First Thoughts
First Thoughts
* Can I feel a pulse?
* ?Immediately life threatening
* Is there a blood pressure?
* Is it stable or unstable?
* ?Regular or irregular
* ?Fast or ?slow
* Can I feel a pulse?
* ?Immediately life threatening
* Is there a blood pressure?
* Is it stable or unstable?
* ?Regular or irregular
* ?Fast or ?slow
Narrow Complex Tachycardia
Narrow Complex Tachycardia
* What rhythm is it? (For AF see treatment slide for AF)
* Can you slow it down to see what it is? eg vagal manoeuvre, adenosine
* What rhythm is it? (For AF see treatment slide for AF)
* Can you slow it down to see what it is? eg vagal manoeuvre, adenosine
Adenosine
Adenosine
* To terminate SVT, or, for other NCT’s transient AV block may help diagnosis
* Dose: 6 mg IV push, then 12mg if no response, further12mg if no response
* Adverse effects: bradyarrhythmias, flushing, chest pain which are Shortlived because t1/2 is just a few seconds
* Other drugs to use: beta blocker (BB), calcium channel blocker(CCB), digoxin
* To terminate SVT, or, for other NCT’s transient AV block may help diagnosis
* Dose: 6 mg IV push, then 12mg if no response, further12mg if no response
* Adverse effects: bradyarrhythmias, flushing, chest pain which are Shortlived because t1/2 is just a few seconds
* Other drugs to use: beta blocker (BB), calcium channel blocker(CCB), digoxin
Atrial Fibrillation
Atrial Fibrillation
* Stable or unstable?? (If unstable consider DC cardioversion)
* >48 hours beware of CLOT: TOE, anti-coagulate before conversion
* Aims: RATE CONTROL or CONVERSION
*BB=beta-blocker, CCB=calcium channel blocker,SCV= synch cardiovert
* Stable or unstable?? (If unstable consider DC cardioversion)
* >48 hours beware of CLOT: TOE, anti-coagulate before conversion
* Aims: RATE CONTROL or CONVERSION
| Rate Control | Conversion | |
| Good LV | BB CCB | Amiodarone SCV |
| Poor LV | Digoxin Amiodarone | SCV Amiodarone |
| WPW (Wolf Parkinson White) | Amiodarone Sotalol |
*BB=beta-blocker, CCB=calcium channel blocker,SCV= synch cardiovert
Synchronized Cardioversion
Synchronized Cardioversion
* Sync mode delivers energy of the shock just after the R wave
Use of sync mode prevents delivering a shock during the T wave, which can trigger off VF eg use in AF,A Flutter, SVT
* Indications
all tachycardias rate > 150 bpm with serious signs and symptoms related to the tachycardia (may give a brief trial of medications if patient not severly unstable)
Note: low threshold for cardioversion if under GA
* Precautions
reactivation of sync mode is required after each attempted cardioversion (machines default to unsynchronized)
* Technique
look for sync markers on the R wave monophasic
shocks sequence is 100J, 200J, 300J, 360J (SVT and atrial flutter often respond to lower energy, start at 50 J)
Treat pulseless VT likeVF: ie unsynchronized monophasic 200, 200, 360, biphasic starts lower 150
* Sync mode delivers energy of the shock just after the R wave
Use of sync mode prevents delivering a shock during the T wave, which can trigger off VF eg use in AF,A Flutter, SVT
* Indications
all tachycardias rate > 150 bpm with serious signs and symptoms related to the tachycardia (may give a brief trial of medications if patient not severly unstable)
Note: low threshold for cardioversion if under GA
* Precautions
reactivation of sync mode is required after each attempted cardioversion (machines default to unsynchronized)
* Technique
look for sync markers on the R wave monophasic
shocks sequence is 100J, 200J, 300J, 360J (SVT and atrial flutter often respond to lower energy, start at 50 J)
Treat pulseless VT likeVF: ie unsynchronized monophasic 200, 200, 360, biphasic starts lower 150
Ventricular Tachycardia with a Pulse
Ventricular Tachycardia with a Pulse
| Type of VT | Good LV | Poor LV |
| Mono | Lignocaine Amiodarone |
Lignocaine Amiodarone |
| Poly, normal QT | BB Lignocaine Amiodarone |
Lignocaine Amiodarone |
| Poly, wide QT | Mg, Lignocaine, Overdrive pace | Lignocaine |
Bradycardia
Bradycardia
* Treatment for symptomatic brady regardless of cause:
-stop vagal stimulation (what is the surgeon doing?)
-?pace or use drugs??
-first line drug atropine, 500 mcg repeated to total of 3 mg
-second line drug either isoprenaline (controversial) or adrenaline
* Unstable symptomatic patients: transcutaneous cardiac pacing (TCP), atropine +/- adrenaline, as temporary measure until transvenous pacing can be inserted
* Stable patients where there is a risk of asystole (eg pauses >3 sec or block at or below the AV node) may need to be paced.
* Treatment for symptomatic brady regardless of cause:
-stop vagal stimulation (what is the surgeon doing?)
-?pace or use drugs??
-first line drug atropine, 500 mcg repeated to total of 3 mg
-second line drug either isoprenaline (controversial) or adrenaline
* Unstable symptomatic patients: transcutaneous cardiac pacing (TCP), atropine +/- adrenaline, as temporary measure until transvenous pacing can be inserted
* Stable patients where there is a risk of asystole (eg pauses >3 sec or block at or below the AV node) may need to be paced.
Types of Bradycardia
Types of Bradycardia
* Sinus Bradycardia, First Degree Block and Second Degree Block-Mobitz Type 1(progressive P-R lengthening until QRS is dropped):
-these are rarely symptomatic
-these can be caused by excess vagal stimulation, especially if patient is on BB, digoxin, verapamil
* Sick Sinus Syndrome (Alternating brady and tachy)
-treatment with combination of permanent pacemaker (PPM) and anti-arrhythmics
* Second Degree Block-Mobitz Type 2 (P-R interval lengthened but fixed, with intermittent drop out of QRS)
-more worrying than Type 1. May progress to 3rd degree heart block (Complete Heart Block)
-causes: eg myocardial infarction, degeneration of conduction system
* Third Degree Block, Complete Heart Block
-this is total failure of AV conduction
-unstable rhythm, often severe bradycardia and can get episode of ventricular asystole
Causes: eg myocardial ischaemia or infarction, or chronic degeneration of conduction system
Treatment: permanent pacemaker PPM)
* Sinus Bradycardia, First Degree Block and Second Degree Block-Mobitz Type 1(progressive P-R lengthening until QRS is dropped):
-these are rarely symptomatic
-these can be caused by excess vagal stimulation, especially if patient is on BB, digoxin, verapamil
* Sick Sinus Syndrome (Alternating brady and tachy)
-treatment with combination of permanent pacemaker (PPM) and anti-arrhythmics
* Second Degree Block-Mobitz Type 2 (P-R interval lengthened but fixed, with intermittent drop out of QRS)
-more worrying than Type 1. May progress to 3rd degree heart block (Complete Heart Block)
-causes: eg myocardial infarction, degeneration of conduction system
* Third Degree Block, Complete Heart Block
-this is total failure of AV conduction
-unstable rhythm, often severe bradycardia and can get episode of ventricular asystole
Causes: eg myocardial ischaemia or infarction, or chronic degeneration of conduction system
Treatment: permanent pacemaker PPM)
Emergency Pacing
Emergency Pacing
* Indications
-haemodynamically unstable bradycardia, especially if not responding to drug treatment
-bradycardia with pause dependent ventricular rhythm (risk of VT or VF)
-cardiac arrest secondary to reversible causes eg drug OD, acidosis, electrolyte disturbance
* Relative contra-indications
-beware of the prolonged brady-asystolic arrest >20 minutes (Is the patient already dead?)
-exclude hypothermia
Technique for Transcutaneous Pacing TCP
-modern defibrillators have TCP ability
-large diameter (8cm) electrodes
(anterior over cardiac apex to left of sternum, posterior on back to left of spine behind anterior electrode)
-start pacing, default rate usually 80 bpm. Select either demand or fixed rate.
-gradually increase output until capture (wide QRS and broad T wave after pacing spike) occurs. Pace at 10% above capture threshold
* Indications
-haemodynamically unstable bradycardia, especially if not responding to drug treatment
-bradycardia with pause dependent ventricular rhythm (risk of VT or VF)
-cardiac arrest secondary to reversible causes eg drug OD, acidosis, electrolyte disturbance
* Relative contra-indications
-beware of the prolonged brady-asystolic arrest >20 minutes (Is the patient already dead?)
-exclude hypothermia
Technique for Transcutaneous Pacing TCP
-modern defibrillators have TCP ability
-large diameter (8cm) electrodes
(anterior over cardiac apex to left of sternum, posterior on back to left of spine behind anterior electrode)
-start pacing, default rate usually 80 bpm. Select either demand or fixed rate.
-gradually increase output until capture (wide QRS and broad T wave after pacing spike) occurs. Pace at 10% above capture threshold
Causes of Arrhthymias- Is there a Treatable Cause?
Causes of Arrhthymias- Is there a Treatable Cause?
* Ischaemia Hypovolaemia
* Electrolyte disturbances
* Acid-base disturbances
* Hypo/hyperthermia
* Endocrine disturbance eg hyperthyroidism
* CVC/SwanGanz insertion
* Drugs-drug error, cocaine, amphetamines
* Ischaemia Hypovolaemia
* Electrolyte disturbances
* Acid-base disturbances
* Hypo/hyperthermia
* Endocrine disturbance eg hyperthyroidism
* CVC/SwanGanz insertion
* Drugs-drug error, cocaine, amphetamines
LIGNOCAINE
LIGNOCAINE
* Indications
-cardiac arrest from VF/VT Class 2 b)
-stable VT, wide complex tachycardia of uncertain type, or wide complex SVT (Class 2 b)
* Precautions
-reduce maintenance dose (not loading dose)
in impaired liver function or left ventricular dysfunction
-discontinue infusion immediately if signs of toxicity develop
* Dose
-Initial dose: 1 to 1.5 mg/kg IV
-Can repeat 0.5 to 0.75 mg/kg every 5-10 minutes, max total dose 3mg/kg
-Maintenance Infusion: 1 to 4 mg/min (30 to 50 mcg/kg per minute)
* Indications
-cardiac arrest from VF/VT Class 2 b)
-stable VT, wide complex tachycardia of uncertain type, or wide complex SVT (Class 2 b)
* Precautions
-reduce maintenance dose (not loading dose)
in impaired liver function or left ventricular dysfunction
-discontinue infusion immediately if signs of toxicity develop
* Dose
-Initial dose: 1 to 1.5 mg/kg IV
-Can repeat 0.5 to 0.75 mg/kg every 5-10 minutes, max total dose 3mg/kg
-Maintenance Infusion: 1 to 4 mg/min (30 to 50 mcg/kg per minute)
AMIODARONE
AMIODARONE
* Indications
-treatment of shock refractory VF/pulseless VT
-treatment of polymorphic VT and wide complex tachycardia of uncertain origin
-control of haemodynamically stable VT when cardioversion unsuccessful (particularly useful in presence of LV dysfunction)
-used as adjunct to electrical cardioversion of SVT
-termination or rate control of atrial fibrillation/atrial flutter
* Precautions
-may produce vasodilation and hypotension
-may have some negative inotropic effects
>-use with caution in renal failure
* DOSE
-Cardiac arrest: 300mg IV push, consider repeating 150 mg IV push in 3 to 5 minutes (max cumulative dose 2.2g/24 hours)
-Other arrhythmias 5 mg/kg in 250 ml 5% dextrose over 20 minutes to 2 hours, then 10-15mg/kg over 24 hours
* Indications
-treatment of shock refractory VF/pulseless VT
-treatment of polymorphic VT and wide complex tachycardia of uncertain origin
-control of haemodynamically stable VT when cardioversion unsuccessful (particularly useful in presence of LV dysfunction)
-used as adjunct to electrical cardioversion of SVT
-termination or rate control of atrial fibrillation/atrial flutter
* Precautions
-may produce vasodilation and hypotension
-may have some negative inotropic effects
>-use with caution in renal failure
* DOSE
-Cardiac arrest: 300mg IV push, consider repeating 150 mg IV push in 3 to 5 minutes (max cumulative dose 2.2g/24 hours)
-Other arrhythmias 5 mg/kg in 250 ml 5% dextrose over 20 minutes to 2 hours, then 10-15mg/kg over 24 hours
BETA BLOCKERS
BETA BLOCKERS
Indications
-to convert to normal sinus rhythm or to slow ventricular response ( or both) in supraventricular tachyarrhythmias eg SVT, atrial fibrillation, atrial flutter
-patients with suspected AMI and in unstable angina in absence of complications: are effective anti-anginal agents and can reduce incidence of VF
* Precautions
-concurrent admin of IV CCB eg verapamil can cause severe hypotensions
-contra-indicated severe LVF, hypoperfusion, 2nd or 3rd degree AV block, caution with bronchospastic disease
* DOSE
Esmolol- 0.5 mg/kgover 1 min, then infusion 0.05mg/kg/min(max 0.3 mg/kg/min)
Atenolol-eg 5 mg slow IV (over 5 minutes), wait 10 minutes then 2nd dose 5mg Slow IV
Indications
-to convert to normal sinus rhythm or to slow ventricular response ( or both) in supraventricular tachyarrhythmias eg SVT, atrial fibrillation, atrial flutter
-patients with suspected AMI and in unstable angina in absence of complications: are effective anti-anginal agents and can reduce incidence of VF
* Precautions
-concurrent admin of IV CCB eg verapamil can cause severe hypotensions
-contra-indicated severe LVF, hypoperfusion, 2nd or 3rd degree AV block, caution with bronchospastic disease
* DOSE
Esmolol- 0.5 mg/kgover 1 min, then infusion 0.05mg/kg/min(max 0.3 mg/kg/min)
Atenolol-eg 5 mg slow IV (over 5 minutes), wait 10 minutes then 2nd dose 5mg Slow IV
CALCIUM CHANNEL BLOCKERS
Verapamil
* Indications
-alternative drug to terminate SVT with narrow QRS complex, adequate blood pressure and preserved LV function
-may control ventricular response in patients with atrial fibrillation, flutter, or multi-focal atrial tachycardia
* Precautions
-do not use for wide QRS tachycardias
-avoid in WPW and atrial fibrillation, sick sinus, and 2nd and 3rd degree AV block without pacemaker
-expect blood pressure may drop due to peripheral vasodilation
-may exacerbate CCF in patients with LV dysfunction
-use with caution in presence of beta blockers
* Dose
2.5mg to 5mg IV bolus over 2-3 minutes. Second dose 5-10mg if needed in 15-30 minutes. Max dose 20mg
* Indications
-alternative drug to terminate SVT with narrow QRS complex, adequate blood pressure and preserved LV function
-may control ventricular response in patients with atrial fibrillation, flutter, or multi-focal atrial tachycardia
* Precautions
-do not use for wide QRS tachycardias
-avoid in WPW and atrial fibrillation, sick sinus, and 2nd and 3rd degree AV block without pacemaker
-expect blood pressure may drop due to peripheral vasodilation
-may exacerbate CCF in patients with LV dysfunction
-use with caution in presence of beta blockers
* Dose
2.5mg to 5mg IV bolus over 2-3 minutes. Second dose 5-10mg if needed in 15-30 minutes. Max dose 20mg
MAGNESIUM CHLORIDE
MAGNESIUM CHLORIDE
* Indications
-in cardiac arrest only if torsades de pointes or suspected hypomagnesaemia is present
-refractory VF (after lignocaine)
-torsades de pointes with a pulse
-life threatening ventricular arrhythmias due to digoxin toxicity
* Precautions
-blood pressure can fall with rapid administration
-caution if renal failure
* Dose
-cardiac arrest (with torsades or hypomagnesaemia) 1-2 mmol diluted to 10 mls and IV push
-torsades de pointes (not in cardiac arrest) 1-2 g mixed in 50-100ml of 5% dextrose, over 5-60 minutes IV. Follow with 0.5 to 1.0 g/hour
* Indications
-in cardiac arrest only if torsades de pointes or suspected hypomagnesaemia is present
-refractory VF (after lignocaine)
-torsades de pointes with a pulse
-life threatening ventricular arrhythmias due to digoxin toxicity
* Precautions
-blood pressure can fall with rapid administration
-caution if renal failure
* Dose
-cardiac arrest (with torsades or hypomagnesaemia) 1-2 mmol diluted to 10 mls and IV push
-torsades de pointes (not in cardiac arrest) 1-2 g mixed in 50-100ml of 5% dextrose, over 5-60 minutes IV. Follow with 0.5 to 1.0 g/hour
