Mechanical Complications of MI (AATS 2025)

Algorithm Steps

1. ▶

   Start

   Suspected Mechanical Complication of AMI

   Sudden deterioration 2-7 days post-MI

   1. ●

      Action

      Clinical Presentation

      Common features of mechanical complications

      • Sudden hemodynamic deterioration
      • New murmur (harsh for VSD, systolic for MR)
      • Cardiogenic shock
      • Pulmonary edema
      • Typically day 2-7 post-MI (can be earlier with reperfusion)
      1. ●

         Action

         Urgent Echocardiography

         TTE/TEE for diagnosis

         • VSD: septal defect with L→R shunt
         • PMR: flail mitral leaflet, severe MR
         • FWR: pericardial effusion/tamponade, myocardial discontinuity
         • Assess LV/RV function
         1. ◆

            Decision

            Which Complication?

            Direct management based on diagnosis

            1. ●

               Action

               Post-Infarction VSD

               Ventricular septal rupture

               • Location: anterior (apical) or inferior (basal)
               • Inferior worse prognosis
               • Qp:Qs >2:1 indicates significant shunt
               • Without surgery: 90% mortality
               1. ●

                  Action

                  Hemodynamic Stabilization

                  Bridge to surgery

                  • Inotropes/vasopressors as needed
                  • IABP (reduces afterload, augments coronary flow)
                  • Consider Impella or VA-ECMO for refractory shock
                  • Avoid excessive volume (worsens VSD shunt)
                  • Intubation if pulmonary edema
                  1. ◆

                     Decision

                     Timing of Surgery?

                     Early vs delayed repair controversy

                     • EARLY (immediate/urgent):
                     • • Cardiogenic shock
                     • • Refractory heart failure
                     • • Expanding lesion
                     • DELAYED (if stable):
                     • • Allow tissue healing (VSD)
                     • • May reduce operative mortality
                     • • Risk of deterioration while waiting
                     1. ●

                        Action

                        VSD Repair

                        Surgical closure

                        • Patch closure (bovine pericardium/synthetic)
                        • Infarct exclusion technique preferred
                        • Concomitant CABG as needed
                        • Operative mortality: 20-50%
                        • Consider percutaneous closure in select cases
                        1. ●

                           Action

                           Post-Operative Care

                           ICU management

                           • Continued MCS as needed
                           • Watch for residual VSD (common)
                           • Arrhythmia management
                           • Heart failure optimization
                           • Cardiac rehab when stable
                     2. ●

                        Action

                        Mitral Valve Surgery

                        Emergent MV replacement or repair

                        • MV replacement usually required
                        • Repair possible if partial rupture
                        • Concomitant CABG as indicated
                        • Operative mortality: 20-25%
                     3. ●

                        Action

                        FWR Repair

                        Emergent surgery or palliation

                        • Suture repair with felt pledgets
                        • Patch repair if larger defect
                        • Infarctectomy may be needed
                        • Mortality >50% even with surgery
                        • Subacute rupture better prognosis
            2. ●

               Action

               Papillary Muscle Rupture

               Acute severe mitral regurgitation

               • Posteromedial papillary > anterolateral (single blood supply)
               • Partial or complete rupture
               • Flail leaflet on echo
               • Severe pulmonary edema
               • Without surgery: 50% mortality at 24h
            3. ●

               Action

               Free Wall Rupture

               LV free wall rupture → tamponade

               • Type I: acute complete rupture → sudden death
               • Type II: subacute with thrombus sealing
               • Type III: pseudoaneurysm formation
               • Pericardial effusion/tamponade on echo
         2. ⚠

            Warning

            ⚠️ High Mortality

            All mechanical complications carry high mortality (20-80%) regardless of treatment approach. Prompt diagnosis and intervention critical.