Surgical Management of Ischaemic Heart Disease By Dilshan Udayasiri HMO2
Introducing Mrs Anne Gina • You’re the intern working in Western Hospital ED. • 52yo female presents with Chest Pain. What do you do next!!!!
History • Pain came on one hour ago on a background of having similar pain on exercise over the last 3 weeks. • Central and crushing • Radiates up the Jaw • Associated with SOB, palpitations, presyncope, diaphoresis. • Did not go away with rest, still present • WHAT DO YOU DO NEXT!!
Management • Obs sats 95%, BP 145/70, HR 100, afebrile • ECG • O2 15L via Hudson Mask • 300mcg of anginine sublingually • 300mg of asprin • Monitored Bed • 2 large bore cannula. • Heparin infusion commenced • Pain relieved. • Bloods and CXR request sent, Cardiology registrar on the way
Further History • PHx (Cardiac Risk factors) • Exsmoker (40 pack year history) • Hypertension • Hyperlipidaemia • T2DM – diet controlled • FHx – Father AMI 50 • SHX • Lives at home with Husband
Medications • Ramipril 2.5mg daily • Atorvastatin 20mg nocte • NKDA • Cardiology Registrar arrives. Is very Happy with your work. Takes the patient off for angiography.
The Coronaries • 2 main coronary arteries • Right Coronary Artery (RCA) • Gives of a Posterior Descending artery branch in approx 70% of patients • 20% of patients the PDA comes of the left circumflex and are hence Left dominant • 10% PDA comes off both and are then Codominant. • Supplies 25% - 35% of the left ventricle and the SA node in 60% of cases (otherwise LCx artery)
Left Main coronary artery • Divides early into the • Left anterior descending artery • Supplies the anterolateral myocardium, interventricular septum and the apex of the heart. In total it supples 45%-55% of the left ventricle. • Gives off septal (run straight into the intaventricular septum at 90degrees to surface, and diagonals that supply the lateral myocardium) • Left Circumflex • Gives off obtuse marginals (OMs) as it curves around the posterior aspect of the heart. • Supples the SA node in 40% of cases. If nonDominant supplies 15%-20% of LV, if dominant 40%-50%. Also supples anterolateral papillary muscles.
Patients Angiography • LMCA • Short left main with ostial 90% stenosis • LAD • Medium calibre vessel with mild dease throughout • LCx • Medium calibre, non-dominant vessel with mild disease. OM1 is tortuous and mildly diseased. Small AV branch diffusely diseased distally. • RCA • Dominant. Small calibre vessel with diffuse disease proximally and totally occluded mid vessel. • Ventriculogram • Lv Function is severely impaired. There is no mitral regurgitation
Some common indications for Coronary Artery Bypass Grafting • Left main artery disease or equivalent • Triple vessel disease • Abnormal Left Ventricular function. • Failed PTCA. • Immediately after Myocardial Infarction (to help perfusion of the viable myocardium). • Life threatening arrhythmias caused by a previous myocardial infarction. • Occlusion of grafts from previous CABGs. • Coronary artery disease with valvular disease • Angina not controlled by maximal medical therapy
Pt arrives at RMH PAC • Note History • Meds are now • Ramipril 2.5mg daily • Atorvastatin 20mg nocte • Metoprolol 25mg BD • Asprin 100mg daily • GTN spray 400mcg PRN
O/E • Comfortable, no chest pain • Obs, BP 140/75, HR 80, sats 98%RA, afeb • Pulse: ulna and radial present bilaterally, strong and regular • Allens test – negative bilaterally • No carotid Bruits • No previous scars on chest. Heart sounds are dual with no added sounds. Chest sounds are vesicular. • Lower limb pulses are present. No varicose veins • Right Handed
What do you want to do before the operation? • Consent patient for surgery • Optimise medical management – increase metoprolol to 50mg BD • W/H asprin 7/7 prior to surg • Tests • TTE • CXR • Bloods (FBE, UEC, Ca/Mg/Phos, Coags, G&S) • Carotid U/S not required
Complications of CABGs • Bleeding • Infection • Stroke • AMI • Arrythmias • Postperfusion syndrome (pumphead) • Sternal dehiscence
In Theatre • Pt prepared by anaesthetics (peripheral lines, CVC, arterial lines inserted.) • Once anaesthetised, TOE inserted. • Body prepped. • Conduits harvested • Heparin commenced • Chest opened and canulated ready for bypass. • Aorta clamped and cardioplegia started to stop heart. • Anastomosis performed. • Drains and pacing wires inserted • Cardioplegia ceased pt taken off bypass • T/fed to ICU
Post Op • Pt extubated day 1. Weaned off ionotropes and t/fed to ward. • First few days post op need to • Continuous cardiac monitoring. • Monitor drain outputs • Daily bloods + ECGs + CXR + weight • Pt normally commenced on frusemide + iv Abs + nebulisers on top of normal meds. • On day 3 post op you are paged by the nurse stating the patient is tachycardic rate 160, (BP 130/75, sats 95% 2L, no CP) • ECG is as follows
What would you do • Send off bloods • Think of and treat reversible causes • Electrolytes • Ischaemia • Hyperthyriodsim • Rate vs Rhythm control