BradyArrhythmiasJohnny Iliff

<60 beats per minute

Types Sinus Brady-Drugs (digoxin, beta blockers, verapamil, diltiazem, amiodarone)-Athletes-Increased Vagal Tone

Sick Sinus (Sinus Node Dysfunction)-characterised by sinus bradycardia, sinus pauses and junctional or ventricular escape rhythms.-tachy-Brady syndrome

AV Block-First-degree block, which has a prolonged PR interval-Second-degree block, which has intermittent AV conduction, ie intermittent dropped beats.-Third-degree block (complete heart block), which is due to complete interruption of AV conduction

Diagnosis Clinical + ECG-syncope, fatigue, shortness of breath on exertion and dizziness. Severe bradycardia can cause haemodynamic consequences of hypotension, altered conscious state, poor perfusion, ischaemic chest pain and cardiac failure

Causes Ischaemia HTN Structural/Congenital- OSA Toxicological- Drugs Metabolic- Electrolyte disturbance (K+) Endocrine- Hypothyroid Environmental- Vagal Tone, Hypothermia

What to do? Stable-Patients with asymptomatic bradycardia usually need no treatment- Stable BP ability to perfuse Unstable-Severe Symptoms and haemodynamic compromise

Treat the cause if identified

Atropine Atropine is most effective in sinus node

dysfunction or block at the level of the atrioventricular (AV) node.

-Comptetitive antagonist of Ach at muscarinic receptors-Reduces vagal tone and therefore increases HR-600mcg boluses up to 3mg

Adrenaline Chronotope-non selective alpha and beta agonist-infusion at 2-10mcg/min- titrate to effect-Adrenaline is preferred if systolic blood pressure is very low (less than 80 mm Hg)

Isoprenaline Chronotrope-Selective B1 Agonist-Caution risk of Hypotension-May require higher doses in patients with B-Blockers-10 to 20 micrograms IV, repeated according to clinical response, followed by an infusion at 1 to 4 micrograms/minute

Transcutaneous Pacing bradycardia unresponsive to drug therapy 3rd degree heart block Mobitz type II second-degree heart block when

haemodynamically unstable or operation planned overdrive pacing asystole

Further Therapy Temporary Pacing Wires/Transvenous Pacing-Central Venous Access (right IJV)

-Permanent Pacemaker

place pads in AP position (black on anterior chest, red on posterior chest) connect ECG leads set pacemaker to demand turn pacing rate to > 30bpm above patients intrinsic rhythm set mA to 70 Sedation (Midazolam+Fentanyl) start pacing and increase mA until pacing rate captured on monitor if pacing rate not captured at a current of 120-130mA -> resite electrodes

and repeat the above. once pacing captured, set current at 5-10mA above threshold Mechanical Capture/Electrical Capture