cardiac nursing 2018 (1).ppt - Cardiac Nursing u2022 Lynn...

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Cardiac Nursing Lynn Herman Nurs 2205 Almost Spring 2018
Anatomy & Overview Know this very well
Conduction System Covered in EKG lectures
Coronary Arteries The heart uses up to 70-80% of the O2 supplied to it by the coronary arteries other organs use only 25%
Coronary Arteries Right and the left coronary arteries stem from the aorta and wrap around the muscle Left main coronary – divides into left anterior descending (LAD) and the circumflex LAD feeds anterior, septum and left ventricle Circumflex feeds the left lateral wall of the ventricle RCA – supplies the right ventricle and forms the posterior descending artery Posterior descending – feeds posterior portion
Coronary Arteries
Important Heart Arteries Understand what arteries feed which side of the heart How does this effect the heart?
Cardiac Hemodynamics Pressure changes fill the vessels Cardiac output (CO) Range CO - determined by stroke volume and HR SV X HR = CO
Determinants of Cardiac Output Heart Rate Stroke Volume Preload Afterload Contractility Cardiac Index 2.5 – 4.2
Stroke Volume Amount of blood ejected with each heart beat Average 70ml/beat Changes in SV; determined by these 3 factors Contractility Decreases with ischemia Preload - the degree of stretch of the muscle before contraction Afterload - the pressure the muscle has to eject against
Influences that affect CO HR Catecholamines (sympathetic) Parasympathetic Preload - vascular volume Afterload - arterial pressures Contractility Baroreceptors and chemoreceptors Kidneys (volume) Temperature Chemicals, hormones, drugs
Systemic & Pulmonary Vascular Resistance SVR This is the measurement of afterload (left afterload) Range - 600-1200 What is the SVR on a hypertensive patient? How does BP medications effect SVR? How does sepsis affect SVR? PVR The amount of pressure it takes to open up the pulmonary valve (right afterload)
Ejection Fraction Represents the fraction of the diastolic volume that is ejected from the heart during systole Normal EF – 50%-70% Can measure right or left ventricle EF
Mean Arterial Pressure MAP Estimated by: diastole x 2 + systole/3 Normal range 70-110 (you need a MAP of 60 to profuse large organs)
Lab Values Sodium Potassium Calcium Magnesium Be prepared to discuss how each of the electrolytes effect the cardiac muscle
CPK Creatine Phosphokinase - CPK or CK Rises in 3-6 hours Has 3 isoenzymes MM - skeletal muscle MB - myocardial band CKMB - rises in 4-8 hours, peaks in 24 hours If CPK normal, then CKMB not needed Ordered Q8 hours X 3 Look at table 30-6
Troponin A more sensitive test for myocardial damage MI or unstable angina Rises in 2- 4 hours, peaks in 24 hours Stays elevated for up to 2 weeks
Cholesterol

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