Cardiac arrhythmia: causes, symptoms, diagnosis and treatment

By Cristiano Antonino Last updated Jun 9, 2023

Let’s talk about cardiac arrhythmia. The heart is a muscle whose basic task is to circulate blood throughout the body

In it there is an electrical circuit, called the excito-conduction system, which activates and regulates cardiac contraction.

Normally, the heart rate varies between 60 and 100 beats per minute and the contractions follow one another in a regular and rhythmic manner, with only slight physiological variations linked to breathing (beats tend to slow down during deep exhalation).

Cardiac arrhythmia is a disorder

of the heart rhythm, in which the beats are not rhythmic (e.g. atrial fibrillation);
of the increased heart rate (tachycardia) in which the rate exceeds 100 beats per minute at rest;
of decreased heart rate (bradycardia) in which the rate is less than 60 beats per minute at rest.

Cardiac arrhythmia occurs when there is a delay or blockage of the electrical signals that control the heartbeat.

This occurs when the special nerve cells that produce the electrical signals do not work properly or if the signal does not travel normally through the heart.

An arrhythmia can also occur as a result of the production of an electrical signal within the heart, which is in addition to the signal produced by the designated nerve cells.

CAUSES AND RISK FACTORS OF CARDIAC ARRHYTHMIA

Among the most common risk factors for an arrhythmia are:

smoking;
alcohol abuse;
coffee or tea abuse;
drug use (e.g. cocaine and amphetamines);
side effects linked to the use of certain drugs;
digestive disorders;
COPD (chronic obstructive pulmonary disease);
severe emotional stress (fear, sadness, anger…)
an increase in blood pressure values
the release of particular stress hormones;
a heart attack;
previous medical conditions (hypertension, coronary artery disease, thyroid dysfunction leading to overproduction or hypoproduction of thyroid hormone, rheumatic heart disease).

In some forms of arrhythmia (e.g. Wolff-Parkinson-White syndrome), congenital cardiac malfunctioning factors, i.e. present from birth, may be involved.

SYMPTOMS

The different forms of arrhythmia are manifested by similar symptoms: palpitations, a sense of weakness, breathlessness and, in the case of atrial fibrillation, a particular sensation in the chest, described as a ‘heart pounding’ or ‘jumping heart’.

Syncope (short-lived loss of consciousness) occurs in the event of insufficient blood supply to the brain (brachycardia with less than 20 beats per minute or sudden tachycardia with a frequency of more than 200 beats per minute).

The patient, if lying down with raised legs, quickly regains consciousness.

If, however, he does not regain consciousness, this is an emergency with danger of cardiac arrest, in which case emergency life-saving measures are required: cardiac massage, artificial respiration, defibrillation, etc., so it may be vital to go to the emergency room immediately.

DIAGNOSIS OF CARDIAC ARRHYTHMIA

For an accurate diagnosis, the cardiologist has certain medical tests available.

Blood tests (cardiac markers) measure any damage to the heart, sugar levels (blood sugar) and thyroid hormones (TSH, T3 and T4).

In young women, cardiac arrhythmia can be caused by an overfunctioning thyroid (hyperthyroidism) or anaemia.

The electrocardiogram (ECG) records the electrical impulses of the heart and is used to find out what type of arrhythmia one is suffering from.

If arrhythmias are frequent, the doctor may ask you to wear a portable ECG (Holter) for 24 consecutive hours.

An echocardiogram with ultrasound highlights the size of the heart and heart valves; while a chest X-ray helps to find out if the cause of the cardiac arrhythmia is a problem related to the lungs.

If cardiac arrhythmia starts during or after physical activity, the doctor may prescribe an exercise test, which assesses how the heart reacts to physical fatigue.

Cardiac activity is recorded while on an exercise bike or treadmill.

If arthritis appears during the test, it means that the heart is not getting enough blood and the health of the arteries needs to be checked.

CURE

Arrhythmias that are not disturbing usually do not require treatment.

If, however, the disturbance is frequent, treatment can be opted for: in the case of extrasystoles, with mildly sedating drugs.

If no results are obtained, anti-arrhythmic drugs are used.

In the case of supraventricular tachycardias, one tries to interrupt them when they have already occurred with antiarrhythmic drugs or by performing special manoeuvres such as immersing the face in ice-cold water or administering electrical stimuli, while trying to prevent their recurrence in the future, again with antiarrhythmic drugs.

For ventricular tachycardias, drugs that control the rhythm are used, although in some cases they are unable to do so, so small probes in the heart connected to a small electronic device that can tell when the tachycardia is in progress and send electrical stimuli that interrupt it are used.

Brachycardias are cured by implanting a pacemaker (cardiac pacemaker) that replaces the cardiovascular circuits that have failed, capable of varying the heart rate according to what the person needs.

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