ACS/Arrythmia Flashcards
Normal QRS complex is
120ms Anything above that is a wide QRS (usually ventricular tachycardia) And Below is a narrow QRS
Types of regular narrow - complex tachy
- Atrial flutter with regular AV block - Re entrant tachycardia: AV nodal (AVNRT) or Atrio ventricular(AVRT) -Atrial tachycardia
What is the diagnosis and characteristic
Atrial flutter
- saw tooth
- High atrial rate
- QRS < 0.12
Management of acute atrial flutter/AF
if <48 since onset and patient is haemodynamically unstable (with no echo or underlying cause):
- Patients should be given heparin + Cardioversted using either:
- DC CARDIOVERSION * electric CV 1st line** OR
- Flecainide or amiodarone if echo normal (to revert to sinus rhythm)
- AMIODARONE if structural heart disease
- Treat any underlying conditions or electrolyte abnormalities
If < 48hr but patient is stable
- Consider rate control (bisoprolol or dilitiazem) or rhythm control ( DC cardiovert or amiodarone)
If > 48 hours/ unclear time of onset and patient stable
- Early Cardioversion after TOE ( transoesophageal echo) OR
- Delayed Cardioversion after 4 weeks of warfarin or NOAC
- Anticoagulation should be given for at least 3 weeks prior to cardioversion.
- Following electrical cardioversion patients should be anticoagulated for at least 4 weeks.
Patient with new onset AF with IHD has agreed on cardioversion. What is the most appropriate treatment if pharmacological cardioversion is agreed upon?
If pharmacological cardioversion has been agreed on clinical and resource grounds for new-onset atrial fibrillation, offer:
- Flecainide or amiodarone if there is no evidence of structural or IHD or
- Amiodarone if there is evidence of structural heart disease.
Treatment for re-entrant tachycardia
- Vagal manoeuvre e.g. Carotid sinus massage or valsava manoeuvre
If fails
- give Adenosine (NOT in acute asthmatics)
- Not in acute asthmatics - alternative: iv verapamil 5-10mg over 2min (not if on beta blocker)
- Side efects (chest pain, SOB,flushing)
- Large IV access 6mg, 12mg then 15mg
If adenosine fails
- Give Flecainide 2mg/Kg ( 30-60mins)
- if fails DC cardioversion - If haemodynamic instability and no response to adenosine or flecainide
- To prevent recurrence - Flecainide or B-blocker
- Consider Ablation for all Re-entrant tachycardias
Diagnosis
Re-entrant tachycardia -
- Characteristic: premature beats
Treatment for narrow complex supraventricular tachyarrythmias
IV adenosine
Beta blockers are contraindicATED IN
asthmatics
Agen ts used to control rate in AF
- beta blockers
- CCB
- Digoxin (not considered first-line anymore as they are less effective at controlling the heart rate during exercise. However, they are the preferred choice if the patient has coexistent heart failure)
Agents used to maintain sinus rhythm in patients with a history of atrial fibrillation
- sotalol
- amiodarone
- flecainide
A 59-year-old woman presents to the emergency department complaining of a three-day history of new-onset palpitations. She has no structural or ischaemic heart disease. Her heart rate is 120bpm, and she shows no signs haemodynamic compromise. Her ECG shows an irregularly irregular rhythm with the absence of p waves. The consultant recommends elective cardioversion for this patient. Which one of these management plans is the most appropriate for this patient?
- Bisoprolol and oral anticoagulant therapy for 3 weeks and then electrical cardioversion
- Bisoprolol for 10 days and then pharmacological cardioversion
- Oral anticoagulant for 10 days and then pharmacological cardioversion
- Bisoprolol and oral anticoagulant therapy for 3 weeks and then electrical cardioversion
This patient has presented with new-onset AF with a duration of greater than 48 hours.
As this is new-onset AF, rhythm control (cardioversion) is appropriate, however, as the patient is haemodynamically stable this is not immediately required.
Because the AF has persisted for more than 48hrs, cardioversion should be delayed until the patient has been anticoagulated for at least 3 weeks.
- During this period rate-control (Bisoprolol) should be offered as appropriate.
- Since the atrial fibrillation has persisted for longer than 48 hours, electrical (rather than pharmacological) cardioversion should be performed.
Diagnosis?
Atrial fibrillation
Acute AF means
AF within the last 7 days
Causes of AF
- Alcohol
- chest infection
- Hyperthyrodism
Symptoms & signs of acute AF
- Palpitations
- Dizziness
- breathlessness
- chest pain
- stroke / pulmonary oedema (severe cases)
- Sign = irregularly irregular pulse
Define:
- Paroxysmal AF
- Persistent AF
- Permanent AF
- Episodes of AF terminate spontaneously then the term paroxysmal AF is used. Such episodes last less than 7 days (typically < 24 hours).
- If the arrhythmia is not self-terminating then the term persistent AF is used. Such episodes usually last greater than 7 days
- there is continuous atrial fibrillation which cannot be cardioverted or if attempts to do so are deemed inappropriate. Treatment goals are therefore rate control and anticoagulation if appropriate
Managment of chronic AF
Offer:
- Rate control and /or Rhythm control (usuall chemical cardoversion e.g. amiodarone or flecainide)
- Offer some form of anticoagulation e.g. Warfarin, aspirin or NOAC - if CHADVASC >1 in men and > 2 in women
There are two key parts of managing patients with AF:
- Rate/rhythm control
- Reducing stroke risk
summary: maintaing sinus rhythm in long term AF
A 65 year old Eithiopian man came for annual review of hypertension and fostering.
Medical examination revealed irregularly irregular pulse - No symptoms
ECG: AF
Echo was normal normal/Left atrium - no dilation)/No evidence of clots/Valves normal/ ventricles normal
What treatment would you offer?
- Anticoagulation
- DC conversion as he had a normal heart structurally
Broad complex tachy is due to QRS >120 - what is its pathophysiology
caused by an automatic focus or re-entry circuit within the ventricles
Diagnosis?
Ventricular tachy
- no p waves
- regular + broad QRS with rate> 200
- no identifiable T-waves
Causes of VT
Managment?
- Underlying heart disease
- coronary heart disease
- hypertensive disease
- Cardiomyopathy
- Drugs ( associated with causing long QT)
Need to be referred to casualty for urgent assessment and DC cardioversion
Ventricular tachy
AF with LBBb
- LBBB best seen in V6 - “RSR” looks like letter M
Reciprocal RSR in V1 “W” can also occur
Remember WilliaM ( LBBB)
- Causes: IHD + aortic stenosis
RBBB
- nRSR” is best seen in V1= looks like M
nreciprocal RSR looks like “W” seen in V6
Remember MaRRoW ( RBBB)
- Causes: normal individuals, Atrial septal defect, Pulmonary embolus and heart failure
Assessing patient with broad complex tachy
- ABC
- IV access
- attach cardiac monitor
Management of VT
- if patient comprimised: Urgent electircal CV
- If patient not compromised & DC Cardioversion not possible: Give IV amiodarone 300mg over 1 hr (then 900mg over 24 hrs via central line)
drugs causing long QT
Diagnosis
Torsades de pointes:
or polymorphic ventricular tachycardia, is a ventricular tachycardia precipitated by and associated with long QT Syndrome which can be acquired or congenital
It can lead to cardiac arrest
Management of torsades
- Iv magnesium
- Overdrive atrial pacing (if no AV block) at rate of 100 bpm is treatment of choice***
- SC cardioversion if sustained
Indications for ICD
- Impaired LV with sustained or non sustained VT
- Resuscitated VF/VT arrests not due to reversible cause
- Patients with Previous MI , LVEF<35%,QRS >120
- Brugada syndrome, ARVD, Long QT syndrome
1st degree heart block
- Delayed AV conduction
- fixed Prolonged PR interval >0.2ms
- 1:1 ratio between p and QRS
- block is at AV node
second degree- mobitz type 1
- prolonging of PR intreval
- odd non-conducted P-wave
2nd block - Type 2
- constant prolonged PR
- with dropped QRS
