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JVP grammar (Jugular venous pressure concepts) Understanding genesis of normal jugular venous pulsa PowerPoint Presentation

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Description : Jugular venous pulsations. "An under utilized , noninvasive right heart cath. data of naturally inserted catheter, the Internal jugular vein”. Today , in 2021 , majority of our residents cannot correctly interpret venous pulsations and unfortunately few of them cannot even perceive these. Yet *Karel Frederik Wenckebach, a Dutch physician , In 1899 , clinically demonstrated the changing relationship between the carotid artery pulse & the a wave in the jugular pulse ,"Wenckebach phenomena “. Surprisingly this was done by curious bedside observation of jugular venous pulse ,before the advent of ECG.

Tags : Negative JVP. Phlebostatic axis. JVP measurement unit.

Published on : Feb 01, 2021 | Views : 3038 | Downloads : 61

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Slide 1-

By Asadullah kundi . JVP grammar ( Jugular venous pressure concepts ). Understanding genesis of normal jugular venous pulsation & pressure.
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Jugular venous pulsations. “ An under utilized , noninvasive right heart cath. data of naturally inserted catheter, the Internal jugular vein”. Today , in 2021 , majority of our residents cannot correctly interpret venous pulsations and unfortunately few of them cannot even perceive these. Yet *Karel Frederik Wenckebach, a Dutch physician , In 1899 , clinically demonstrated the changing relationship between the carotid artery pulse & the a wave in the jugular pulse ,"Wenckebach phenomena “. Surprisingly this was done by curious bedside observation of jugular venous pulse ,before the advent of ECG.
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Fig. Wenckebach's mechanical recording on a smoked drum of 4:3 atrioventricular conduction.1899 Note that the a-c interval gradually increases until the a wave is not followed by the expected c wave. a = a wave of jugular vein , c = carotid artery pulsation. Copied from J Cooper and H J MarriottTo Wenckebach: a centenary salute. Tex Heart Inst J. 1999; 26(1): 8–11 The first, type 1, 2nd degree AV block ,"Wenckebach" in a human being was observed , recorded & published by Karel Frederik Wenckebach,In 1899.
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In this presentation we will try to understand JVP concepts (JVP grammar) under the following headings. Surface anatomy of internal jugular vein. Visible pulsations in the neck, is it venous or arterial ? What is Phlebostatic zero pressure reference point & what is its importance ? Why it is recommended to measure JVP as vertical distance (at right angle) above the sternal angle ? Why is sternal angle reference point for measuring jugular venous pressure ( JVP ) ? What is distance of sternal angle (SA ) to right atrium (RA) in different angles of inclination (Zero to 90*) ? What is unit of JVP measurement ? Is JVP same as right atrial (RA) pressure ? Can bedside JVP measurement estimate abnormally high RA pressure without RA pressure measurement ? What is the best position (Angle) of the patient inclination ,to measure JVP? What could be fallacy of measuring JVP only at 45*elevation ? Concept of measuring negative (Below zero ) JVP. Genesis of normal Jugular venous pulsations & their bedside timings.
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5 Jugular venous pressure (JVP ) related pretest. Select true & false among the following statements. Don’t guess if you don’t know , don’t attempt the question. Q 1. Negative wave ( descent ) is most dominant visible wave in venous pulsation of neck .T/F ? Q2. Phlebostatic zero reference point lies at the sternal angle .T/F ? Q3. Estimated Jugular venous pressure (JVP ) in cm is equal to RA pressure in mm Hg. T/F ? Q4.Best patient inclination , to measure JVP is 45* .T/F ? Q5.Sternal angle is 5 cm above the right atrium, irrespective of patient position . T/F?. Q6. JVP of minus one cm (-1cm ) is suggestive of abnormally low RA pressure. T/F ? Q7.JVP of >3cm above the sternal angle in any patient position , is considered as abnormally elevated . T. Q8. X descent is systolic wave and y descent is diastolic . T/F ?.
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6 Anatomy Internal jugular (IJ) vein is continuation of the sigmoid sinus (in skull) at the base of skull in jugular foramina. It extends between inferiomedial aspect of mastoid bone superiorly to medial end of clavicle inferiorly. IJ vein travels with the carotid artery in the neck , enclosed in the carotid sheath . It lies anterolateral to the carotid artery runs under the medial portion of the upper part of the sternocleidomastoid muscle. Lower down it travels under the apex of the triangle formed by the sternal & clavicular heads of the sternocleidomastoid. It joins the subclavain to form brachiocephalic vein behind sternal end of clavicle. Brief anatomy of internal jugular vein. Copied from https://www.google.com/search?q=surface+anatomy+of+internal+jugular+vein&safe=active&sxsrf=ALeKk00zgkEV7QCQyFd5va7tIxXbsGlPAg:1611201200572&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiFzeKZkKzuAhXhQEEAHW6KDy4Q_AUoAXoECB0QAw&cshid=1611201201212284&biw=1040&bih=617#imgrc=3SZvbC8gS-_XhM
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Surface anatomy of internal jugular vein (IJV). Surface anatomy of IJV is represented superiorly by a vertical line drawn from the mid point between mastoid process & angle of the jaw above. Inferiorly ,extending down to medial side of the insertion point of the clavicular head of the sternocleidomastoid muscle. Angle of the mandible Copied & modified from https://www.google.com/search?q=surface+anatomy+of+internal+jugular+vein&safe=active&sxsrf=ALeKk01I1VikEJ9TaYR_3NxmDhptWEE6hg:1611202050005&tbm=isch&source=iu&ictx=1&fir=P7lF2fWrQ6HNaM%252CUZ4xGAOKOYVbiM%252C_&vet=1&usg=AI4_-kTaHna9-umG8wVmUjrhIQM0UwWzXg&sa=X&ved=2ahUKEwit8Oeuk6zuAhUDuRoKHbVhDCAQ9QF6BAgREAE&biw=1366&bih=657#imgrc=5TwKgVGY8cNO5M
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Which side of internal jugular vein (IJV) is preferable to measure JVP , right or left ? Right internal jugular vein (IJV)is preferable as it has straight course , connected to SVC which open into RA. As compared to left IJV, right IJV is less likely to be compressed by aorta or other structures in the neck. Persistent left superior vena cava (SVC ) may falsely elevate JVP on the left side. Internal jugular veins does have valves , however in a *study of normal subjects, majority (90%) valves were found incompetent ). *Valecchi D et al , (IJV)valves: an assessment of prevalence, morphology and competence by color Doppler echography in 240 healthy subjects. Copied from. https://epomedicine.com/wp-content/uploads/2013/11/Jugular-veins.png IJV= Internal jugular vein, RA = Right atrium , SVC= Superior vena cava.
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9 Visible pulsations in the neck, is it venous or arterial ? Characteristics of venous pulsations. Venous pulsations have multiple waves of expansions & recessions (undulating ) . Dominant pulsation in jugular vein is descents (Recession wave). Artery has single wave of expansion. Venous pulsation is not palpable . It can be easily occluded by applying mild manual pressure . Height of venous pulsation varies with change in the position of patient. (Supine to sitting ). Upper level of venous pulsations changes with respiration too. Height of venous pulsation transiently increases with abdominal pressure.
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Copied from https://sketchymedicine.com/tag/surface-anatomy/ Visible pulsation in the neck, Venous versus arterial pulsation. ?
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11 What is Phlebostatic zero pressure reference point & what is its importance ? (See figure in next slide). This is considered as the reference (Zero /baseline) pressure point for measuring venous as well as arterial pressures. Zero pressure point is just like ground is a reference point for measuring height . Phlebostatic point is located at mid right atrium . What is reference point for mid right atrium (RA) ? Mid right atrium is at point of intersection of a mid chest point of anteroposterior chest diameter ,at 4th intercostal space. What is reference for Mid chest point ? Mid axillary line is considered as reference level for mid chest point. Pressure at this point of the heart does not change with the body position.
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Phlebostatic zero pressure reference point for measuring venous & arterial pressures.(continued) Phlebostatic zero pressure reference point is located in the mid right atrium. Mid right atrium is at point of intersection of a mid chest point of anteroposterior chest diameter ,at 4th intercostal space. Mid axillary line is considered as reference level for mid chest point. Copied from https://www.google.com/search?q=+phelbostatic+point&tbm=isch&ved=2ahUKEwj2sM_urKzuAhUZ0oUKHf-RAmoQ2-cCegQIABAA&oq=+phelbostatic+point&gs_lcp=CgNpbWcQDFDHlgJYyKECYPyyAmgAcAB4AIABtAKIAeMMkgEFMi01LjGYAQCgAQGqAQtnd3Mtd2l6LWltZ8ABAQ&sclient=img&ei=vhgJYPbZKpmklwT_o4rQBg&bih=657&biw=1366&safe=active#imgrc=asbSXwuolccn9M Mid axillary line Phlebostatic
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Copied and modifed from https://www.google.com/search?q=+phelbostatic+point&tbm=isch&ved=2ahUKEwj2sM_urKzuAhUZ0oUKHf-RAmoQ2-cCegQIABAA&oq=+phelbostatic+point&gs_lcp=CgNpbWcQDFDHlgJYyKECYPyyAmgAcAB4AIABtAKIAeMMkgEFMi01LjGYAQCgAQGqAQtnd3Mtd2l6LWltZ8ABAQ&sclient=img&ei=vhgJYPbZKpmklwT_o4rQBg&bih=657&biw=1366&safe=active#imgrc=SGkp-28er3ag-M Phlebostatic point. Phlebostatic point is considered as the reference (Zero /baseline) pressure point for measuring venous as well as arterial pressures during cardiac catheterization. For accurate pressure measurement transducer should be at the level of Phlebostatic axis .(Figure). Note that if the transducer is place above or below the Phlebostatic axis the pressure recorded will be falsely low or high respectively. Importance of Phlebostatic point in recording pressure in catheterization lab. Mid axillary line
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14 http://occonline.occ.cccd.edu/online/tgibbs/Chapter%2018.pdf Importance of Phlebostatic zero pressure reference in measuring bedside arterial & venous pressure. It systolic blood pressure measured (Non invasively ) in a person with the arm at the level of the Phlebostatic axis (4th intercostal space ) is 150 mm Hg , What will be the expected systolic blood pressure if the cuff is placed at following levels ? 1. Blood pressure cuff at level of knee ? 225 mm Hg. 2. BP cuff at level of feet ? 250 mm Hg 3. BP cuff with arm level at level of ears.? 120 mm Hg. Thus Phlebostatic is important zero reference point for accurate measurement of both arterial and venous pressures. If BP is measured with the BP cuff at level above the Phlebostatic point reading will be falsely low. BP reading will be falsely high if measured with BP cuff at level below the Phlebostatic level.
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Copied from Sir Thomas Lewis, T. Remarks on early signs of cardiac failure of the congestive type. Brit Med J 1930; May10:849-852 Figure shows a reservoir of water has a wide pipe joined to it . Manometers a, b,& c of different lengths are attached to the pipe. Note the water level in all the manometers rises to the same vertical zero level ( Z.L ). Confirms Pascal law. JVP is defined as vertical distance above or below the sternal angle , up to to the highest level of internal jugular vein pulsations. Why it is recommended to measure JVP as vertical distance (at 90* ) above/below the sternal angle ? This is because fluids keeps It level. Explanation ? According to Pascal’s law “Pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and the walls of the containing vessel.”
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16 Fig. shows fluid filled pipe under pressure. Three glass tubes of variable lengths & angles are connected to the pipe. Note that all the glass tubes are filled up to 2cm vertical height (Red line ). The level of the liquid rises to the same horizontal level in all tubes, regardless of their length and inclination.( Pascal's principle). Therefore fluid will continue tracking along its vessel until it reaches a vertical height of 2 cm. Though the fluid have travelled further up the tubes ,it will always reach the same vertical height is all tubes. So the vertical distance above the reservoir of fluid truly represent the pressure , not the oblique length . Why it is recommended to measure JVP as vertical distance (at 90* ) above/below the sternal angle ?
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17 Why it is recommended to measure JVP as vertical distance above /below the sternal angle ? ((continued) 10 cm . Fig. shows three glass tubes of variable lengths & angles ,diagrammatically connected to right atrium (RA). If the pressure in the RA is 10 cm it will be transmitted equally to all the tubes connected to RA. Thus vertical distance between the zero point and top of the blood column in all the tubes will be 10 cm . Therefore it is vertical distance above RA which truly represent the pressure , not the oblique length . This is reason why JVP is measured as vertical distance above or below the Phlebostatic reference level. 10 cm . Copied and modified from. https://epomedicine.com/wp-content/uploads/2013/11/Jugular-veins.png 0.
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18 Why is sternal angle reference point for measuring jugular venous pressure ( JVP ) ? In the past it was believed that distance between sternal angle (SA) and mid right atrium is 5 cm & does not change with change of patient position (Inclination ). Therefore it was selected as reference point for measurement of JVP. RA pressure was estimated by adding 5 cm to the JVP & it was considered as surrogate of RA pressure. However it was later proved that the distance between sternal angle and RA changes with change patient inclination.
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19 What is distance of sternal angle (SA ) to right atrium (RA) in different angles of inclination (Zero to 90*) ? Following is the conclusion of the *study “How Far Is the Sternal Angle from the Mid-right Atrium”? “The sternal angle (SA ) to mid right atrium (RA ) distance was found to be approximately 5 cm only in the supine position (patient lying flat at zero angle inclination). At an angle of 45* , SA-RA distance was found to be approximately 9.5 cm. Smoking, increased age, and increased chest wall AP diameter were all independently associated with an increased SA-RA distance.” * Ratika Seth et al,,How Far Is the Sternal Angle from the Mid-right Atrium? J Gen Intern Med. 2002 Nov; 17(11): 861–865.
Slide 20-

Figure shows variation in distance between the sternal angle to mid right atrium with change in the inclination of the patient. Between 30 and 60 degrees elevation, the median calculated SA-RA distance was close to 8 cm. Copied from * Ratika Seth et al,,How Far Is the Sternal Angle from the Mid-right Atrium? J Gen Intern Med. 2002 Nov; 17(11): 861–865.
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21 What is unit of JVP measurement ? JVP is a peak pressure and not mean pressure as usually reported in invasive (Catheterization ) data. Peak occurs with expiration in spontaneously breathing . The unit of measuring JVP commonly mentioned in literature is centimeter of water although blood level in the vein is measured. Thus the true unit of JVP is centimeters of blood. However as the density of blood and water has minor difference , therefore unit of JVP in cm of water & cm of mercury are used interchangeably. In the catheterization laboratory (invasive ) measurements are done in mmHg, we can express JVP in mmHg. As Mercury is heavier than blood with density approximately 13 times that of blood. For conversion of JVP of blood in mm to mm of Mercury (Hg ), height of JVP in mm of blood is divided by 13. JVP in mm of Hg (Mercury ) = JVP of blood in mm ÷ 13
Slide 22-

Is JVP same as right atrial (RA/CVP) pressure ? Jugular venous pressure (JVP) is not same as RA pressure but is a non-invasive substitute of RA pressure. Difference between JVP and RA pressure (Central venous pressure ,CVP) . JVP is defined as vertical distance above or below the sternal angle , up to the highest level of internal jugular vein pulsations. The RA pressure (CVP) is measured as the vertical distance from the top of the column of blood in the internal jugular vein to mid right atrium (Phlebostatic point). RA pressure is best measured invasively (Cardiac catheterization ) with transude at the Phlebostatic axis. If JVP is not true RA pressure , then why is sternal angle reference point for measuring JVP? 1.Phlebostatic point has least postural variation of venous pressure, yet its precise location may not be easy at bedside. Thus clinically exact RA pressure measurement may be difficult . 2. Moreover sternal angle is easy to locate . 3. Interestingly and more important fact is JVP pressure measurement can reliably estimate abnormally high CVP even without knowing the exact RA(CVP) pressure , How ?
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23 Can bedside JVP estimate abnormally high RA pressure without RA pressure measurement ? Sir Thomas Lewis proposed that JVP is abnormally elevated if its bedside measurement is > 3 cm, (vertical distance) , above the sternal angle (SA) at any patient position . What is the evidence for Thomas Lewis proposal ? We have already discussed that 1. Minimum sternal angle ( SA ) to mid right atrium (RA ) distance is 5 cm (that too only in supine position.) 2. This (SA to RA ) distance is increased to > 9.5 cm in subject at angle of 45* inclination. If a person has peak JVP level of 3 cm (30 mm) of blood , measured at an angle of 45* elevation. Then at 45* inclination his RA will be at a distance of 9.5 cm below the sternal angle. Thus his peak RA pressure will be =9.5 +3 =12.5 cm or 125 mm of blood. As 13 mm of blood = 1mm Hg .Therefore 125 mm of blood = 125 ÷ 13 = 9.6 mmHg. Thus JVP of 3 cm at 45 degree is = Peak RA pressure of 9.6 mm Hg which is abnormally elevated .
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*Conclusions. “Clinicians should avoid making decisions about exact degrees of RA pressure (CVP ) elevation that is imprecise & difficult to reproduce. Instead, they should determine during physical diagnosis merely whether the CVP is abnormally elevated. Until further research is done, the best definition of abnormally elevated CVP is that proposed by of Sir Thomas Lewis. When the top of the external or internal jugular veins is >3 cm of vertical distance above the sternal angle, the CVP is abnormally high.” *Steven R. McGee, MD Seattle, Wash Physical examination of venous pressure: A critical review. Am Heart J 1998; 136:10-8.
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Figure showing patient lying in supine position , at zero angle. Observe the relation of clavicle with sternal angle ? Clavicle is below the sternal angle .( Green arrow directed down ). What is the best position (Angle) of the patient inclination , to measure JVP? Most clinician believe that patient inclined at an angle of 45* is the best position to measure JVP. This is not always true, but physicians still emphasize to measure JVP at 45* elevation . Why ? We will discuss the background of this misconception ? 0* Sternal angle axis. Clavicle.
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26 Figure shows a patient in sitting , inclined at 90 *angle to the ground .Observe the relation of sternal angle with the clavicle.? Clavicle is above the sternal angle (Green arrow directed upwards ). 90* Clavicle Relation of clavicle with sternal angle at an elevation of 90* ( Sitting position ) ?
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Figure showing patient lying at an angle of 45* inclination. At 45* elevation sternal angle and clavicle are almost at the same level .(Black arrow ). Therefore physician use clavicle as reference level for measuring JVP instead of sternal angle . This is the reason why clinician believe that 45* inclination is the best & easy to measure JVP. JVP can be measured accurately at 45* elevation but not always .What is its limitation ? Relation of clavicle with sternal angle in a patient lying at an angle of 45* inclination ? clavicle
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Fig A shows Patient with elevated JVP, pulsations are visible at the top of neck, even in sitting position, 90*. Estimated JVP ≥ 15 cm (Black arrow Fig, A). Same patient with elevated JVP , this time examined at 45* elevation. The estimated JVP ≥ 3.5 cm (Black arrow Fig B ). This is maximum measurable height at this angle . JVP of this patient is ≥ 15 cm or ≥ 3.5 cm? Justification ? This patient has JVP ≥ 15cm as measured in sitting position . In 45* elevation it is not possible to measure JVP > 3.5cm, in this case. Thus correct estimation of JVP be measurement at 90* (sitting ). What could be fallacy of measuring JVP at 45* elevation? 15 cm 3.5 cm B A 90*
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What is the best position (Angle) of the patient inclination ,to measure JVP? (continued ). The best angle of patients inclination to measure JVP , is an angle at which one can see the top of venous pulsations in lower third of the neck. Justification ? . Figure A shows a patient with very high JVP the top of pulsation is invisible at 45* . Best angle to measure JVP in this patient is 90* (sitting position). Thus their will be significant underestimation if the measurement is done at 45* elevation. His JVP is ≥15 cm.(Measured at 90* elevation) . In Fig B patient shown has low JVP Pressure is below the sternal angle (Red arrow ). Pulsation will not be visible in 45* elevation. Best angle to measure JVP in such patient is zero angle (supine position). A B Zero Reference (Sternal angle). JVP level Copied & modified from https://image.slidesharecdn.com/2160817134558/95/pulse-jvp-42-638.jpg?cb=1471441572
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What is the best position (Angle) of the patient inclination ,to measure JVP? (Continued ). Learning points. We can start examining patient at 45* inclination. If JVP is elevated & venous pulsations are visible at ear lobe we need to examine the patient in sitting position.(90* elevation ) If venous pulsations are not visible at 45*elevation, inclination angle has to be reduced ,in some patients to even 0* (Supine position ). Thus we need to adjust patient position ( 0* to 90* ) such that the top of pulsation are visible in the lower 3rd of the neck.
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Concept of measuring negative Jugular venous pressure (JVP below zero ). In Hypovolemia RA pressure & JVP level may be very low & only visible in supine position (0*). Figure shows diagrammatic representation of low JVP level in a hypovolemic patient. Summit (Top level ) of venous pressure in this patient is located below the sternal angle (vertical black arrow ). Top of JVP is below the zero reference point , JVP in this patient may be around -3 cm. Peak JVP level Copied & modified from https://image.slidesharecdn.com/2-160817134558/95/pulse-jvp-42-638.jpg?cb=1471441572 Zero Reference level (Sternal angle). - 3 cm
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Peak JVP level Below zero. Copied & modified from https://image.slidesharecdn.com/2-160817134558/95/pulse-jvp-42-638.jpg?cb=1471441572 Zero Reference level (Sternal angle). - 3 cm Concept of measuring negative JVP (Below zero ). ( Continued ). If this patient has JVP of -3 cm, what will the be the approximate peak RA pressure in mm Hg ? In supine position RA is 5 cm below the sternal angle. Therefore his peak RA pressure = 5 -3 = 2 cm( 20 mm). of blood. 13 mm of blood = 1 mmHg , therefore 20 mm of blood = 20/13= 1.5 mm Hg. Peak RA pressure = 1.5 mm Hg. Note normal lower range of mean RA pressure mentioned in literature is 0 to 2 mmHg. Therefore negative JVP pressure may be found in healthy persons.
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Normal Jugular venous pulsation and their timing. Increase & decrease in RA pressures are recorded as positive & negative pressure waves respectively . These pressure waves are transmitted to internal Jugular vein and visualized as periodic waves of expansion or recession in the neck. In absence of tachycardia , four waves are easily perceptible in the Jugular vein ? Two of them, a & v waves, are waves of expansion (positive waves ) generated due to increase in RA pressure . Other two waves , X & Y waves ,are recession waves (Negative waves) generated due to reduction of RA pressure .
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Genesis of positive (expansion ) waves in right atrium & jugular vein due to increase in RA pressure. As discussed in previous slide , two positive waves can be perceived in jugular vein a and v waves. a wave is a expansion ( positive ) wave due to the increased atrial pressure during right atrial contraction. It is late ventricular diastolic event , immediately follows P wave on an ECG. v wave is expansion ( positive ) wave which appears during early phase of ventricular diastole. This wave is produced by gradual rise in RA pressure due to its filling during closed tricuspid valve. c is expansion ( positive ) wave It can be recorded but is difficult to visualize clinically. During Isovolumetric contraction bulging of the tricuspid valve into the right ventricle increase RA pressure & generate c wave. Carotid impulse at onset of systole may contribute to genies of c wave in the neck. Copied from. https://www.google.com/search?q=jvp+waves&safe=active&sxsrf=ALeKk02DoJnngYGEVtsucXTxyyteXb6XsQ:1610728500254&source=lnms&tbm=isch&sa=X&ved=2ahUKEwif-Nigr57uAhUmRBUIHbC7AUMQ_AUoAXoECBQQAw&biw=1366&bih=657#imgrc=EHNcvjjp2BetMM
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Genesis of negative (recession )waves in right atrium & jugular vein due to reduction of RA pressure . Two negative waves can be perceived in jugular vein , x and y waves due to reduction in RA pressure. x wave is recession (negative ) wave due to reduction of RA pressure, during ventricular systole. During rapid ejection phase ,the base of the heart is pushed down resulting reduction in RA pressure. y descent wave is recession (negative ) wave . This is produced due to reduction in RA pressure due to opening of tricuspid valve & emptying of right atrium (RA) , during rapid filling phase. Under normal conditions, x descent is the most prominent perceived wave in jugular vein. Copied from. https://www.google.com/search?q=jvp+waves&safe=active&sxsrf=ALeKk02DoJnngYGEVtsucXTxyyteXb6XsQ:1610728500254&source=lnms&tbm=isch&sa=X&ved=2ahUKEwif-Nigr57uAhUmRBUIHbC7AUMQ_AUoAXoECBQQAw&biw=1366&bih=657#imgrc=EHNcvjjp2BetMM
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Copied from. https://www.google.com/search?q=jvp+waves&safe=active&sxsrf=ALeKk02DoJnngYGEVtsucXTxyyteXb6XsQ:1610728500254&source=lnms&tbm=isch&sa=X&ved=2ahUKEwif-Nigr57uAhUmRBUIHbC7AUMQ_AUoAXoECBQQAw&biw=1366&bih=657#imgrc=EHNcvjjp2BetMM Timing of venous waves with ventricular systolic & diastolic phases of cardiac cycle. Systole is highlighted blue and diastole with pink color. c and x waves are systolic. As c wave is difficult to perceive, x descent is the only clearly visible wave during systole. a, v & y waves can be visualized during ventricular diastole.
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Bedside timing of internal jugular pulsations. Copied and modified from http://clinicalmethods.blogspot.com/2011/08/chapter-19-jugular-venous-pressure-and.html S1 S2 If heart rate is not fast four JVP waves can be visualize & timed at bed side examination, Positive, A wave in JVP can been be seen just before first heart sound (S1 ) and carotid artery pulse. Positive V wave can be visualize immediately after second heart sound ( S2 ). Negative (recession ) X wave , is systolic can be seen before S2. Negative, recession wave ,Y wave is diastolic & can be visualized after S2.
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38 JVP related post test. Select true & false among the following statements. Don’t guess if you don’t know, don’t attempt the question. Q 1 .Negative wave ( descent ) is most dominant visible wave in JVP . T/F ? Q2. Phlebostatic zero reference point lies at the sternal angle .T/F ? Q3. Estimated Jugular venous pressure (JVP ) in cm is equal to RA pressure in mm Hg. T/F ? Q4.Best angle to measure JVP is 45*. T/F ? Q5.Sternal angle is 5 cm above the Right atrium, irrespective of patient position . T/F?. Q6. JVP of minus one cm (-1cm ) is suggestive of abnormally low RA pressure. T/F ? Q7.JVP of >3cm above the sternal angle in any patient position , is considered as abnormally elevated . T. Q8. X descent is systolic wave and y descent is diastolic . T/F ?. For key please see the last slide.
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Clinical tips for the residents to acquire skills of accurate JVP interpretation . Having read and understood JVP concepts (JVP grammar ) doesn’t mean you will be able to interpret it. In fact few residents , examining the venous pulsation for the first time, may even have difficulty to perceive these. You need careful examination, sitting comfortably on the bedside with patience in a well lighted room . Examining quite a few cases methodically will surprise you to observe waves pouring into your eyes which you couldn’t perceive at the beginning. In the first go examine normal subjects or non cardiac cooperative patients , with regular, slow pulse . Your first goal is to differentiate venous from the arterial pulsations. Next step is correct measurement of JVP, lying at an appropriate inclination. Last step is to achieve Karel Frederik Wenckebach target of timing and interpretations of normal & abnormal jugular vein pulsations. This is achievable by any resident who is keen to learn has determination , devotion & patience. “Genius is one percent inspiration and ninety-nine percent perspiration”. Thomas Edison.
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40 Key of JVP related post test. If your score is < 75% (< 6 correct questions ) , please review and reattempt the post test. Q 1 . Negative wave ( descent ) is most dominant visible wave in JVP . T Q2. Phlebostatic zero reference point lies at the sternal angle . F Q3. Estimated JVP pressure in cm is equal to RA pressure in mm Hg. F. Q4.Best angle to measure JVP is 45* .F. Q5.Sternal angle is 5 cm above the Right atrium, irrespective of patient position . F . Q6. JVP of minus one cm (-1cm ) is suggestive of abnormally low RA pressure. F. Q7.JVP of >3cm above the sternal angle in any patient position , is considered as abnormally elevated . T. Q8. X descent is systolic wave and y descent is diastolic . T.