Cardiogenic shock is characterized by a decreased pumping potential of the heart that causes a shocklike state (ie, global hypoperfusion). Cardiogenic shock has a death rate of about 60% and is the major cause of death in patients hospitalized for a heart attack. It most generally occurs in relationship with, and as a direct consequent of, acute myocardial infarction (Ami). The most tasteless cause of cardiogenic shock is extensive acute myocardial infarction, although a smaller infarction in a outpatient with previously compromised left ventricular function may also precipitate shock. Cardiogenic shock is defined by sustained hypotension with tissue hypoperfusion despite sufficient left ventricular filling pressure. Signs of tissue hypoperfusion include oliguria. Cardiogenic shock is characterized by both systolic and diastolic dysfunction. Patients who build cardiogenic shock from acute Mi consistently have evidence of progressive myocardial necrosis with infarct extension. Decreased coronary perfusion pressure and increased myocardial oxygen demand play a role in the vicious cycle that leads to cardiogenic shock.
Cardiogenic shock occurs in 8.6% of patients with St-segment elevation Mi with 29% of those presenting to the hospital already in shock. It occurs only in 2% of non-St-segment elevation Mi. Outcomes significantly improve only when rapid revascularization can be achieved. The up-to-date Shock trial demonstrated that extensive mortality when revascularization occurs is 38%. When rapid revascularization is not attempted, mortality rates approach 70%. Cardiogenic shock can also be caused by mechanical complications--such as acute mitral regurgitation, rupture of the interventricular septum, or rupture of the free wall--or by large right ventricular infarctions. Myocardial ischemia causes a decrease in contractile function, which leads to left ventricular dysfunction and decreased arterial pressure; these, in turn, exacerbate the myocardial ischemia. The extensive incidence of cardiogenic shock is higher in men compared to women because of the increased prevalence of coronary artery disease in males.
Cardiogenic shock can be caused by disorders of the heart muscle, the valves, or the heart's electrical conduction system. Cardiogenic shock is life threatening and requires accident curative treatment. Dopamine, dobutamine, epinephrine, norepinephrine, amrinone, or other medications may be required to increase blood pressure and heart functioning. Echocardiography may show arrhythmia, signs of Ped, ventricular septal rupture (Vsr), an obstructed outflow tract or cardiomyopathy. Pain rehabilitation may be given if necessary. Bed rest is recommended to sacrifice demands on the heart. Coronary artery bypass grafting. In this surgery, arteries or veins from other parts of the body are used to bypass (that is, go around) narrowed coronary arteries. The use of the Iabp reduces systolic left ventricular afterload and augments diastolic coronary perfusion pressure, thereby expanding cardiac production and enhancing coronary artery blood flow. Heart monitoring, including hemodynamic monitoring, to guide treatment.
Treatment for Cardiogenic Shock Tips
1. Inotropic medications should be carefully in systems with appropriately trained paramedical personnel.
2. In case of cardiac arrhythmia several anti-arrhythmic agents may be administered, i.e. Adenosine, verapamil, amiodarone, ß-blocker.
3. Balloon angioplasty (Ptca) may be an alternative to surgical operation in some cases.
4. Oxygen reduces the workload of the heart by reducing tissue demands for blood flow.
5. Heart monitoring, including hemodynamic monitoring, to guide treatment
6. Coronary artery bypass grafting. In this surgery, arteries or veins from other parts of the body are used to bypass (that is, go around) narrowed coronary arteries.
