An arrhythmia is an abnormal heart rhythm that’s triggered by a problem with the heart’s electrical system. It can cause the cardiac muscle to beat too quickly, too slowly, or in an irregular pattern. Atrial fibrillation (A-fib) is the most common type of arrhythmia.
While mild arrhythmias often self-correct and go unnoticed, intense arrhythmias can trigger erratic heart beats and turbulent rhythms that ripple chaotically through each chamber. This is why severe arrhythmias are also a leading cause of stroke and sudden cardiac arrest.
If you’re at risk of having these dangerous arrhythmias, our team at Sunnyvale Cardiology in Sunnyvale, Texas, can help you control them with an implantable cardioverter defibrillator (ICD). Here’s when we may recommend this life-saving medical device.
An ICD is a battery-powered device that continuously monitors your heart rate and rhythm. When it senses either a dangerous arrhythmia or cardiac arrest, its pulse generator delivers a high-energy electric charge to either restore normal rhythms or restart the heart.
This critical treatment is called defibrillation.
Surgically inserted in your chest just below the skin, an ICD (including pulse generator and battery) is about the size of a stopwatch. Thin attached wires, called leads, go into your heart chambers to regulate their rhythm. We use an ICD to:
An ICD is different from a pacemaker, which is another type of implanted cardiac device that works consistently to help your heart maintain a normal rate. An ICD simply monitors your heart’s rhythm and rate — intervening only when a problem arises.
Some ICDs also have pacing capabilities, providing controlled electric pulses to bring the heartbeat up to a normal rate when its rhythm is dangerously slow. Some devices offer dual ICD-pacemaker function, too.
In addition to being a frontline defense against life-threatening arrhythmias, an ICD is also a go-to solution for other conditions that carry a higher risk of sudden cardiac arrest. You may be a candidate for an ICD if you have:
ICDs are frequently recommended to control dangerous high-risk arrhythmias, including ventricular arrhythmias that have caused fainting.
The two arrhythmias that are most likely to cause sudden cardiac arrest are ventricular tachycardia (V-tach), which triggers a rapid heartbeat, and ventricular fibrillation (V-fib), which makes the heart’s ventricles twitch or quiver instead of pump blood.
If you’ve already survived a sudden cardiac arrest due to V-fib, an ICD is typically an essential part of your cardiovascular care going forward.
Congestive heart failure with a low ejection fraction (HFrEF) — also called systolic heart failure — occurs when the heart’s left ventricle is weak and doesn’t pump enough blood. Besides causing symptoms like shortness of breath, fatigue, and swelling, HFrEF makes sudden cardiac arrest more likely. An ICD can mitigate this risk.
Cardiomyopathy is a disease that weakens the heart muscle, leaving it less capable of pumping blood effectively. Dilated cardiomyopathy (enlarged heart) and hypertrophic cardiomyopathy (thickened heart muscle) can increase the likelihood of life-threatening arrhythmias, making an ICD beneficial.
Certain inherited cardiac conditions can trigger dangerous heart arrhythmias that require an ICD. Examples include Long QT syndrome (LQTS), which occurs when the heart takes longer than normal to recharge itself between beats, and Brugada syndrome, which disrupts normal cardiac electrical activity and often gives rise to V-fib or V-tach.
Having a family history of sudden cardiac arrest is another genetic risk factor that may call for ICD placement, depending on other pertinent risk factors.
Structural heart conditions like coronary artery disease, valvular heart disease, and congenital heart defects can make dangerous arrhythmias more likely, as can damage from a previous myocardial infarction (heart attack) or heart surgery. In such cases, an ICD can be beneficial as a preventive measure.
Do you have questions about ICDs? We have answers. Schedule an appointment online or via the phone with one of our board-certified cardiologists today.
