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  2. Artificial cardiac pacemaker - Wikipedia

    en.wikipedia.org/wiki/Artificial_cardiac_pacemaker

    The primary purpose of a pacemaker is to maintain an even heart rate, either because the heart's natural cardiac pacemaker provides an inadequate or irregular heartbeat, or because there is a block in the heart's electrical conduction system. Modern pacemakers are externally programmable and allow a cardiologist to select the optimal pacing ...

  3. Cardiac pacemaker - Wikipedia

    en.wikipedia.org/wiki/Cardiac_pacemaker

    Image showing the cardiac pacemaker or SA node, the primary pacemaker within the electrical conduction system of the heart The cardiac pacemaker is the heart 's natural rhythm generator. It employs pacemaker cells that produce electrical impulses, known as cardiac action potentials , which control the rate of contraction of the cardiac muscle ...

  4. Sinoatrial node - Wikipedia

    en.wikipedia.org/wiki/Sinoatrial_node

    These cells produce an electrical impulse known as a cardiac action potential that travels through the electrical conduction system of the heart, causing it to contract. In a healthy heart, the SA node continuously produces action potentials, setting the rhythm of the heart (sinus rhythm), and so is known as the heart's natural pacemaker.

  5. Cardiac conduction system - Wikipedia

    en.wikipedia.org/wiki/Cardiac_conduction_system

    The conduction system consists of specialized heart muscle cells, situated within the myocardium. [3] There is a skeleton of fibrous tissue that surrounds the conduction system which can be seen on an ECG. Dysfunction of the conduction system can cause irregular heart rhythms including rhythms that are too fast or too slow.

  6. Cardiac action potential - Wikipedia

    en.wikipedia.org/wiki/Cardiac_action_potential

    Pacemaker activity of these cells is vital, as it means that if the SAN were to fail, then the heart could continue to beat, albeit at a lower rate (AVN= 40-60 beats per minute, Purkinje fibres = 20-40 beats per minute). These pacemakers will keep a patient alive until the emergency team arrives. [citation needed]

  7. Cardiac physiology - Wikipedia

    en.wikipedia.org/wiki/Cardiac_physiology

    The cardiomyocytes make up the bulk (99%) of cells in the atria and ventricles. These contractile cells respond to impulses of action potential from the pacemaker cells and are responsible for the contractions that pump blood through the body. The pacemaker cells make up just (1% of cells) and form the conduction system of the heart.

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  9. Cardiology - Wikipedia

    en.wikipedia.org/wiki/Cardiology

    The electrical system of the heart is centered on the periodic contraction (squeezing) of the muscle cells that is caused by the cardiac pacemaker located in the sinoatrial node. The study of the electrical aspects is a sub-field of electrophysiology called cardiac electrophysiology and is epitomized with the electrocardiogram (ECG/EKG). The ...