Heart Rhythm Disorders

An EKG (or ECG) is a test that records the electrical activity of your heart, shows abnormal rhythms (arrhythmias), and can sometimes detect heart muscle damage.

When testing with a Holter monitor, you will wear a small, portable, battery-powered EKG machine worn to record heartbeats over a period of 24 to 48 hours during normal activities. At the end of the time period, you will return the monitor to the doctor’s office so it can be read and evaluated.

While undergoing this test, you wear a small, portable, battery-powered machine used to record EKGs over a long period. You may keep the recorder for several weeks. Each time you experience symptoms, you press a button on the recorder to record the EKG sample. As soon as possible, this sample is transmitted to the doctor’s office for evaluation.

An echo is a non-invasive test that uses sound waves to evaluate your heart’s chambers and valves. The echo sound waves create an image on the monitor as an ultrasound probe is passed over your heart.

Also called a treadmill test or exercise ECG, this test is given to you as you walk on a treadmill or pedal a stationary bike to monitor the heart during exercise. Breathing and blood pressure rates are also monitored.

A stress test may be used to detect coronary artery disease, and/or to determine safe levels of exercise following a heart attack or heart surgery.

For this test, you are connected to EKG and blood pressure monitors and strapped to a table that tilts you from a lying to a standing position. This test is used to determine if you are prone to sudden drops in blood pressure or slow pulse rates with position changes.

This imaging procedure uses an X-ray machine and a computer to create 3-dimensional pictures of your heart. Sometimes a dye is injected into a vein so that your heart arteries can be seen as well.

With this diagnostic procedure, a combination of large magnets, radio frequencies, and a computer produce detailed images of organs and structures within your body. 

MRI of the heart may be used to:

• Evaluate your heart valves and major vessels
• Detect coronary artery disease and the extent of damage it has caused
• Evaluate congenital defects
• Detect the presence of tumors or other abnormalities. 

The cardiac MRI may also be used prior to other cardiac procedures such as:

• Angioplasty
• Stenting of the coronary arteries
• Cardiac or vascular surgery

This specialized type of MRI procedure is used to evaluate blood vessels in your heart.

During an electrophysiology study, insulated electric catheters are placed through the large vein in your upper leg and threaded into the heart. With this procedure, doctors can test the heart’s electrical system to find irregular heart rhythms.

When you need it, this small device is put in the chest under the skin. It will record heart activity when you feel dizzy or faint.

Defibrillation is the use of a device to send a shock of electricity to your heart and make it pump regularly.

A variety of medications may help control your heart rhythm and prevent blood clots.

Sometimes changes in your diet or exercise can help with some heart rhythm problems.

A pacemaker is a small device that is implanted under your skin (most often in the shoulder area just under the collarbone) that sends electrical signals to start or regulate a slow heartbeat.

A permanent pacemaker may be used to make the heart beat if the heart’s natural pacemaker (the sinus node) is not functioning properly and has developed an abnormally slow heart rate or rhythm, or if the electrical pathways are blocked.

Biventricular Pacemaker

A newer type of pacemaker, a biventricular pacemaker, is currently used in the treatment of ventricular dyssynchrony (irregular conduction pattern in the lower heart chambers) or heart failure. Sometimes in heart failure, the two ventricles do not pump together in a normal manner. When this happens, less blood is pumped by the heart. A biventricular pacemaker paces both ventricles at the same time, increasing the amount of blood pumped by the heart. This type of treatment is called cardiac resynchronization therapy.

An implantable cardioverter defibrillator (ICD) looks very similar to a pacemaker, except that it is slightly larger. It has a generator, one or more leads, and an electrode for each lead. 

These components work very much like a pacemaker. However, the ICD is designed to deliver two levels of electrical energy: a low-energy shock that can convert a beating heart that is in an abnormal rhythm back to a normal heartbeat, and a high-energy shock that is delivered only if the arrhythmia is so severe that the heart is only quivering instead of beating.

An ICD senses when your heart is beating too fast and delivers an electrical shock to convert the fast rhythm to a normal rhythm. Many devices combine a pacemaker and ICD in one unit for people who need both functions. After the shock is delivered, a backup pacing mode is available if needed for a short while.

In this procedure, a thin tube (catheter) is put into a blood vessel in your groin. A wire is put through the catheter and sent up to your heart. A small part of your heart that is causing the arrhythmia is destroyed with radiofrequency energy.