Cardiology Education

Atrial Fibrillation

Atrial fibrillation is an abnormal heart rhythm where the top chambers of the heart (the atria) beat chaotically and out of sync with the lower pumping chambers of the heart (the ventricles). This causes the heart rhythm to be irregular and often fast (tachycardic). 

Episodes of atrial fibrillation can come and go (paroxysmal) or it can be present all the time (persistent/chronic). Symptoms can include palpitations, shortness of breath, dizziness, weakness and fatigue, but it can also be asymptomatic. 

Atrial fibrillation itself is not usually life-threatening; however, it is a serious medical condition though, and can increase the risk of stroke. Treatment for atrial fibrillation can include medications including blood thinners, cardioversion (a procedure to reset the heart rhythm), and ablation (a procedure to block where the atrial fibrillation comes from). 

Atrial Flutter

Atrial flutter is the cousin to atrial fibrillation. In atrial flutter the top chambers of the heart (the atria) beat too quickly, but more organized than in atrial fibrillation. This causes the pumping chambers of the heart (the ventricles) to beat rapidly, but not always irregularly. 

Similar to atrial fibrillation, the episodes can come and go or be more persistent. Symptoms can include palpitations, shortness of breath, dizziness, weakness and fatigue. It may also be asymptomatic. A person can have both atrial flutter and atrial fibrillation. Atrial flutter can increase the risk of stroke, heart failure and other complications. Treatment can include medications and ablation. Ablation, a catheter procedure used to block atrial fibrillation from starting, is often a very successful treatment. 

Supraventricular Tachycardia (SVT)

Supraventricular Tachycardia (SVT) is a fast heart rhythm originating from the top chambers of the heart (the atria). The main symptom of SVT is a very fast heart rate. A normal heart rate is usually between 60-100 beats per minute. In SVT, the heart rate can be 150-220 beats per minute. Other symptoms can include fluttering or pounding in the chest, weakness, lightheadedness, chest pain, shortness of breath and even fainting or loss of consciousness. 

There are different types of SVT. The three most common include: atrioventricular reentrant tachycardia (AVNRT), most common, atrioventricular reciprocating tachycardia, typically seen in younger patients, and atrial tachycardia. This type is more commonly associated with other cardiac diagnoses. Other more rare diagnoses include, inappropriate sinus tachycardia, sinus node reentrant tachycardia, multifocal atrial tachycardia, and junctional ectopic tachycardia. 

Testing can include an EKG, heart monitor, echocardiogram, and electrophysiology (EP) study. SVT can be treated with medication, but is often treated with ablation. Ablation can be done at the same time as an EP study and can be curative. 

SVT is generally not life threatening unless you have other heart damage or cardiac disease. You should call 911 for SVT associated with chest pain, shortness of breath, near fainting or fainting. 

Electrocardiogram (EKG or ECG)

An electrocardiogram (EKG or ECG) is a test that records electrical signals from the heart to check for certain cardiac conditions. With each heartbeat, electrical signals travel through the heart which cause the heart to contract. Electrodes are placed on the chest and sometimes limbs to measure these electrical signals. There is no harm from having an EKG. The machine does not send electricity to the heart. It will not be painful, other than possibly from removing electrodes.


An echocardiogram uses high frequency sound waves (ultrasound) to record pictures of the heart. This is done to determine the heart structure and function. It can determine if a heart valve is leaky or too tight. It can also determine size and shape of the heart and see how the walls of the heart move while pumping. 

Echocardiograms are performed by technicians specially trained to do these tests and interpreted by a physician. During the test you will lie on a table. The room is darkened to see the images better. Gel is applied to the chest and a probe is moved over the chest. The echo will not hurt and causes no side effects. 

Electrophysiology (EP) Study

An electrophysiology (EP) study is done to assess the heart’s electrical system and diagnose abnormal heart rhythms (dysrhythmias or arrhythmias). EP studies are done at the hospital. During this test, catheters and wire electrodes are inserted through a large blood vessel in the groin. The catheters are passed into the heart. These special catheters can both record the heart’s electrical activity and pace the heart to cause certain abnormal heart rhythms for observation in a controlled environment. Medication may also be used to stimulate the heart and cause the arrhythmia. You may feel your heart racing or pounding during the procedure. If you have uncomfortable symptoms, such as chest pain, shortness of breath, or nausea, let the nurse or doctor know. 

After the procedure you will lie still in bed to allow the catheter site to heal. You will need to limit your activity for several days after the procedure. Do not lift more than 10 lbs. If you notice new blood on your dressing, press firmly on the area for 15 minutes. If this continues to bleed, let the office know so you can be evaluated, or go to the ER for evaluation after hours. Call us if you have pain or redness at your catheter site. Also call us for any chest pain, shortness of breath or palpitations after the procedure.

Cardiac Ablation

Cardiac ablation is a procedure that uses heat  or cold to create tiny scars in the heart that can block irregular electrical activity. This is done using catheters, thin flexible tubes and is done in conjunction with an EP study. Ablations are done to correct or improve heart rhythm problems (arrhythmias).

Ablation can be used as primary treatment for some arrhythmias such as SVT or WPW. It can also be used after medications have failed to treat arrhythmias or if medications cause significant side effects. 

Sick Sinus Syndrome

Sick sinus syndrome is a heart rhythm disorder that affects the sinus node, the heart’s normal, intrinsic pacemaker. Heart rate is controlled by the sinus node. A normal heart rate is usually between 60-100 beats per minute. Sick sinus syndrome causes slow heart beats (bradycardia) and long periods between heart beats (pauses). The risk of developing sick sinus syndrome increases with age. 

Symptoms may be mild or people may be asymptomatic at first. Symptoms can include fatigue, shortness of breath, lightheadedness or dizziness, confusion or syncope (fainting). The slow heart rate can be worsened by some cardiac medications. 

Sick sinus syndrome is diagnosed by an EKG or a cardiac monitor that can be worn at home. Treatment can include placement of a permanent pacemaker. A pacemaker can deliver tiny amounts of electricity to the heart to cause the heart to beat when it does not beat on its own. 


A pacemaker is a small electrical device that is implanted in the chest to treat slow heart rhythms. There are wires (leads) that connect from the pacemaker (pulse generator) to the heart. These special wires can see the heart’s electrical activity and deliver small amounts of electricity to the heart to make the heart beat when needed. Pacemakers should be checked (interrogated) every 3-6 months to ensure proper function. This can be done in the office and usually can be done at home using a home monitor. Pacemakers can be programmed in the office using a special machine that pairs to the pacemaker. 

Pacemakers only work when needed. They typically only treat slow heart rates. Newer pacemakers can sense movement and breathing and help the heart rate to increase and decrease during exercise and activity. Pacemakers can have one, two, or three wires. Which type of pacemaker will be decided by the doctor and discussed with you prior to implant. 

Pacemakers are implanted at the hospital. You will stay overnight and can go home in the morning after a chest x-ray and pacemaker check. You will be seen in the office 7-10 days after for a wound check and to have staples or sutures removed. For 4-6 weeks, you will need to be careful with the arm on the side of the pacemaker. You should not lift, push or pull with that arm. You should not raise the arm past the level of the shoulder. You will be seen back 4-6 weeks after pacemaker placement to finalize pacemaker programming and release you from restrictions. 

People with pacemakers lead normal lives. There are some precautions though. Anything that produces a strong electromagnetic field can interfere with the pacemaker. If your job brings you into contact with strong electrical fields, such as arc welding, diathermy, working with high power 

If your job brings you into contact with strong electrical fields, such as arc welding, diathermy or working with high-power radio or TV transmitters, or you have direct contact with car ignition systems, check with your cardiologist or pacemaker technician before returning to work.

Automatic Internal Cardioverter Defibrillator (AICD or defibrillator)

An AICD is a small electrical device that is implanted in the chest to monitor and correct dangerous abnormal heart rhythms. These are life saving devices. AICDs are recommended for patients that have had dangerous abnormal heart rhythms (ventricular tachycardia or ventricular fibrillation), cardiac arrest, or severe cardiomyopathy (poor heart muscle function) that predisposes them to these rhythms. 

Wires (leads) connect the AICD to the heart. AICDs are larger than pacemakers as they need to be able to deliver larger amounts of energy to correct abnormal heart rhythms. All AICDs have pacemaker functions, but pacemakers are not defibrillators. AICDs can also use antitachycardia pacing (using small amounts of electricity) to correct abnormal heart rhythms. This is generally not felt by the patient. If this is not successful, the AICD will deliver a discharge (shock) to correct the abnormal heart rhythms. This is usually felt by the patient as a hit or kick in the chest or a jolt. 

AICDs have similar follow up to pacemakers. Patients are seen in the office 7-10 days after for a wound check and to have staples/sutures removed. For 4-6 weeks after the procedure, patients need to be careful with the arm on the side of the AICD. No lifting, pushing, pulling more than 5 pounds with that arm and no lifting the arm above shoulder height. AICDs are checked (interrogated) every 3-6 months. This can be done in the office or at home using a home monitor. It should be checked in the office at least twice a year.