PACEMAKERS - traducción al
![Arne Larsson]] (1915–2001) became the first to receive an implantable pacemaker. He had 26 devices during his life and campaigned for other patients needing pacemakers.](https://commons.wikimedia.org/wiki/Special:FilePath/Arne Larsson.jpg?width=200 "Arne Larsson]] (1915–2001) became the first to receive an implantable pacemaker. He had 26 devices during his life and campaigned for other patients needing pacemakers.")
![atrium]]. Note the circle around one of the sharp electrical spikes in the position where the P wave would be expected.](https://commons.wikimedia.org/wiki/Special:FilePath/AtrialPacemakerECG.JPG?width=200 "atrium]]. Note the circle around one of the sharp electrical spikes in the position where the P wave would be expected.")
.jpg?width=200 "Dual-chamber DDDR pacemaker")
![ECG rhythm strip of a threshold determination in a patient with a temporary (epicardial) ventricular pacemaker. The epicardial pacemaker leads were placed after the patient collapsed during [[aortic valve]] surgery. In the first half of the tracing, pacemaker stimuli at 60 beats per minute result in a wide QRS complex with a [[right bundle branch block]] pattern. Progressively weaker pacing stimuli are administered, which results in [[asystole]] in the second half of the tracing. At the end of the tracing, distortion results from muscle contractions due to a (short) hypoxic [[seizure]]. Because decreased pacemaker stimuli do not result in a ventricular [[escape rhythm]], the patient can be said to be pacemaker-dependent and needs a definitive pacemaker.](https://commons.wikimedia.org/wiki/Special:FilePath/Pacemaker dependent asystole.jpg?width=200 "ECG rhythm strip of a threshold determination in a patient with a temporary (epicardial) ventricular pacemaker. The epicardial pacemaker leads were placed after the patient collapsed during [[aortic valve]] surgery. In the first half of the tracing, pacemaker stimuli at 60 beats per minute result in a wide QRS complex with a [[right bundle branch block]] pattern. Progressively weaker pacing stimuli are administered, which results in [[asystole]] in the second half of the tracing. At the end of the tracing, distortion results from muscle contractions due to a (short) hypoxic [[seizure]]. Because decreased pacemaker stimuli do not result in a ventricular [[escape rhythm]], the patient can be said to be pacemaker-dependent and needs a definitive pacemaker.")
![Posteroanterior and lateral [[chest radiograph]]s of a pacemaker with normally located leads in the right atrium (white arrow) and right ventricle (black arrowhead), respectively.](https://commons.wikimedia.org/wiki/Special:FilePath/X-ray of pacemaker with right atrial and ventricular lead.jpg?width=200 "Posteroanterior and lateral [[chest radiograph]]s of a pacemaker with normally located leads in the right atrium (white arrow) and right ventricle (black arrowhead), respectively.")
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Wikipedia
An artificial cardiac pacemaker (artificial pacemaker, and sometimes just pacemaker, although the term is also used to refer to the body's natural cardiac pacemaker) is a medical device, nowadays always implanted, that generates electrical pulses delivered by electrodes to the chambers of the heart, either the upper atria or lower ventricles. Each pulse causes the targeted chambers to contract and pump blood, thus regulating the function of the electrical conduction system of the heart.
The primary purpose of a pacemaker is to maintain an adequate heart rate, either because the heart's natural pacemaker is not fast enough, or because there is a block in the heart's electrical conduction system. Modern pacemakers are externally programmable and allow a cardiologist, particularly a cardiac electrophysiologist, to select the optimal pacing modes for individual patients. Most pacemakers are on demand, in which the stimulation of the heart is based on the dynamic demand of the circulatory system. Others send out a fixed rate of impulses.
A specific type of pacemaker called an implantable cardioverter-defibrillator combines pacemaker and defibrillator functions in a single implantable device. Others, called biventricular pacemakers, have multiple electrodes stimulating different positions within the ventricles (the lower heart chambers) to improve their synchronization.
