The heart is a muscular organ that beats incessantly to pump blood to the whole body. The heart has muscles and an electrical nervous system that work in coordination to pump the blood. The electrical conduction system consists of the pacemaker, which generates the impulses, and the conduction fibers that carry the impulses throughout the heart. Any problem with this conduction system may cause irregular beats or rhythm.
Sick sinus syndrome (SSS), also known as sinus node disease or sinus node dysfunction is a group of heart rhythm problems in which the sinus node (heart’s natural pacemaker) does not work properly. The electrical impulses released from the sinus node controls the sinus rhythm. Improper release of the electrical impulse from the sinus node leads to an irregular heartbeat.
Classification of SSS
The improper functioning of the sinus node leads to multiple disorders that include:
- Sinus bradycardia: Reduced heart beat, i.e., less than 60 (bpm)
- Sinus arrest: The sinus node stops working temporarily or causes the change in the heart beat.
- Sinoatrial block: It is the blockage of sinus node impulse reaching the atria.
- Tachycardia-bradycardia syndrome: The heart beats alternates between a very slow and fast heartbeat, usually with a long pause between the beat.
CAUSES OF SICK SINUS SYNDROME
Scientists believe that SSS is caused by the breakdown of the heart muscles that sends electrical impulses through the heart. This inturn leads to malfunctioning of the sinus node and abnormal heartbeat.
SSS may be also caused by number of factors which include:
- Damage or scarring of the heart’s electric system: The damage to the heart’s electric system is caused by a disease or any other health conditions.
- History of heart surgery: Scar tissue from a past heart surgery might be one of the causes for SSS.
- Medications: Certain medications such as calcium channel blockers or beta-blockers used to treat high blood pressure, heart disease, and other conditions may cause SSS.
- Age: The breakdown of the heart muscle due to age is the most common risk factor for SSS.
TREATMENT OPTIONS FOR SICK SINUS SYNDROME
The primary goal of the treatment for sick sinus syndrome is to eliminate or reduce the unpleasant symptoms.
Checking the current medication: Reviewing the current medication would avoid the chances of any drug interactions with the sinus node functioning. Additional medications may also be prescribed that have a direct action on heart rhythms.
Placing artificial pacemaker: A permanent artificial pacemaker is surgically implanted into the chest or abdomen to regulate the heartbeat. It is programmed to stimulate or “pace” your heart to beat normally. Sometimes single chamber pacemaker is used to treat irregular heartbeats.
Using stem cells: Stem cells are immature cells that are capable of developing into any specific type of mature cells. These cells when inserted potentially grow into the same type of heart tissue as the sinus node and maintain the regular heart rate.
Additional treatment for fast heart rate
If you have a rapid heart rate, then you need to take additional treatment to control these rhythms.
Medications: If your heart rate is too fast after placing a pacemaker, then your doctor may prescribe anti-arrhythmic medications to prevent it.
AV node ablation: This treatment is used to control the fast heart rate in people with artificial pacemakers. It involves applying the radiofrequency energy through a catheter (a long, thin tube) to destroy the tissue around the atrioventricular node between the atria and the ventricles. This stops fast heart rate from reaching the ventricles.
Radiofrequency ablation of atrial fibrillation: It is similar to AV node ablation. But in this procedure, the ablation targets the tissue that triggers the atrial fibrillation.
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