Related Subjects:
|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 Infarction
Those with inferior infarcts usually do not need paced unless haemodynamically compromised. In these the conduction issues resolve within 2 weeks and permanent pacing is rarely required. In those with MB2/CHB in Anterior STEMI conduction system damage is usually permanent and needs paced.
Indications for temporary Pacing Post MI
- Mobitz II heart block with anterior MI.
- Complete heart block (CHB) with inferior MI if hypotensive or cardiac failure
- Complete heart block with anterior MI.
- New Bifascicular block (RBBB with left or right axis deviation): usually Anterior MI and at risk of CHB.
- Trifascicular block (long PR interval and either LBBB or RBBB with axis deviation): usually anterior MI and at risk of CHB.
- Alternating LBBB and RBBB: suggests extensive myocardial injury and high risk of CHB.
- Avoid subclavian route after thrombolysis. Consider internal jugular or the femoral route because there is less risk of haemorrhagic complications
Managing Early ventricular arrhythmias
- Evidence seems to be to avoid treating unless forced to. Evidence that antiarrhythmics may be harmful post MI.
- Ventricular Ectopics and non-sustained VT are very common especially post reperfusion. They usually require no treatment. Correct K⁺, Mg²⁺ and Ca²⁺, and correct if needed.
- Sustained VT or after VF, standard practice is IV bolus Lignocaine 100 mg over 5 min, then infusion of 2–4 mg/min) for 24 h after cardioversion. Amiodarone is also used.
- Early use of IV beta-blockers, e.g. metoprolol, often reduces the incidence of ventricular arrhythmias.
Managing Early ventricular arrhythmias
- AF/SVT: seen with pericarditis or heart failure. Tends to settle with digoxin. Cardioversion if persists. Treat pericarditis/infection or cardiac failure actively.
- VT: as a late event carries a bad prognosis. Acutely consider IV amiodarone: if there is recurrent VT that has not settled with beta-blockers. Get Echo to check LV function. Consider criteria for AICD
- Beta-blockers: indicated in all those who can take them.
- Consider early inpatient angiography, appropriate EP investigations and management as necessary (AICD).
- Avoid other anti-arrhythmic, especially those that are negatively inotropic, e.g. flecainide.