Thyroidectomy for Amiodarone-Induced Thyrotoxicosis with CRT-D

You are reviewing in the clinic a 60-year-old man listed next week for a total thyroidectomy for amiodarone induced thyrotoxicosis. Past medical history: Ischaemic cardiomyopathy Cardiac resynchronisation therapy with implantable defibrillator (CRT-D) placed two months ago Type II Diabetes Obesity – 110kg, 174cm. Neck circumference 44cm Hypercholesterolaemia Gastro-oesophageal reflux disease Drugs: Aspirin 100mg once daily Bisoprolol 2.5mg once daily Sacubitril / Valsartan 97/103 mg twice daily Spironolactone 25mg once daily Frusemide 40mg once daily Rosuvastatin 40mg once daily Metformin XR 1g twice daily Dapagliflozin 10mg once daily Semaglutide 1mg weekly sub cut Esomeprazole 40mg once daily CRT-D report: attached Echo summary report: attached Echocardiogram Summary (performed day before clinic) Severe ischemic cardiomyopathy with global LV dysfunction (EF 25%) Dilated LV with extensive wall motion abnormalities, consistent with prior infarcts LA moderately dilated; RA mildly dilated Mild-moderate functional MR due to LV remodelling Mild TR. Aortic valve normal structure, no stenosis or regurgitation Biventricular pacing active, with evidence of improved mechanical synchrony Mild pulmonary hypertension (RSVP 40mmHg) and mildly dilated RV with reduced function IVC: normal diameter, normal respiratory collapse Pacemaker report Date of Evaluation: 12th May, 2025 Device Model: Medtronic Claria MRI Quad CRT-D Implant Date: March 27th, 2025 Indication for CRT-D: Severe ischemic cardiomyopathy (LVEF 20%), NYHA Class III heart failure, history of ventricular arrhythmias Device Type: Cardiac Resynchronization Therapy with Defibrillator (CRT-D) Leads & Positioning: Right Atrium (RA): Lead in right atrial appendage Right Ventricle (RV): Lead in RV apex (shock lead) Left Ventricle (LV): Lead via coronary sinus to lateral/posterolateral vein Intrinsic Rhythm & Pacing Dependence Underlying Rhythm: Normal sinus rhythm (NSR) Atrial Pacing (AP): 1% (Minimal pacing, appropriate sinus node function) Ventricular Pacing (VP): 96% biventricular pacing (Effective CRT delivery) Biventricular Pacing Capture: >95% (Adequate resynchronization)