SAS 12

• The cardiovascular system is composed of the heart and blood vessels, which deliver oxygen and nutrients to the cells of the body, remove waste products, and maintain perfusion to the organs and tissues.
• The heart is the pump that drives circulation of the blood and the blood vessels are the pathways to and from the tissues.
• To assess a patient’s cardiovascular health, the nurse gathers a thorough focused health history and uses this information to perform an appropriate physical examination of the patient’s heart and blood vessels.
• The heart is a hollow muscular organ a little larger than the patient’s fist, lies in the pericardial cavity in the mediastinum under the sternum and between the 2nd and 5th intercostal spaces, and about two thirds of the heart lies to the left of the midline of the sternum.
• The area of the exterior chest that overlays the heart and great vessels is called the precordium, which is helpful to visualize the underlying structures of the heart as you examine the precordium.
• The right ventricle of the heart, which occupies most of the anterior cardiac surface, narrows as it rises to meet the pulmonary artery just below the sternal angle, forming the base of the heart at the right and left 2nd intercostal spaces next to the sternum.
• Cardiac output is the product of heart rate, pulse pressure, myocardial contractions, and stroke volume.
• The layers of the heart that contain cardiac muscle are the myocardium and the endocardium.
• A preload is the degree of vascular resistance to ventricular contraction.
• Contrary to widely held views, a recent study has reaffirmed inspection of the right external jugular vein as a useful and accurate method for estimating CVP.
• The area found on the exterior chest where the health worker examines in order to detect the underlying structures of the heart is the precordium.
• The structures that can best estimate the jugular venous pressure are the right external jugular vein and the right internal jugular vein.
• The normal peak pressure of systole is 70 mmHg.
• The point of maximal impulse (PMI) is located at the right and left 2nd intercostal space next to the sternum.
• Ask for the patient’s past history and family history on any cardiovascular disease and ask about their lifestyle habits such as nutrition, smoking, alcohol, exercise, and medications.
• The right external jugular vein is a useful and accurate method for estimating CVP.
• The equipment used in measuring the blood pressure include the sphygmomanometer, stethoscope, watch, and ruler.
• The left ventricle of the heart, behind the right ventricle and to the left, forms the left margin of the heart and its tapered inferior tip is often termed the cardiac apex.
• The apical impulse, identified during palpation of the precordium as the point of maximal impulse, or PMI, locates the left border of the heart and is normally found in the 5th intercostal space 7 cm to 9 cm lateral to the midsternal line, at or just medial to the left midclavicular line.
• In supine patients the diameter of the PMI may be as large as a quarter, approximately 1 cm to 2.5 cm.
• A PMI 2.5 cm is evidence of left ventricular hypertrophy (LVH), or enlargement.
• Displacement of the PMI lateral to the midclavicular line or 10 cm lateral to the midsternal line also suggests LVH, or enlargement.
• The locations on the chest wall where heart sounds and murmurs are heard help to identify the valve or chamber where they originate, as the sounds produced by the heart valves travel with the flow of blood.
• Increased arterial blood pressure causes increased afterload.
• The areas where murmurs are usually heard overlap, as illustrated, and you will need to correlate auscultatory findings with other cardiac examination findings to identify sounds and murmurs accurately.
• Murmurs originating in the aortic valve may be heard anywhere from the right 2nd intercostal space to the apex.
• The sinus node acts as the cardiac pacemaker and automatically discharges an impulse about 60 to 100 times a minute.
• With each contraction, the left ventricle ejects a volume of blood into the aorta and on into the arterial tree.
• The oscillations visible in the internal jugular veins, and often in the externals, reflect changing pressures within the right atrium.
• Murmurs arising from the pulmonic valve are usually heard best in the 2nd and 3rd left intercostal spaces close to the sternum but at times may also be heard at higher or lower levels.
• The JVP is best estimated from the right internal jugular vein, which has a more direct anatomic channel into the right atrium.
• Jugular venous pressure (JVP) reflects right atrial pressure, which in turn equals central venous pressure (CVP) and right ventricular end-diastolic pressure.
• The ensuing pressure wave moves rapidly through the arterial system, where it is felt as the arterial pulse.
• Myocardial contractility refers to the ability of the cardiac muscle, when given a load, to contract or shorten.
• Each electrical impulse is initiated in the sinus node, a group of specialized cardiac cells located in the right atrium near the junction of the vena cava.
• Cardiac output, the volume of blood ejected from each ventricle during 1 minute, is the product of heart rate and stroke volume.
• Preload refers to the load that stretches the cardiac muscle before contraction.
• The left and right ventricles pump blood into the systemic and pulmonary arterial trees, respectively.
• Sounds and murmurs arising from the mitral valve are usually heard best at and around the cardiac apex.
• Sources of resistance to left ventricular contraction include the tone in the walls of the aorta, the large arteries, and the peripheral vascular tree (primarily the small arteries and arterioles), as well as the volume of blood already in the aorta.