Sick sinus syndrome occurs when the patient’s sinus node is not working adequately. This can lead to slow resting heart rates, an inability for heart rate to rise with exercise (chronotropic incompetence), pauses, or no heart rhythm for an extended period of time (asystole).
Often, this syndrome is synonymous with tachy-brady syndrome because patients can have a fast abnormal heart rhythm (tachycardia), such as atrial fibrillation, alternating with a slow sinus rhythm (bradycardia).
People can experience various symptoms associated with the slow heart rate as well as from the fast heart rate. A pacemaker may be required to fix the slow heart rate, while medications or other treatments may be required for the fast heart rate.