Multifocal atrial tachycardia
Background
- Multiple (3 or more) ectopic foci in the atria causing an irregular atrial tachycardia
- Increased automaticity due to causes listed below
Causes
- COPD
- CHF
- Sepsis
- Methylxanthine toxicity
- Electrolyte abnormalities
- Other associations
- Valvular heart disease
- DM
- Acute renal failure
- Postoperative state
- Pulmonary embolism
- Pneumonia
- Anemia
Clinical Features
- Palpitations
- Dyspnea
- Chest pain
- Presyncope/syncope
Differential Diagnosis
Palpitations
- Arrhythmias:
- Non-arrhythmic cardiac causes:
- Psychiatric causes:
- Drugs and Medications:
- Alcohol
- Caffeine
- Drugs of abuse (e.g. cocaine)
- Medications (e.g. digoxin, theophylline)
- Tobacco
- Misc
Diagnosis
- ECG
- Irregular tachycardia (>100 bpm)
- At least 3 distinct p wave morphologies
- No dominant pacemaker site
- Etiologic work up
- BMP, Magnesium
- Hb/Hct
- Consider infectious disease work up
- Consider ABG/VBG
Management
- Treat the underlying cause
- Replace magnesium
- Replace potassium
- Increased AV nodal activity is unlikely to be effective
- Vagal maneuvers and adenosine may help reveal underlying rhythm/p-waves
- Can consider BB/CCB in hemodynamically stable patient (caution with pulmonary disease)
- Cardioversion not definitive, likely recurrence if underlying illness not addressed
Disposition
- Disposition depends on the underlying illness, but often requires admission due to illness severity/age
- Poor prognostic sign when developed during hospitalization/illness
- 60% in hospital mortality
- mean survival around 1 year
- Due to illness not arrhythmia