Heart Failure

Heart failure can be categorized into several types. It can cause no decrease in ejection fraction or it can decrease the ejection fraction. Failure can be right-sided, left-sided or biventricular. It can occur primarily during diastole or systole. It can arise acutely or it can exist as a chronic condition. Cardiovascular support and treatment of these varied entities is tailored to the specific type and underlying cause of cardiac dysfunction. In the surgical intensive care setting, one primarily deals with acute forms of cardiac failure.

Pathophysiology involving the pericardium, myocardium, endocardium, cardiac valves and great vessels can all cause acute heart failure.

Strategies for treatment of severe acute left heart failure include: reducing afterload (vasodilators & diuretics) and augmenting iontropy (inotropes). In right heart failure: volume replacement with goals to reach pulmonary artery wedge pressure target of ~ 20 mmHg. Once that target is reached, ionotropic support may be attempted. Close monitoring is needed so that normal right ventricular volumes are not exceeded, since septal displacement may occur with over-distension of the right ventricle. When this does happen, left ventricular filling is compromised. If right heart failure includes A-V dissociation or complete heart block, sequential A-V pacing can be attempted. Ventricular pacing should be avoided in these instances.

For cardiogenic shock: Mechanical support consists of placement of intra-aortic balloon pump.