The sudden death of cardiac origin (often also called cardiac arrest) results from an abrupt stop of the heart’s function, causing it to cease functioning. A fundamental feature of the concept of sudden death is that it occurs unexpectedly concerning the time and manner of its occurrence. It usually appears a few minutes after the onset of symptoms. The main underlying cause of sudden death is a disease of the coronary arteries, which become occluded by the deposition of fatty plaques and blood clots. The coronary arteries are responsible for supplying blood to the heart muscles.
When the occlusion of a coronary artery acutely blocks the blood supply to the heart muscle, instability in a heartbeat (arrhythmias) can occur. These can become very rapid (ventricular tachycardia) and chaotic (ventricular fibrillation). These arrhythmias eventually progress to the heart’s stop beating. Another source of cardiac arrest can arise in situations where the heart becomes extremely slow, called bradycardia.
Most patients who are victims of sudden cardiac death are already present, in their postmortem examinations, with the involvement of two or more essential arteries of the heart, at least one of which is usually acutely completely occluded. Two-thirds of victims already have scars from previous heart attacks. It is interesting to note that many of these previous infarctions may have passed without previous diagnosis and treatment. The patient often interprets the episode as a “stomach problem” or “gas”; it is common for the patient to refuse medical attention.
When sudden cardiac death occurs in a young person, the most likely causes are usually other than coronary artery occlusions. The release of adrenaline during intense physical activity often acts as a trigger for cardiac arrest. This situation occurs more frequently when the individual already has some previous clinical condition, often congenital.
Under certain conditions, drugs and illicit drugs can precipitate sudden cardiac death in individuals, including young people who do not have coronary heart disease. The mechanism, in these cases, is the emergence of cardiac arrhythmias; these arrhythmias evolve to the cessation of heartbeats.
“Massive heart attack” is often misused to describe sudden cardiac death.
“Heart attack” or “heart infarction” refers to the death of the heart muscles due to the loss of blood supply to the coronary arteries. Still, it does not necessarily result in cardiac arrest or the patient’s death. A heart attack can lead to cardiac arrest and sudden cardiac death, but the terms are not synonymous.
Cardiac arrest which can be treated by a cardio doctor such as cardiocare cardio doctor is reversible in many conditions. Victims if treated in a few minutes with an electric shock applied to the chest (the medical term is defibrillation) by a defibrillator device. A victim’s chance of recovering decreases by 7-10% for every minute that passes without defibrillation. Brain death and permanent death occur within 4 to 6 minutes after cardiac arrest. Few resuscitation attempts are successful after 10 minutes. Resuscitation maneuvers can be performed by trained laypersons (immediately), paramedics, and physicians. In addition to defibrillation (which depends on the equipment, the defibrillator), maneuvers include cardiac massage and artificial ventilation (which can be initiated with mouth-to-mouth resuscitation).
The definitive treatment for people who have recovered from cardiac arrest includes investigating the causes and treating them to prevent future episodes. The leading causes treated are coronary obstructions and arrhythmias. These, often when diagnosed as malignant and potentially lethal arrhythmias, may require the implantation of cardiac pacemaker devices.
Examinations and further treatment include cardiac catheterization, electrophysiological tests, angioplasties and stent implants, coronary artery bypass grafting, antiarrhythmic drugs, and pacemaker implants.