NURS 487 Cardiac Exam | Questions & 100% Correct Answers (Verified) | Latest Update | Grade A+

Cardiac Output (CO) : - Amount of blood pumped through the heart each minute - Normal 4-8 L/min (varies significantly depending on body size) - Determined by stroke volume and heart rate; CO= SV x HR - Cardiac Index is the cardiac output corrected for body size and more specific than CO; use this in obese pts (CI= CO/BSA; Normal 2.4-4 L/min) - Obtained through a pulmonary artery catheter Nursing Assessment of Cardiac Function : Increased Preload= increased volume-blood backs up (right heart-JVD, peripheral edema, ascites, hepatic engorgement; left heart- SOB, cough, S3, S4, pulmonary edema) Decreased Preload= hypovolemia Increased Afterload= cool clammy extremities, non-healing wounds, brittle nails (not enough blood perfusing) Decreased Afterload= warm flushed extremities (massive vasodilation) 2 | P a g e Contractility= quality of heart beat at radial artery; usually diagnosed by exclusion of other sources of CO; Pulse Pressure which is how much the heart is able to increase pressure with each beat, may be useful in non-invasive assessment of contractility (Pulse Pressure = SBP-DBP; Normally 30-40 mm Hg) Lab Assessment of CO : - Cardiac Enzymes: when cardiac ischemia occurs, myocardial cells die and release their intracellular contents into the circulation (CK-MB, Troponin I) - CK-MB: released in blood 4-12 hours post myocardial necrosis, specific to myocardium; peaks 18-24 hrs and remains elevated for 72 hrs - Troponin I: protein appearing in blood 1-3 hours post myocardial damage; peaks in 24- 36 hrs; elevated for 7-10 days