Suspected mechanical complication of MI
Sudden deterioration after MI, usually day 3-7. It can occur earlier.
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Cardiothoracic SurgeryEmergency
Mechanical Complications of MI (ESC 2023, AHA 2021)
Mechanical Complications of MI (ESC 2023, AHA 2021): Suspected mechanical complication of MI → Look for shock, a new murmur, pulmonary oedema or tampona...
Pathway Overview
18 steps
Algorithm Steps
18 total
01Start 02Action Look for shock, a new murmur, pulmonary oedema or tamponade
Late or no reperfusion, older age, female sex and first MI raise the risk.
- Sudden hypotension or cardiogenic shock
- New murmur of VSD or MR (in PMR the murmur can be absent)
- Acute pulmonary oedema or recurrent chest pain
- Raised JVP, tamponade signs or PEA arrest: suspect free wall rupture
03Action Emergency echocardiography now
ESC 2023: emergency TTE for suspected mechanical complication (class I). Add TEE if TTE is not diagnostic.
- VSD: septal defect with left-to-right shunt
- PMR: severe, often eccentric MR; flail leaflet or mobile papillary muscle head
- FWR: pericardial effusion or clot, tamponade, contained rupture
- TTE can miss partial PMR: do TEE if MR is suspected
- Assess LV and RV function
04Warning ⚠️ Surgical emergency: call the cardiac surgeon and Heart Team now
In-hospital mortality is about 42% in STEMI with a mechanical complication (ESC 2023).
- No cardiac surgery on site: arrange emergency transfer
- On P2Y12 inhibitor, anticoagulant or recent fibrinolysis: tell the surgeon (bleeding risk); do not delay emergency surgery
- Free wall rupture or peri-arrest: go straight to theatre
05Decision Which complication does echo show?
Each next step names its own finding.
- FWR
06Action FWR (free wall rupture) with tamponade: immediate surgery
Do not wait to stabilise. Take the patient straight to theatre.
- Tamponade: give IV fluid to support preload; inotrope if needed
- Induction and positive-pressure ventilation can cause arrest: prep and drape before induction
- Pericardiocentesis is a relative contraindication: only if peri-arrest, drain a small volume as a bridge
- If ventilated: low tidal volume, low or no PEEP
- VA-ECMO can support before repair, but tamponade can limit flow
- Contained rupture (pseudoaneurysm) also needs urgent surgery
07Action FWR: emergency repair
Immediate surgery unless the risk is prohibitive. Hospital mortality is over 35% even with surgery.
- Patch repair over the defect, often with infarctectomy
- Small or oozing tear: sutureless patch and glue
- MCS or LV vent to lower LV pressure after repair
- Prohibitive surgical risk: Heart Team; palliative care with blood pressure control
08Action Post-operative ICU care
Continue care in cardiac ICU.
- Wean MCS as function recovers
- After VSD repair: echo for residual or recurrent shunt
- After mitral valve surgery or FWR repair: echo for valve function or recurrent effusion
- Treat arrhythmias and heart failure
- Secondary prevention after MI and cardiac rehabilitation
09Outcome Discharge with cardiology and cardiac surgery follow-up
Secondary prevention after MI and cardiac rehabilitation.
- PMR
10Action PMR (papillary muscle rupture): acute severe MR
A surgical emergency. Usually the posteromedial muscle after inferior or lateral MI.
- Posteromedial muscle has a single blood supply, so it ruptures most often
- Rupture can be partial or complete
- Hospital mortality 10-40%
11Action PMR: support while theatre is prepared; do not delay surgery
Lower afterload to reduce regurgitant flow and support cardiac output. RV infarction or PDE5 inhibitor in past 24-48 h: no nitrate.
- IABP to reduce MR; not if moderate or severe AR or aortic dissection
- IV vasodilator (e.g. GTN) and diuretic if blood pressure allows. No nitrate if hypotension, RV infarction or PDE5 inhibitor in past 24-48 h. RV infarction: diuretic only with care (RV needs preload)
- Shock: noradrenaline to keep perfusion, then add an inotrope; high vasopressor doses raise afterload and worsen MR
- Respiratory failure: positive-pressure ventilation helps; induction can cause collapse, so have surgical and MCS teams ready
- Refractory shock: Impella (not if LV thrombus, mechanical aortic valve, moderate or severe AR, severe AS or significant RV failure) or VA-ECMO; VA-ECMO raises LV afterload, so plan LV venting
- Coronary angiography only if it does not delay surgery
12Action PMR: emergency mitral valve surgery
Emergency operation, preferably within 24 h (AHA 2021).
- Chordal-sparing mitral valve replacement is usual
- Repair only for partial rupture, a stable patient and an expert surgeon
- CABG at the same operation if revascularisation is needed
- Operative mortality about 20%
- Prohibitive surgical risk: Heart Team to consider transcatheter edge-to-edge repair, MCS as a bridge, or palliative care
- Path rejoins step 08Shared downstream outcome
- VSD
13Action VSD (post-infarction ventricular septal rupture)
Left-to-right shunt. Without repair, mortality approaches 80% at 30 days.
- Anterior or apical VSD: LAD infarct
- Inferior or basal VSD: often complex; may have RV infarction and MR
- Right heart catheter: oxygen step-up from RA to PA
14Action VSD: stabilise with afterload reduction
Bridge to repair. Lower afterload to reduce the shunt and support cardiac output. RV infarction or PDE5 inhibitor in past 24-48 h: no nitrate.
- IABP (ESC 2023, class IIa); not if moderate or severe AR or aortic dissection
- IV vasodilator (e.g. GTN) and diuretic if blood pressure allows. No nitrate if hypotension, RV infarction or PDE5 inhibitor in past 24-48 h. RV infarction: diuretic only with care (RV needs preload)
- Shock: noradrenaline to keep perfusion, then add an inotrope; high vasopressor doses raise afterload and increase the shunt
- Refractory shock or organ failure: VA-ECMO; it raises LV afterload, so plan LV venting. Impella is contraindicated in post-infarct VSD on its label: Heart Team only
- MCS can increase or reverse the shunt
- Coronary angiography if it does not delay surgery
15Decision VSD: shock, respiratory failure, RV failure or worsening on support?
Decide timing with the Heart Team: cardiac surgeon, cardiologist and intensivist.
- If Yes
16Action Unstable VSD: urgent repair
Urgent surgical repair; mortality is about 40% in cardiogenic shock. With multi-organ failure, the Heart Team may use MCS as a bridge first.
- Patch repair: infarct exclusion (David) or Daggett technique
- CABG at the same operation if revascularisation is needed
- Consider MCS around surgery to protect the patch
- Prohibitive surgical risk: Heart Team to consider percutaneous closure, MCS as a bridge to transplant or VAD, or palliative care
- Path rejoins step 08Shared downstream outcome
If No17Action Stable VSD, no organ or respiratory failure: Heart Team may delay repair
Delay lets the tissue firm up (ESC 2023 table: beyond 7 days). Operate at once if the patient worsens.
- Continue afterload reduction; MCS if needed
- Review haemodynamics, urine output, renal and liver function at least daily
- Delay also lets the oral antiplatelet effect wear off
- Then patch repair, with CABG if needed
- Path rejoins step 08Shared downstream outcome
- Not confirmed
18Outcome No mechanical complication on echo: manage as cardiogenic shock or ACS
If suspicion stays, repeat echo or do TEE (partial PMR can be missed on TTE).
Guideline Source
2023 ESC Guidelines for the management of acute coronary syndromes (section 12.2.2 Mechanical complications)
Clinical Safety Information
Clinical Decision Support — Not a Substitute for Clinical Judgment
Individual patient factors may require deviation from these recommendations.
Known Limitations
- Evidence is mostly observational. Timing of VSD repair is a Heart Team decision.
- Needs on-site cardiac surgery and MCS; otherwise transfer early.
- PMR timing: AHA 2021 advises emergency surgery; the ESC 2023 table allows delay in selected stabilised patients.
- Late post-MI pseudoaneurysm (weeks to years) is not covered in detail.
Contraindicated Populations
ChildrenRupture after cardiac surgery, trauma or endocarditis (not post-MI)
Applicable Regions
USEUAU
AU: Consistent with the NHFA/CSANZ ACS guideline 2025: consider IABP for mechanical complications; perform CABG at the time of surgical repair. No drug doses are given.
Version 2Next review: 2027-09-30
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Related Resources
Frequently Asked Questions
What is the Mechanical Complications of MI (ESC 2023, AHA 2021)?
The Mechanical Complications of MI (ESC 2023, AHA 2021) is a emergency clinical algorithm for Cardiothoracic Surgery. It provides a structured decision tree to guide clinical decision-making, based on 2023 ESC Guidelines for the management of acute coronary syndromes (section 12.2.2 Mechanical complications).
What guideline is the Mechanical Complications of MI (ESC 2023, AHA 2021) based on?
This algorithm is based on 2023 ESC Guidelines for the management of acute coronary syndromes (section 12.2.2 Mechanical complications) (DOI: 10.1093/eurheartj/ehad191).
What are the limitations of the Mechanical Complications of MI (ESC 2023, AHA 2021)?
Known limitations include: Evidence is mostly observational. Timing of VSD repair is a Heart Team decision.; Needs on-site cardiac surgery and MCS; otherwise transfer early.; PMR timing: AHA 2021 advises emergency surgery; the ESC 2023 table allows delay in selected stabilised patients.; Late post-MI pseudoaneurysm (weeks to years) is not covered in detail.. Individual patient factors may require deviation from these recommendations.
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