HISTORY. Question: What diagnosis is suggested by this history? CHIEF COMPLAINT: Increasing shortness of breath for the past month and

HISTORY 36-year-old man. CHIEF COMPLAINT: Increasing shortness of breath for the past month and recent onset of neck pain. PRESENT ILLNESS: He first...
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HISTORY 36-year-old man.

CHIEF COMPLAINT: Increasing shortness of breath for the past month and recent onset of neck pain.

PRESENT ILLNESS: He first noted eight years ago the onset of pulsations in the neck while shaving and “felt” his heart beat when recumbent. Progressive dyspnea on exertion and profuse sweating without fever have been noted for the past two months. There is a history of a murmur in early childhood, but no history of acute rheumatic fever.

Question:

What diagnosis is suggested by this history?

17-1

Answer:

The presence of a murmur in early childhood is compatible with a congenital etiology, although rheumatic heart disease may occur without a definite history of rheumatic fever. Prominent pulsations in the neck may be arterial or venous. The neck pain suggests that the pulsations are arterial. This pain may be due to a vigorously pulsating artery that stretches the carotid sheath, causing arteritis. Prominent arterial pulsations in the neck usually reflect a large stroke volume, as seen in aortic regurgitation (AR) and patent ductus arteriosus (PDA). Dyspnea on effort is a common and relatively early symptom of left ventricular failure. Sweating may be a clue to the diagnosis of severe AR, and is thought to be secondary to autonomic dysfunction.

Proceed

17-2

PHYSICAL SIGNS: a. GENERAL APPEARANCE- 36-year-old mildly dyspneic man.

b. VENOUS PULSE - The CVP is estimated to be 7 cm H2O.

ECG

JUGULAR VENOUS PULSE

Question:

How do you interpret the venous pulse? 17-3

Answer:

The estimated CVP is at the upper limits of normal and the venous wave form is normal.

c. ARTERIAL PULSE - (BP = 160/35 mm Hg)

CAROTID PULSE

ECG

Question:

How do you interpret the arterial pulse? 17-4

Answer:

The pulse pressure is wide and the diastolic pressure is low. This suggests a lesion with increased stroke volume and rapid diastolic runoff, such as AR or PDA. The carotid pulse is bifid or bisferiens (twice beating) in systole. Its presence is most consistent with the diagnosis of AR, with or without a mild degree of aortic stenosis. While hypertrophic obstructive cardiomyopathy may be associated with a bifid arterial pulse, the wide pulse pressure is inconsistent with this lesion.

Question:

How do you explain the bisferiens pulse?

17-5

Answer:

The first (percussion) wave relates to the forceful initial contraction of the pre-(volume) loaded left ventricle (Starling’s Law of the Heart). In addition, the velocity of left ventricular contraction is increased due to the reduced after-(pressure) load associated with compensatory peripheral vasodilation. The second (tidal) wave is likely caused by reflected waves from the periphery that are accentuated because of the large stroke volume in association with a decreased peripheral resistance. Following the second peak of the pulse wave, there is a rapid fall in the pressure during late systole, the so-called “systolic collapse.” This likely relates to the rapid loss of blood volume into the dilated peripheral vessels and across the incompetent aortic valve.

Proceed

17-6

d. PRECORDIAL MOVEMENT and e. CARDIAC AUSCULTATION

ECG

S2 S1 PHONO UPPER RIGHT STERNAL EDGE

APEXCARDIOGRAM 5TH & 6TH ICS ANTERIOR AXILLARY LINE

Questions: 1. How do you interpret the precordial movement? 2. How do you interpret the acoustic events at the upper right sternal edge? 17-7

Answers: 1. The apical impulse is displaced laterally, enlarged, hyperdynamic and nonsustained. The displacement and enlargement are consistent with a chronically preloaded left ventricle, as seen in mitral or aortic regurgitation or PDA. The hyperdynamic non-sustained character of the impulse is due to an increased stroke volume associated with the increased preload and an increased velocity of contraction due to the reduced afterload.

2. There is an ejection sound (arrow), a short early systolic crescendodecrescendo murmur and a high frequency diastolic decrescendo murmur at the upper right sternal edge.

Proceed

17-8

Answer

(continued): An ejection sound may arise from either a pliable congenitally abnormal semilunar valve or in association with a dilated great vessel. The fact that it is heard at the upper right sternal edge makes it most likely aortic in origin. Aortic ejection sounds, in contrast to pulmonary ejection sounds, have no respiratory variation, and in some cases may be heard at the apex. The short systolic murmur is most likely due to increased flow across a non-stenotic aortic valve, as it occurs only during maximum ejection, and may be related to turbulence alone. A diastolic murmur of high frequency and decrescendo character in this location is consistent with AR. Auscultation at the mid left sternal edge may help to further define this murmur.

Proceed

17-9

e. CARDIAC AUSCULTATION (continued)

PHONO MID LEFT STERNAL EDGE

S1 S2 ECG

Question:

How do you interpret the murmur at the mid left sternal edge?

17-10

Answer:

The murmur begins with the aortic sound (A2), because the aortic root diastolic pressure exceeds left ventricular pressure (LV) diastolic pressure immediately after the onset of diastole. The murmur then diminishes as the aortic root pressure falls and left ventricular pressure rises in diastole.

PRESSURE (mm Hg)

There is a high frequency (blowing), early diastolic, decrescendo murmur consistent with AR. The murmur is typically loudest at the mid left sternal edge, but may be audible in other areas.

AORTA

LV

PHONO S1

S1 A2

Proceed 17-11

e. CARDIAC AUSCULATION (continued)

ECG S1

S2

PHONO APEX (Low Frequency)

PHONO UPPER RIGHT STERNAL EDGE (High Frequency)

Question:

How do you interpret these acoustic events? 17-12

Answer:

At the apex, the first heart sound is diminished, and there is a low frequency apical diastolic murmur (arrow) which is either an Austin Flint rumble secondary to AR, or due to associated mitral stenosis. These findings are also well heard posterolateral to the mitral area over the enlarged left ventricle. The Austin Flint murmur is related to the premature closure of the mitral valve. With severe AR, the left ventricular diastolic pressure rises early and approaches that of the left atrium causing the mitral valve leaflets to begin to close prematurely. The velocity and turbulence of diastolic flow through the reduced mitral valve orifice causes this low frequency murmur of “relative” mitral stenosis. The reduced intensity of the first heart sound is also explained by premature mitral valve closure. The simultaneously recorded phonocardiogram at the upper right sternal edge helps to correlate the diastolic murmur of aortic regurgitation with the Austin Flint rumble. The broken arrow denotes the ejection sound previously described. f.

PULMONARY AUSCULTATION

Question:

How do you interpret the acoustic events in the pulmonary lung

fields? Proceed

17-13

Answer: In all lung fields, there are normal vesicular breath sounds. ELECTROCARDIOGRAM I

II

III

aVR

aVL

aVF

V1

V2

V3

V4

V5

V6

ALL LEADS 1/2 STANDARD

Question:

How do you interpret the ECG? 17-14

Answer:

The ECG shows first degree heart block (P-R>0.20), left axis deviation and left ventricular hypertrophy associated with an intraventricular conduction delay.

CHEST X RAYS

POSTEROANTERIOR (PA)

Question:

LEFT ANTERIOR OBLIQUE (LAO)

How do you interpret these chest X rays? 17-15

Answer:

In the PA view, the cardiac silhouette is convex or “boot shaped” (arrow) and extends below the diaphragm. This is typical of a markedly dilated, inferolaterally displaced left ventricle due to chronic volume overload. Moderate dilatation of the aortic root (broken arrow) is also consistent with chronic volume overload. The findings are confirmed in the LAO view which shows the dilated ventricle extending beyond the spine (arrow) and the dilated aortic root (broken arrow).

Question:

Based on the history, physical examination, ECG and chest X rays, what is your initial diagnostic impression and plan to further evaluate this patient?

17-16

Answer:

The history, physical examination, ECG and chest X rays are all consistent with a preloaded left ventricle due to isolated, severe aortic regurgitation with left ventricular dysfunction. With rheumatic heart disease, the mitral valve is essentially always involved. Although the exact etiology of the aortic regurgitation is not definite, the history of a murmur in childhood, the absence of rheumatic fever and the absence of other valvular involvement detectable at the bedside, suggest a congenital etiology. An echocardiogram is likely to further define the cause of the apical murmur and may define the etiology of the aortic regurgitation. The patient’s study follows.

Proceed

17-17

LABORATORY - ECHOCARDIOGRAM TWO-DIMENSIONAL PARASTERNAL LONG AXIS (Systole)

RV = Right Ventricle

LV = Left Ventricle Ao = Aorta LA = Left Atrium

Question:

How do you interpret this echocardiogram? 17-18

Answer:

The two-dimensional echocardiogram shows systolic doming (arrow), a characteristic of a congenitally malformed aortic valve. The left ventricle is moderately dilated. In the real-time study the left ventricle is hyperkinetic, the aortic valve bicuspid, and the mitral valve structurally normal.

Proceed

17-19

LABORATORY (continued) A color Doppler flow study clearly demonstrates the jet of aortic regurgitation (arrow) as shown below.

RV LV Ao LA MV

= = = = =

Right Ventricle Left Ventricle Aorta Left Atrium Mitral Valve

PARASTERNAL LONG AXIS (DIASTOLE)

The configuration moderately severe.

of

the

jet

suggests

that

the

regurgitation

is

Proceed 17-20

The echocardiographic studies support the clinical diagnosis of isolated severe AR due to a congenitally bicuspid aortic valve. In the presence of isolated AR, a dilated hyperkinetic left ventricle is virtually diagnostic of chronic AR.

Question:

How would you treat this patient?

17-21

Answer:

The patient was treated with salt restriction, digitalis, diuretics and a vasodilator to reduce afterload. He improved significantly, but still had mild dyspnea and cardiomegaly. Because of this and his bedside findings of severe AR, he is a candidate for valve replacement. While catheterization is not mandatory, it will confirm the diagnosis, assess left ventricular function and define the anatomy of the coronary arteries.

Proceed

17-22

LABORATORY (continued) - CARDIAC CATHETERIZATION

ECG

Cardiac Index = 2.2 L/Min/M2

200 mm Hg

ADDITIONAL DATA: No gradient across the mitral valve.

INTRA AORTIC PHONO

INTRA VENTRICULAR PHONO

100

LV = Left Ventricle AO = Aorta

AO LV

0

Question:

How do you interpret the above data? 17-23

Answer:

There is a wide pulse pressure (110 mm Hg), typical of severe AR. There is no significant systolic gradient across the aortic valve, confirming the clinical impression that the systolic murmur was due to increased flow alone. The left ventricular end-diastolic pressure is increased (30 mm Hg) and the cardiac index is reduced (normal = 2.5-4.0 L/Min/M2), reflecting a decrease in left ventricular function. The intraaortic phonocardiogram shows systolic and diastolic murmurs, while the intraventricular phonocardiogram shows only a diastolic murmur and correlates exactly with the bedside examination.

Proceed

17-24

LABORATORY

(continued)

AORTIC ROOT ANGIOGRAM

ADDITIONAL DATA: The coronary arteriograms were normal. Left ventricular injection showed no mitral regurgitation.

Ao = Aorta LV = Left Ventricle

PA

Question:

LATERAL

How do you interpret the angiograms? 17-25

Answer:

In both the PA and lateral views, injection of dye into the aortic root results in marked opacification of the left ventricle, reflecting severe aortic regurgitation. The ventricle and ascending aorta are dilated. Based on the clinical and laboratory evaluation, the patient underwent prosthetic aortic valve replacement. His postoperative course was uneventful and he improved markedly.

Proceed for Summary

17-26

SUMMARY Aortic regurgitation can be secondary to intrinsic aortic valve disease (e.g., rheumatic, infectious, congenital, traumatic) or aortic root disease (e.g., syphilis, cystic medial necrosis, aortic dissection, ankylosing spondylitis). When the etiology is rheumatic, the mitral valve is nearly always involved.

A congenital bicuspid aortic valve may leak because the two cusps are unequal in size, with the larger cusp prolapsing into the left ventricle during diastole. Fibrosis and calcification often occur over a period of years, resulting in a rigid structure associated with both stenosis and regurgitation. Left ventricular volume overload is the basic hemodynamic abnormality. The compensatory response of the left ventricle is hypertrophy and dilation. The left ventricle is able to tolerate significant volume overload for years prior to decompensation.

Proceed 17-27

SUMMARY(continued) The peripheral manifestations of AR related to the wide pulse pressure have been described with a variety of eponyms: Corrigan’s pulse = abruptly rising and falling pulsations (or Waterhammer) de Musset’s sign = rhythmical nodding of the head synchronous with each heart beat Quincke’s sign = alternate reddening and blanching of the nail bed when the tip of the nail bed is slightly compressed Duroziez’s murmur = biphasic to and fro bruit detected by mild pressure of the stethoscope over the femoral artery Hill’s sign = disproportionate femoral systolic hypertension detected by leg blood pressure Pistol shots = sharp, high frequency systolic sounds, analogous to Korotkoff sounds, heard over the peripheral arteries

Proceed 17-28

SUMMARY(continued) Endocarditis prophylaxis is mandatory in AR, since infection of the deformed valve is the most important factor in producing sudden deterioration. Proper timing of surgery is essential. Patients with mild AR may have a long and uncomplicated course with normal life expectancy. Those with a wide pulse pressure, those with moderate to severe left ventricular enlargement by echocardiography and those with decrements in left ventricular function should be considered for surgery. The onset of angina pectoris or symptoms of left ventricular failure are indications for further evaluation. The goal of management is to operate before irreversible deterioration in ventricular function occurs.

Proceed 17-29

PATHOLOGY Specimen of a bicuspid aortic valve associated in life with aortic regurgitation. RAPHE

OSITA Right Coronary Artery and Accessory Vessel

(

)

OSTIUM LEFT CORONARY ARTERY

COMMISSURE

AORTIC CUSPS (Pliable, noncalcified)

LEFT VENTRICLE

Proceed for Case Review 17-30

To Review This Case of Isolated Congenital Aortic Regurgitation: The HISTORY is typical, including a murmur in childhood and the later onset of prominent arterial pulsations and left ventricular failure. Additional features include neck pain and diaphoresis.

PHYSICAL SIGNS a. The GENERAL APPEARANCE reveals a mildly dyspneic man in his mid 30’s. b. The JUGULAR VENOUS PULSE mean pressure and wave form are normal. c. The CAROTID PULSE is bisferiens and the pulse pressure is wide, reflecting increased stroke volume and rapid diastolic runoff.

Proceed 17-31

d. PRECORDIAL MOVEMENT is hyperdynamic displaced, consistent with a preloaded left ventricle.

and

inferolaterally

e. CARDIAC AUSCULTATION reveals the characteristic features of chronic AR: 1) The diastolic decrescendo murmur of AR; 2) The basilar systolic crescendo-decrescendo murmur secondary to increased flow across the aortic valve; 3) The apical diastolic Austin Flint rumble and diminished first sound due to premature closure of the mitral valve that are also well heard posterolateral to the mitral area over the enlarged left ventricle. 4) An ejection click characteristic of a bicuspid aortic valve. A fourth murmur, not present in this case, and due to mitral regurgitation associated with dysfunction of the mitral apparatus from left ventricular dilation, may occasionally be heard. f. PULMONARY AUSCULTATION reveals normal vesicular breath sounds in all lung fields.

Proceed 17-32

The ELECTROCARDIOGRAM shows first degree heart block, left axis deviation, an intraventricular conduction delay and left ventricular hypertrophy, reflecting the chronically volume loaded left ventricle. The CHEST X RAY also reflects chronic volume overload, with marked left ventricular enlargement and mild aortic root enlargement.

LABORATORY STUDIES

include echo Doppler showing a congenitally abnormal aortic valve associated with severe AR. Catheterization and angiography show isolated AR of severe degree, normal coronary arteries and evidence of left ventricular failure.

TREATMENT is aortic valve replacement.

17-33

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