Diagnosis
Electrocardiographic features include:
Atrial rate: 100 to 250 BPM
Ventricular conduction can be variable
Irregular or irregularly irregular in the setting of variable AV block
Regular if 1 to 1, 2 to 1, or 4 to 1 AV block
P wave morphology
Unifocal, but similar in morphology to each other
Might be inverted
Differs from normal sinus P wave
May exhibit either long RP or short PR intervals
Rhythm may be paroxysmal or sustained
May demonstrate an increase in the rate at initiation (e.g., "warm up," or "rev up")
May demonstrate a decrease in the rate at termination (e.g., "cool down")

Treatment
Initial management of focal atrial tachycardia should focus on addressing underlying causes: treating acute illness, cessation of stimulants, stress reduction, appropriately managing digoxin toxicity, or chronic disease management. The ventricular rate is controllable with the use of beta blockers or calcium channel blockers. If atrial tachyarrhythmia persists and the patient is symptomatic, the patient may benefit from class IA, IC, or class III antiarrhythmics. Catheter ablation of focal atrial tachycardia may be appropriate in patients failing medical therapy. Epidemiology
A European study of young males applying for pilot licenses demonstrated that 0.34% had asymptomatic atrial tachycardia and 0.46% had symptomatic atrial tachycardia. References


== External links ==
Causes
Circulatory disorders
Diabetic vasculopathy
Sepsis with peripheral necrosis
Peripheral artery disease which can lead to gangrene
A severe deep vein thrombosis (phlegmasia cerulea dolens) can cause compartment syndrome and gangrene

Neoplasm
Cancerous bone or soft tissue tumors (e.g. osteosarcoma, chondrosarcoma, fibrosarcoma, epithelioid sarcoma, Ewings sarcoma, synovial sarcoma, sacrococcygeal teratoma, liposarcoma), melanoma

Trauma
Severe limb injuries in which the limb cannot be saved or efforts to save the limb fail. Traumatic amputation (an unexpected amputation that occurs at the scene of an accident, where the limb is partially or entirely severed as a direct result of the accident, for example, a finger that is severed from the blade of a table saw)
Amputation in utero (Amniotic band)

Congenital anomalies
Deformities of digits and/or limbs (e.g., proximal femoral focal deficiency, Fibular hemimelia)
Extra digits and/or limbs (e.g., polydactyly)

Infection
Bone infection (osteomyelitis) and/or diabetic foot infections
Gangrene
Trench foot
Necrosis
Meningococcal meningitis
Streptococcus
Vibrio vulnificus
Necrotizing fasciitis
Gas gangrene
Legionella
Influenza A Virus
Animal bites
Sepsis
Bubonic plague

Frostbite
Frostbite is a cold-related injury occurring when an area (typically a limb or other extremity) is exposed to extreme low temperatures, causing the freezing of the skin or other tissues. Its pathophysiology involves the formation of ice crystals upon freezing and blood clots upon thawing, leading to cell damage and cell death. Treatment of severe frostbite may require surgical amputation of the affected tissue or limb; if there is deep injury autoamputation may occur. Athletic performance
Sometimes professional athletes may choose to have a non-essential digit amputated to relieve chronic pain and impaired performance. Australian Rules footballer Daniel Chick elected to have his left ring finger amputated as chronic pain and injury was limiting his performance.