Inserción del marcapasos (Mayo 2024)
Marcapasos, dispositivo electrónico de soporte cardíaco que produce impulsos eléctricos rítmicos que se encargan de la regulación de los latidos cardíacos en pacientes con ciertos tipos de enfermedades cardíacas.
enfermedad cardiovascular: marcapasos cardíacos
El ritmo normal del corazón es generado por la actividad eléctrica espontánea en las células en un área del corazón llamada nodo sinoauricular.
Un corazón humano sano contiene su propio sistema de conducción eléctrica capaz de controlar tanto la frecuencia como el orden de las contracciones cardíacas. Los impulsos eléctricos se generan en el nodo sinoauricular en la aurícula derecha, una de las dos cámaras superiores del corazón. Luego pasan a través de los músculos de ambas aurículas para desencadenar la contracción de esas dos cámaras, lo que fuerza la sangre hacia los ventrículos. La ola de actividad eléctrica auricular activa un segundo parche de tejido conductor, el nodo auriculoventricular, iniciando una segunda descarga a lo largo de un conjunto de fibras conductoras llamado haz de His, que induce la contracción de los ventrículos. Cuando se interrumpe la conducción eléctrica a través del nódulo auriculoventricular o haz de His, la afección se denomina bloqueo cardíaco.Se puede emplear un marcapasos artificial temporalmente hasta que la conducción normal regrese o permanentemente para superar el bloqueo.
In temporary pacing, a miniature electrode attached to fine wires is introduced into the heart through a vein, usually in the arm. The pacing device, an electric generator, remains outside the body and produces regular pulses of electric charge to maintain the heartbeat. In permanent pacing, the electrode may again be passed into the heart through a vein or it may be surgically implanted on the surface of the heart; in either case the electrode is generally located in the right ventricle. The electric generator is placed just beneath the skin, usually in a surgically created pocket below the collarbone.
The first pacemakers were of a type called asynchronous, or fixed, and they generated regular discharges that overrode the natural pacemaker. The rate of an asynchronous pacemaker may be altered by the physician, but once set it will continue to generate an electric pulse at regular intervals. Most are set at 70 to 75 beats per minute. More-recent devices are synchronous, or demand, pacemakers that trigger heart contractions only when the normal beat is interrupted. Most pacemakers of this type are designed to generate a pulse when the natural heart rate falls below 68 to 72 beats per minute.
Once in place, the electrode and wires of the pacemaker usually require almost no further attention. The power source of the implanted pulse generator, however, requires replacement at regular intervals, generally every four to five years. Most pacemakers use batteries as a power source.
Pacemakers designed to communicate wirelessly, using radio-frequency telemetry-based technology, have enabled physicians to gather information about a patient remotely. The implanted pacemakers transmit information to home monitoring systems and to programming devices used by doctors. As a result, a doctor working in a clinic can collect important information about a patient’s heart function while the patient is at home. This type of wireless device also sends out alert signals to the physician when the patient’s heart rate becomes abnormal.
