B P8 C73 Aortic Regurgitation Flashcards
_____________________ can result from primary disease of the aortic valve leaflets and/or dilation of the aortic root and ascending aorta
Aortic regurgitation (AR)
Among patients with isolated AR who undergo aortic valve replacement (AVR), the percentage with primary disease of the aorta has been increasing steadily during the past few decades; it now represents the most common cause, accounting for more than 50% of all such patients in some series.
There are two predominant groups of patients who present with AR caused by a primary valve abnormality that is at least moderately severe.
(1) Young adults with noncalcified bicuspid aortic valves (BAVs) age 20 through 40 with AR caused by incomplete closure and/or prolapse of a valve leaflet.
(2) Patients age 60 or older with calcific aortic valve disease
In _____ aortic valve disease, fusion of the commissures and fibrotic retraction of leaflet tissue lead to a fixed orifice with a central defect often producing combined AS and AR
Rheumatic
AR secondary to _____ is now more common than primary valve disease in patients undergoing AVR for isolated AR.
Marked dilation of the ascending aorta
Patients with severe chronic AR, left unchecked, can develop the largest LV end-diastolic volumes of any form of heart disease, resulting in so-called _______________
Cor bovinum
During exercise, _____ declines and, with an increase in heart rate, diastole shortens and the regurgitation per beat decreases, facilitating an increment in effective (forward) cardiac output without substantial increases in end-diastolic volume and pressure.
Peripheral vascular resistance
Because the major portion of coronary blood flow occurs during diastole, when aortic pressure is lower than normal in AR, coronary perfusion pressure is _____.
Reduced
LV dilation also increases the LV systolic tension required to develop any level of systolic pressure.
Thus in AR, there is an increase in both preload and afterload. LV systolic function is maintained through the combination of chamber dilation and hypertrophy.
This leads to ________________, with replication of sarcomeres in series and elongation of myocytes and myocardial fibers
Eccentric hypertrophy
As AR persists and increases in severity over time, however, wall thickening fails to keep pace with the hemodynamic load, and end-systolic wall stress rises. At this point, the ____________________ results in a decline in systolic function, and the LVEF fall
Afterload mismatch
The principal manifestations, including exertional dyspnea, orthopnea, and paroxysmal nocturnal dyspnea, usually develop gradually.
_____ is prominent late in the course; nocturnal angina may be troublesome and often is accompanied by diaphoresis, which occurs when the heart rate slows and arterial diastolic pressure falls to extremely low levels.
Angina pectoris
_____ are particularly distressing because of the great heave of the volume-loaded left ventricle during the postextrasystolic beat.
Premature ventricular contractions
In patients with chronic, severe AR, the head may bob with each heartbeat (_____ sign), and water hammer pulses, with abrupt distention and quick collapse (_____ pulse), are evident
de Musset sign
Corrigan pulse
The arterial pulse often is prominent and can be best appreciated by palpation of the radial artery with the patient’s arm elevated. A _____ pulse may be present and is more readily recognized in the brachial and femoral arteries than in the carotid arteries
Bisferiens
The _____ sign (also known as pistol shot sounds) refers to booming systolic and diastolic sounds heard over the femoral artery
Traube sign
The _____ sign consists of systolic pulsations of the uvula
Müller sign
The _____ sign consists of a systolic murmur heard over the femoral artery when it is compressed proximally and a diastolic murmur when it is compressed distally
Duroziez sign
Capillary pulsations can be detected by transmitting a light through the patient’s fingertips or exerting gentle pressure on the tip of a fingernail.
Quicke sign
The _____ in diastolic pressure reflects severity of AR and has prognostic implications.
Reduction
Korotkoff sounds often persist to zero even though the intra-arterial pressure rarely falls below 30 mm Hg.
The point of change in Korotkoff sounds (i.e., the muffling of these sounds in phase ____) correlates with the diastolic pressure
Phase IV
The apical impulse is _____ and is displaced _____.
Diffuse and hyperdynamic
Laterally and inferiorly
The diastolic murmur, the principal physical finding in AR, is of high frequency and begins immediately after A2.
It may be distinguished from the murmur of pulmonic regurgitation by its _____ onset and usually by the presence of a _____.
Earlier onset (i.e., immediately after A2 rather than after P2)
Widened pulse pressure
The murmur is heard best with the _____ of the stethoscope while the patient is sitting up and leaning forward, with the breath held in deep exhalation.
Diaphragm
In severe AR, the murmur reaches an early peak and then shows a dominant decrescendo pattern throughout diastole.
The severity of AR correlates better with the _____ of the murmur
Duration than with the intensity
In mild AR, the murmur may be limited to _____ diastole and typically is _____ pitched and blowing
MILD AR:
Early diastole
High pitched and blowing
In severe AR, the murmur is _____ and may have a rough quality.
When the murmur is musical (cooing dove murmur), it usually signifies _____ of an aortic cusp.
SEVERE AR:
Holodiastolic
Eversion or perforation of aortic cusp (musical, cooing dove murmur)
When AR is caused by primary valvular disease, the diastolic murmur is heard best along the _____.
However, when it is caused mainly by dilation of the ascending aorta, the murmur often is more readily audible along the _____.
Primary: left sternal border in the 3rd and 4th ICS
Dilation of Ascending Aorta: Right sternal border
Many patients with chronic AR have a harsh systolic outflow murmur caused by the increased total LV stroke volume and ejection rate, which often radiates to the _____.
Carotid vessels
- The systolic murmur often is more readily audible than the diastolic murmur
- Palpation of the carotid pulses will elucidate the cause of the systolic murmur and differentiate it from the mur- mur of AS.
A _____ correlates with an increased LV end- diastolic volume.
Its development may be a sign of impaired LV function, which is useful in identifying patients with severe AR who are can- didates for surgical treatment
S3
A mid-diastolic and late diastolic apical rumble, the _____ murmur, is common in severe AR and may occur in the presence of a normal mitral valve.
Austin Flint murmur
This murmur appears to be created by severe AR impinging on the anterior leaflet of the mitral valve or the free LV wall; convincing evidence for obstruction to mitral inflow in these patients is lacking.
Stage D Chronic AR
Symptomatic severe AR
Valve Anatomy:
Calcific valve disease
Bicuspid valve (or other congenital abnormality)
Dilated aortic sinuses or ascending aorta
Rheumatic valve changes
Previous IE with abnormal leaflet closure or perforation
Valve Hemodynamics:
Severe AR: Doppler jet width 65% of LVOT
Vena contracta >0.6 cm
Holodiastolic flow reversal in the proximal abdominal aorta
RVol 60 mL/beat
RF 50%
ERO 0.3 cm2
Angiography grade 3+ to 4+
In addition, diagnosis of chronic severe AR requires evidence of LV dilation
Hemodynamic Consequences:
Symptomatic severe AR may occur with normal systolic function (LVEF >55%), mild to moderate LV dysfunction (LVEF 40% to 55%), or severe LV dysfunction (LVEF <40%).
Moderate to severe LV dilation is present
Symptoms:
Exertional dyspnea or angina, or more severe HF symptoms
Class I indications for AVR in patients with AR
- In symptomatic patients with severe AR (stage D), aortic valve surgery is indicated regardless of LV systolic function (IB)
- In asymptomatic patients with chronic severe AR and LV systolic dysfunction (LVEF </=55%) (stage C2), aortic valve surgery is indicated if no other cause for systolic dysfunction is identified (IB)
- In patients with severe AR (stage C or D) who are undergoing cardiac surgery for other indications, aortic valve surgery is indicated (IC)
In acute AR, the echocardiogram reveals a dense, diastolic Doppler signal with a _____ diastolic half time and an end-diastolic velocity approaching zero
Short
The most sensitive and accurate noninvasive techniques for the diagnosis and evaluation of AR.
As the severity of AR increases, there will be a larger area of turbulence in the LV outflow tract on color flow imaging, but this is only a semi-qualitative measure.
Doppler echocardiography and color flow Doppler imaging
There are indirect Doppler findings in severe AR including a
High LV outflow velocity
Reversal of flow in the descending aorta
Short diastolic half-time of the AR
This is the most accurate noninvasive technique for assessing LVESV, end-diastolic volume, and mass and is recommended when echocardiographic evaluation of LV size and function or severity of regurgitation is suboptimal.
CMR
