Arrhythmias March 2018 | by EMauthor Atrial fibrillation (AF) •Disorganized atrial activity, resulting in an irregular ventricular response •Presents with palpitations, dizziness, shortness of breath (SOB) and heart failure irregularly irregular pulse, with or without haemodynamic compromise •Perform ECG and investigations into the underlying cause •Treat underlying cause; rate control (digoxin if septic / bad failure, otherwise metoprolol) •Anticoagulate or discuss this with pt as per CHA₂DS₂-VASc •ED cardioversion if unstable as per ALS or (rarely) if known onset <48h Atrial flutter •Atrial re-entry tachycardia, leading to rapid atrial rate (300 beats/min]; usually occurs with slower ventricular rate due to 2:1 or 3:1 block in the atrioventricular (AV) node •Palpitations, dizziness and heart failure, tachycardia, with or without haemodynamic compromise •ECG: usually reveals characteristic saw-tooth pattern with AV block •Rate control: anti-arrhythmics, anticoagulation as AF •Curative: DC cardioversion, catheter ablation of aberrant pathway as OPD Wolff-Parklnson-White Syndrome (WPW) •Atrial re-entry tachycardia, with an accessory excitatory pathway linking the atrium to the ventricle (bundle of Kent) •Palpitations, dizziness and collapse, tachycardia •ECG: short PR interval, delta wave [slurred upstroke to QRS), wide QRS •Treat with B-blockers, calcium-channel blockers, possibly DC cardioversion or catheter ablation •Rarely may progress to ventricular fibrillation (VF) Ventricular tachycardia (VT) •Sustained VT is VT that lasts for >30 secs or causes haemodynarnic compromise •Most commonly due to ischaemic heart disease i MI; cardiomyopathy, metabolic abnormalities, drug toxicity, long QT syndrome •Palpitations, chest pain, syncope, tachycardia with hypotension •Varying 1st heart sound, occasional cannon waves (giant ‘a’ waves in JVP) •ECG (wide complex tachycardia) •Anti-arrhyrhmics (amoidarone), very low threshold for ED cardioversion AV Block •Due to damage lo the atrial node, AV node or His-Purkinje system, secondary to Myocardial infarction, drugs (digitalis. calcium channel blockers, B-blockers, myocarditis, acute rheumatic fever, sarcoid, infections. •CLASSIFICATION OF AV BLOCK o1st degree: PR interval >0.20 s (five small squares on ECG) o2nd degree: some atrial impulses fail to conduct to the ventricles ■Mobitz type 1 (Wenckebach): the PR interval gradually increases in length until there is a ‘missed beat’ ■Mobitz type 2: occasional dropped QRS complexes are not related to changes in the PR interval o3rd degree: atrial and ventricular impulses are completely dissociated •ECG and cardiac monitoring •Atropine, isoprenaline (B-agonist); any patients with symptomatic 2nd or 3rd degree heart block should have cardiac pacing
|
Links •HOME |
Created with the Personal Edition of HelpNDoc: Free EBook and documentation generator