HISTORY 45-year-old man. CHIEF COMPLAINT: Dyspnea of two days duration. PRESENT ILLNESS: His dyspnea began suddenly and has been associated with orthopnea, but no chest pain. For two months he has felt tired, rather weak, and has had a low grade fever. He has had no cough, hemoptysis, leg pain or edema. His previous health was excellent. Question: How do you interpret the patient s history? 6-1
Answer: Orthopnea is more consistent with acute left ventricular failure than a primary pulmonary problem such as embolism. Possible causes include acute myocardial infarction (even without pain), arrhythmia, and sudden valvular regurgitation. The latter is supported by his systemic symptoms which suggest infective endocarditis. Proceed 6-2
PHYSICAL SIGNS a. GENERAL APPEARANCE - Tired, dyspneic 45-year-old man (temperature 100º F). b. VENOUS PULSE - The mean CVP is estimated to be 5 cm H 2 O, but one wave measures 9 cm H 2 O. Question: What is the significance of the large venous pulse? 6-3
Answer: The very large wave is a giant a wave and reflects an enhanced right atrial contraction against an increased resistance to outflow. Possible etiologies include tricuspid or pulmonary stenosis, as well as pulmonary arterial hypertension and right ventricular failure of any cause. c. ARTERIAL PULSE - (BP = 140 / 80 mm Hg) CAROTID DICROTIC NOTCH ECG Question: What is your interpretation of the arterial pulse? 6-4
Answer: The carotid pulse is rapid rising. This suggests that the ventricle is contracting against a reduced resistance and hence empties more rapidly, as in patients with mitral or aortic regurgitation. In this case, fever further enhances the carotid upstroke by the same mechanism. d. PRECORDIAL MOVEMENT APEX IMPULSE ECG.20 sec. Question: How do you interpret the precordial movements at the apex? 6-5
Answer: There is a palpable fourth sound at the apex followed by a somewhat sustained systolic impulse and then a palpable third sound. d. PRECORDIAL MOVEMENT (continued) PHONO UPPER LEFT STERNAL EDGE ECG 200 CPS S1 A 2 P 2 MID LEFT STERNAL EDGE.20 sec. Question: How do you interpret the precordial movements at the mid-left sternal edge? 6-6
Answer: There is a sustained right ventricular impulse. This finding, coupled with a loud pulmonary second sound at the upper left sternal edge, is consistent with pulmonary hypertension and a pressure-(after) loaded right ventricle. e. CARDIAC AUSCULTATION LOWER LEFT STERNAL EDGE APEX MED. Hz MED. Hz A 2 P 2 CAROTID Questions: 1. Is the murmur holosystolic or mid-systolic? 2. What pathologic heart sounds are present and what is their significance? 6-7
Answers: 1. The murmur is holosystolic, but decrescendo. This configuration is consistent with mitral regurgitation of recent onset where the left atrium is small and relatively noncompliant. Hence left atrial pressure rises rapidly and approaches left ventricular pressure in late systole, reducing the degree of regurgitation and hence the intensity of the murmur. 2. A pathologic fourth sound is present due to an enhanced atrial contraction into a relatively nondistensible left ventricle. This is rare in chronic mitral regurgitation where the dilated atrium cannot generate much contractile force. A pathologic third sound is likely related to the large volume of diastolic flow across the mitral valve as blood rushes from the preloaded left atrium into the ventricle and then rapidly decelerates, causing the cardiohemic system (e.g., valve apparatus, ventricular wall, blood) to vibrate. f. PULMONARY AUSCULTATION Question: lung fields? How do you interpret the acoustic events in the pulmonary Proceed 6-8
Answer: In all lung fields, there are inspiratory and expiratory crackles, reflecting acute severe pulmonary edema. ELECTROCARDIOGRAM I II III avr avl avf V1 V2 V3 V4 V5 V6 Question: How do you interpret the ECG? 6-9
Answer: The R wave progression in the precordial leads is somewhat slow, and there are minimal ST variations. Overall the tracing is not strikingly abnormal, suggesting that a hemodynamically significant lesion could not have been present for long. The absence of changes consistent with acute ischemia, injury, or infarction is evidence against severe papillary muscle dysfunction due to atherosclerotic heart disease as the etiology of the patient s mitral regurgitation. Proceed 6-10
CHEST X RAY Question: How do you interpret this PA X ray? 6-11
Answer: There is pulmonary congestion with distended pulmonary veins and interstitial pulmonary edema bilaterally in the hilar areas. The heart size is normal. The lateral chest X ray is unremarkable (not shown). Question: Based on the history, physical examination, ECG and X rays, what is your diagnostic impression and plan to further evaluate the patient? 6-12
Answer: The history, physical examination, ECG and X rays are all consistent with acute mitral regurgitation. The differential diagnosis includes aortic stenosis because the murmur may radiate toward the left sternal edge and base, and because it may have a crescendo-decrescendo diamondshape. This pattern of radiation is due to the regurgitant jet that strikes the interatrial septum that lies adjacent to the base of the aorta. The phonocardiograms of four patients with acute mitral regurgitation follow. It is easy to see how this diamond-shaped murmur could be confused with aortic stenosis. 6-13
ACUTE MITRAL REGURGITATION MIMICKING AORTIC STENOSIS LEFT STERNAL EDGE A 2 A 2 A 2 A 2 200 CPS APEX 200 CPS S.S. P.McL. J.C. R.R. CAROTID 6-14
Ruptured chordae tendineae are a major cause of acute mitral regurgitation and may be due to infective endocarditis, that is suggested by the patient s history of systemic symptoms and fever. Routine laboratory studies showed the patient to be anemic with a hemoglobin of 10.0, and blood cultures grew out Streptococcus viridans. Careful re-questioning of the patient revealed that he had a tooth extraction three months ago that could have been the source of his infection. Question: What further diagnostic test will be most helpful? 6-15
Answer: Echocardiography. LABORATORY - TWO-DIMENSIONAL ECHOCARDIOGRAM RV = Right Ventricle LV = Left Ventricle LA = Left Atrium RA = Right Atrium AL = Anterior Mitral Leaflet Ao = Aorta PARASTERNAL LONG AXIS APICAL FOUR CHAMBER Question: How would you interpret this echocardiogram? 6-16
Answer: A large vegetation (arrow) is present on the posterior mitral leaflet. The Doppler study confirms that the mitral regurgitation is severe. Question: What is your initial treatment for this patient? 6-17
Answer: Treatment should be directed at two problems. 1. Infective endocarditis - The patient was treated with parenteral penicillin and an aminoglycoside for several weeks. He became afebrile within 72 hours and his hemoglobin slowly came up to normal levels over six weeks. 2. Congestive heart failure - The patient was treated with sodium restriction, diuretics and afterload reducing agents. He improved transiently. As he tried to resume his normal activities, congestive heart failure reappeared. Because of his deterioration, an echocardiogram was repeated. Proceed 6-18
LABORATORY - ECHOCARDIOGRAM TWO DIMENSIONAL APICAL FOUR-CHAMBER VIEWS RV = Right Ventricle LV = Left Ventricle RA = Right Atrium LA = Left Atrium LATE DIASTOLE EARLY SYSTOLE Question: How do you interpret this echocardiogram? 6-19
Answer: The mitral leaflets are thickened but the vegetation is not seen. The posterior mitral leaflet (arrow) is displaced well into the left atrium and does not coapt with the anterior leaflet in systole. This is characteristic of a flail posterior leaflet due to valvular disruption of the chordae tendineae. It can be even better delineated by transesophageal echocardiography. The cavity sizes of the left atrium and left ventricle are at the upper limits of normal. The patient s cardiac catheterization follows. Proceed 6-20
LABORATORY (continued) ADDITIONAL DATA: Pulmonary Artery Pressure = 90/30 mm Hg (mean = 60) Cardiac Index = 2.2 L/Min/M 2 Pulmonary Capillary Wedge = 30 mm Hg *Obtained by wedging the catheter in the distal pulmonary artery and reflecting left atrial pressure (though with slight delay). mm Hg 100 80 Left Ventricle 60 40 20 0 WEDGE* Question: How do you interpret the pressure tracing? 6-21
Answer: Severe mitral regurgitation is reflected in the characteristic very high pressure v waves (arrow) seen in the wedge pressure. Clinically, this elevated left atrial pressure increases the work of breathing by elevating pulmonary venous pressure, which increases lung stiffness. The pulmonary artery pressure shows severe pulmonary hypertension (normal = 30/12, mean = 20). The cardiac index is diminished (normal = 2.5-4.5), and left ventricular end diastolic pressure increased (normal = 0-12), reflecting left ventricular failure. Proceed 6-22
LABORATORY (continued) LEFT VENTRICULAR ANGIOGRAM - Right Anterior Oblique Coronary angiograms were also performed and were normal. Questions: 1. How do you interpret the left ventricular angiogram? 2. What is your advice to the patient based on hemodynamic data? 6-23
Answers: 1. In systole, the left atrium is opacified (arrows) due to mitral regurgitation. Despite a substantial degree of regurgitation, neither the left atrium nor the left ventricle (broken arrow) is significantly enlarged, as the regurgitation is acute. 2. The patient was advised to undergo surgery. Valve repair was performed without complications and he did very well. Proceed for Summary 6-24
SUMMARY Acute severe mitral regurgitation is usually caused by ruptured chordae tendineae from endocarditis, trauma, myxomatous connective tissue disease or spontaneous rupture of unknown cause. When present after acute myocardial infarction, acute mitral regurgitation is usually due to severe papillary muscle dysfunction or rupture. The typical gross pathology of a patient with ruptured chordae due to infective endocarditis follows. 6-25
PATHOLOGY LEFT ATRIUM POSTERIOR MITRAL LEAFLET ANTERIOR MITRAL LEAFLET RUPTURED CHORDAE ANTEROLATERAL PAPILLARY MUSCLE POSTEROMEDIAL PAPILLARY MUSCLE Proceed 6-26
SUMMARY(continued) The symptoms and physical findings are due to the very high left atrial pressures which are produced when the large regurgitant volume enters the normal sized left atrium. The high pressures are then reflected back into the pulmonary circulation. These physiologic events are anatomically associated with hypertrophy of the left atrium, pulmonary vessels and right ventricle. This small left atrium-high pulmonary artery pressure syndrome may be contrasted to the syndrome of longstanding mitral regurgitation, where the left atrium is larger, more compliant and absorbs the regurgitant volume without an increase in pressure. Consequently, the pulmonary vessels remain normal, and the right ventricular wall does not thicken. A diagrammatic representation of these concepts follows. 6-27
THE SYNDROME OF MITRAL REGURGITATION PA RA PT Ao LA PV RA = Right Atrium RV = Right Ventricle PT = Pulmonary Trunk RV LV PA = Pulmonary Arteries PV = Pulmonary Veins LA = Left Atrium LV = Left Ventricle Ao = Aorta Small Left Atrium - High Pressure PA Ao PT RA LA PV Proceed for Case Review RV Large Left Atrium - Normal Pressure LV 6-28
To Review This Case of Acute Severe Mitral Regurgitation due to Ruptured Chordae Tendineae from Infective Endocarditis: The HISTORY is typical with the sudden onset of dyspnea and orthopnea and the associated systemic symptoms of infective endocarditis in a previously healthy man. A tooth extraction was the likely source of his infection. PHYSICAL SIGNS: a. The GENERAL APPEARANCE reveals an acutely ill, dyspneic and febrile patient. b. The JUGULAR VENOUS PULSE reveals a normal mean pressure, but a giant a wave due to the enhanced right atrial contraction against an increased resistance to outflow caused by pulmonary hypertension. 6-29
c. The ARTERIAL PULSE is rapid rising, as the initial velocity of contraction of the left ventricle is enhanced due to the decreased resistance afforded by mitral regurgitation. d. PRECORDIAL MOVEMENT reveals a palpable fourth sound, a sustained systolic left ventricular impulse, and a third sound at the apex. There is a separate sustained systolic right ventricular impulse at the left sternal edge due to pulmonary hypertension. 6-30
e. CARDIAC AUSCULTATION reveals an increase in the intensity of the pulmonary second sound at the upper left sternal edge from pulmonary hypertension. The third and fourth sounds at the apex are confirmed. The former reflects volume overload, the latter, contraction of the thickened and powerful atrium against the non-distensible ventricle. The murmur is holosystolic with late systolic decrease as left atrial pressure approaches left ventricular pressure in late systole. Note that the murmur is well heard at the left sternal edge. This is typical of posterior mitral leaflet regurgitation where the regurgitant jet strikes the interatrial septum that lies adjacent to the base of the aorta. f. PULMONARY AUSCULTATION reveals inspiratory and expiratory crackles in all lung fields, reflecting acute severe pulmonary edema. Proceed 6-31
The ELECTROCARDIOGRAM shows normal sinus rhythm. There is no evidence of atrial fibrillation or left atrial or left ventricular enlargement, that are commonly seen in more chronic forms of mitral regurgitation. The CHEST X RAYS show the butterfly pattern of hilar pulmonary edema with prominent pulmonary veins, but without significant left atrial and left ventricular enlargement, as would be expected in chronic mitral regurgitation. Proceed 6-32
LABORATORY STUDIES determined the causative organism, Streptococcus viridans, and the patient s anemia. Non-invasive ECHOCARDIOGRAPHY showed a typical flail posterior leaflet. CATHETERIZATION showed gigantic characteristic v waves in the wedge pressure (reflecting the left atrium), pulmonary hypertension, reduced cardiac output and an elevated left ventricular end diastolic pressure. The ANGIOGRAM confirmed severe mitral regurgitation, and normal coronary arteries. TREATMENT with parenteral antibiotics cured the infective endocarditis, but medical therapy with salt restriction, diuretics and afterload reducing agents did not adequately control the patient s symptoms of congestive heart failure. Mitral valve repair was, therefore, carried out with an excellent result. 6-33