Arritmia cardíaca

If you'd like to see more scientifically accurate 3D medical images, subscribe to our channel:    / nucleushealthvideose   MEDICAL ANIMATION TRANSCRIPT: Depending on the level of activity, the heart beats approximately 60 to 100 times per minute. It may beat faster during physical activity or slower at rest. A normal heart rate and rhythm ensure that oxygen-rich blood reaches all the body's organs, such as the brain and lungs. A group of cells in the heart, called the cardiac conduction system, uses electrical impulses to control the speed and rhythm of each heartbeat. Each heartbeat begins in the right atrium, at the sinoatrial (SA) node. It then spreads through the walls of the heart's chambers, called the atria and ventricles, causing them to contract. This process repeats with each heartbeat. Problems in the cardiac conduction system cause the heart to have an abnormal rhythm called an arrhythmia. This can produce an irregular pulse. Arrhythmias can occur in the atria or ventricles. The types of arrhythmia are: fibrillation, which is an irregular heart rhythm; tachycardia, which is a rapid heartbeat with more than 100 beats per minute; and bradycardia, which is a slow heartbeat of fewer than 60 beats per minute. Atrial fibrillation is the most common type of arrhythmia. Random impulses cause the atria to fibrillate, or contract rapidly and randomly. Tachycardia in the atria is called supraventricular tachycardia. In focal atrial tachycardia, small areas within the atrial wall initiate or pass impulses that cause the atria to contract rapidly, but with a regular rhythm. In atrial flutter, larger areas within the atrial wall initiate or pass impulses that cause the atria to contract rapidly, but with a regular rhythm. Tachycardia can also occur in the ventricles with rapid, regular contractions. The body doesn't receive enough blood because the ventricles contract before they are fully filled with blood. The most serious type of arrhythmia is ventricular fibrillation, in which many random impulses fire rapidly within the ventricular walls. During ventricular fibrillation, the ventricles quiver instead of beating. This is a medical emergency because the heart cannot effectively pump blood to the body or to itself. Sometimes problems in the SA node or in the pathway of electrical impulses to the ventricles can cause a slow heartbeat in bradycardia. If the heart beats too slowly, the body doesn't receive enough oxygenated blood. Depending on the type of arrhythmia, a doctor may recommend one or more of the following treatments: lifestyle changes—such as a heart-healthy diet, physical activity, and quitting smoking—medications—such as antiarrhythmic drugs or beta-blockers, catheter ablation (a procedure in which thin wires are placed in the heart to destroy the tissue causing the arrhythmia using cold or hot energy), and implantable devices, such as a pacemaker or cardioverter defibrillator, to correct the heart's speed or rhythm. ANH14135es