How Common is SCD?
SCD is a leading cause of death in adults in the U.S. and affects approximately 300,000 adults each year. Controlling the abnormal heart rhythm that leads to most cases of SCD might significantly reduce death from heart diseases. About half of all deaths from heart disease are sudden and unexpected, regardless of the underlying cause. This includes 50 percent of all deaths due to arteriosclerosis (clogged blood vessels – a condition sometimes called “hardening of the arteries”) as well as 50 percent of deaths due to degeneration of the heart muscle, or to enlargement of the heart in patients with congestive heart failure. SCD is particularly devastating because of its unexpectedness. Although studies have shown that most victims have underlying disease, many victims of SCD are outwardly healthy, active individuals who do not know they are at risk. Although economic studies have not yet been done and the direct medical costs are less than for lingering illnesses, the economic and social impacts of SCD are huge. Sudden cardiac death claims many people during their most productive years and devastates unprepared families.
What is the difference between atrial fibrillation and ventricular fibrillation?
atrial fibrillation affects the upper chambers of the heart. ventricular fibrillation affects the lower chambers. ventricular fibrillation is a life-threatening arrhythmia, which causes sudden cardiac arrest within minutes if not interrupted. atrial fibrillation, while not imminently life threatening, in most cases seems to have serious long-term consequences if left untreated.
What can heart attack survivors do to find out if they are at risk for SCD?
Cardiac patients should educate themselves on their risk for sudden cardiac death. If they have had a prior heart attack, especially if severe, they could be at increased risk for SCD. Patients should consult an Electrophysiologist (a cardiologist specially trained in rhythm dysfunctions of the heart) if they have had a prior heart attack, have advanced heart failure or a reduced ejection fraction.
How does an implantable cardioverter defibrillator prevent SCD?
An implantable cardioverter defibrillator (ICD) is a pacemaker-like device and is about the size of three silver dollars. It is placed under the skin just below the collarbone. Signals from wires or leads that are threaded into the heart”s chambers monitor every single heartbeat. If a lethal rhythm appears, the ICD shocks the heart back to a normal rhythm.
How is the ejection fraction measured?
The ejection fraction can be measured using a simple and painless heart ultrasound called an echocardiogram or “echo.” An echo can be performed in a physician”s office in just a few minutes. It can also be measured with Nuclear Scan, Cardiac Catheterization, CT scan or MRI of the heart.
Who else is at risk for sudden cardiac death?
Sudden cardiac death can also appear without warning in people with no prior history of heart disease. However, certain heart attack survivors are at increased risk for SCD depending on the severity of the scar(s) from their heart attack(s). A key measurement of risk is knowing and understanding a heart attack”s effect on the ejection fraction.
Why do heart attack survivors experience sudden cardiac death?
Some heart attack survivors are at increased risk of SCD because of the extent of the damage or scar caused by their heart attack. Not only does the scar impair the heart”s ability to pump blood, but it also disrupts the heart”s normal electrical conduction and can do so without warning.When this occurs, it creates a fatal heart rhythm called ventricular fibrillation.
Is sudden cardiac death the same as a heart attack?
No. While the lay public may equate them, they are two separate problems. SCD is a disorder of the heart”s electrical conduction system. Heart attacks, on the other hand, are caused by blockages of the heart”s coronary arteries due to disease and plaque buildup that prevent blood flow to the heart tissue.
What causes sudden cardiac death?
Sudden cardiac death (SCD) can be caused by a sudden chaotic heart rhythm called ventricular fibrillation. The ventricle, or the heart”s main pumping chamber, fibrillates or quivers so that it stops pumping blood to the body. Although there are other causes of SCD, the vast majority are due to ventricular fibrillation.