Makindo Medical Notes

Related Subjects: |Acute Coronary Syndrome (ACS): Complications |Atherosclerosis |Ischaemic heart disease |Assessing Chest Pain |ACS - General |ACS - STEMI |ACS - NSTEMI |ACS - GRACE Score |ACS - ECG Changes |ACS -Cardiac Troponins |ACS - Post MI arrhythmias |ACS: Right Ventricular STEMI |ACS: Sgarbossa Criteria

Arrhythmias

• Ventricular tachycardia: often seen acutely during ischaemia/infarction. Treat with IV lidocaine, IV amiodarone if persistent VT. Ensure normal potassium and magnesium. DC shock if compromised to return to sinus rhythm
• Idioventricular tachycardia: wide complex regular rate < 120/min often stable and a sign of reperfusion. Ensure normal potassium and magnesium. Usually settles without treatment
• Ventricular fibrillation: seen early on. Needs Defibrillation. manage of telemetry on ITU. Antiarrhythmics not usually needed. VF after the first 24 hrs is more concerning and may need ICD long term. Commence beta-blockade. late arrhythmias or persisting seek expert help.
• Atrial fibrillation is not uncommon and is treated with digoxin (ensure potassium over 4 mmol/l) or amiodarone for rate control. Rhythm control can be attempted through drugs such as amiodarone or DC cardioversion may be contemplated. Warfarin should be considered.
• Sinus bradycardia seen with inferior MI. Withhold beta-blockade and Give atropine and consider Isoprenaline if persists. Temporary basis if compromise remains
• Third-degree AV Block: Consider Atropine and External pacing. A temporary pacing wire may be needed or permanent pacemaker if stable at first opportunity. Avoid the subclavian route if on anticoagulants.
• Second-degree AV Block: A 2:1 or 3:1 block is often more concerning than Wenckeback type and may be a warning of CHB. A temporary pacing wire may be needed or permanent pacemaker if stable at first opportunity. Avoid the subclavian route if on anticoagulants. Take advice.
• First-degree heart block: Needs no treatment. If associated with new-onset LBBB it may suggest widespread anterior wall infarction and pacing may be needed.

Thromboembolic Complications

• Systemic Embolism: Clots formed within the heart, particularly in the setting of atrial fibrillation or LV thrombus, can embolize to other parts of the body, leading to strokes or peripheral embolism. Should be reduced by the use of LMWH and antiplatelets.
• Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE): Prolonged immobility and inflammation associated with ACS increase the risk of developing DVT, which can lead to PE. Should be reduced by the use of LMWH and antiplatelets.

Structural

• Cardiac rupture into the pericardium with tamponade and death usually, after the first few days as the necrotic wall softens. Clinically causes electromechanical dissociation and cardiac arrest. Seen with large anterior STEMIs. Usually at about 5-7 days. Less common with better early treatment.
• Severe loss of LV Muscle results in pump failure and Pulmonary oedema. Treat with IV diuretics e.g. Furosemide 50-100 mg IV. Suggests LV impairment and poor prognostic marker. Can progress to Cardiogenic shock - again suggests poor prognosis and suggests severe loss of LV myocardial muscle mass.
• Papillary muscle rupture can occur acutely with breathlessness and a loud pansystolic murmur. There may be acute severe MR with marked pulmonary oedema. Echo to confirm. Usually seen with a small infarct of the posteromedial papillary muscle in RCA or Cx distribution. Benefit from IABP as a bridge to surgery. Cardiac surgical assessment for MVR within 48 hours.
• Ventricular septal rupture can occur and present as heart failure with a loud PSM. Treat as a failure. Echo to confirm. May require IABP. Surgery within 48 hours.
• Ventricular remodelling: harmful reaction to large transmural STEMI with thinning of the ventricular wall. Prevent with ACEI.
• Right Ventricular MI: raised JVP but no pulmonary oedema. Leads V4R, V5R, and V6R are particularly important. ST-segment elevation in these leads is indicative of RVMI. Inferior Leads (II, III, aVF): Often show ST-segment elevation, as RVMI commonly occurs with IWMI. May benefit from fluid loading to help RV filling rather than diuresis.

Recurrent Ischemia and Reinfarction

• Reinfarction if there is plaque thrombosis with vessel occlusion. Consider urgent thrombolysis or repeat PCI. Discuss with local centre.
• RV Infarction: Volume loading treats the apparent hypotension, raised JVP and clear lung fields with an inferior STEMI. Echo is useful and evidence of a Right coronary artery infarction on ECG. Tall R wave in V1. ST elevation in V4R.

Inflammatory Complications

• Pericarditis: Inflammation of the pericardium, the lining around the heart, can occur post-MI, presenting as chest pain that is often sharp and worsens with inspiration. Can be seen on day 2 or 3 and maybe positional and affected by respiration. May need opiates. Avoid NSAIDs.
• Dressler’s Syndrome: A form of pericarditis that occurs weeks to months after an MI. It is thought to be immune-mediated and is characterized by fever, pericardial pain, and a pericardial effusion. Treat with NSAIDS/Steroids.

Psychological Complications

• Many patients experience significant psychological distress following an ACS event, including depression and anxiety, which can affect their quality of life and adherence to treatment.