Bradycardia-tachycardia syndrome; Sinus node dysfunctionSymptoms
Usually, no symptoms occur. Symptoms that do occur are nonspecific and may mimic other disorders.
Symptoms may include:
Signs and tests
Chest pain or angina
Confusion or other changes in mental status
Fainting or near-fainting
Dizziness or light-headedness
- Sensation of feeling the heart beat (palpitations)
- Shortness of breath
The patient's heart rate may be very slow at any time. Blood pressure may be normal or low.
Sick sinus syndrome may cause symptoms of heart failure to occur or worsen. Sick sinus syndrome is diagnosed when the symptoms occur only during episodes of arrhythmia. However, this often is difficult to prove.
An ECG may show various abnormal heart rhythms related to this syndrome.
Holter monitoring is an effective tool for diagnosing sick sinus syndrome because of the episodic nature of the disorder. Extremely slow heart rate and prolonged pauses may be seen during Holter monitoring, along with episodes of atrial tachycardias.
An EPS (intracardiac electrophysiology study) is a very specific test for this disorder, although it is often unable to confirm the diagnosis. It is not often needed.
Exercise testing has not proven particularly effective as a screening tool.
Review Date: 05/04/2010
Reviewed By: Issam Mikati, MD, Associate Professor of Medicine. Feinberg School
of Medicine, Northwestern University, Chicago, IL. Review provided
by VeriMed Healthcare Network.Also reviewed by David Zieve, MD,
MHA, Medical Director, A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)