Sudden cardiac death (SCD, also referred to as sudden cardiac arrest) is an unexpected death that occurs as a result of malfunctioning in the heart’s electrical system. Death occurs within an hour of the onset of symptoms. This condition is most common in older adults, but can affect people of any age. Many times, symptoms appear as a result of heart disease which may not be known prior to the SCD.
The heart issues which lead to SCD result from abnormal heart rhythms, the most dangerous and deadly of which is ventricular fibrillation. This condition can cause complete pump failure or interruptions in the heart’s ability to supply the rest of the body with oxygen which can pose a serious threat to your life..
According to a report by the American Heart Association, sudden cardiac death is the leading cause of death in the U.S., claiming up to 300,000 lives nationwide every year. This represents about half of all deaths caused by heart disease in the United States.
While a previous heart attack (myocardial infarction) can increase your risk of sudden cardiac death, the two conditions are distinct from one another. A heart attack is a malfunction of the heart muscle which is caused by a sudden blockage in the coronary artery, while SCD is caused by an electrical disturbance.
However, any heart attack which is not treated in a timely manner can deteriorate into sudden cardiac death. SCD can also occur in patients who have previously had a heart attack, or patients with certain abnormal congenital heart conditions like, hypertrophic cardiomyopathy or arrhythmogenic right ventricular cardiomyopathy, or patients with genetic abnormalities in the electrical system of the heart.
Sudden cardiac death is caused by an abnormality in the electrical impulses which cause your heart to pump blood throughout the body. Irregular heartbeats can vary in type and root cause, but is often more likely to occur if damage has occurred to the heart due to a previous issue such as:
When sudden cardiac arrest occurs, the symptoms are immediate and devastatingly clear. SCD is marked by a sudden loss of consciousness along with the cessation of breathing and lack of a pulse. For this reason, getting screened for sudden cardiac death is incredibly important, especially if you have had a previous cardiovascular condition that puts you at a higher risk.
In some cases, symptoms will be observable prior to the collapse which accompanies sudden cardiac arrest. Potential warning signs include:
Any of these warning signs should be taken very seriously and reported to a doctor immediately.
Victims of sudden cardiac death can range widely in age, genetics, and background., but this condition is more likely to occur in older adults, especially those with a history of coronary artery disease (CAD), heart attacks, diabetes, or structural heart disease. Heart abnormalities which cause SCD can also result from a variety of lifestyle factors, including smoking, sedentary lifestyle, obesity, high blood pressure, and high cholesterol.
There are also several genetic factors which may impact your susceptibility to sudden cardiac arrest. The most common genetic markers include:
While still quite rare, SCD is the leading cause of death in young athletes. This most commonly occurs as the result of a heart issue which was previously unknown. Some of these include hypertrophic cardiomyopathy (unusual thickening of the heart muscle), congenital heart defects, or an undiagnosed blunt force injury to the chest cavity. These may present no symptoms prior to the onset of sudden cardiac death, and can only be detected through diagnostic testing by a cardiologist.
Young athletes, as well as their parents and coaches, should also take seriously any potential symptoms of imminent cardiac arrest, such as shortness of breath, chest pain, or heart palpitations.
Because cardiac arrest is fatal within a very brief timeline, it is highly important to know what causes it in the first place and have regular SCD screenings, especially if you have had heart problems in the past or have had anyone in your family suffer sudden cardiac arrest..
New diagnostic technology, such as heart monitors and genetic testing can predict those who are at risk of life-threatening ventricular arrhythmias that can cause SCD. You can also decrease your likelihood of related conditions like heart attacks and heart failure by getting routine cardiovascular exams with EKG and echocardiograms. At Manhattan Cardiology, we are able to perform all of these diagnostic procedures in order to determine that the heart is structurally and electrically normal and pumping as it should.
When cardiac arrest occurs, immediate action is crucially important to increasing the odds of survival. The first emergency treatment for SCD is cardiopulmonary resuscitation (CPR). Chest compressions should be properly performed by someone who is certified to perform CPR, with two people alternating if at all possible in order to prevent fatigue.
The most effective treatment for sudden cardiac death is to defibrillate with a nearby AED. Again, this should be performed by someone who is trained and qualified to do so.
Once a pulse is observed and noted, CPR can be halted and the patient must be taken in for cardiac imaging to identify the cause of the sudden cardiac death. If the cause is due to a myocardial infarction then a coronary angioplasty must be done to remove the blockage from the cardiovascular system.
In the case of hypertrophic cardiomyopathy (HCM) some possible treatments include an automatic implantable cardioverter defibrillator (AICD) – and implant which monitors your heartbeat and releases a corrective electrical impulse when necessary – and/or a surgical myectomy.
Beyond getting regular SCD screenings, the best preventative measures for sudden cardiac death are to maintain a healthy lifestyle, getting enough exercise, avoiding cigarettes and unhealthy foods, and to control the most cardiac risk factors such as blood pressure and diabetes. It is also important to take necessary medications to manage any clotting disorders and arrhythmias which may be present.
The most vital preventative measure of sudden cardiac death is getting proper screening on a regular basis and controlling the risk factors that lead to CAD and subsequent heart attacks.
As noted earlier, the primary treatment of sudden cardiac death is immediate defibrillation to save the patient’s life. Most of the victims of SCD die before they get to the hospital. If you suspect cardiac arrest – signs typically include fainting or collapsing and loss of heartbeat or pulse – you should call 911 immediately. Warning signs, such as a racing heartbeat or dizziness, chest pain, nausea, vomiting. or shortness of breath, also require immediate action in order to minimize harm and risk of death.
The condition most commonly tied to sudden cardiac death is coronary artery disease (CAD). According to a PubMed study, 80% of SCD cases are caused by CAD. The remaining 20% are caused by cardiomyopathies. Another similar condition is Commotio cordis (Latin, “agitation or disruption of the heart”) which is an often lethal disruption of heart rhythm that occurs as a result of a blow to the area directly over the heart (the precordial region) at a critical time during the cycle of a heartbeat.
Sudden cardiac death is an unexpected death that occurs as a result of malfunctioning in the heart’s electrical system. It can affect anyone, but is most common in older adults and especially people who have a known or unknown pre-existing heart condition. Death occurs within an hour of the onset of symptoms, making it highly important to get screened in order to establish your risk of SCD and take preventive measures before it occurs. When cardiac arrest does occur, treatment must be implemented and performed immediately by CPR and AED defibrillator.