There are many different causes that can create rhythm disturbances in patients with congenital heart disease. The type of structural anatomy that you were born with, surgical procedures performed on your heart, long term consequences of chamber enlargement and scar formation can alter the anatomy of the electrical system of the heart, can all cause various

rhythm disturbances. Rhythms can often be too fast or too slow, producing a wide range of symptoms that patients may report. Common abnormal fast rhythms are: atrial tachycardia, atrial flutter, atrial fibrillation, supraventricular tachycardia, junctional rhythms, premature atrial or ventricular contractions, or ventricular tachycardia. Common abnormally slow rhythms are: sinus node dysfunction, and varying degrees of heart block that may require pacemaker implantation.

 

Signs and symptoms:

Symptoms are patient specific and have a wide range at presentation. Patients may be asymptomatic and the finding of an arrhythmia may be detected incidentally during a routine evaluation. Other common reported symptoms are chest pain, palpitations, heart racing, dizziness, shortness of breath, decrease energy, or fainting.

 

Diagnosis:

When there is a suspicion that a patient with CHD may be having arrhythmias your Cardiology/Electrophysiology team may order testing. Some of the tests that may be ordered are:

 

Resting ECGs  The ECG machine records the electrical activity for approximately one minute and produces a one-page tracing, showing only a few beats from each electrode to represent the overall activity measured during the test.

Echocardiogram (or echo): an ultrasound that assess how well the heart is functioning (squeezing) and will identify if there are any structural abnormalities.

Exercise ECGs, also called Exercise Stress Tests, are performed in exercise laboratories and require electrodes to be placed on the skin just like resting ECGs.  However, instead of lying down, patients will engage in physical activity, like walking on a treadmill or pedaling a stationary bike, with the ECG recording the entire time.  This test is used to look for changes in the ECG that may occur as the result of exercise and the increased work being done by the heart.  You may be asked to exercise until you are too tired to continue or the test may be stopped if certain changes are seen on the ECG.  Brief post exercise ECG monitoring will also be recorded while you recover from the exercise test.

Holter monitors are ECGs recorded over a period of 24 hours or more.  Electrode stickers are placed and connected with wires to small ECG recorder. You can engage in regular activities (other than bathing, swimming, or activities that cause excessive sweating or may cause the leads to become loose or to fall off).  With a continuous Holter, the device is worn for a specific duration, typically 24 or 48 hours, and then returned to clinic so the information can be analyzed.  The Holter records every beat while wearing it, providing a lot of information for your healthcare team to review.  It can be used for routine surveillance or for a suspected arrhythmias.

Event monitors are a special type of Holter monitor worn for up to 60 days.  Some are programmed to automatically record arrhythmias, or the recorder has a button to press that will record the rhythm when they have symptoms.  As they are collected, these recordings are typically transmitted to a monitoring service on a regular schedule, which then reports them to your healthcare provider.  Event monitors record every beat while they are worn, but only save “events” that are automatically triggered or patient activated.  The limitation of event recorders is that symptoms must be felt to be able to push the activator button to correlate symptoms with the rhythm of the heart.

Implantable loop recorders are small event monitors implanted under the skin that are battery-powered and can stay in place for 2-3 years.  They may be placed with local anesthesia, conscious sedation, or general anesthesia.  Like other event monitors, implantable loop recorders can be programmed to automatically detect arrhythmias and have a patient-activated recorder for symptomatic episodes.  Implantable recorders communicate wirelessly with the recording-activating button (which needs to be with the patient at all times) and with the special home monitoring system that transmits the rhythm information back to your healthcare team.  These transmissions can be scheduled automatically or can be initiated by families when a symptomatic event has been recorded.  The information on the device can also be read in your electrophysiologist’s office.  Implantable loop recorders can be helpful for patients who have very infrequent symptoms that may indicate an arrhythmia.

 

Treatment:

Treatment is targeted towards the cause and the type of rhythm disturbance. Treatment options may be management with medications to slow fast rhythms or an attempt to prevent reoccurring arrhythmias. Your cardiologist/electrophysiologist may recommend that you undergo electrophysiology study (EPS) with or without an ablation. This procedure can reveal information about your conduction system. Most EPS are performed with the intent to successfully get rid of the abnormal rhythm with an ablation.  An ablation is a procedure that may be recommended in attempt to provide a potential cure or minimize the frequency of your arrhythmia.  EPS can also be done to gather information only. Some EPS may be done to assess if you are at risk to go into a life threatening rhythm. For this small patient population an implantable cardioverter defibrillator (ICD) may be recommended to prevent sudden cardiac arrest (SCA). Other necessary procedures that may be performed for rhythm management or control is to undergo a pacemaker or defibrillator implantation.

 

Lifestyle changes:

We encourage routine active heart healthy lifestyles. Ongoing close management with your cardiologist/electrophysiologist is essential. They can discuss activities with you that are safe for you to participate in.  Depending on rhythm control and medical management, lifestyle changes may be individualized.