College answer
- Left or Right ventricular failure
- Severe mitral regurgitation
- Septal rupture
- Cardiac tamponade/ventricular free wall rupture
- Arrhythmia (brady or tachy)
- Drug induced
Discussion
This is an exercise in generating differentials for causes of shock which are applicable to the post-MI period. Thus:
Differential Diagnosis of Shock following MI
|
Artifactual or spurious
- Inaccurately measured blood pressure
- Noradrenaline line is not connected
Mechanical support failure
- IABP augmentation failure
- VA ECMO malfunction
Hypovolaemic
- Loss of blood
- Retroperitoneal (post angio)
- Pulmonary / intrathoracic (ventricla damage post angio)
|
Cardiogenic
- Ischaemic LV dysfunction
- Sudden "valve failure", eg. papillary muscle rupture
- Septal or ventricular rupture
- Cardiac contusion (commotio cordis) following CPR
- Drug overdose (of negative inotropes)
- Rate problem: too fast or too slow
- AF (loss of atrial kick)
- Severe acidosis (myocardial depression)
Distributive
- Anaphylaxis to angio contrast
- Drug overdose (of vasodilators)
- Reperfusion "post arrest" syndrome
Obstructive
- Valve obstruction (thrombosis, myxoma)
- LVOT or RVOT obstruction
- Cardiac tamponade due to perforation or rupture
|