Sometimes called pump failure, cardiogenic shock is a condition of diminished cardiac output that severely impairs tissue perfusion. It reflects severe left-sided heart failure and occurs as a serious complication in nearly 15% of all patients hospitalized with acute myocardial infarction (AMI).
Cardiogenic shock typically affects patients whose area of infarction exceeds 40% of muscle mass; in such patients, the fatality rate may exceed 85%. Most patients with cardiogcnlc shock die within 24 hours of onset. The Prognosis for those who survive is extremely poor.
Cardiogenic shock can spring from disorders of the heart muscle, the heart valves, or the heart's electrical conduction system. Some 5 to 15 percent of patients hospitalized for heart attacks develop the condition. It may also stem from other cardiac problems, such as heart failure, cardiomyopathy (an inflammation of the heart muscle), rupture of the heart, irregular heartbeats (arrhythmias), and valve disorders
Signs and symptoms
Additional tests determine other conditions that can lead to pump dysfunction and failure, such as cardiac arrhythmias, cardiac tamponade, papillary muscle infarct or rupture, ventricular septal rupture, pulmonary embolus, venous pooling (associated with venodilators and continuous intermittent positive-pressure breathing), and hypovolemia.
Cardiogenic shock is a medical emergency! Treatment requires hospitalization. The goal of treatment is to save the patient's life and treat the underlying cause of shock. Treatment combines various cardiovascular drugs and mechanical-assist techniques.
Drug therapy may include LV. dopamine, a vasopressor that increases cardiac output, blood pressure, and renal blood flow, and LV. amrinone or dobutamine, inotropic agents that increase myocardial contractility. When a more potent vasoconstrictor is necessary, norepinephrine is used.
I.V. nitroprusside, a vasodilator, may be used with a vasopressor to further improve cardiac output by decreasing peripheral vascular resistance (afterload) and reducing left ventricular end diastolic pressure (preload). However, the patient's blood pressure must be adequate to support nitroprusside therapy and must be monitored closely.
The intra-aortic balloon pump (IABP) is a mechanical-assist device that attempts to improve coronary artery perfusion and decrease cardiac workload. The inflatable balloon pump is surgically inserted through the femoral artery into the descending thoracic aorta.
Once in place, the balloon inflates during diastole to increase coronary artery perfusion pressure and deflates before systole (before the aortic valve opens) to reduce resistance to ejection (afterload) and therefore lessen cardiac workload. Improved ventricular ejection, which significantly improves cardiac output, and a subsequent vasodilation in the peripheral vasculature lead to lower preload volume.
When drug therapy and IABP insertion fail, treatment may require an experimental device - the ventricular assist pump or the artificial heart.
Surgery: In many cases, surgery may be needed to repair the cause of the damage.
(c) Health-care-clinic.org All rights reserved
Disclaimer: Health-care-clinic.org website is designed for educational purposes only. It is not intended to treat, diagnose, cure, or prevent any disease. Always take the advice of professional health care for specific medical advice, diagnoses, and treatment. We will not be liable for any complications, or other medical accidents arising from the use of any information on this web site. Please note that medical information is constantly changing. Therefore some information may be out of date.