Common ITU Arrhythmias

CATEGORY: SOP

CLASSIFICATION: Clinical

PURPOSE Common ITU Arrhythmias

Controlled Document Number: C017

Version Number: 1.0

Document Author: QEHB Critical Care Tactical Working Group

Approved By: Medical Scientific Advisory Group (COVID-19)

Date / Time: 06/04/2020

Review Date: 30/09/2020

Distribution:

• Recommended Reading for:

Clinicians, all non medical Prescribers, Pharmacists and nurses

• Information for: Wards Managers, Senior Nurses, ADNs, Divisional Directors

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Page 1 of 1 CDN: C017 V 1.0 Title: Common ITU Arrhythmias Issued 06.04.2020

B Pouchet

Common ITU Arrhythmias

Arrhythmias

� Most common is atrial fibrillation often with rapid ventricular response (fast AF)

� Other potential life threatening arrhythmias include: � Ventricular tachycardia (VT) � Supraventricular tachycardia (SVT) � Heart block

� These arrhythmias can decrease cardiac output (cause

shock) or can potentially or actually cause cardiac standstill (cardiac arrest)

Atrial Fibrillation

Atrial Fibrillation

� Most common arrhythmia – occurs in 15 – 28% of non- cardiac ITU patients

� Associated with increased mortality and length of stay in non-cardiac surgery patients

� Risk factors: � Increased Right Atrial Pressure regardless of fluid status � Presence of SIRS (inflammation) � Increased catecholamines � Hypovolaemia � Fluid overload in post cardiac surgery

Fast AF

� Evidence lacking for prophylaxis outside cardiothoracic surgery units

� Magnesium may be effective treatment (40% conversion)

� DC cardioversion poor conversion rate and frequent recurrence

� Digoxin rate control <50% success

� Beta blocker rate control more effective (75-80%)

� Amiodarone most effective in CTS and in general ITU for rate control and cardioversion, less favourable haemodynamics than beta blockers

AF

� May not resolve until inflammatory process such as sepsis resolves

� Rate control is needed to prevent rapid ventricular rate and reduced cardiac output from inadequate filling times

� AF reduces atrial contribution to stroke volume (about 33%)

� Cardiac beta blocker such as bisoprolol or metoprolol can be used for rate control

� Amiodarone is suitable alternative with loading dose (300mg) followed by continuous infusion for 24hours (600- 900mg/24hrs) which can be repeated without re-loading

AF - Management

� Get 12 lead ECG to confirm diagnosis � Correct electrolytes

� Rate control with beta blockers or amiodarone

� Do not try to chemically or electrically cardiovert patients unless you have ECHO evidence of no atrial thrombi or onset less than 48 hours – risk of stroke or PE

� Cardioversion only for patients who are haemodynamically unstable because of AF and have evidence of no atrial thrombi

� Consider anticoagulation for patients if AF persists more than 48hours

SVT

SVT

� Less common in ITU

� Not usually associated with electrolyte disturbance

� Treatment: adenosine and DC cardioversion

� If recurrent consider: beta blocker or verapamil +/- flecainide or amiodarone

VT/VF

� Treat as per ALS guidelines

� Medical emergency

Heart Block

� Decreased conduction through AV node resulting in bradycardia

� Three degrees: 1st, 2nd, and 3rd degree

� Type II second degree and third degree require urgent intervention

� Treatment is with atropine, isoprenaline to increase heart rate, then pacing

� Need 12 lead ECG and cardiology input

Heart block

� Ist degree: � Prolonged PR interval (>5 small squares) � Every p wave (atrial depolarization) has a QRS (ventricular

depolarization/repolarization)

� 2nd degree: � Dropped beats (p waves with no corresponding QRS) � Two types

� Mobitz type I – gradual increase in p-R interval until dropped beat occurs – relatively benign

� Mobitz type II – dropped beats ( p wave with no QRS) occurring with no preceding increase in PR interval; usually fixed ratio of p waves to QRS (eg 3:1, 3:2) – associated with structural defect in conducting system

� 3rd degree: AV dissociation – no relationship between p waves

and QRS; ventricular rate is because of ventricular pacemakers and very slow

Heart Block

Heart Block

� Get 12 lead ECG

� Contact cardiology if IIb or III degree for urgent consideration of pacing

� Cardiac output can be increased using catecholamine infusions such as isoprenaline, dobutamine or adrenaline