Editing Circulation (section)

== Specific problems ==

* '''Tachycardia'''
**
* '''Tachyarrhythmia'''
**

*
* '''Supraventricular tachycardia''' (a/w increased risk of cardiac event)
** Sinus
*** Caused by pain/anxiety, fever, hypovolaemia, hypovolaemia/anaemia, PE; less commonly heart failure, MI, thyrotoxicosis, phaeochromocytoma
** Atrial
*** AF
**** See separate topic under 'Cardiology'
*** Atrial flutter
**** Regular flutter P waves at 300/min. QRS is normal with variable AV block. There is usually underlying cardiac disease.
**** AF and flutter may be present in the same patient.
**** May respond to adenosine
**** Treatment is cardioversion, digoxin or verapamil.
****
** Paroxysmal SVT
*** Any tachycardia originating in AV node, atria or sinoatrial node
*** Changes to P waves or missing P waves
* '''Ventricular'''
** PVC
*** Consider hypoxia, hypokalaemia, hypocapnia
** Ventricular tachycardia
** VF

* '''Bradyarrhythmia'''
** Problematic if associated with hypoperfusion or hypotension
** Causes:
*** Autonomic
**** Pain, especially visceral
**** Raised ICP
**** Beta-blockers
**** Epidural
*** Non-autonomic
**** MI, especially inferior MI
**** Sepsis
**** Hypoxia
**** Digitalis toxicity
**** Hypothyroidism
**** Hypothermia
** Management:
*** Atropine 0.6-1.2mg may help
*** Pacing may be needed
*** Isoprenaline infusions can be used in ICU
* '''Heart block'''
** RBBB
*** Right ventricular depolarisation occurs via the left ventricle
*** M-shaped QRS in V1, V2 and V3
*** RBBB with left axis deviation suggests bifascicular block - discuss with cardiology
** Left ventricle depolarises via right ventricle
** M-shaped QRS in V5, V6, I and aVL. W-shaped QRS in reciprocal leads, III and aVF