Introduction
For sudden cardiac death (MIC) we want to indicate an unexpected and unexpected natural death that occurs due to causes of cardiac origin .
This is a death that occurs quickly within an hour of the onset of acute symptoms which, however, sometimes do not manifest themselves, making it difficult - if not impossible - to identify the imminent onset.
The underlying causes of sudden cardiac death can be multiple: from the obstruction of the coronary arteries, up to congenital anomalies, unfortunately not always diagnosed.
In some cases, sudden cardiac death can be avoided by intervening in a timely manner with specific first aid measures. Unfortunately, however, despite timely rescue, the death of the individual may not always be avoided.
What is that
What is Sudden Cardiac Death?
Sudden cardiac death is defined as a natural death that occurs quickly and unexpectedly due to causes of a cardiac nature .
Normally, "sudden cardiac death" and "cardiac arrest" are considered synonymous. Nevertheless, from a physiopathological point of view, it could be stated that sudden cardiac death is immediately preceded by cardiac arrest, that is by the cessation of the function of the heart which - acting like a pump - guarantees blood circulation throughout the body. Cardiac arrest is immediately followed by circulatory arrest and drop in blood pressure with consequent loss of consciousness after just 10-15 seconds. After a few moments, the missed perfusion of the respiratory centers leads to respiratory arrest and already 4 minutes after the cardiac arrest - due to the lack of blood supply, therefore, of oxygen - the brain cells enter into suffering, they start to die and yes irreversible neuronal damage occurs.
Causes
What are the Causes of Sudden Cardiac Death?
As mentioned, the causes of sudden cardiac death can be multiple, but all have a cardiovascular origin .
In the vast majority of cases (around 70-80%), sudden cardiac death occurs due to ventricular fibrillation (the heart contracts rapidly, irregularly and ineffectively); while in 10-15% of cases the MIC occurs due to asystole (absence of cardiac systole). More rarely, on the other hand, sudden cardiac death occurs due to electro-mechanical dissociation, ie a condition in which there is electrical activity but there is no mechanical pumping action that allows blood circulation and oxygen transport to organs and tissues.
What diseases are associated with Sudden Cardiac Death?
The pathologies associated with sudden cardiac death are manifold, among which we mention a few:
- Cardiomyopathies : these are pathologies deriving from primitive myocardial anomalies . The cardiomyopathies that are most associated with sudden cardiac death are substantially three:
- Hypertrophic cardiomyopathy : it is characterized by a ventricular hypertrophy, in particular, of the left ventricle; it generally has a family trend and is the leading cause of death in athletes under the age of 35.
- Dilated cardiomyopathy : it is characterized by a progressive dilation of the cardiac chambers which is associated with a thinning of the wall with consequent impairment of the functionality of the heart.
- Cardiomyopathy-arrhythmogenic dysplasia of the right ventricle : it is characterized by fibro-adipose substitution of the ventricular myocardium. It mainly affects the right ventricle, but can also involve the left one. Generally, it has a family character and is caused by mutations located on specific genes and transmitted in an autosomal dominant manner. This type of cardiomyopathy is responsible for many sudden cardiac deaths "induced" by exercise.
- Hereditary arrhythmogenic cardiopathies : these are cardiac pathologies in which the heart is morphologically normal, but there is the presence of anomalies and defects at the level of cardiac ion channels capable of favoring the onset of malignant ventricular arrhythmias and, consequently, of sudden cardiac death .
- Congenital heart diseases : these are diseases present from birth, some examples are aortic stenosis and tetralogy of Fallot.
- Coronary artery disorders, also known as coronary arteries (for example, narrowing or obstruction of the coronary arteries which, in turn, can lead to cardiac ischemia or myocardial infarction and, finally, to sudden cardiac death).
- Anomalies and pathologies of the heart valves .
Risk factors
One of the most important risk factors for sudden cardiac death is the presence of previous heart attacks. Indeed, it has been estimated that about 75% of people who died of sudden cardiac death had a history of heart attacks. In addition to this, additional risk factors are represented by:
- Presence of cardiac arrhythmias whose causes are not known;
- Presence of tachycardia even at rest;
- Low ventricular ejection fraction;
- Episodes of fainting due to unknown causes;
- Family history of heart disease or sudden cardiac death.
Other factors that could contribute to increasing the risk of sudden cardiac death are:
- The smoking habit;
- Diabetes;
- The stress;
- Hyperlipidemia and hypercholesterolemia;
- Alcohol abuse;
- Use of certain types of drugs.
Incidence
What is the incidence of sudden cardiac death in the population?
Sudden cardiac death is responsible for about 50, 000 deaths a year in Italy. The incidence is about 1 / 1, 000 individuals per year and increases to 8 / 1, 000 subjects per year with a history of heart disease.
It has also been estimated that sudden cardiac death is responsible for about 70% of all deaths due to causes of cardiovascular origin.
MIC occurs predominantly in males in all age groups; however, it can also occur in women, especially if there is the presence of a pathological cardiovascular substrate.
At the same time, sudden cardiac death can also affect children, especially, within the first 6-12 months of age. In these cases we speak more precisely of sudden infant death syndrome, also known by the acronym SIDS, from the English Sudden Infant Death Syndrome .
Incidence of Sudden Cardiac Death in Sportspeople
Sudden cardiac death is an event that can occur even in athletes, both amateurs and amateurs alike.
In these cases, more often than not, it can be traced back to cardiopathies / cardiomyopathies or silent cardiac anomalies that have not been diagnosed.
In truth, sudden cardiac death is not a widespread phenomenon among athletes (low incidence: it does not exceed 1-2% of all sudden cardiac deaths); however, it is an event that causes a sensation because it usually occurs in young individuals (under the age of 35) and apparently healthy who, also by virtue of the level of physical activity they perform, should not have - in theory - any kind of problem.
Curiosity
One of the best-known cases of sudden cardiac death of an Italian athlete is that of midfielder Piermario Morosini, who died in 2012 during a football match.
Signs and Symptoms
What are the Signs and Symptoms of Sudden Cardiac Death?
In most cases, sudden cardiac death occurs, as its name suggests, in a sudden and unexpected way: the subject loses consciousness and falls to the ground apparently already devoid of life.
Note : the use of the term "apparently" is not accidental. In fact, while in some cases sudden cardiac death (understood as cardiac arrest which leads to circulatory and respiratory arrest) and death of the individual are events that coincide; in other situations, cardiac arrest is the beginning of the death process which, however - through timely relief - can be slowed down or even interrupted, increasing the probability of survival of the individual.
More detailed information can be found in the "First Aid" chapter.
In some cases, before reaching the loss of consciousness, patients may experience "warning signs" that indicate imminent cardiac arrest, such as:
- Localized pain in the center of the chest - often similar to that of a stomach ache - which radiates to the arms, back, throat and even the jaw;
- Cold sweats ;
- Breathing difficulties, dyspnea and cough ;
- Weakness ;
- Agitation ;
- Nausea and vomiting .
Unfortunately, however, the aforementioned signs do not always manifest themselves, making it difficult if not impossible to recognize the imminent arrival of sudden cardiac death which only becomes apparent with the onset of unconsciousness.
First aid
First Aid Maneuvers in Sudden Cardiac Death
As mentioned, an individual suffering from sudden cardiac death usually loses consciousness and falls to the ground seemingly lifeless.
The only possibility of survival of the individual is given by the timely intervention and by the execution of particular first aid maneuvers: cardiopulmonary resuscitation (CPR) and early defibrillation using an external semi-automatic defibrillator (AED).
However, it is good to remember that, before putting into practice CPR maneuvers and early defibrillation, it is essential to evaluate the individual's conscience. In fact, the aforementioned first aid operations can only be performed if the patient is not conscious and is not breathing, or in any case breathing in a difficult and / or non-normal manner.
Once unconsciousness and the lack or irregularity of the breath are ascertained, it is necessary to call - or call personally if you are alone - 118 to alert health care. Only then is it possible to proceed with the SPC and early defibrillation. Naturally, any call to 118 must take place as quickly as possible.
Did you know that ...
In the absence of cardiopulmonary resuscitation, the chances of survival of an individual affected by cardiac arrest are halved after only 5 minutes from the event and tend to gradually decrease every minute that passes. After 10 minutes without first aid maneuvers, the chances of survival are almost nil and the apparent and potentially avoidable death of the individual becomes definitive.
It is however necessary to point out that, unfortunately, cardiopulmonary resuscitation and defibrillation are not always able to avoid death.
CPR maneuvers should be carried out until the arrival of 118. Afterwards, once the medical aid has arrived, the individual will be taken in charge and transported to the hospital where - after having diagnosed the cause of cardiac arrest - he will receive all the care of the case.
To know in detail the maneuvers used in cardiopulmonary resuscitation and the treatments received by the patient in the hospital, we recommend reading the dedicated articles: Cardiopulmonary Resuscitation - Treatment of Cardiac Arrest.
Did you know that ...
In an attempt to avert the various and widespread cases of sudden cardiac death on the Italian territory, special BLS ( Basic Life Support ) and BLS-D ( Basic Life Support and Defibrillation - Function Support Basic Vital and Early Defibrillation) for both healthcare personnel and non-healthcare personnel (ie, for so-called "ordinary people").
The purpose of these courses for non-healthcare personnel is to instruct the majority of citizens to essential first aid maneuvers to increase the possibility of survival of the very many patients who every year are affected by sudden cardiac death.
