Med School Notes (Year 4) - Cardiovascular - Arrhythmias [Sub. Atrial Fibrillation] Part 2

¢ Drug treatment: consider digoxin (increases heart block — slows ventricle = improved pump action), flecainide (in those without structural heart disease), Amiodarone (extensive toxicity issues) or Sotalol: Agent Action Adverse effects Amiodarone Prolongs action potential, [3- Pulmonary fibrosis, thyroid and blocker activity. Hepatic hepatic dysfunction (do baseline metabolism, active metabolites. bloods), muscle weakness, peripheral T" of weeks. neuropathy, skin discoloration Digoxin Tvagal tone, renal elimination, T% Nausea, vomiting and confusion. VK =36 hours (eg diuretics) — Ttoxicity. Diltiazem, amiodarone and flecainide — Tdigoxin concentration. Diltiazem Ca channel blocker. Hepatic Hypotension, headache, bradycardia, elimination. T% = 4 hours. oedema, heart failure. TDigoxin levels. Flecainide Na Channel blocker. Renal and Sudden cardiac death in those with hepatic metabolism. T2 =10—17 structural heart disease, CHF or heart hours block Metoprolol B-blocker. Hepatic metabolism. Hypotension, heart block, worsening T% = 4 hours. High first pass of heart failure if larger doses, asthma metabolism Sotalol B-blocker, prolongs action Ventricular arrhythmia, hypotension, potential. Renal elimination. T2 = heart block, worsening of heart failure, 8 hours asthma e Antithrombotic therapy: Reduces annual risk in those at risk from 5% to 1.5% (60% relative risk reduction), with 1% having material anti-coagulant side effects. Use warfarin with a goal of an INR from 2 to 3. Use aspirin if warfarin contra-indicated (only 10 — 15% relative risk reduction) e Atrial flutter: probably due to atrial re-entry. Regular atrial saw tooth pattern with ventricular beat every 3:1 or 4:1. If unstable hypotension, synchronised counter-shock at 50J (treat as for AF)