AMIS Overview p>
AMIS is a type of clinical syndrome in which cardiac output is significantly reduced due to acute myocardial ischemia and necrosis, resulting in tissue hypoperfusion. Controlled ischemic symptoms with hemodynamically unstable, life-threatening
In the early stage of AMICS, typical ischemic chest pain or equivalent symptoms, such as severe squeezing pain in the retrosternal or precordial area with or without With radiating pain, also dyspnea, nausea,
Acute
Recommendations for Diagnostic Evaluation of AMICS
1. Invasive arterial pressure monitoring should be performed in AMICS patients
Non-invasive blood pressure monitoring in
2.AMIS patients should be treated with arterial
Dynamic monitoring of lactate levels every 2-4 hours can determine the severity of low cardiac output, the efficacy of fluid resuscitation and the improvement of tissue hypoxia situation etc. After improving tissue perfusion by optimizing hemodynamics, the blood lactate level should begin to decrease in about 1 hour, and a persistent increase indicates a poor prognosis. Blood lactate level >6.5 mmol/L was an important independent predictor of increased in-hospital mortality in AMICS patients.
3. AMICS should be evaluated with bedside echocardiography
Dynamic echocardiography should be performed every 24 hours and before and after invasive procedures. Emphasis is placed on evaluating left and right ventricular systolic function, valve stenosis or regurgitation, pericardial effusion, cardiac tamponade, and mechanical complications, and attention should be paid to looking for evidence of intraventricular thrombus.
4. Central venous pressure monitoring should be performed in patients with AMICS< /p>
Central venous pressure (CVP) monitoring is used to assess patient volume load, right ventricular function, cardiac compliance, etc. CVP reflects the balance between right ventricular function and blood return to the heart. When blood volume increases, venous return increases, or right ventricular dysfunction occurs, CVP increases. Since CVP directly measures right ventricular filling pressure, it can guide the regulation of fluid input and velocity. It should be noted that when left ventricular dysfunction is combined withThe normal pressure volume changes in wall motion disorders, so CVP cannot correctly reflect left ventricular filling pressure in patients with AMICS.
5. Invasive cardiac output monitoring is not recommended for all patients
Invasive cardiac output monitoring should be performed in critically ill patients or in patients whose symptoms of AMICS have not improved significantly after initial optimized therapy. Pulmonary artery catheter pressure monitoring can reflect continuous changes in cardiac output, pulmonary artery pressure, right heart pressure, systemic circulation and pulmonary circulation resistance.
Treatment recommendations for AMICS
AMIS treatment principles include etiological treatment, stabilization of hemodynamics, protection of important organ function, maintenance of internal environment stability, prevention of arrhythmia, improvement of myocardial metabolism and synthesis. supportive care, etc.
1. Vasoactive drugs
The hemodynamic changes of AMICS require the application of vasoactive drugs to restore systemic blood perfusion, usually requiring a mean arterial pressure (MAP) of at least 65 mmHg. Commonly used vasoactive drugs include vasopressors and inotropes.
The general principle is to use the lowest possible dose and shorten the application time under the premise of effective blood pressure boosting, and at the same time to avoid peripheral vascular complications , it is recommended to try central intravenous administration.
2. Revascularization
(1) AMICS shock stage A and B, usually should go directly to emergency
(2) Patients with acute myocardial infarction and cardiac arrest were successfully resuscitated, after recovery of spontaneous circulation and neurological function (Glasgow Coma Scale ≥ 8 points) , should be transferred to the cardiac catheterization laboratory as soon as possible for a comprehensive assessment of coronary blood flow; if the coma (Lasgow Coma Scale score <8) after resuscitation or if simple instructions cannot be performed, target temperature should be given as soon as possible (32-36 ℃) management.
3. Percutaneous mechanical circulatory assist device therapy p>
(1) IABP is the most rapid and convenient percutaneous mechanical circulatory assistance (pMCS) currently used in my country, and it can be used first in AMICS emergency situations. Under the premise of sufficient blood volume, when the hemodynamics cannot be rapidly stabilized after combined treatment with high-dose vasoactive drugs, rapid initiation of IABP support therapy should be considered; such as combined with high-risk coronary lesions and severe left ventricular function impairment , IABP should also be started early. When IABP assistance still requires a large amount of vasoactive drugs to maintain circulation, cardiac electrical activity is still unstable, tissue perfusion is poor, or
(2) Under the premise of sufficient blood volume, if the patient still has persistent tissue hypoperfusion, hypotension, and the use of a large number of vasoactive drugs, pMCS placement should be considered prior to emergency revascularization.
(3) It is recommended to establish a multidisciplinary pMCS team consisting of interventional cardiology, cardiac surgery, cardiac critical care, anesthesiology, and sonographers. It is beneficial to start pMCS quickly and formulate an appropriate treatment plan.
4. Vital organ function support therapy
(1) Respiratory support
AMICS patients if If there is respiratory failure or the airway needs to be protected, mechanical ventilation should be used as soon as possible. When the arterial partial pressure of oxygen (PaO2) is less than 60 mmHg, and/or the oxygen saturation is less than 90%, and/or the partial pressure of carbon dioxide (PaCO2) is greater than 50 mmHg after high-flow oxygen inhalation, it is recommended to actively use mechanical ventilation to assist breathing.
Non-invasive breathing is very important for mild to moderate respiratory failure and can be used in patients with acute cardiogenic pulmonary edema, where continuous positive airway pressure and Both bilevel positive airway pressures can be treated as the preferred mode of ventilation.
For patients with impaired consciousness and non-invasive ventilator-assisted respiration still unable to correct hypoxemia, tracheal intubation should be performed in time, and the Invasive ventilation therapy.
(2) Support for acute renal impairment p>
For patients with acute renal impairment (
Literature Index: Chinese Expert Consensus on Diagnosis and Treatment of Acute Myocardial Infarction Complicated with Cardiogenic Shock (2021). Chinese Journal of Cardiovascular Diseases, 2022; 50(3): 231-242.