Heart and Neck Vessels

Key Points Jarvis: Physical Examination & Health Assessment Heart and Neck Vessels Key Points This section discusses key points about the structure and function of the heart and neck vessels.  The cardiovascular system consists of the heart, which is a muscular pump, and the blood vessels, which provide pulmonary and systemic circulation through two continuous loops.  The major anatomical features of the heart are the pericardium, myocardium, endocardium, atria, ventricles, valves, and chordae tendineae.  The rhythmic movement of blood through the heart is the cardiac cycle, which has two phases: diastole and systole. o In diastole, the ventricles relax and fill with blood. o In systole, the heart contracts and pumps blood from the ventricles into the pulmonary and systemic arteries.  Events in the cardiac cycle produce heart sounds you can hear with a stethoscope. o The first heart sound (or S1) results from closure of the atrioventricular valves. Its mitral component (or M1) slightly precedes its tricuspid component (or T1), but you usually hear these two components fused as one sound. o The second heart sound (or S2) results from closure of the semilunar valves. Its aortic component (or A2) slightly precedes its pulmonic component (or P2).  Besides these normal heart sounds, you may hear extra heart sounds, such as: o A third heart sound (or S3), resulting from the vibration of ventricles that resist early, rapid filling o A fourth heart sound (or S4), resulting from the vibration of noncompliant ventricles when the atria contract and push blood into them o Or murmurs, which are gentle, blowing or swooshing sounds resulting from turbulent blood flow  For all heart sounds, describe their pitch, intensity, duration, and timing.  The heart contracts in response to an electrical current in its conduction system. o The cardiac impulse originates in the sinoatrial node and spreads through the atria and to the atrioventricular node, where it is delayed. Then, the impulse Key Points travels to the bundle of His, the right and left bundle branches, and then to the ventricles.  The cardiac output equals the stroke volume (or blood volume in each systole) times the rate (or beats per minute). Preload is the venous return that builds during diastole. Afterload is the opposing pressure that the ventricle must generate to open the aortic valve against the higher aortic pressure.  Electrocardiography (ECG) waves are arbitrarily labelled PQRST, which stand for the following elements:  o P wave: depolarization of the atria o P–R interval: the interval from the beginning of the P wave to the beginning of the QRS complex o QRS complex: depolarization of the ventricles o T wave: repolarization of the ventricles Vascular structures in the neck include the carotid artery and jugular veins. o The carotid artery is located in the groove between the trachea and the sternomastoid muscle. Its pulse closely coincides with ventricular systole. o The jugular veins give information about filling pressures and volume changes in the right side of the heart. Because volume and pressure increase when the right side of the heart fails to pump efficiently, the jugular veins expose this. The jugular pulse has five components: the A wave, C wave, X descent, V wave, and Y descent.  The cardiovascular system undergoes developmental changes. o Before birth, the foramen ovale allows oxygenated blood from the placenta to be shunted to the left side of the heart and out to the general circulation. The ductus arteriosus lets any remaining blood being directed to the lungs to be shunted into the aorta. At birth, lung inflation causes circulatory changes. o During pregnancy, blood volume increases by 30% to 40%, increasing the stroke volume, cardiac output, and pulse rate. However, blood pressure actually decreases during pregnancy due to the effects of estrogen on the maternal system. o In older adults, the systolic pressure increases, and the left ventricular wall thickness increases somewhat. The heart has a decreased ability to augment cardiac output with exercise, supraventricular and ventricular arrhythmias are more likely, and some ECG changes occur.  The major risk factors for heart disease and stroke are high blood pressure, smoking, high cholesterol levels, obesity, and type 2 diabetes mellitus. Lifestyle changes can modify the development of cardiovascular disease. Key Points This section presents critical points about subjective and objective assessments of the heart and neck vessels.  To obtain subjective data, ask questions that investigate these topics: o Chest pain o Dyspnea o Orthopnea o Cough o Fatigue o Cyanosis or pallor o Edema o Nocturia o Cardiac history o Family cardiac history o Personal habits that reflect cardiac risk factors  To obtain objective data, focus on the neck vessels first. o Palpate each carotid artery separately, feeling the contour and amplitude of the pulse. If indicated, auscultate each carotid artery for a bruit. o Inspect the jugular venous pulse and assess its characteristics. o Also, estimate the jugular venous pressure. If it is elevated, perform hepatojugular reflux.  Next, examine the precordium. Use inspection and palpation to: o Describe the location, size, amplitude, and duration of the apical impulse o Detect any heave or thrill  To prepare for heart auscultation, identify the anatomical areas where you should listen. There are four traditional valve areas: o The second right interspace is the aortic valve area. o The second left interspace is the pulmonic valve area. o The left lower sternal border is the tricuspid valve area. o The fifth interspace near the left midclavicular line is the mitral valve area.  In these and other listening areas, auscultate with the diaphragm of the stethoscope, using a Z pattern: o Identify the rate and rhythm of the heartbeat. Key Points o Assess S1 and S2 separately, noting any variations. o Listen in systole and diastole for any extra heart sounds. o Also, listen for murmurs. If you detect a murmur, grade its timing, loudness, pitch, pattern, quality, location, radiation, and postural changes. o Repeat these actions with the bell of the stethoscope. o Then, auscultate at the apex with the patient in the left lateral position. o Also, auscultate at the base with the patient in a sitting position.  Incorporate health promotion when assessing the heart and neck vessels. For example, teach women that heart attacks produce atypical symptoms in women. Instead of chest pain or discomfort, women often feel a hot or cold sensation or even tenderness to touch in the back, shoulders, arms, or jaws. Other symptoms may include nausea, vomiting, indigestion, shortness of breath, or extreme fatigue.