Understanding Cardiac Auscultation: A Guide for Nursing Students Gwendalyn Slone R.N., M.B.A NUR 226
Learning Objectives To assist second year nursing student to understand and master auscultation techniques for cardiac Upon completion, students will: Verbally describe normal cardiac anatomy and physiology Write a written pathway detailing coronary cicrculation Demonstrate appropriate use of stethoscope for cardiac auscultation Identify, through demonstration, the four auscultation points in cardiac assessment
Learning Activities Powerpoint presentation: Provide overview of cardiac anatomy, physiology, circulation, and conduction Provide overview of disease process, common diagnostics and treatments Clinical simulation Utilize SimMan high fidelity mannequin, to demonstrate appropriate techniques for cardiac assessment using the stethoscope Allow students to perform cardiac assessment on the Sim Man. SimMan will be programmed to exhibit normal heart sounds and various levels of murmurs. assessment on the SimMan. Program Physical assessment Utilizing two live patient volunteers, students will demonstrate appropriate techniques for conducting a focused patient history and demonstrate appropriate techniques for cardiac auscultation.
Cardiac Anatomy 4 chamber system – two atria & two ventricles Chambers are separated by a system of four valves: tricuspid, aortic, pulmonary, and mitral Major blood vessels include the superior and inferior vena cava, ascending and descending aorta, and the pulmonary arteries and veins. Cardiac conduction system will be discussed in a future lecture.
Coronary Circulation Unoxygenated blood returns to the heart through the inferior and superior vena cava and passively fills the right atrium Tricuspid valve opens and allows the right ventricle to fill with blood Right atria contracts forcing additional blood into the right ventricle. Right ventricle contacts forcing blood through the pulmonary valve and into the lungs where gas exchange occurs—uptake of oxygen and release of carbon dioxide. Oxygenated blood travels back from the lungs to the left atria. Upon atrial contraction, the mitral valve opens allowing blood to fill the left ventricle Upon left ventricular contraction, the blood leaves the left ventricle via the aortic valve out into the systemic circulation Adequate oxygenation depends on a sufficient heart rate and effective pump mechanisms – atrial & ventricular
Tricuspid valve opens to allow the right ventricle to fill
Right ventricle contracts, pulmonary valve opens, blood flows to the lungs for oxygenation
Oxygenated blood fills the left atria, mitral valve opens allowing blood to flow to the left ventricle
When the left ventricle contracts, the aortic valve opens and allows oxygenated blood to flow out to the body
What are heart sounds? Heart sounds are generated by the beating heart and the resultant flow of blood through the cardiac circulation, also referred to as the heartbeat. In cardiac auscultation, the nurse uses a stethoscope to listen for normal heart sounds and any other adventitious sounds or murmurs that may be present. In healthy adults, there are two normal heart sounds often described as a lub and a dub (or dup), that occur in sequence with each heart beat. These are the first heart sound (S1) and the second heart sound (S2), produced by the closing of the atrioventricular valves (tricuspid and mitral valves ) and the semilunar valves (pulmonic and aortic) respectively.
Auscultation Techniques AUSCULTATION OF THE HEART • be sure to use both sides of the stethoscope to examine the heart • the diaphragm is best for hearing high-pitched sounds, including S1, S2 and most heart murmurs • the bell is bests for hearing low-pitched sounds, including S3, S4 and a few murmurs (e.g. mitral stenosis) • use LIGHT TOUCH when using the bell. Pressure turns it into a diaphragm