To operate and control the rhythm of the heart, there is the sinus node that consists of specialized cells of the upper right atrium. The sinus node is also called the sinoatrial node or SA node. The SA node is the biological pacemaker that keeps a constant pace of regular electrical impulses which squeeze and release the muscles of the heart. In other words, the sinoatrial node regulates the heart to pump the blood. The electrical impulses that are generated in the right atrium by the SA node travel along the cardiac muscles from the atria to the ventricles; this is what gives us our rhythmic heart contractions.
In general, a normal rhythm of the heart should be between 60 to 90 beats per minute. When there is an abnormality in the sinus node, the natural rhythm of the heartbeat becomes erratic and disturbed.
Types of arrhythmias associated with sick sinus syndrome
Disorders of the heart rhythm are medically termed as arrhythmias. The group of arrhythmias is collectively termed as sick sinus syndrome. Thus, a person suffering from sick sinus syndrome has a heart that beats too fast or too slow with prolonged pauses in between, or a combination between a slow and fast heart rate. There are 3 different types of sinus arrhythmias. The types are sinus bradycardia, sinus tachycardia and bradycardia-tachycardia.
The types of sinus arrhythmias of the heartbeat are explained below.
Sinus bradycardia – Sinus bradycardia is a slow heartbeat resulting from slower electrical impulses from the sinus node.
Sinus tachycardia – Sinus tachycardia is a fast heartbeat generated by quick impulses from the sinus or SA node.
Bradycardia-tachycardia – Bradycardia-tachycardia is a mixture of alternating heart rhythms vacillating from slow to fast. The sinoatrial node, the heart’s pacemaker, sends out electrical impulses at an irregular slow and fast rate.
Symptoms of sick sinus syndrome
Sick sinus syndrome has been observed predominantly in older adults, but this can also happen to anyone of any age. At the start of sick sinus syndrome there may not be any physical symptoms to correlate and diagnose the disorder. In some cases, these arrhythmias appear off and on without a regular pattern. However, upon careful observation, certain symptoms can be isolated and recognized in the elderly patients. The patient may experience fatigue, dizziness and shortness of breath. There may also be chest pain, sleeplessness, fluttering of the heart, palpitations, fainting or feeling faint. There may also be confusion, loss of memory that could be temporary or permanent and difficulty making coherent speech. The patient may have difficulty in finding the words to express his or her thoughts.
Sometimes scar tissue occurs from previous heart surgeries; this could be an underlying cause for sick sinus syndrome. Certain medications such as calcium channel blockers or beta blockers, commonly prescribed for hypertension and heart disease, could trigger abnormalities with the sinus node. However, in most cases the sinus node abnormality is age related. Sick sinus syndrome could easily be kept under control if diagnosed and treated properly.
People having the above mentioned symptoms should be evaluated by a medical professional for sick sinus syndrome. Artificial pacemakers are required to be surgically embedded into the heart system to keep the heart functioning in normal sinus rhythm.