Atrial tachycardia is a type of heart rhythm problem in which the hearts electrical impulse comes from an ectopic pacemaker (that is, an abnormally located cardiac pacemaker) in the upper chambers (atria) of the heart, rather than from the sinoatrial node, the normal origin of the hearts electrical activity. As with any other form of tachycardia (rapid heart beat), the underlying mechanism can be either the rapid discharge of an abnormal focus, the presence of a ring of cardiac tissue that gives rise to a circle movement (reentry), or a triggered rapid rhythm due to other pathological circumstances (as would be the case with some drug toxicities, such as digoxin toxicity). Classification
Forms of atrial tachycardia (ATach) include multifocal atrial tachycardia (MAT), focal atrial tachycardia and atrial flutter. Paroxysmal atrial tachycardia (PAT) is an episode of arrhythmia that begins and ends abruptly. Etiology
Atrial tachycardia tends to occur in individuals with structural heart disease, with or without heart failure, and ischemic coronary artery disease. However, focal atrial tachycardia often occurs in healthy individuals without structural heart disease. Other possible etiologies are listed below:
Hypoxia
Pulmonary disease
Ischemic heart disease
Stimulants: cocaine, caffeine, chocolate, ephedra
Alcohol
Metabolic disturbances
Digoxin toxicity
Heightened sympathetic toneA study noted 10 to 15% of patients presenting for supraventricular tachycardia ablation had atrial tachycardia.
Lymphangitis is an inflammation or an infection of the lymphatic channels that occurs as a result of infection at a site distal to the channel. The most common cause of lymphangitis in humans is Streptococcus pyogenes (Group A strep), hemolytic streptococci, and in some cases, mononucleosis, cytomegalovirus, tuberculosis, syphilis, and the fungus Sporothrix schenckii. Lymphangitis is sometimes mistakenly called "blood poisoning". In reality, "blood poisoning" is synonymous with sepsis. Lymphatic vessels are smaller than capillaries and tiny venules and are ubiquitous in the body. These vessels are fitted with valves to direct flow in only one direction. Fluid diffusing through the thin-walled small capillaries should be collected and the lymphatic system does just that: a fluid rich in protein, minerals, nutrients, and other substances useful for tissue growth. As well as essential nutrients, the lymphatic system can also transport or carry cancer cells, defective or damaged cells, and pathogens such as bacteria and viruses, as well as foreign bodies and organisms. The lymph nodes are found in close proximity to unique white blood cells that engulf or metabolize pathogens (bacteria and viruses) and defective or cancerous cells, preventing infections and malignant cancer cells from spreading. Infection spreads out of the wound site to enter the lymphatic system. The wound may be small or it may be an abscess constantly feeding bacteria into the lymphatic system. After infection, lymph nodes enlarge. Ear, skin, nose, and eye infections can spread into the lymphatic system.