Diagnosis

Symptoms of sick sinus syndrome — such as dizziness, shortness of breath and fainting — are also symptoms of many other diseases and conditions.

However, in sick sinus syndrome, these symptoms only occur when the heart is beating abnormally. In order to diagnose and treat sick sinus syndrome, your doctor will need to establish a connection between your symptoms and an abnormal heart rhythm.

Electrocardiogram

Testing for sick sinus syndrome usually starts with a standard electrocardiogram (ECG). However, if your abnormal heart rhythms tend to come and go, they may not be detected during the brief time a standard ECG is recording. You may need additional types of ECG:

  • Standard ECG. During this test, sensors (electrodes) are attached to your chest and limbs to create a record of the electrical signals traveling through your heart. The test may show patterns that indicate sick sinus syndrome, including fast heart rate, slow heart rate or a long pause in the heartbeat (asystole) after a fast heart rate.
  • Holter monitor. This portable device is carried in your pocket or in a pouch on a belt or shoulder strap. It automatically records your heart's activity for an entire 24- to 48-hour period, which provides your doctor with an extended look at your heart rhythms. This type of monitoring can be very helpful for diagnosing sick sinus syndrome.
  • Event recorder. This portable electrocardiogram device can also be carried in your pocket or worn on a belt or shoulder strap for home monitoring of your heart's activity. You will often be given this device to use for up to a month.

    When you feel symptoms, you push a button, and a brief ECG recording is saved. This allows your doctor to see your heart rhythm at the time of your symptoms, which can help pinpoint sick sinus syndrome.

  • Implantable loop recorder. This small device is implanted just under the skin of your chest and is used for continuous, long-term monitoring of your heart's electrical activity. An implantable loop recorder may be worn from months to years.

    This device is automatically triggered by an irregular heart rhythm (arrhythmia) or may be triggered manually when you feel symptoms.

Electrophysiologic testing

This test isn't commonly used to screen for sick sinus syndrome. However, in some cases, electrophysiologic testing can help check the function of your sinus node, as well as other electrical properties of your heart.

During this test, thin, flexible tubes (catheters) tipped with electrodes are threaded through your blood vessels to various spots along the electrical pathways in your heart. Once in place, the electrodes can precisely map the spread of electrical impulses during each beat and may identify the source of heart rhythm problems.

Treatment

Treatment for sick sinus syndrome focuses on eliminating or reducing unpleasant symptoms. If you aren't bothered by symptoms, you may only need regular checkups to monitor your condition. For people who are bothered by symptoms, the treatment of choice is usually an implanted electronic pacemaker.

Medication changes

Your doctor may start by looking at your current medications to see if any of them could be interfering with the function of your sinus node. Medications used to treat high blood pressure or heart disease — such as beta blockers or calcium channel blockers — can worsen abnormal heart rhythms. In some cases, adjusting these medications can relieve symptoms.

Pacing the heart

Most people with sick sinus syndrome eventually need a permanent artificial pacemaker to maintain a regular heartbeat. This small, battery-powered electronic device is implanted under the skin near your collarbone during a minor surgical procedure. The pacemaker is programmed to stimulate or "pace" your heart as needed to keep it beating normally.

The type of pacemaker you need depends on the type of irregular heart rhythm you're experiencing. Some rhythms can be treated with a single chamber pacemaker, which uses only one wire (lead) to pace one chamber of the heart — in this case, the atrium. However, most people with sick sinus syndrome benefit from dual chamber pacemakers, in which one lead paces the atrium and one lead paces the ventricle.

You'll be able to resume normal or near-normal activities after you recover from pacemaker implantation surgery. The risk of complications, such as swelling or infection in the area where the pacemaker was implanted, is small.

Additional treatments for fast heart rate

If you have rapid heart rate as part of your sick sinus syndrome, you may need additional treatments to control these rhythms:

  • Medications. If you have a pacemaker and your heart rate is still too fast, your doctor may prescribe anti-arrhythmia medications to prevent fast rhythms.

    If you have atrial fibrillation or other abnormal heart rhythms that increase your risk of stroke, you may need a blood-thinning medicine, such as warfarin (Coumadin) or dabigatran (Pradaxa).

  • AV node ablation. This procedure can also control fast heart rhythms in people with pacemakers.

    It involves applying radiofrequency energy through a long, thin tube (catheter) to destroy (ablate) the tissue around the atrioventricular (AV) node between the atria and the ventricles. This stops fast heart rates from reaching the ventricles and causing problems.

  • Radiofrequency ablation of atrial fibrillation. This procedure is similar to AV node ablation. However, in this case, ablation targets the tissue that triggers atrial fibrillation. This actually eliminates atrial fibrillation itself, rather than just preventing it from reaching the ventricles.

Lifestyle and home remedies

In some cases, inflammation and narrowed arteries caused by underlying heart disease can cause sick sinus syndrome. Your doctor may suggest that, in addition to other treatments, you make lifestyle changes that will keep your heart as healthy as possible.

Take the following steps to treat or eliminate risk factors that may lead to heart disease:

  • Exercise and eat a healthy diet. Live a heart-healthy lifestyle by exercising regularly and eating a healthy, low-fat diet that's rich in fruits, vegetables and whole grains.
  • Maintain a healthy weight. Being overweight increases your risk of developing heart disease.
  • Keep blood pressure and cholesterol under control. Make lifestyle changes and take medications as prescribed to correct high blood pressure (hypertension) or high cholesterol.
  • Don't smoke. If you smoke and can't quit on your own, talk to your doctor about strategies or programs to help you break a smoking habit.
  • If you drink, do so in moderation. If you drink alcohol, drink in moderation. For some conditions it's recommended that you completely avoid alcohol. Ask your doctor for advice specific to your condition. If you can't control your alcohol use, talk to your doctor about a program to quit drinking and manage other behaviors related to alcohol abuse.
  • Don't use illegal drugs. Talk to your doctor about an appropriate program for you if you need help ending illegal drug use.
  • Control stress. Avoid unnecessary stress and learn coping techniques to handle normal stress in a healthy way.
  • Go to scheduled checkups. Have regular physical exams and report any signs or symptoms to your doctor.

Preparing for your appointment

Symptoms of sick sinus syndrome, if present at all, may be so mild that you don't realize they're cause for concern. For this reason, sick sinus syndrome may not be diagnosed until it's in an advanced stage, when the risk of complications is greater.

Call your family doctor or general practitioner if you have symptoms of sick sinus syndrome. In some cases when you call to set up an appointment, you may be referred to a doctor trained in diagnosing and treating heart conditions (cardiologist).

Here's some information to help you prepare for your appointment.

What you can do

  • Find out if you need to follow any pre-appointment restrictions, such as changing your activity level or your diet to prepare for diagnostic tests.
  • Write down any symptoms you've been experiencing, and for how long.
  • Write down key personal information, including any major stresses or recent changes in your life.
  • Make a list of your key medical information, including other medical problems for which you've recently been treated and the names of any medications you're taking, including over-the-counter medications, vitamins and supplements.
  • Find a family member or friend who can come with you to the appointment, if possible. Someone who accompanies you can help remember what the doctor says.
  • Write down the questions you want to be sure to ask your doctor.

For sick sinus syndrome, some basic questions to ask your doctor include:

  • What is likely causing my symptoms?
  • Are there any other possible causes for these symptoms?
  • What kinds of tests do I need?
  • What treatment approach do you recommend?
  • If you're recommending a pacemaker implantation, what's involved in the procedure?
  • Will I need to stay in the hospital?
  • What risks are associated with a pacemaker implantation?
  • What will my recovery from surgery be like?
  • Will I be able to resume normal activity? When?
  • Do you expect a pacemaker will manage my symptoms permanently?
  • Will I need additional surgery to maintain or, eventually, replace my pacemaker?
  • Will I need any additional treatment for my condition?
  • How will you monitor my health long term?
  • I'm also being treated for another health problem. Will I need to change the treatments I'm using to manage that condition?
  • Should my children or other close relatives be screened for heart problems?
  • Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?

In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to talk about in-depth. Your doctor may ask:

  • What are your symptoms?
  • When did you first begin experiencing symptoms?
  • Have your symptoms changed over time? If so, how?
  • Do your symptoms include feeling lightheaded or dizzy?
  • Have you ever fainted?
  • Do you experience rapid, fluttering or pounding heartbeats (palpitations)?
  • Do you experience squeezing, pressure, heaviness, tightness or pain in your chest (angina)?
  • Does exercise or physical exertion make your symptoms worse?
  • Are you aware of any history of heart problems in your family?
  • Are you being treated for any other health conditions?

What you can do in the meantime

While you wait for your appointment, check with your family members to find out if any relatives have been diagnosed with heart problems. Knowing your family health history will help your doctor plan the right diagnostic tests and treatments based on your individual risks.

Although sick sinus syndrome is rare, the symptoms of this condition mimic those of many other cardiac illnesses. If exercise makes your symptoms worse, avoid exercise until you've been seen by your doctor.

May 13, 2014
References
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