- Multifocal atrial tachycardia
Multifocal atrial tachycardia Classification and external resources ICD-9 427.89 eMedicine article/759135
Causes and epidemiology
It is more common in the elderly.
It is mostly common in patients with lung disorders, but it can be occur after acute MI, hypokalemia, and hypomagnesemia.
It is sometimes associated with digitalis toxicity in patients with heart disease.
It is most commonly associated with hypoxia and COPD
Presentation and pathophysiology
It is characterized by an electrocardiogram (ECG) strip with 3 or more P-waves of variable morphology and varying P–R intervals, plus tachycardia, which is a heart rate exceeding 100 beats per minute. Narrow QRS complexes are visible as well.
The P-waves and P–R intervals are variable due to a phenomenon called wandering atrial pacemaker (WAP). The electrical impulse is generated at a different focus within the atria of the heart each time. WAP is positive once the heart generates at least three different P-wave formations from the same ECG lead. Then, if the heart rate exceeds 100 beats per minute, the phenomenon is called multifocal atrial tachycardia.
Its rate may in some cases be reduced by administering verapamil.
- ^ Bradley DJ, Fischbach PS, Law IH, Serwer GA, Dick M (August 2001). "The clinical course of multifocal atrial tachycardia in infants and children". J. Am. Coll. Cardiol. 38 (2): 401–8. doi:10.1016/S0735-1097(01)01390-0. PMID 11499730. http://linkinghub.elsevier.com/retrieve/pii/S0735-1097(01)01390-0.
- ^ http://library.med.utah.edu/kw/ecg/ecg_outline/Lesson5/supra.html#multifocal
- ^ McCord J, Borzak S (January 1998). "Multifocal atrial tachycardia". Chest 113 (1): 203–9. doi:10.1378/chest.113.1.203. PMID 9440591. http://www.chestjournal.org/cgi/pmidlookup?view=long&pmid=9440591.
- ^ American College of Physicians; Acp (15 June 2008). MKSAP for students four. ACP Press. pp. 37–. ISBN 9781934465035. http://books.google.com/books?id=jgjGG5SLSS4C&pg=PA37. Retrieved 11 November 2010.
Cardiovascular disease: heart disease · Circulatory system pathology (I00–I52, 390–429) IschaemicActive ischemia LayersValves Conduction/
arrhythmiaAtrial (Multifocal) · Junctional (AV nodal reentrant, Junctional ectopic)Premature contractionWolff-Parkinson-White · Lown-Ganong-LevineFlutter/fibrillationPacemakerOther/ungrouped
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