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36 Cards in this Set
- Front
- Back
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What occurs during cardiac diastole?
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In diastole, the ventricles are relaxed and the AV vales (tricuspid and mitral) are open. The pressure in the atria is higher than that of the ventricles, so blood pours rapidly into the ventricles. This first passive filling phase is called early or protodiastolic filling. This takes up 2/3s of the cardiac cycle. Towards the end of diastole, the atria contract and push the last amount of blood (about 25% of stroke volume) into the ventricles. This active filling phase is called presystole., or atrial systole, or sometimes the “atrial kick.” It causes a small rise in left ventricular pressure. (Note that atrial systole occurs during ventricular diastole.)
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What occurs during cardiac systole?
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In systole, blood is pumped from the ventricles and fills the pulmonary and systemic arteries. This is one third of the cardiac cycle. Now that so much blood has been pumped into the ventricles that ventricular pressure is finally higher than that in the atria, so the mitral and tricuspid valves swing shut. The closure of the AV valves contributes to the first heart sound (S1) and signals the beginning of systole. The AV vales close to prevent any regurgitation of blood back up into the atria during contraction.
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What is the S1 heart sound?
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The first heart sound; lub. It occurs with closure of the AV valves thus signals the beginning of systole. The mitral component of the first sound (M1) slightly precedes the tricuspid component (T1), but you usually hear these two components fused as one sound. You can hear S1 over all the precordium (region or thorax immediately in front of the heart), but it is usually loudest at the apex.
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What is the S2 heart sound?
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The second heart sound; dub. It occurs with closure of the semilunar valves and signals the end of systole. The aortic component of the second sound (A2) slightly precedes the pulmonic component (P2). Although it is heard over all the precordium, S2, is loudest at the base.
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What is the S3 heart sound?
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The third heart sound. Normally, diastole is a silent event. However, in some conditions, ventricular filling creates vibrations that can be heard over the chest. These vibrations are S3. S3 occurs when the ventricles are resistant to filling during the early rapid filling phase (protodiastole). This occurs immediately after S2, when the AV vales open and atrial blood first pours into the ventricles.
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What is the S4 heart sound?
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The fourth heart sound. S4 occurs at the end of diastole, at presystole, when the ventricle is resistant to filling. The atria contract and push blood into a noncompliant ventricle. This creates vibrations that are hearts as S4. S4 occurs just before S1.
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What are some of the characteristics of heart sounds?
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Frequency (pitch) – heart sounds are described as high pitched or low pitched, although these terms are relative because all are low-frequency sounds, and you need a good stethoscope to hear them.
Intensity (loudness) – loud or soft. Duration – very short for heart sounds; silent periods are longer. Timing – systole or diastole |
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What are the conditions that contribute to a heart murmur?
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Blood circulating through normal cardiac chambers and valves usually make no noise. However, some conditions create turbulent blood flow and collision currents. These results in a murmur, much like a pile of stones or sharp turn in a stream creates a noisy water flow. A murmur is a gentle, blowing, swooshing sound that can be heart on the chest wall. Conditions resulting in a murmur as are follows:
1. Velocity of blood increases (flow murmur) (e.g., exercise, thyrotoxicosis) 2. Viscosity of blood decreases (e.g., in anemia) 3. Structural defects in the vales (narrowed valve, incompetent valve or unusual openings occur in the chambers (dilated chamber, wall defect) |
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Define cardiac output.
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Cardiac output – the volume of blood in each systole (called stroke volume) times the number of beats per minute (rate):
CO = SV x R In the resting adult, the heart normally pumps 4-6 L of blood per minute throughout the body. Preload and afterload affect the heart’s ability to increase cardiac output. |
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Define preload.
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Preload – the venous return that builds during systole. It is the length to which the ventricular muscle is stretched at the end of diastole just before contraction. When the volume of blood returned to the ventricles is increased, the muscle bundles are stretched beyond their normal resting state to accommodate. The force of this switch is the preload. According to the Frank-Starling law, the greater the stretch, the stronger is the heart’s contraction. This increased contractility results in an increased volume of blood ejected (increased stroke volume).
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Define afterload.
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Afterload – the opposing pressure the ventricle must generate to open the aortic valve against the higher aortic pressure. It is the resistance against which the ventricle must pump its blood. Once the ventricle is filled with blood, the ventricular end diastolic pressure is 5-10 mm Hg, whereas that in the aorta is 70-80 mm Hg. To overcome this difference, the ventricular muscle tenses (isovolumic contraction). After the aortic valve opens, rapid ejection occurs.
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Trace a drop of blood anatomically as it circulates through the body.
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-From liver to right atrium (RA) through inferior vena cava. Superior vena cava drains venous blood from the head and upper extremities. From RA, venous blood travels through tricuspid valve to right ventricle (RV).
-From RV, venous blood flows through pulmonic valve to pulmonary arteries. Pulmonary artery delivers unoxygenated blood to lungs. -Lungs oxygenate blood. Pulmonary veins return fresh blood to left atrium (LA). -From LA, arterial blood travels through mitral valve to left ventricle (LV). LV ejects blood through aortic valve into aorta. -Aorta delivers oxygenated blood to body |
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Name the arteries in the arms.
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The major artery supplying the arm is the brachial artery., which runs in the biceps-triceps furrow of the upper arm and surfaces at the antecubital fossa in the elbow medial to the biceps tendon. Immediately below the elbow, the brachial artery bifurcates into the ulnar and radial arteries. These run distally and form two arches supplying the hand; these are called the superficial and deep palmar arches. The radial pulse lies just medial to the radius at the wrist; the ulnar artery is in the same relation to the ulna, but it is deeper and often difficult to feel.
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Name the arteries in the legs.
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The major artery to the leg is the femoral artery, which passes under the inguinal ligament. The femoral artery travels down the thigh. At the lower thigh, it courses posteriorly; then it is termed the popliteal artery. Below the knee, the popliteal artery divides. The anterior tibial artery travels down the front of the leg on to the dorsum of the foot, where it becomes the dorsalis pedis. In the back of the leg, the posterior tibial artery travels down behind the medial malleolus and in the foot forms the platar arteries.
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Name the veins in the arms.
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Each arm has two sets of veins; superficial and deep. The superficial veins are in the subcutaneous tissue and are responsible for most of the venous return.
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Name the veins in the legs.
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The legs have three types of veins:
1. The deep veins run alongside the deep arteries and conduct most of the venous return from the legs. These are the femoral and popliteal veins. As long as these veins remain intact, the superficial veins can be excised without harming the circulation. 2. The superficial veins are the great and small saphenous veins. The great saphenous vein, inside the leg, starts at the medial side of the dorsum of the foot. You can see it ascend in front of the medial malleolus; then it crosses the tibia obliquely and ascends along the medial side of the thigh. The small saphenous vein, outside the leg, starts on the lateral side of the dorsum of the foot, ascends behind the lateral malleolus, up the back of the leg, where it joins the popliteal vein. 3. Perforators are connecting veins that join the two sets. They also have one-way valves that route blood from the superficial into the deep veins. |
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What are the functions of the lymph nodes?
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Lymph nodes are small, oval lumps of lymphatic tissue that filter out microorganisms that could be harmful to the body from the fluid before it is returned to the blood stream. The pathogens are exposed to B and T lymphocytes in the lymph nodes. The lymphocytes mount an antigen-specific response to eliminate the pathogens. With local infection, the nodes in that area become swollen and tender.
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Describe arteries.
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The heart pumps freshly oxygenated blood through arteries. The artery walls are strong, tough, and tense to withstand pressure demands. Arteries contain elastic fibers, which allow their walls to stretch with systole and recoil with diastole. Arteries also contain muscle fibers (vascular smooth muscle, or VSM), which control the amount of blood delivered to the tissues. Each heartbeat creates a pressure wave, which makes arteries expand and then recoil. All arteries have this pressure wave, or pulse, throughout their length and you can feel it only at body sites where the artery lies closest to the skin and over a bone.
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Describe veins.
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Veins drain the deoxygenated blood and its waste products from the tissues and return it to the heart. They have thinner walls than those of arteries; they also have a larger diameter and are more distensible (they can expand and hold more blood when blood volume increases). Unlike arteries, veins are a low-pressure system. Because veins do not have a pump to generate their blood flow, the veins need a mechanism to keep blood moving. This is accomplished by:
(1) contracting skeletal muscles to milk the blood proximally, back toward the heart (2) the pressure gradient caused by breathing, in which inspiration makes the thoracic pressure decrease and the abdominlal pressure increase (3) the intraluminal valves, which ensure unidirectional flow |
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Describe lymphatics.
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A different vessel system that retrieves excess fluid from the tissue spaces and returns it to the bloodstream. The functions are:
(1) to conserve fluid and plasma proteins that leak out of the capillaries (2) to form a major part of the immune system that defends the body against disease (3) to absorb lipids from the intestinal tract Also, lymphatic vessels have a unique structure. Lymphatic capillaries start as microscopic open-ended tubes, which siphon interstitial fluid. The capillaries converge to form vessels. The vessels, like veins, drain into larger ones. The vessels have valves, so flow is one way from the tissue spaces into the bloodstream. The many valves make the vessels look beaded. The flow of lymph is slow compared with that of the blood. Lymph flow is propelled by contracting skeletal muscles, by pressure changes secondary to breathing, and by contraction of the vessels walls themselves. |
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Where would the nurse put the stethoscope to auscultate the pulmonic valve area?
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Second left interspace – pulmonic valve area
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Where would the nurse put the stethoscope to auscultate the aortic valve area?
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Second right interspace – aortic valve
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Where would the nurse put the stethoscope to auscultate the tricuspid valve area?
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Left lower sternal border – tricuspid valve area
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Where would the nurse put the stethoscope to auscultate the mitral valve area?
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Fifth interspace at around left midclavicular line – mitral valve area
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What is the first step in listening to the heart with a stethoscope?
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-Identify the auscultatory areas where you will listen:
Second right interspace – aortic valve Second left interspace – pulmonic valve area Left lower sternal border – tricuspid valve area Fifth interspace at around left midclavicular line – mitral valve area -Clean both end pieces of stethoscope with an alcohol wipe. -Before you being, alert the patient, “I always listen to the heart in a number of places on the chest. Just because I am listening a long time, it does not necessarily mean that something is wrong.” -After you place the stethoscope, try closing your eyes briefly to tune out any distractions. Concentrate, and listen selectively to one sounds at a time. Consider that at least two, or perhaps three or four, sounds may be happening in less than 1 second. You cannot process everything at once. Begin with the diaphragm end piece and use the following routine: (1) note the rate and rhythm (2) identify S1 and S2 (3) assess S1 and S2 separately (4) listen for extra heart sounds (5) listen for murmurs |
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Where is the base and apex of the heart?
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Think of the heart as an upside-down triangle in the chest. The “top” of the heart is the broader base, and the “bottom” is the apex., which points down and to the left. During contraction, the apex beats against the chest wall, producing an apical impulse. This is palpable in most people, normally at the fifth intercostals space, 7-9 cm from the midsternal line.
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How much does maternal blood volume increase during pregnancy?
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Blood volume increases by 30-40% during pregnancy, with most rapid expansion occurring during the second trimester. This creates an increase in stroke volume and cardiac output and an increased pulse rate of 10-15 beats per minute.
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How much does systolic blood pressure increase in aging?
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From 20-60 yrs, systolic BP increases 20 mm HG. Increases another 20 mm Hg between ages 60-80 due to stiffening of the larger arteries which is due to calcification of vessel walls (arteriosclerosis).
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How do patients describe chest pain?
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Onset: When did it start? How long have you had it this time? Had this type of pain before? How often?
Location: Where did the pain start? Does the pain radiate to any other spot? Character: How would you describe it? Crushing, stabbing, burning, viselike? *A squeezing “clenched fist” sign is characteristic of angina, an important cardiac symptom that occurs when the heart’s own blood supply cannot keep up with the metabolic demand. Pain brought on by: activity – what type; rest; emotional upset; after eating; during sexual intercourse; with cold weather? Any associated symptoms: sweating, ashen gray or pale skin, heart skips beat, shortness of breath, nausea or vomiting, racing of heart? Pain made worse by moving the arms or neck, breathing, lying flat? Pain relieved by rest or nitroglycerin? How many tablets? |
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What is an elevated JVP?
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Normal jugular venous pressure/pulsation is 2 cm or less above the sternal angle. Elevated pressure is a level of pulsation that is more than 3 cm above the sternal angle while at 45˚. This occurs with heart failure, where the jugular veins will elevate and stay elevated as long as you push and perform a hepatojugular reflex.
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What should a nurse know about murmurs in children?
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Heart murmurs that are innocent (or functional) in origin are very common through childhood. Some authors say they have a 30% occurrence, and some authors say nearly all children may demonstrate a murmur at some time. Most innocent murmurs have these characteristics: soft, relatively short systolic ejection murmur; medium pitch; vibratory; best heart at the left lower sternal or midsternal border, with no radiation to the apex, base, or back. For the child whose murur has been shown to be innocent, it is very important that the parents understand this completely. They need to believe that this murmur is just a “noise” and has no pathologic significance. Otherwise, the parents may become overprotective and limit activity for the child, which may result in the child developing a negative self-concept.
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What are the clinical observations for Atrial Septal Defect?
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Atrial Septal Defect (ASD) – Sternal lift often present. S2 has fixed split, with P2 (pulmonic) often louder than A2 (aortic). Murmur is systolic, ejection, medium pitch, best heard at base in second left interspace. Murmur caused not by shunt itself but by increased blood flow through pulmonic valve.
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What are the clinical observations for Ventricular Septal Defect?
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Ventricular Septal Defect (VSD) – Loud, harsh holosystolic murmur, best heard at left lower sternal border, may be accompanied by thrill. Large defects also have soft diastolic murmur at apex (mitral flow murmur) due to increased blood flow through mitral valve.
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What are the clinical observations for Coarctation of the Aorta?
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Coarctation of the Aorta – upper extremity HTN over 20 mm Hg higher than lower extremity measures is a hallmark of coarctation. Another important sign is absent or greatly diminished femoral pulses. A systolic murmur is heard best at the left sternal border, radiating to the back.
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What does Homan's sign indicate?
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A positive Homan’s sign can indicator of and occurs in 35% of cases of deep vein thrombosis. But it is not specific for this condition because it can also occur with superficial phlebitis, Achilles tendonitis, gastrocnemius and plantar muscle injury, and lumbosacral disorders.
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What three mechanisms prevent venous stasis and provide for efficient venous return?
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Efficient venous return depends on contracting skeletal muscles, competent valves in the veins, and a patent lumen. Problems with any of these three elements lead to venous stasis.
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