TY - CHAP M1 - Book, Section TI - Cardiovascular Failure A1 - Bradley, Nori L. A1 - Cotton, Bryan A. A2 - Feliciano, David V. A2 - Mattox, Kenneth L. A2 - Moore, Ernest E. PY - 2020 T2 - Trauma, 9e AB - KEY POINTSCardiac output (heart rate × stroke volume) is determined by rate, preload, afterload, and contractility.Ventricular filling determines left ventricular end-diastolic volume, which in turn determines the force of ventricular contraction.Hemodynamic transesophageal echocardiography (TEE) is performed with a miniaturized two-dimensional monoplane disposable TEE probe that can be left in place for up to 72 hours.Right heart failure is characterized by increased right ventricular (RV) afterload (increased pulmonary resistance), which decreases the ability of the RV to pump blood forward to the left heart, thus decreasing left ventricular preload.In valvular aortic stenosis, symptoms of left heart failure include dyspnea on exertion, angina, lightheadedness, and syncope.Management of myocardial dysfunction includes vasopressors (eg, norepinephrine, vasopressin, phenylephrine), inotropes (eg, epinephrine, dobutamine, milrinone, dopamine, digoxin), and intra-aortic balloon pump counterpulsation.A low mixed venous oxygen saturation occurs with decreased oxygen delivery (decreased hemoglobin, oxygen saturation, or flow) or increased oxygen demand (hyperthermia, pain, seizure, or shivering).In the management of acute heart failure, nitroprusside reduces afterload by acting on arteriolar smooth muscle and has a rapid onset of action, and its effects cease within minutes of stopping the infusion.In diastolic dysfunction, β-adrenergic blockade or calcium channel blockade reduces heart rate and increases left ventricular filling, which reduce mortality.Cardiac death or a myocardial infarction occurs in 1% to 5% of unselected patients undergoing noncardiac surgery, and this concern is the most common indication for a preoperative cardiac evaluation. SN - PB - McGraw Hill CY - New York, NY Y2 - 2024/10/14 UR - accesssurgery.mhmedical.com/content.aspx?aid=1175136598 ER -