or no symptoms. In the most severe cases, the probable symptoms (perceived solely by the patient themselves), are weakness and dizziness.

The doctor may ask for a holter to be fitted on the patient when in these symptoms are experienced.


The holter

The holter records the heartbeat during a complete day. It can show, depending on the situation, the importance of the bradycardia and the links between the symptoms experienced by the patient.


The treatment

The treatment consists of removing the reason for the symptomatic bradycardia, or, in other words, the slow heart that is responsible for these symptoms.

A review of the patient’s medication list is necessary.

Changing the dose or removing the medication is the first step a health professional will take.


Always carry your list of medications

It is very important that you carry your list of medications with you when meeting with a health professional. Do not take for granted that he has this information.

Ask your pharmacist to give you your health record that you can place in your wallet or handbag.


A pacemaker is rarely necessary

In the case where a slow heartbeat is caused by the natural pacemaker of the electric system, an actual pacemaker also known as a heart stimulator or “battery” is necessary.


ECG example;

Normal at right and sinusal bradycardia, 45 beats per minute.

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