Arrhythmias Flashcards
What are arrhythmias?
Abnormal Heart rhythms
Shockable rhythms
- Ventricular tachycardia
- Ventricular fibrillation
Non shockable rhythyms
- Pulseless electrical activity(all electrical activity except VF/VT, including sinus rhythm without a pulse)
- Asystole
What is A Fib
- chaotic irregular atrial arrhythmia and is considered a type of supraventricular tachycardia
- Most common A
- M > F
RFs for A Fib
- Age
- DM
- HT
- Hyperthyroidism
- Congestive HF
- Valvular Heart disease
A fib pathophysiology
- SA node produces electrical activity coordinates contraction of atria of heart
- A fib contraction of atria is uncoordinated, rapid and irregular - due to disorganised electrical activity overriding normal organised activity
What does A Fib lead to?
Irregular conduction of impulses to ventricals - leads to:
- Irregularly irregularventricular contractions
- Tachycardia
- Heart failuredue topoor fillingof the ventricles duringdiastole
- Risk ofstroke
Types of A fib
- First episode
- Paroxysmal: recurrent episodes that stop on their own in less than 7 days
- Persistent: recurrent episodes that last more than 7 days
- Permanent:
Causes of A Fib - PIRATES
- Pulmonary- PE and COPD
- IHD
- Rheumatic heart disease
- Aneamia + Age
- Thyroid - hyper
- Electrolye - hypo/hyperkalemia
- Sepsis + Sleep apnoea
S + S of Afib
- Irregular irregular pulse
- Hypotension:red flag; suggest haemodynamic instability
- Evidence of heart failure:red flag; such as pulmonary oedema
- Palpitations
- Dyspnoea
- Chest pain: red flag
- Syncope: red flag
Features to do DC cardioversion with AFib
- Shock
- Syncope
- MI
- HF
Investigations for Afib
- ECG: Irregularly irregular QRS complexes + absent P waves and chaotic baseline
- Serum electrolytes
- TFTs
What do we have to for Afib management
- Determine if rate control or rhythm control is more appropriate
- Rate control - patient not in sinus rhythym - aim to get HR under 100
- Rhthym - restore normal sinus - known as cardioversion
Haemodynamic unstable management
Unstable - Emergency electrical synchronised DC cardioversion
Stable haemodynamically management
- Onset of AF < 48 hours: 1) rate control or 2) rhythm-control
- Onset of AF > 48 hours / unknown onset: offer rate-control and anticoagulation for at least 3 weeks, then offer rhythm control if appropriate e.g. if rate control is unsuccessful or the patient remains symptomatic
Rate + Rhythym control
- Rate: 1st line - BB (Bisoprolol) or CCB (verapamil)/ Digoxin for patients with HF and AF just digoxin
- 2nd line Combine
- Rhythm control: Amiodarone or electrical cardioversion
If treatment for Afib fails then what
- Left atrial ablation: thepulmonary veinssupply the premature depolarisations that trigger AF; radiofrequency energy is delivered in this area
Complications of Afib
MI
Stroke
HF
Reduced quality of life
What is atrial flutter
Atrial flutter is usually an organised atrial rhythm with an atrial rate typically between 250-350bpm
Aetiology of Atrial flutter
- Idiopathic (30%)
- Coronary heart disease
- Obesity
- Hypertension
- Cardiomyopathy
- Heart failure
What is the cause of atrial flutter?
- caused by a re- entrant rhythm in either atrium.
- electrical signal is in a self perpetuating loop due to an extra electrical pathway in the atria
what is the rate of atrial contraction in atrial flutte
300bpm
What would you see on an ECG for Atrial flutter
saw tooth shapes , p wave after p wave
Assosciated conditions with atrial flutter
- Hypertension
- Ischaemic heart disease
- Cardiomyopathy
- Thyrotoxicosis
Aflutter treatment
- Treat the reversible underlying condition (e.g. hypertension or thyrotoxicosis)
- Rate/rhythm controlwith beta blockers or cardioversion
- Radiofrequency ablationof the re-entrant rhythm
- Same as A fib
What is wolf Parkinson White Syndrome
- caused by an extra electrical pathway causing the ventricles to contract early
- accessory pathway and av signal merge to contract both ventricles
- the extra pathway that is present is called the bundle of kent
2 types of WPWS
- Type A: +ve delta wave in V1
- Type B: -ve delta wave in V1
What can WPWS cause
Supraventricular tachycardia: may be due to AVRT or pre-excited AF/ flutter
ECG for WPWS
- Short pr interval
- wide qrs complex
- ’delta wave’ - a slurred upstroke on the qrs complex
Management of WFPW syndrome
- Flecainide, propafenone, sotalol, or amiodarone
- Ablation of the accessory pathway
Complications of WPWS
- Prone to AF
- May degenerate to VF and cause sudden death
What is SVT
Supraventricular tachycardia (SVT) is caused by the electrical signal re-entering the atria from the ventricles.
Elderly females affected
RFs for SVT
- Increasing age: five times more common in elderly patients
- Female gender: two times more common in females
- Hyperthyroidism
- Smoking
- Excessive caffeine or alcohol consumption
SVT main types
WPWS
A FIB + FLUTT
Paroxysmal
Pathophysiology of SVT
Elec signals finds way back from ventricles to atria - once back travels back through AV node causing another ventricular contraction
QRS <0.12
What is Atrioventricular nodal reentry tachycardia (AVNRT)
when the re-entry point is back through the AV node.
ECG for AVNRT
12-lead ECG: regular, narrow-complex tachycardia (QRS <0.12) with a rate of 151 to 250 beats per minute - it looks like a QRS complex followed immediately by a T wave, QRS complex, T wave etc
S + S of SVT
- Tachycardia + Tachypnoea
- Hypotension
- Pallor
- Cold and clammy
- Palpitations
- Shortness of breath
- Chest pain
Long term management of those with SVT
- Medication (beta blockers,calcium channel blockersoramiodarone)
- Radiofrequency ablation
