Cardiogenic shock is a very serious condition in which multiple organ systems begin to fail because the heart is unable to pump enough blood to the body. Cardiogenic shock occurs with severe heart failure. It is characterized by a low blood pressure (hypotension) associated with inadequate oxygenation of tissues (hypoperfusion). It may be caused by a heart attack (acute myocardial infarction), a large blood clot in the lungs (pulmonary embolus), or a mechanical dysfunction due to valvular heart disease. Shock due to blood loss (hypovolemic shock) and infection (septic shock) are not expressions of cardiogenic shock.
Blood is the carrier of oxygen to the tissues. Irrespective of whether the cause of cardiogenic shock is an acute myocardial infarction (AMI), a pulmonary embolus, or valvular heart disease, the result is insufficient blood reaching all organs of the body.Incidence and Prevalence: Approximately 5% to 10% of patients with AMI suffer cardiogenic shock (Hostetler). Most cases of cardiogenic shock occur in the first 24 hours following hospital admission. |
Source: Medical Disability Advisor
| Cardiogenic shock is always secondary to another condition, so prevalence and incidence depend on the condition causing it (AMI or pulmonary embolism). |
Source: Medical Disability Advisor
History: Individuals with cardiogenic shock may describe severe chest pain related to the underlying AMI or pulmonary embolism. Shock in itself does not usually produce symptoms clearly recognizable by the individual. Physical exam: The exam reveals hypotension, usually less than 80 mm Hg systolic. The heart rate is generally increased, and the skin is cool and discolored (cyanotic and mottled). Profuse sweating may occur. The individual may have a loss of mental alertness or be confused, anxious, disoriented, or sometimes unconscious (comatose). The pulse may be weak or absent. There may be "crackles" (rales) in the lungs that are audible with a stethoscope. Decreased or no urine output may be revealed. Tests: An echocardiogram, which uses sound waves to create a moving picture of the heart, is one of the first diagnostic procedures performed to diagnose cardiogenic shock. An electrocardiogram (ECG) often shows an AMI if a heart attack is the cause of cardiogenic shock. If a pulmonary embolism is the cause, the ECG may show inferential changes of the embolism. These changes include a fast heart rate (tachycardia) and evidence of enlargement or strain of the right side of the heart.
Blood tests (cardiac enzymes) are abnormal if an AMI is the cause. A complete blood count (CBC), blood chemistry tests, and arterial blood gas tests may be performed. Special x-ray tests of the lungs (lung scan and a pulmonary angiogram) are abnormal if a pulmonary embolism is the cause. A coronary angiogram, in which a contrast material is injected into one of the arteries of the heart and then viewed through an x-ray, may be ordered to see the flow of blood through the heart. Nuclear scans may also be performed. |
Source: Medical Disability Advisor
Cardiogenic shock is treated with intravenous (IV) adrenergic agonists that increase the blood pressure. When cardiogenic shock complicates open-heart surgery, a drug called amrinone that increases the strength of cardiac contraction is often also used.
A temporary mechanical device known as an intra-aortic balloon pump (IABP) is frequently used to treat cardiogenic shock due to an AMI or following open-heart surgery. Heart monitoring, including hemodynamic monitoring, is often used to guide treatment.
Measures to improve blood flow to the damaged heart muscle are sometimes performed in individuals with cardiogenic shock due to an AMI. These measures include the administration of IV drugs to dissolve the blood clot in the coronary artery causing the AMI (thrombolytic therapy), percutaneous transluminal coronary angioplasty (PTCA), and coronary artery bypass surgery (CABG). When a specific mechanical complication of an AMI is the primary reason for cardiogenic shock, surgery to repair the complication is performed. These mechanical complications of AMI include rupture of a heart valve, rupture of the wall between the two sides of the heart, and rupture of the free wall of the heart.
If a pulmonary embolism is the cause of cardiogenic shock, measures to dissolve the embolus with an IV drug specifically designed for that purpose (thrombolysis) or removal of the embolus by a surgical technique (embolectomy) may be utilized. |
Source: Medical Disability Advisor
| Approximately 80% of cases of cardiogenic shock are fatal (Keller). Medications can elevate the blood pressure but do not decrease mortality because the underlying cause (AMI or pulmonary embolism) has not been addressed. In the case of AMI, only early revascularization procedures (thrombolytic therapy, PTCA, and CABG) appear to reduce mortality. |
Source: Medical Disability Advisor
| Cardiogenic shock is itself a major complication of the condition that caused it (AMI or pulmonary embolism). Cardiogenic shock may have serious consequences, as opposed to complications due to the under perfusion of various organs with oxygenated blood. This may result in a stroke, "shock" lung, and liver or kidney failure. |
Source: Medical Disability Advisor
There will be few, if any, work restrictions for individuals who recover and whose work is relatively sedentary and primarily cognitive in nature. Individuals performing more strenuous work may need to be reassigned to less physically demanding duties.
Some individuals will never regain functional capacity following cardiogenic shock and will be permanently disabled. |
Source: Medical Disability Advisor
| If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case. Regarding diagnosis:
- Does individual complain of severe chest pain?
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Is individual hypotensive?
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Is the heart rate elevated?
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Is the skin cyanotic?
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Does individual appear to be confused or disoriented?
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Are there abnormal lung sounds?
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Does an ECG reveal evidence of an AMI?
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Does the ECG show changes indicative of a pulmonary embolus?
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Are cardiac enzymes normal?
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Are a lung scan and/or pulmonary angiogram normal?
Regarding treatment:
- Did IV drug therapy successfully increase the blood pressure?
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Did individual require placement of an IABP? Is the pump functioning properly?
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Did individual require thrombolytic therapy? Was this treatment successful?
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Did individual require PTCA or CABG? How successful was PTCA or CABG in improving blood flow to the heart?
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Did individual require surgery to repair a mechanical complication of AMI? If so, was surgery successful? What is the recovery period for the surgery?
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Did individual require thrombolytic therapy? Did therapy dissolve the embolus?
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Did individual require an embolectomy? Was surgery successful? What is the recovery period for this surgery?
Regarding prognosis:
- What was the cause of the cardiogenic shock?
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If AMI, were early revascularization procedures successful?
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Have complications developed?
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Is individual expected to recover?
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Source: Medical Disability Advisor
| CitedHostetler, Mark A. "Shock, Cardiogenic." eMedicine. Eds. Daniel J. Dire, et al. 19 Oct. 2004. Medscape. 21 Sep. 2004 <http://emedicine.com/EMERG/topic530.htm>.Mikati, Issam. "Cardiogenic Shock." MedlinePlus. National Library of Medicine. 21 Sep. 2004 <http://www.nlm.nih.gov/medlineplus/ency/article/000185.htm>. |
Source: Medical Disability Advisor