Cardiac Pacemaker
posted May 12, 2021, 9:00 AM by Laurel Palli (2023)
Your heart is what supplies your body with oxygen rich blood. It is a muscular, fist-sized pump with four chambers, two on the left side and two on the right. The upper chambers (right and left atria) and the lower chambers (right and left ventricles) work with your heart's electrical system to keep your heart beating at an appropriate rate — usually 60 to 100 beats a minute for adults at rest.
Your heart's electrical system controls your heartbeat, beginning in a group of cells at the top of the heart (sinus node) and spreading to the bottom, causing it to contract and pump blood. Aging, heart muscle damage from a heart attack, some medications, and certain genetic defects can cause an abnormal heart rhythm. Heart damage and defects could be life threatening problems, and a pacemaker can help your heart beat maintain a regular rate. There are three different types of pacemakers. The first type is a single chamber pacemaker which carries electrical impulses to the right ventricle of your heart. The second type is a dual chamber pacemaker. This type carries electrical impulses to the right ventricle and the right atrium of your heart to help control the timing of contractions between the two chambers. Lastly, a biventricular pacemaker is for people with heart failure and also have abnormal electrical systems. This type of pacemaker stimulates the lower chambers of the heart (the right and left ventricles) to make the heart beat more efficiently. All pacemakers are implanted under your skin and in your chest.
An implanted electronic pacemaker mimics the action of your natural electrical system. A pacemaker comprises two parts:
Pulse generator: This is a small metal container houses a battery and the electrical circuitry that regulates the rate of electrical pulses sent to your heart.
Leads (electrodes): One to three flexible, insulated wires are each placed in a chamber, or chambers, of your heart and deliver the electrical pulses to adjust your heart rate.
Pacemakers work only when needed. If your heartbeat is too slow (bradycardia), the pacemaker sends electrical signals to your heart to correct the beat. Also, newer pacemakers have sensors that detect body motion or breathing rate, which signal the pacemakers to increase heart rate during exercise, as needed.
So when a person has heart damage or an abnormal rhythm a person may have a pacemaker implanted into their chest. They would have one of three types: the single chamber pacemaker, a dual chamber pacemaker, or a biventricular pacemaker. All these pacemakers copy the action of your electrical system which keeps your heart pumping blood using two parts: a pulse generator and leads. The technology of the pacemaker can and has saved many lives.