Bradycardia-tachycardia syndrome; Sinus node dysfunction
Usually, no symptoms occur. Symptoms that do occur are nonspecific and may mimic other disorders.
Symptoms may include:
Chest painor angina Confusionor other changes in mental status Faintingor near-fainting Fatigue Dizzinessor light-headedness
- Sensation of feeling the heart beat (
palpitations) Shortness of breath
Signs and tests
heart ratemay be very slow at any time. Blood pressuremay be normal or low.
Sick sinus syndrome may cause symptoms of
heart failureto occur or worsen. Sick sinus syndrome is diagnosed when the symptoms occur only during episodes of arrhythmia. However, this often is difficult to prove.
ECGmay show various abnormal heart rhythms related to this syndrome. Holter monitoringis 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.
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.