The heart is basically a pump made up of smooth muscle tissue that is stimulated by electrical impulses, which normally follow a specific path or “circuit” within the heart. This electrical circuit begins in the sinoatrial (SA) node, which is a small mass of specialized tissue located in the upper right chamber (atrium) of the heart. The SA node generates electrical impulses at a rate of 60 to 100 times per minute (under normal conditions) and these electrical impulses are what initiate the heartbeat.
These electrical impulses travel from the SA node to the atrioventricular (AV) node in the bottom of the right atrium. From there the impulse continues down an electrical conduction “pathway” into the lower chambers (ventricles) of the heart. When the electrical stimulus occurs it causes the heart muscle to contract and pump blood to the rest of the body. This process of electrical stimulation followed by muscle contraction is what makes the heart beat.
What Is A Pacemaker?
A pacemaker is a small battery-operated device used to regulate your heart’s rhythm. A pacemaker is composed of three components: a pulse generator, one or more leads, and an electrode on each lead. When your heart’s electrical system does not signal it to contract often enough, or if the signal is not transmitted to the entire heart, you may need a pacemaker to do this work for you. A pacemaker signals the heart to beat when the heartbeat is too slow or irregular.
If the heart’s rate is slower than the programmed limit, an electrical impulse is sent through the lead to the electrode and causes the heart to beat at a faster rate. When the heart beats at a rate faster than the programmed limit, the pacemaker generally monitors the heart rate and will not pace. Pacemakers are programmed to work on demand only, so they do not compete with your body’s natural heartbeat. Generally, no electrical impulses will be sent to the heart unless the heart’s natural rate falls below the pacemaker’s preset lower limit.
Why are Pacemakers Used?
A pacemaker may be implanted in order to stimulate a faster heart rate when the heart is beating too slowly, and causing problems that cannot otherwise be corrected with medication or other methods.
Problems with the heart rhythm can cause problems due to the fact that the heart is unable to pump an adequate supply of oxygenated of blood to the body. If the heart rate is too slow, the blood is pumped too slowly also. Conversely, if the heart rate is too fast, out of sync or irregular in nature, the heart chambers are unable to fill properly with enough blood to pump out with each beat. When the body does not receive enough oxygenated blood, symptoms such as chest pain, dizziness, fatigue, dizziness or fainting can occur.
Some examples of heart rate and rhythm problems for which a pacemaker might be inserted include:
- BRADYCARDIA. Bradycardia is a slower than normal heart rate. The heart usually beats between 60 and 100 times a minute in an adult at rest. If you have bradycardia, your heart beats fewer than 60 times a minute.
- TACHY-BRADY SYNDROME. In tachy-brady syndrome, also called tachycardia-bradycardia syndrome, the heart sometimes beats too quickly (tachy) and sometimes beats too slowly (brady).
- HEART BLOCK. Heart block refers to an abnormality in the way electricity passes through the normal electrical pathways of the heart. The abnormality “blocks” the electrical impulse from continuing through the normal pathways and usually results in a slower heart rate.
Dr. Khoo will evaluate you and select the proper type of pacemaker for your specific needs.
What is Pacemaker Implantation?
A pacemaker insertion is the implantation of a small electronic device that is usually placed in the chest to help regulate slow electrical conduction problems with the heart. A pacemaker may be recommended to ensure that the heartbeat does not slow to a dangerously low rate.
After a pacemaker insertion, regularly scheduled appointments will be made to ensure the pacemaker is functioning properly. Dr. Khoo uses special equipment to review the pacemaker’s activity and adjust the settings when needed.
A pacemaker may be needed when problems occur with the electrical conduction system of the heart. When the timing of the electrical stimulation of the heart to the heart muscle and the subsequent response of the heart’s pumping chambers is altered, a pacemaker may help.
A Defibrillator, also known as and implantable cardioverter defibrillator (ICD), is a small device, similar to a pacemaker that is implanted under the skin. The ICD senses the rate and regularity of the heartbeat and when the heart rate exceeds a rate programmed into the device, the ICD delivers a small, electrical pulse to the heart to slow the heart rate. Most newer ICDs can also function as a pacemaker by pacing the heart out of a rapid rhythm and taking over when the heart rate is dangerously low.
When the heartbeat becomes so erratic and unpredictable that the heart muscle cannot pump enough blood from the ventricles, an ICD can deliver a stronger electrical pulse — often referred to as a “shock” — that can restore organized electrical activity, and therefore an effective heartbeat, to the ventricles.
We encourage you to ask as many questions as necessary until you are confident that you understand your heart condition, medications or procedures you may be considering.
In her practice as a top heart doctor in Albuquerque, Dr. Michelle Khoo wants you to be informed, comfortable and confident about your treatment plan.
Quality Healthcare is at the Heart of Everything We Do.
To schedule a consultation with Dr. Khoo call 1-505-248-1802 or click here to request an appointment online.
Khoo & Associates Cardiology and Wellness is a boutique Cardiovascular Health & Wellness practice that is focused on delivering outstanding, comprehensive and ethical cardiovascular care to patients in Albuquerque and the surrounding counties of Bernalillo, Sandoval, Torrance and Valencia in New Mexico.
Our experienced and dedicated team offers our patients the combined collective experience and knowledge necessary to ensure the highest level of patient care in two convenient office locations – Downtown Albuquerque and Rio Rancho.