Yasmine Darwazeh FY1 – General Surgery Arrhythmias Yasmine Darwazeh FY1 – General Surgery

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.

What can you see?

Types of bradyarrhythmia

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)

What can you see?

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

What can you see?

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)

What can you see?

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

What can you see?

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.

Adult Bradycardia Algorithm

What can you see?

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

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

What can you see?

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.

What can you see?

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

What can you see?

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.

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)

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'.

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

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.

Any Questions