This requires no treatment unless it is causing symptoms. If treatment is deemed necessary, give atropine 600-1200micrograms IV in the first instance.
Persistent symptomatic bradycardia requires pacing (temporary or permanent). If temporary pacing is required, transvenous pacing under x-ray control is optimal. For advice, contact the Cardiology Consultant on call.
First and second –degree block found incidentally do not usually need emergency treatment but further investigation is often necessary. After acute MI patients with second degree block will need temporary pacing if the block is impairing cardiac function.
Complete (3rd degree) AV block requires careful evaluation and should be discussed with the cardiology consultant on call immediately.
Patients with symptomatic block usually require immediate pacing even if symptoms have resolved upon arrival. Asymptomatic patients with marked bradycardia (heart rate <40bpm), a broad complex escape rhythm (QRS>120ms) and/or significant QT prolongation (QTc>500ms) are at high risk of arrest and will require urgent pacing. This is preferably achieved by prompt implantation of a permanent pacemaker but a temporary one may suffice for overnight/over –weekend management.
If patient has symptomatic bradycardia atropine may be administered in increments of 0.5mcg-1mg to total of 3mg.
If patient fails to respond to atropine and remains symptomatic, external pacing may be required prior to insertion of Temporary Pacing wire or Permanent Pacemaker.
Acute MI with:
Bradycardia not associated with acute MI:
VT secondary to bradycardia e.g Torsades de Pointes
Suppression of drug–resistant VT or SVT
Drug overdose e.g. digoxin, beta blockers, verapamil
Complete AV block associated with inferior myocardial ischaemia is usually transient but will require temporary pacing if the patient is compromised; or permanent pacing if the heart rate remains slow. When associated with anterior infarction temporary pacing is always indicated regardless of presence or absence of symptoms. Patients with acute bifascicular block following acute myocardial infarction should be considered for temporary pacing particularly if the PR interval is increased or increasing. Contact the cardiology consultant for advice and x-Ray guided temporary pacemaker.
The commonest types are:
A 12-lead ECG must be obtained in all cases. It is important to diagnose the disturbance accurately, as therapy will depend on the particular rhythm. All types can be paroxysmal or persistent and treatment should be tailored accordingly. Paroxysms should be terminated and preventive treatment started. Chronic arrhythmias which cannot be terminated should be slowed.
Patients with AF should be offered a Personalised Package of care (new NICE recommendation 2014).
Chronic AF, flutter and atrial tachycardia can be treated with AV nodal blocking drugs (beta-blockers, other than sotalol, or diltiazem). AF of recent onset (<24 hours) is best terminated by IV flecainide (1-2mg/kg over 10 min; maximum dose 150mg). In the presence of heart failure or acute ischaemia, amiodarone should be used (300mg bolus via a small cannula in a large vein inserted as far down the arm as possible but not directly over the wrist point, or centrally, then a 900mg infusion over 23 hours). Consider digoxin monotherapy for patients with non-paroxysmal AF only if they are sedentary (new NICE recommendation 2014).
Unless otherwise contraindicated, patients in AF for more than a day should be anticoagulated with either warfarin or a new novel oral anticoagulant as they are at risk of developing cardiogenic embolism. Stroke and bleeding risk should be assessed in all patients with AF by using CHA²DS²VASC and HAS-BLED tools. Do not withhold anticoagulation solely because the patient is at risk of having a fall (new NICE recommendation 2014). Do not offer Aspirin monotherapy solely for stroke prevention (new NICE recommendation 2014).
Assess anticoagulation control with vitamin K antagonists. Calculate individual time in therapeutic range (TTR) over a maintenance period of at least six months of treatment but excluding measurements taken during the first six weeks of treatment.(New NICE recommendation 2014). Consider switching to a novel oral anticoagulant (NOAC) if TTR less than 65% (New NICE recommendation 2014), if two INR values higher than 5 or one INR value higher than 8 within the past six months, or if have two INR values less than 1.5 within the past six months.
When there is haemodynamic compromise, DC cardioversion should be considered.
Junctional re-entry tachycardias are most effectively terminated with IV adenosine. Give an initial 6mg dose over 2secs. If no effect is seen within 1 min give a second injection of 12mg. Further doses are not recommended. Remember, adenosine should not be given to patients with asthma or severe obstructive airways disease.
Refer patients promptly at any stage if treatment does not control the symptoms of AF and more specialised management is needed.
All supraventricular arrhythmias may be treated by ablation. Patients, who have syncope due to Wolff Parkinson White (WPW) syndrome or atrial flutter with 1:1 conduction, should be referred immediately to the cardiology consultant. Any other patient who has an episode of atrial flutter or junctional re-entry tachycardia should be referred to a cardiologist as an outpatient so that therapy by ablation can be discussed. Patients with recurrent and highly symptomatic AF should also be referred.
NB DO NOT GIVE AV NODAL BLOCKING DRUGS TO WPW PATIENTS WITH PRE-EXCITED ATRIAL ARRHYTHMIAS.
This is very common and may present with a wide range of symptoms from moderate discomfort (haemodynamically stable tachycardia) to profound collapse or arrest (haemodynamically unstable tachycardia). Do not be misled into thinking that stability excludes a diagnoses of VT! The commonest causes include acute infarction/ischaemia and chronic left ventricular scarring after infarction.
First get the diagnoses correct by examining the 12 lead ECG. If this cannot be obtained because of collapse, urgent DC shock is required - otherwise record the ECG. Most instances of VT can be correctly diagnosed but if in doubt, treat broad complex tachycardia as VT.
Features of VT include:
Therapy depends on the clinical situation. If the patient is hypotensive, in cardiac failure or has ischaemia, DC cardioversion should be undertaken. If stable then initially treatment should be amiodarone (300mg bolus via a small bore cannula in a large vein or centrally, then a 900mg 23 hour infusion). Do not give more than one additional drug – polypharmacy can be dangerous. If drug therapy fails, or the patient has poor cardiac function, direct current cardioversion (200-360J) under sedation is the best therapy (if help needed contact the cardiology consultant for advice). Whatever method is used; full facilities for resuscitation should be to hand. Further cardiological assessment is mandatory in all cases not associated with acute ischaemia or infarction. Remember to check electrolyte levels. The administration of magnesium, initial dose 8mmol (4ml of 50%) may help when the arrhythmia is refractory.
NB: DO NOT TREAT A POSSIBLE VT WITH VERAPAMIL
Some patients presenting with ventricular arrhythmias who have an ICD implant may have received shocks from the device. The presence of an ICD does not prevent the use of emergency defibrillation or cardioversion in the event of a cardiac arrest or compromising VT that has not responded to ICD therapy. Follow UK Resuscitation Council Guidelines (2010) by defibrillating away from the device itself (usually left infraclavicular site). Haemodynamically stable VT or successfully treated patients can benefit from immediate ICD reprogramming. Contact the pacing clinic 9-5pm Monday- Friday for assistance as well as the Cardiology consultant.
This is less common and usually causes presyncope, syncope or cardiac arrest depending on the duration of arrhythmia. It may be associated with QT prolongation (Torsade de Pointes). Temporary pacing, beta-blockers and potassium and magnesium replacement may treat the arrhythmia successfully but certain drugs that prolong the QT interval or hypokalaemia must be removed. Other causes include ischaemia when QT prolongation may not be present. Beta-blockers and urgent assessment for cardiac catheterisation will be necessary. Involve the cardiology consultant on call early in these cases.
These are ubiquitous and do not require treatment unless they are causing symptoms such as palpitations or dizziness, when the patient should be referred for investigation and management. The urgency of this or the need for in- patient investigation will depend on the severity of symptoms, e.g., syncope requires in-patient assessment. Frequent ectopy, whether symptomatic or not, may indicate underlying structural heart disease and referral for non–urgent investigation as a minimum requirement is appropriate.
Patients with acute MI who develop CARDIAC FAILURE or CARDIOGENIC SHOCK, should be referred to the on-call cardiology consultant as soon as possible.
| Version | 2 |
|---|---|
| Author: | Dr M Faircloth, Consultant Cardiologist |
| Lead Director: | Dr M Faircloth, Consultant Cardiologist |
| Implementation Date: | October 2011 |
| Ratified By: | Drugs and Therapeutics Committee, Date October 2011 |
| Revised by: | Andrea Lavous, June 2015 |
| Review Date: | June 2017 |
Based on St Georges Handbook of Medical Emergencies “The Grey Book”. With the permission of Dr Elijah Behr and Dr Lisa Anderson.
UK Resuscitation Council Guidelines (2010)
NICE Clinical Guideline 180 AF : The management of AF (June 2014)
FPH Vascular Access Policy