1. Yasmine Darwazeh FY1 – General Surgery
Arrhythmias
Yasmine Darwazeh
FY1 – General Surgery

2. Objectives Define bradyarrhythmia and tachyarrythmia
Know the most common brady- & tachyarrythmias
Recognise them on an ECG.
Know the main signs and symptoms, aetiology and treatments of each.

3. What can you see?

4. Types of bradyarrhythmia

5. Sinus Bradycardia HR < 60bpm Causes Treatment
Physiological (normal in athletic people)
Iatrogenic (Beta blockers, Ca channel blockers, digoxin, anticholinergics)
Hypothyroidism
Metabolic e.g. hyperkalemia
Hypoxia
Hypothermia
Acute MI/ischemia
Treatment
Remove cause (ie drugs)
Treat cause (ie hypothyroidism)

6. What can you see?

7. 1st degree AV node block
PR interval >0.2secs (more than 5 small squares)
Delayed conduction through/near the AVN
Usually asymptomatic
Narrow QRS complex indicates block within AVN
Wide QRS complex indicates His-Purkinje block.
Causes MI
Myocarditis/endocarditis
SLE
Treatment
Usually benign
Can progress to other forms of AV block
If symptomatic, consider pacemaker

8. What can you see?

9. Mobitz type 1 (Wenkebach)
PR interval progressively lengthens until a P wave is not followed by a QRS complex.
Continues as a cycle.
Due to a conduction defect within the AVN
Causes:
Inferior MI
Drugs
Myocarditis
Treatment
None required (unless reversible cause)

10. What can you see?

11. Mobitz type 2 Intermittent non-conducting P waves.
May occur in regular pattern e.g. every 3rd p wave is not followed by a QRS complex (3:1 block)
Causes
Anterior MI
Inflammatory (rheumatic fever, myocarditis)
Autoimmune (SLE, systemic sclerosis)
Hyperkalaemia
Infiltration (sarcoid, haemochromatosis, amyloid)
Treatment
Internal pacing eventually as likely to progress to 3rd degree heart block

12. What can you see?

13. Complete AV block
Complete dissociation between atrial & ventricular depolarisations
All impulses from atria blocked by the AVN
Very symptomatic & very syncopal.
Causes
Inferior MI
Drugs (ca channel blockers, beta blockers, digoxin)
Progression of Mobitz 1 & II
Congenital (if mother has SLE)
Lev's disease: idiopathic fibrosis & calcification of conducting system
Treatment
Internal pacing
Ventricular depolarisations occur as a result of an escape rhythm. Escape rhythms are initiated by one of the heart's back-up pacemakers. If the QRS complexes are narrow on the ECG then the escape rhythm is being initiated from the AV node itself. If the QRSs are wide then the escape rhythm is being initiated further down the conducting system or by an ectopic ventricular pacemaker. The ECG will show no pattern between the p waves and the QRS complexes. The patient will be bradycardic as a result of the escape rhythm which is usually 30-40bpm.

14. Adult Bradycardia Algorithm

15. What can you see?

16. Sinus tachycardia HR > 100bpm Causes: Treatment
Intra-cardiac causes 
Ishcaemic heart disease
Valvular heart disease
Heart failure
Cardiomyopathy
Congenital heart disease
Treatment
Treat the cause.
Extra-cardiac causes
Drugs
Alcohol
Stimulants e.g. caffeine
Stress
Hyperthyroidism
Infection/Sepsis

17. Broad and Narrow Complex tachycardias
Broad Complex Tachyarrhythmias
Ventricular Tachycardia
Torsades de Pointes
Ventricular Fibrillation
Narrow Complex Tachyarrhythmias (Supraventricular Tachycardias)
Sinus Tachycardia
Atrial Tachycardia
Reentrant Tachycardias (AVNRT and AVRT)
Atrial Fibrillation
Atrial Flutter

18. What can you see?

19. Atrial Flutter SVT, regular Saw-tooth flutter waves.
Flutter waves rate = 300 bpm
Ventricular rate = 150 bpm or 100 bpm, due to AVN block ratio of 2:1 or 3:1
Ectopic atrial beat causes a re-entrant circuit within the atria.
Causes
As for AF
Hyperkalaemia
Digoxin toxicity.
Treatment
As for AF (discussed later)
Can be differentiated from Fast AF with vagal manouvres/adenosine.
Right atrium usually involved with an anticlockwise circuit.

20. What can you see?

21. Ventricular tachycardia
Broad complex tachycardia
Causes
Electrolyte derangement (hypokalaemia, hypomagnesaemia, hypocalcaemia)
Myocardial ischaemia/infarct
Cardiomyopathy
Congenital (HOCM, long QT)
Treatment
Amiodarone
ICDs

23. What can you see?

24. Atrial Fibrillation Atria chaotically fibrillate.
Fibrillation rate between 350 & 600bpm.
Variable impulse conduction through the AVN
Irregularly irregular rhythm
Most common arrhythmia.
10% of population >80 years old.
Significant morbidity due to thromboembolic disease
Unmanaged = 5% yearly stroke risk.

25. Atrial Fibrillation Types Causes
Paroxysmal (acute onset, spontaneous termination within 1 week)
Persistent (>7 days, can be cardioverted)
Permanent (> 1 year not terminated by cardioversion)
Causes
Cardio (HTN, valvular disease, CAD, myositis)
Pulmonary (PE, pneumonia, COPD, lung Ca)
Metabolic (hyperthyroidism)
Infection
Drugs (alcohol, illicit drugs)

26. AF Investigations Management (Rate vs Rhythm) Rate – Rhythm
Bedside – ECG/24 hour tape
Bloods – FBC, U&Es, LFTs, TFTs, coag screen
Imaging – CXR, echo
Management (Rate vs Rhythm)
Rate –
Beta blockers
Digoxin
Rhythm
Cardioversion
Sotalol
Amiodarone (HF)
eta-Blockers and rate limiting calcium channel blockers (Verapamil and Diltiazem) are first line choices to lower the ventricular rate in AF. These are used first line in those with permanent AF, those over 65, those with ischaemic heart disease and those who can't tolerate antiarrhythmic drugs. They are used with caution in congestive heart failure, as they can make it worse. Digoxin is preferable in this situation, due to it's concomitant inotropic action on the heart.
Rhythm Control
Sotalol is commonly used first line as a rhythm control agent. Amiodarone and flecainide are also commonly used. Rhythm control is often the preferred option to treat paroxysmal AF, AF in younger patients, symptomatic AF, if there is no reason for the patient to be in AF (lone AF) or the precipitant has been treated and the AF persists. Rhythm control is sometimes preferred for those in congestive heart failure due to the dangers of slowing the ventricular rate with rate control drugs.
Those with infrequent, symptomatic episodes of paroxysmal AF, can self-administer a single dose ofanti-arrhythmic treatment at the onset of their AF symptoms. This is known as the 'pill in the pocket approach'.

27. AF - CHA2DS2-VASc score Thromboprophylaxis C – cardiac failure (1)
H – HTN (1)
A - >75 (2, 1 if 65-74)
D – diabetes (1)
S- stroke/TIA (2)
Va – vascular disease
Sc – female (1)
0 = Low Risk
1 = Moderate risk
2 or more = high risk

28. Summary Define bradyarrhythmia and tachyarrythmia
Know the most common brady- & tachyarrythmias
Recognise them on an ECG.
Know the main signs and symptoms, aetiology and treatments of each.

29. Any Questions