Difference between revisions of "Atrial Standstill"
(Created page with '*Temporary or permanent lack of atrial activity resulting from a failure of atrial depolarisation. Ventricles still function normally. ====Causes==== Electrolyte abnormalities…') |
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| − | + | ==Introduction== | |
| + | The temporary or permanent '''lack of atrial activity''' resulting from a '''failure of atrial depolarisation'''. The ventricles still function normally. | ||
| + | ==Aetiology== | ||
| + | The '''atrial muscle fails to depolarise''', despite the production of an impulse from the sinoatrial node. So instead impulses pass from the '''sinoatrial node''' to the '''atrioventricular node''' by '''internodal pathways'''. This produces a '''sinoventricular rhythm'''. This can be caused by '''electrolyte abnormalities''' (especially hyperkalaemia), '''cardiomyopathies, muscular dystrophy, hypoadrenocorticism and toxicity'''. | ||
| − | == | + | ==Clinical Signs== |
| − | + | '''Heart sounds are normal''' on auscultation. As ventricular depolarisation occurs a '''normal pulse''' can be felt. It is common for the heart rate to be '''slow''', at less than 60 beats a minute in small animals. | |
| + | ==Diagnosis== | ||
| + | Diagnosis can be confirmed by '''ECG''' or '''fluoroscopy'''. | ||
| − | ''' | + | ===ECG=== |
| + | An ECG should show an '''absence of P waves'''. '''Heart rate is regular''' but normally '''slow''', due to the presence of an '''escape rhythm'''. The '''QRS complexes are normal or slightly wide'''. | ||
| + | It is important to have an artefact-free ECG of diagnostic quality to confirm atrial standstill. | ||
| − | ==== | + | ==Treatment== |
| − | + | Treat the '''underlying cause'''. | |
| + | |||
| + | {{Learning | ||
| + | |flashcards = [[Feline Medicine Q&A 01]] | ||
| + | }} | ||
| + | |||
| + | ==References== | ||
| + | Martin, M (2002) '''ECG interpretation in small animals : 2. Abnormalities in the conduction system''' ''In Practice 2002 24: 194-20'' | ||
| + | |||
| + | Sparks, AH & Caney, SMA (2005) '''Self-Assessment Colour Review Feline Medicine''' ''Manson'' | ||
[[Category:Impulse_Conduction_Abnormalities]][[Category:To_Do_-_Cardiovascular]] | [[Category:Impulse_Conduction_Abnormalities]][[Category:To_Do_-_Cardiovascular]] | ||
| + | [[Category: To Do - Siobhan Brade]] | ||
Revision as of 16:40, 10 August 2011
Introduction
The temporary or permanent lack of atrial activity resulting from a failure of atrial depolarisation. The ventricles still function normally.
Aetiology
The atrial muscle fails to depolarise, despite the production of an impulse from the sinoatrial node. So instead impulses pass from the sinoatrial node to the atrioventricular node by internodal pathways. This produces a sinoventricular rhythm. This can be caused by electrolyte abnormalities (especially hyperkalaemia), cardiomyopathies, muscular dystrophy, hypoadrenocorticism and toxicity.
Clinical Signs
Heart sounds are normal on auscultation. As ventricular depolarisation occurs a normal pulse can be felt. It is common for the heart rate to be slow, at less than 60 beats a minute in small animals.
Diagnosis
Diagnosis can be confirmed by ECG or fluoroscopy.
ECG
An ECG should show an absence of P waves. Heart rate is regular but normally slow, due to the presence of an escape rhythm. The QRS complexes are normal or slightly wide.
It is important to have an artefact-free ECG of diagnostic quality to confirm atrial standstill.
Treatment
Treat the underlying cause.
| Atrial Standstill Learning Resources | |
|---|---|
 Test your knowledge using flashcard type questions |
Feline Medicine Q&A 01 |
References
Martin, M (2002) ECG interpretation in small animals : 2. Abnormalities in the conduction system In Practice 2002 24: 194-20
Sparks, AH & Caney, SMA (2005) Self-Assessment Colour Review Feline Medicine Manson