FREQUENTLY ASKED QUESTONS

Frequently Asked Questions
<Back to FAQs index page>

Presented in part with the support of Novartis Pharmaceuticals and Boston Scientific / Guidant

Sudden Cardiac Arrest

What is it?
Sudden cardiac arrest (SCA) occurs when the heart stops abruptly. Of course different things can cause your heart to suddenly stop—an electrocution, for example. But with SCA your heart stops because its electrical signals malfunction.

Electrical signals travel down certain pathways in your heart to make it beat correctly. Each signal causes the heart to beat or contract. Unless the person is exercising, a normal heart usually creates about 60-100 signals per minute. SCA occurs when the heart rate is far too slow or, more likely, when the heart rate is much too fast.

In either case a cardiac arrest occurs because the heart is not pumping out enough blood to supply the oxygen needed by the brain. This causes the person to quickly lose consciousness. If the person doesn't receive immediate treatment with defibrillation, brain damage can occur. Without defibrillation treatment the person can die within 7-10 minutes from sudden cardiac death (SCD). Therefore SCA is a serious and life-threatening medical emergency.

To learn more about your heart's electrical system, go to the Heart & Blood Vessel Basics section.

What is the cause?
Usually a sudden cardiac arrest (SCA) occurs when there are irregular heartbeats in the heart's lower chambers (ventricles). These irregular heartbeats are called arrhythmias. The arrhythmia that typically causes SCA is a fast and chaotic rhythm called ventricular fibrillation (VF). When electrical signals are sent too quickly—such as during VF—the heart is unable to pump at all. Instead, the heart muscle just quivers. Because the heart isn't pumping blood to the body, the brain very quickly becomes starved for oxygen. This causes the person to lose consciousness.

But what triggers the heart's electrical system to malfunction? Most heart or blood vessel diseases can lead to SCA:

• Atherosclerosis—blockage of an artery with fatty substances, like cholesterol, in your blood. About 90% of adult victims of sudden cardiac death have atherosclerosis in two or more major heart arteries (coronary arteries).
• Heart attack—about 75% of sudden cardiac death victims have scarring in their heart muscle from a prior heart attack.
• Other heart problems—when SCA occurs in young adults, other rare heart conditions are likely causes.

Other factors can also lead to atherosclerosis. The more of the following risk factors you have, the greater your chances of developing atherosclerosis—and potentially SCA.

Risk factors you can change

• Eating high-fat foods
• Lack of exercise
• Smoking
• Stress
• Excess weight

Risk factors you cannot change

• Age—the risk increases with age
• Heredity—the risk increases if there is family history of heart or blood vessel disease

Other health conditions that can increase your risk

• Diabetes
• Heart failure
• High blood pressure
• High cholesterol
• Low ejection fraction

To learn more, go to the Risk Factors section and the Health Conditions section (for the individual conditions listed above).

What are the symptoms?
Some sudden cardiac arrest (SCA) survivors report symptoms like fatigue in the days leading up to the cardiac arrest. But usually SCA strikes without warning. The first and often the only symptom of SCA is loss of consciousness—from lack of blood reaching the brain.

What tests could I have?
Your doctor may suggest one or more of the tests listed below. Some of the tests check the electrical system in your heart. Other tests check to see how your heart is pumping. The test results can also help your doctor choose the best treatment(s) for you.

In some cases you may be sent to specialists for diagnosis and testing—and sometimes for treatment. To learn more, go to the Your Treatment Team section.

Echocardiogram
Electrocardiogram (ECG or EKG)
Electrophysiology (EP) Study

Echocardiogram

What is an echocardiogram?
An echocardiogram (also called an echo) is a three-dimensional, moving image of your heart. An echo uses Doppler ultrasound technology. It is similar to the ultrasound test done on pregnant women. The echo machine emits sound waves at a frequency that people can't hear. The waves pass over the chest and through the heart. The waves reflect or "echo" off of the heart, showing:
The shape and size of your heart
How well the heart valves are working
How well the heart chambers are contracting
The ejection fraction (EF), or how much blood your heart pumps with each beat

What can I expect?
When you have an echocardiogram, you undress from the waist up, put on a hospital gown, and lie on an exam table. The technician spreads gel on your chest and side to help transmit the sound waves. The technician then moves a pen-like instrument (called a transducer) around on your chest or side. The transducer records the echoes of the sound waves. At the same time, a moving picture of your heart is shown on a special monitor. You may be asked to lie on your back or your side during different parts of the test. You may also be asked to hold your breath briefly so that the technician can get a good image of your heart. An echo is a painless test. You feel only light pressure on your skin as the transducer moves back and forth.

Electrocardiogram (ECG or EKG)

What is an ECG?
An electrocardiogram (ECG or EKG) reveals how your heart’s electrical system is working. The ECG senses and records your heartbeats, or heart rhythms. The results are printed on a strip of paper. An ECG can also help your doctor diagnose whether:
You have arrhythmias
Your heart medication is effective
Blocked coronary arteries (in the heart) are cutting off blood and oxygen to your heart muscle
Your blocked coronary arteries have caused a heart attack

In all, there are three kinds of tests that record your heart's electrical activity, each for a different period of time:
Electrocardiogram (ECG)—done in the doctor's office. It records your heart rhythms for a few minutes.
Holter monitoring—records and stores (in its memory) all of your heart rhythms for 24-48 hours.
Event recorder—constantly records your heart rhythms. But it stores the rhythms (in its memory) only when you push a button.

What are the parts of an ECG strip?
The peaks on an electrocardiogram (ECG) strip are called waves. Together, all the peaks and valleys give your doctor important information about how your heart is working:

• The P-wave shows your heart's upper chambers (atria) contracting
• The QRS complex shows your heart's lower chambers (ventricles) contracting
• The T-wave shows your heart's ventricles relaxing

What can I expect?
When you have an electrocardiogram (ECG) you undress from the waist up, put on a hospital gown, and lie on an exam table. As many as 12 small patches called electrodes are placed on your chest, neck, arms, and legs. The electrodes, which connect to wires on the ECG machine, sense the heart's electrical signals. The machine then traces your heart’s rhythm on a strip of graph paper.

Electrophysiology (EP) Study

What is an EP study?
An electrophysiology (EP) study is a test of your heart's electrical system. While an electrocardiogram (ECG) gives an overview of your heart's electrical system, the EP study gives a more in-depth view. The test helps find out details about abnormal heart rhythms, called arrhythmias. The EP study can reveal:

• If you have an arrhythmia
• The cause of the arrhythmia
• Where the arrhythmia begins in the heart
• If you are at risk for sudden cardiac arrest (SC)
• The best treatment for an arrhythmia

The EP study begins when one or more leads are inserted into a blood vessel, usually in the groin. The doctor gently "steers" the leads toward your heart. Once in place, the leads sense your heart's electrical activity. One special lead also delivers electrical signals to your heart to trigger an arrhythmia. That’s to help find out how easily your heart can produce arrhythmias on its own.

During the EP study, your doctor closely monitors your heartbeats. If an arrhythmia occurs, the doctor treats you with:
Medications given through the intravenous (IV) line in your arm or hand
Electrical signals delivered to the outside of your chest through patches

In some cases, ablation (a form of treatment) is done at the same time as your EP study. (To learn about ablation, go to the Procedures part of the Medications & Procedures section.) Or your doctor can suggest other types of treatment after the EP study.

What can I expect?
Your test will be performed in a "cath lab." You undress, put on a hospital gown or sheet, and lie on an exam table. An intravenous (IV) line put into your arm delivers fluids and medications during the test. The medication makes you groggy, but not unconscious. Patches called electrodes are put on your chest. The electrodes monitor your heart's electrical signals during the test. A blood pressure cuff on your arm also regularly takes your blood pressure.

The doctor makes a small incision (usually in the groin) for the catheter. The groin area will be numbed so you shouldn't feel pain, but you may feel some pressure as the catheter is inserted. If the doctor delivers electrical signals to your heart, you might feel your heart racing or pounding. You won't be fully asleep, so during the test your doctor or nurse might ask you questions. Afterwards you may be in the hospital overnight, but most people have a fairly rapid recovery.

What are the treatment options?
It's essential to get immediate treatment, since more than 95% of sudden cardiac arrest (SCA) victims die before reaching the hospital.

On-the-spot treatment includes:
Immediate CPR (cardiopulmonary resuscitation)—involves chest compressions and mouth-to-mouth breathing. CPR is critical in getting some oxygen to the brain until an electrical shock can be delivered.
Defibrillation—sends a strong electrical shock to the heart to stop the arrhythmia and restore a normal heartbeat. Because brain damage begins within 4-6 minutes, defibrillation should be done as soon as possible.

There are two types of defibrillators:

• External defibrillators use paddles to deliver the shock to the outside of the chest. You've often seen this on TV medical dramas. Some public buildings like sports arenas and airports now have external defibrillators available for such emergencies.
• Implantable cardioverter defibrillators (ICDs) are implanted devices that can sense arrhythmias and deliver lifesaving shocks.

People who are at high risk of SCA—or who are SCA survivors—might also be treated with procedures or medications. However, medications alone have not proven to be very effective in reducing SCA.

Procedures
Defibrillator Implant

Defibrillator Implant (ICD Device Implant)

What is a defibrillator (ICD device)?
An implantable cardioverter defibrillator (ICD) is a small device that treats abnormal heart rhythms called arrhythmias. Specifically, an ICD treats fast arrhythmias in the heart's lower chambers (ventricles). Two such arrhythmias are ventricular tachycardia (VT) and ventricular fibrillation (VF).

Arrhythmias result from a problem in your heart's electrical system. Electrical signals follow a certain path through the heart. It is the movement of these signals that causes your heart to contract. To learn more about your heart's electrical system, go to the Heart & Blood Vessel Basics section.

During VT or VF, however, far too many signals are present in the ventricles. In addition, the signals often do not travel down the proper pathways. The heart tries to beat in response to the signals, but it cannot pump enough blood out to your body. If you have either VT or VF, you are at high risk of sudden cardiac arrest (SCA). If not treated immediately with defibrillation, SCA can result in sudden cardiac death (SCD).

An ICD can treat VT and VF and restore your heart to a normal rhythm. So it reduces your risk of SCD. The device can deliver several types of treatment:

• Anti-tachycardia pacing (ATP) delivers very small amounts of energy to your heart—so small that you can't feel the treatment.
• Cardioversion is a low-energy shock that treats fast but regular arrhythmias.
• Defibrillation is a high-energy shock that treats fast and chaotic (irregular) rhythms. Defibrillation is painful for an instant, but it can also save your life. A device implant is a procedure that uses local numbing. General anesthesia is usually not needed.

How is the implant procedure done?
An Implantable cardioverter defibrillator (ICD) system has two parts.
Device—the device is quite small and easily fits in the palm of your hand. It contains small computerized parts that run on a battery.
Leads—the leads are thin, insulated wires that connect the device to your heart. The leads carry electrical signals back and forth between your heart and your device.

Your doctor inserts the leads through a small incision, usually near your collarbone. Your doctor gently steers the leads through your blood vessels and into your heart. Your doctor can see where the leads are going by watching a video screen with real-time, moving x-rays called fluoroscopy.

The doctor connects the leads to the device and tests to make sure both work together to deliver treatment. Your doctor then places the device just under your skin near your collarbone and stitches the incision closed.

What can I expect?
Usually you are told not to eat or drink anything for a number of hours before the procedure. You undress and put on a hospital gown or sheet. Your procedure will be performed in a ”cath lab." You lie on an exam table and an intravenous (IV) line is put into your arm. The IV delivers fluids and medications during the procedure. The medication makes you groggy, but not unconscious.

The doctor makes a small incision near your collarbone to insert the leads. The area will be numbed so you shouldn't feel pain, but you may feel some pressure as the leads are inserted. You may be sedated when the device is tested, since it delivers a shock to your heart.

You may be in the hospital overnight, and there may be tenderness at the incision site. Afterwards most people have a fairly quick recovery.

Important Safety Information
Medications, procedures and tests can have some risks and possible side effects. Results may vary
from patient to patient. This information is not meant to replace advice from your doctor. Be sure to talk
to your doctor about these risks and possible side effects.

An implantable cardioverter defibrillator can protect you from the effects of sudden cardiac arrest by
reviving your heart rhythm. But it is not for everyone, including people with certain steroid allergies.
Procedure risks include infection and tissue damage. In some cases, the device may not respond to
irregular heartbeats or may deliver inappropriate shocks. In rare cases severe complications or device
failures can occur. Electrical or magnetic fields can affect the device. Only your cardiologist knows what
is right for you.

GUIDANT is a trademark and HEARTISTRY is a service mark of Guidant Corporation. All other brand names mentioned are used for identification purposes only and are trademarks of their respective owners.

Guidant Corporation
4100 Hamline Avenue North
St. Paul, MN 55112-5798 USA
Tel: 651.582.4000 Fax: 651.582.4166
Medical Professionals: 1.800.CARDIAC (227.3422) Toll Free
Patients and Families: 1.866.GUIDANT (484.3268) Toll Free
www.guidant.com

©2006 Guidant Corporation All rights reserved. C4-196-0506

| Home | About Us | Prestigious Accreditations | Physicians | Services | FAQs | Links | Directions | Disclaimer | Contact Us |

Cardiology Associates of Fort Lauderdale, P.A.
4725 N. Federal Hwy, Suite #401
The Jim Moran Heart and Vascular Center
Fort Lauderdale, FL 33308
Phone: (954) 772-2136
Fax: (954) 772-7156

©2010, Cardiology Associates of Fort Lauderdale, P.A. All rights reserved.
Web site by Ticsay Internet.