Essential Revision Notes for MRCP Third Edition - PasTest

Cardiologyor alter the rhythm:• Surprisingly, rhythm control does not reduce therisk of stroke (indeed paroxysmal AF carries thesame stroke risk as chronic AF) and thereforedoes not affect the indications foranticoagulation• Cardioversions, multiple drugs and ablations areall used to alter rhythm• In asymptomatic individuals rate control isrecommendedAssociations with atrial ¢brillation• Ischaemic heart disease• Pericarditis• Mitral valve disease• Pulmonary embolus• Hypertension• Atrial myxomas• Thyroid disease• LVH• Acute alcohol excess/chronic alcoholiccardiomyopathy• ASD• Post-coronary artery bypass graft (CABG)• Caffeine excess• Dilated left atrium (.4.5 cm)• Pneumonia• WPW syndrome• Bronchial malignancy• Risk factors for stroke with non-valvular AF• Previous history of cerebrovascularaccident or transient ischaemic attack(risk 322.5)• Diabetes (31.7)• Hypertension (31.6)• Heart failure• Risk factors for recurrence of AF aftercardioversion• Long duration (.1–3 years)• Rheumatic mitral valve disease• Left atrium size .5.5 cm• Older age (.75 years)• Left ventricular impairmentThe CHADS 2 score can be used for stratifyingthromboembolic risk in AF:• 1 point is awarded for each of: congestiveheart failure, hypertension, age over 75,diabetes• 2 points are awarded for systemic emboli• A score of 3 indicates a high risk ofthrombus formation and is a strongindication for anticoagulation• Scores of 1 and 2 are intermediate values(anticoagulation is given at the discretion ofthe physician)• The score has the virtue of simplicity but isquite conservative, probablyunderestimating the risk associated withprior stroke/transient ischaemic attackThe overall risk of systemic emboli is 5%–7%annually (higher with rheumatic valve disease); thisfalls to 1.6% with anticoagulation. Transoesophagealechocardiography (TOE) may exclude atrialappendage thrombus but cannot predict thedevelopment of a thrombus in the early stages postcardioversion;anticoagulation is therefore alwaysrecommended post-cardioversion.1.5.4 Ventricular arrhythmias andchannelopathiesVentricular tachycardia (monomorphic)Ventricular tachycardia (VT) has a poor prognosiswhen left ventricular function is impaired. After theexclusion of reversible causes such patients may27