Clinicopathological Case Conference

Shock and Pulmonary Edema

GERARD B. MARTIN, MD,* KIRK JENSEN, MD,t RICHARD M. NOWAK, MD**

CASE PRESENTATION

Dr. Kirk Jensen: A 6%year-old white woman was trans- ferred to the University of Chicago Emergency Department with the diagnosis of pulmonary edema and cardiogenic shock.

She was well until approximately two weeks previously, when she experienced several transitory episodes of weak- ness and palpitations, each lasting seconds to minutes. She denied having chest pain, shortness of breath, diaphoresis, or loss of consciousness.

On the day of admission the patient had an episode of syncope lasting several minutes. There was no associated chest pain, shortness of breath, or diaphoresis. Upon re- gaining consciousness, the patient noted a generalized feeling of weakness and called the emergency dispatch ser- vice. A Chicago Fire Department ambulance subsequently transported her to a local community hospital.

Upon her arrival at the community hospital, her vital signs were as follows: temperature, 38°C; pulse, 100 beats per minute; respiratory rate, 24 per minute; blood pressure, 901 60 mm Hg.

On examination the patient was awake, alert, and some- what pale. There was jugular venous distension at 40” ele- vation. A loud midsystolic murmur was heard. Inspiratory rales were heard over both lungs.

The electrocardiogram was interpreted as showing left ventricular hypertrophy, and the chest radiograph was read as showing pulmonary edema (Fig. 1). The complete blood count and levels of serum electrolytes, glucose, and cardiac enzymes were reported as normal.

The patient had several episodes of what was believed to be supraventricular tachycardia, marked by restlessness and

From the *Department of Emergency Medicine, Henry Ford Hos- pital, Detroit, Michigan, the TUniversity of Chicago Hospitals, Chicago, Illinois, and the *Education committee, Michigan Chapter, American College of Emergency Physicians.

Presented at the Ninth Annual Michigan Emergency Medicine Assembly in Traverse City, Michigan, July 1982.

Address reprint requests to Dr. Nowak: Education Committee, Michigan Chapter, American College of Emergency Physicians, 1305 Abbott Road, Suite 109, East Lansing, Ml 48823.

Key Words: Cardiogenic shock, hypertrophic cardiomyopathy, idiopathic hypertrophic subaortic stenosis (IHSS), mitral regur- gitation.

232

obtundation. Approximately one hour after the patient’s ar- rival in the community emergency department, a sinus arrest developed (Fig. 2). At that point a temporary transvenous pacemaker was inserted, followed by infusions of dopamine and norepinephrine for persisting hypotension. After an un- successful one-hour attempt to locate a cardiologist, a de- cision was made to transfer the patient.

Three hours after the patient’s arrival at the community hospital, a call was placed to the University of Chicago Emergency Department to inform the senior resident that the patient was enroute via private ambulance; she arrived half an hour later.

Further questioning of the patient revealed a history of acute rheumatic fever in childhood. requiring extended hos- pitalization. There were no subsequent difficulties. Eight years before the present illness, routine physical examina- tion disclosed a heart murmur. Two years before the present illness, she had an episode of weakness and diaphoresis. She was hospitalized and a pacemaker was suggested, but the patient refused. She had a forty pack/year history of smoking and a history of hypertension, but was currently not re- ceiving any medications. There was a family history of hy- pertension but no history of diabetes mellitus or coronary artery disease. There were no recent operative procedures.

When the patient arrived at the University of Chicago Emergency Department, her temperature was 37.9”C; pulse, 100 beats per minute; respirations, 22 per minute; and blood pressure, 84/58 mm Hg.

On examination the patient was seen to be thin, awake, alert, and somewhat pale. The skin was moist without rash or petechiae. A temporary transvenous pacemaker and two peripheral intravenous lines were in place. The neck was supple, with a brisk carotid pulse. There was no evidence of thyromegaly. The jugular veins were distended 5 cm above the sternal notch at 30” elevation. Inspiratory rales were heard over the lower half of both lung fields. A prom- inent PM1 was palpable at the sixth intercostal space, 3 cm to the left of the midclavicular line. There was a palpable thrill, and a harsh, grade 4/6 holosystolic murmur was heard best at the apex, with radiation to the axilla and to the left upper sternal border. A soft, short, diastolic murmur (grade 2/6) was heard at the apex and left lateral sternal border. An S, was heard at the apex, but no S, was appreciated. The abdominal examination was noncontributory. The extremi- ties were warm, without clubbing, cyanosis, edema, or in- flammation. The neurologic examination showed no abnor- malities.

MARTIN ET AL B CARDIOGENIC SHOCK AND PULMONARY EDEMA

An electrocardiogram demonstrated a sinus rhythm with a rate of 100 beats per minute, with evidence of left atria1 enlargement and left ventricular hypertrophy. The chest ra- diograph demonstrated pulmonary edema. The hematocrit was 32%, the leukocyte count was 13,300lcu mm, and the differential count was as follows: bands, 1%; polymorpho- nuclear cells, 87%; lymphocytes, 5%; monocytes, 5%, and eosinophils, 2%. Coagulation; levels of serum electrolytes, urea nitrogen, creatinine, glucose, calcium and magnesium; and results of urinalysis were all normal. Serum enzyme levels were as follows: creatine phosphokinase, 14 mIUlm1; lactate dehydrogenase, 63 units; SGOT, 41 Karmen units/ ml; SGPT, 26 Karmen units/ml; and alkaline phosphatase, 64 units/dl. Blood for culture was obtained.

Analysis of arterial blood gases, with the patient breathing room air and blood being taken from the radial artery, showed a pH of 7.45, a Po2 of 53 mm Hg, and a Pco2 of 29 mm Hg.

In the Emergency Department, the norepinephrine infu- sion was discontinued, with no change in pulse or blood pressure. The dopamine infusion was continued, and 40 mg of furosemide was administered intravenously, with a rapid onset of diuresis. Forty-five minutes after the patient’s ar- rival, atria1 fibrillation occurred, with a ventricular rate of 90 beats per minute, followed by atrial flutter (atria1 rate, 300; ventricular rate, 150). At this point the patient’s blood pressure was 78/54 mm Hg. Digoxin, 0.125 mg, was admin- istered intravenously, with a subsequent conversion to a normal sinus rhythm.

The patient was admitted to the coronary care unit, where a Swan-Ganz catheter was inserted. Later that night an intro-aortic balloon pump was used for persistent hypoten- sion.

The diagnosis was confirmed the next day.

DISCUSSION

Dr. Gerard Martin: This case involves the

problem of acute pulmonary edema and hypotension in an elderly woman with syncope, fever, and heart

murmurs. An organized approach to this patient’s problems with emphasis on differential diagnosis and pathophysiology will be presented.

Syncope of cardiac origin can be divided into two major groups: arrhythmia- and nonarrhythmia-related. Arrhythmia-related causes include supraventricular tachycardias (SVT), ventricular arrhythmias, second and third degree heart block, and sick sinus syndrome.

Aortic stenosis, hypertrophic cardiomyopathy’ (previously and less accurately known as idiopathic hypertrophic subaortic stenosis),* and atria1 myxoma are structural abnormalities that may also lead to syn- cope through a temporary decrease in cardiac output. The history of transient episodes of weakness accom- panied by palpitations is suggestive of an arrhythmia. This is further supported by the episodes of SVT ac- companied by restlessness and obtundation. At one point there was sinus arrest of unspecified duration. This combination of supraventricular tachycardia and

FIGURE 1. Initial radiograph demonstrating pulmonary edema.

sinus arrest is characteristic of the sick sinus syn- drome .

The term sick sinus syndrome was first used by Lown3 to describe patients whose hearts failed to achieve a stable sinus rhythm following cardioversion for supraventricular arrhythmias. Since then this syn- drome has come to denote a variety of arrhythmias indicative of sinus node dysfunction, including the fol- lowing:4

1. Chronic and persistent sinus bradycardia without significant change in sinus rate during stressful situa- tions and exercise.

2. Cessation of sinus activity for short periods of time, with no escape rhythm, or for longer periods, with atria1 or junctional escape rhythms.

3. Long periods of sinus arrest without appearance of any escape rhythm, thus resulting in atrioventric- ular standstill.

4. Inability of the heart to resume sinus rhythm fol- lowing cardioversion for chronic atria1 fibrillation or flutter.

5. Episodes of sinoatrial exit block not related to drug therapy.

6. Episodes of supraventricular tachycardia in ad- dition to, or terminating in, long asystolic pauses (brady-tachy syndrome).

The patient in this case is a member of the brady- tachy subgroup. Moss and Davis5 reviewed the rec- ords of 74 patients with the brady-tachy syndrome and found it to be a disease of the elderly with an average age of 68 years. Coronary artery disease and idiopathic causes together accounted for 85% of associated and possibly etiologic cardiac diseases in this study. How- ever, there is controversy concerning the relationship between coronary artery disease and the sick sinus

233

AMERICAN JOURNAL OF EMERGENCY MEDICINE n Volume 2, Number 3 n May 1984

FIGURE 2. Sinus arrest while patient was at community hospital.

syndrome. Engel et al6 found no angiographic evi- dence of sinus node artery involvement in five of six patients with sick sinus syndrome and coronary artery disease. Fibrosis from any cause has been proposed.‘,8 as a final common pathway in most patients. This seems likely, since a wide variety of conditions have been reported in association with sick sinus syndrome. The symptomatology has been well documented; syn- cope and near-syncope are the most common pre- senting symptoms. Palpitations and increased conges- tive heart failure occur less frequently.5*9

In this case, it is unlikely that sick sinus syndrome alone was the cause of the acute pulmonary edema and hypotension, since there was no improvement in the patient’s clinical status once the cardiac rhythm had stabilized. Instead, the patient had a continued downhill course with findings indicative of another or- igin of her acute illness.

The causes of acute cardiogenic pulmonary edema include arrhythmias, high-output states, severe hyper- tension, acute myocardial infarction, ventricular or ar- terial left-to-right shunts, cardiomyopathy, and val- vular disease. Arrhythmias, as mentioned, are not to- tally responsible for this patient’s condition. The common causes of high-output states include thyro- toxicosis, beri-beri, anemia, and systemic arteriove- nous listulas. There is no evidence to suggest that the first two conditions are responsible, and although the patient is somewhat anemic, with a hematocrit of 32%, the anemia is not severe enough to explain her clinical findings. Systemic arteriovenous Iistulas often occur secondary to trauma or surgery. Increased pulse pres- sure, a key tinding,iO is absent in this patient. Severe hypertension cannot be the cause of the pulmonary edema in this hypotensive patient without evidence of severe, long-standing hypertensive heart disease.

Acute myocardial infarction or ischemia with re- sulting left ventricular dysfunction is unlikely as a cause of the problems. The patient gives no history of angina or chest pain prior to this episode, although “silent” myocardial infarctions have been well docu- mented, particularly in diabetic patients. The electro- cardiogram shows only left atria1 enlargement with left ventricular hypertrophy and no evidence of ischemia or infarction. Initial cardiac enzyme levels are re- ported as normal; subsequent levels almost four hours later are still within normal limits. Since the creatine phosphokinase level begins to rise within four to six 234

hours after an infarct,‘* some increase would be ex- pected.

Acute ventricular septum rupture presents with the abrupt onset of pulmonary edema and hypotension.‘* It usually occurs, however, during the first week after an acute transmural myocardial infarction, an event for which there is no evidence in this patient.

Cardiomyopathies are considered in three major groups based on abnormalities of structure and func- tion: dilated congestive, restrictive/obliterative, and hypertrophic.’ The patient with congestive cardiomy- opathy typically presents with increasingly severe symptoms of left ventricular failure. Although these patients may at times during their course present with pulmonary edema, it is uncommonly the first manifes- tation of disease. Cardiomegaly on chest radiograph is a characteristic finding, absent in this case.

Amyloidosis is the most common cause of restric- tive cardiomyopathy in this part of the world. Amyloid deposits in the heart extensive enough to cause such cardiac dysfunction are virtually never isolated to the heart.’ This patient has no evidence of systemic amy- loidosis; thus, restrictive cardiomyopathy is effec- tively eliminated.

Hypertrophic cardiomyopathy can mimic a large number of cardiovascular disorders and is more difti- cult to exclude. However, several features make it less likely in this case. The main symptoms of hypertrophic cardiomyopathy (HC) are chest pain and dyspnea; syncope and palpitations are noted less frequently. Also, patients with HC most commonly present with symptoms at a young age. In their review of 85 pa- tients with HC, Swan et d3 found the average age of onset of symptoms to be 24 years.

Congestive heart failure occurs in a minority of pa- tients with HC and is frequently related to an exten- sive myocardial infarct or the onset of atria1 fibrilla- tion: two events for which there is no evidence in this patient. Although compatible with HC, some of the characteristic electrocardiographic findings are ab- sent; these include left anterior hemiblock, Q waves in the inferior and left precordial leads, and a short PR interval. The midsystolic murmur present early in the case is consistent with HC, but its progression to a holosystolic murmur helps rule out that condition.

Therefore, acute valvular disease must be the cause of this patient’s hypotension and pulmonary edema. Patients with adult aortic valvular stenosis typically

MARTIN ET AL n CARDIOGENIC SHOCK AND PULMONARY EDEMA

have the onset of symptoms when the valve area has become critically reduced from the normal 4 cm* to about 0.7 cm* or less, with a systolic gradient ex- ceeding 50 mm Hg or more if the cardiac output is normal.14 The patient in this case is noted to have a “brisk” carotid upstroke, which virtually eliminates aortic stenosis as a possibility.

In contrast to aortic stenosis, the natural history of mitral stenosis is marked by a gradual deterioration over several years after the onset of symptoms. The symptomatic decline of these patients commonly be- gins with the onset of atria1 fibrillation. In some pa- tients, this event can precipitate pulmonary edema with or without hypotension. The patient in this case arrives in sinus rhythm, and atria1 fibrillation develops only later; mitral stenosis is thus eliminated as a cause of for her sudden decline.

Acute mitral regurgitation (AMR) is a well-recog- nized clinical entity with a characteristic picture sim- ilar to that in our patient. The abrupt onset of severe congestive heart failure or sudden worsening of pre- existing symptoms is typical. Acute mitral regurgita- tion is often associated with the new appearance of, or an increase in the intensity of, a previously noted pansystolic murmur. The persistence of sinus rhythm and radiographic evidence of a nearly normal-size heart with severe pulmonary vascular congestion are characteristic. I5

Acute mitral regurgitation may be classified ac- cording to the part of the mitral apparatus involved and the pathogenesis of the involvement. Almost all cases of acute severe mitral regurgitation are a con- sequence of rupture of either the papillary muscles or the chordae tendineae. Disorders affecting the mitral leaflets are commonly associated with chronic mitral insufficiency, but rarely with the acute severe regur- gitation evident in this case.t5

The mitral valve consists of two leaflets anchored by chordae tendineae to two papillary muscle groups arising from the left ventricular myocardium. Approx- imately two thirds of the closure area of this valve is contributed by the more mobile anterior, or aortic, leaflet. The smaller, less mobile posterior leaflet is re- sponsible for closing approximately one third of the mitral orifice. The chordae tendineae, whose numbers vary, are tough fibrous structures of fixed length that attach the mitral valve leaflets to the papillary mus- cles. These muscles are located anterolaterally and posteromedially and are firmly anchored to the left ventricular wall by numerous muscular bands. The chordae tendineae and associated papillary muscles are parallel to the left ventricular wall and insert into the mitral valve leaflets at nearly right angles, thus providing maximal mechanical advantage. Mitral val- vular competency depends on the anatomic, spatial, and temporal integrity of the entire mitral valvular ap- paratus.

Rupture of a papillary muscle most commonly OC-

curs in the setting of a recent myocardial infarction. The posteromedial muscle is more frequently involved because of its less abundant collateral supply.‘* Rup- ture occurs within the first few days after an acute infarct, after necrosis has developed but before the muscle has become fibrotic. Transection of an entire muscle almost always occurs in the setting of an in- ferior or posterior infarct.‘*.t6 This is incompatible with survival, since each muscle has chordae to ad- jacent halves of both leaflets, and complete papillary muscle rupture leads to massive mitral regurgitation through approximately one half of the valvular orifice. In immediate survivors, only one or a few of the sev- eral heads of a papillary muscle are ruptured. Acute mitral regurgitation due to papillary muscle dysfunc- tion from ischemia or infarction without rupture has been described, with identical clinical pictures.17 In this patient, there is no evidence to suggest infarction or ischemia; papillary muscle rupture or infarction is therefore unlikely.

Patients with hypertrophic cardiomyopathy fre- quently have some degree of mitral regurgitation be- cause of the papillary muscle dysfunction that occurs with the distortion of normal ventricular contraction in this disease.‘s Abnormal bending caused by the bulging ventricular septum results in excessive tension on the chordae tendineae, preventing complete closure of the mitral value orifice. Acute severe mitral regur- gitation occurs infrequently with hypertrophic cardio- myopathy, making it a less likely possibility, as pre- viously noted.

Rupture of the chordae tendineae was first de- scribed by Couvisart in the nineteenth century. Sev- eral published studies have appeared over the past two decades, leading to a clearer understanding of this clinical entity. 19-*j Bacterial endocarditis is considered by some22*26 to be the single most common cause of rupture chordae tendineae, while others believe that spontaneous rupture is more common.27 Osmundson et al** reported a series of 20 patients with ruptured chordae tendineae in whom there was a clinical history of bacterial endocarditis with positive blood cultures or pathologic evidence of healed endocarditis in ten patients. Three other patients had diagnostic findings, and three had evidence suggestive of infective endo- carditis at autopsy. Rheumatic endocarditis results in shortened, thickened, fused chordae tendineae, which are more susceptible to bacterial infection. Pre-ex- isting rheumatic heart disease has been cited as a cause of ruptured chordae tendineae in both the ab- sence or presence of active or healed bacterial endo- carditis.19*24,28 The patient in this case has had a prior episode of rheumatic fever, probably with some re- sultant mild mitral valvular disease, as indicated by the left atria1 enlargement and left ventricular hyper- trophy on electrocardiogram. The absence of atria1 fi-

235

AMERICAN JOURNAL OF EMERGENCY MEDICINE n Volume 2, Number 3 n May 1984

brillation until late in her course and the lack of symp- tomatology rule out a severe, long-standing mitral val- vular pathologic condition. The presence of fever, mild leukocytosis, and anemia in this patient are compatible with bacterial endocarditis.

The physical findings associated with ruptured chordae tendineae have been well described.*9,20 Ex- amination of the jugular venous system reveals in- creased pressure with abnormally tall “a” waves. There is a prominent left ventricular impulse and a hyperactive precordium. An apical systolic thrill is fre- quently palpated, as in this case. There may be a sys- tolic thrill at the base of the heart as well.

The character of the heart sounds are not noted in this case but are important. The first heart sound (St) is usually normal, but there is an increase in intensity in the pulmonic component of the second heart sound (P2). Physiologic splitting of the second heart sound is present. Third heart sounds (S,) are typically present, as in this case. Cohen et a129 found an atria1 gallop sound (S,) in nine of 11 patients with ruptured chordae tendineae and believed that it was a very important diagnostic sign. The absence of an S, gallop in this case indicates that other pathologic conditions may be involved.

An apical systolic murmur is always present but may have variable characteristics. The murmur is gen- erally described as grade IV/VI, although softer mur- murs may occur. Holosystolic murmurs are commonly noted, but the murmur may be interpreted as starting after S, and ending before S,, even though it may be phonocardiographically holosystolic. The murmur characteristically is a plateau with a late systolic de- crease in intensity. It may, however, appear as a cres- cendo-decrescendo, and when associated with a basal thrill, it may simulate aortic stenosis. The murmur fre- quently radiates to either the base of the heart and cervical vessels or to the left axilla and posterior left hemithorax .

Diastolic murmurs in cases of severe mitral regur- gitation have been described and are thought to result from a relative obstruction to flow of the large regur- gitant volume across the finite mitral valvular orifice. Since most studies of patients with ruptured chordae tendineae do not report diastolic murmurs, other pathologic conditions must be considered in this case.

Acute pulmonary edema is typically present on the chest radiograph, as in this case. Sanders et d9 be- lieve that the most useful sign in the diagnosis of rup- tured chordae tendineae is the radiographic demon- stration of a small left atrium in the presence of gross mitral regurgitation.

The electrocardiogram of the patient with ruptured chordae tendineae provides no diagnostic signs. The presence of left atria1 enlargement and left ventricular

236

hypertrophy are not specific and suggest some pre- existing mild mitral valvular disease and hypertension.

The diagnosis of ruptured chordae tendineae can be suspected clinically but is best confirmed with cardiac catheterization. Pressure measurements of the right side of the heart with a Swan-Ganz catheter will show the striking V wave, which may equal left venntricular systolic pressure. The cardiac output and index are uniformly low. Left ventricular angiography reveals mitral regurgitation.

Two findings in this patient are especially notable: the absence of an S, gallop and the presence of a di- astolic murmur. The new appearance of a diastolic murmur not initially heard suggests an ongoing de- structive process. It may be secondary to severe mitral regurgitation, as mentioned, but may also be due to aortic insufficiency. Acute mitral insufficiency sec- ondary to aortic valvular endocarditis has been re- ported by Edwards.30

The tendency for secondary mitral valvular involve- ment to occur is predicated on the close anatomic re- lationships between the aortic and mitral valves. The anterior mitral leaflet lies immediately subjacent to the aortic valve and may become infected by either of two mechanisms. There may be direct extension of infec- tion from the aortic valve onto the mitral leaflet or impingement of regurgitant blood through the aortic valve onto either the ventricular surface of the mitral valve or the chordae tendineae. In either case, the destructive process may have a greater effect on the mitral valve than on the aortic valve, and the patient may present with signs and symptoms primarily suggestive of mitral regurgitation.

In the presence of both aortic and mitral regurgita- tion, an S, gallop would not be expected, since there is no left ventricular presystolic tilling from the left atrium. A short, soft diastolic murmur is common in acute aortic insufficiency (AI), in contrast to chronic AI. Tachycardia is an extremely important sign in acute AI, and its absence calls the diagnosis into ques- tion. In contrast to chronic severe AI, the pulse pres- sure widens little in acute AI.

The chest radiograph in acute AI provides important negative information. The lack of left ventricular di- latation in this patient argues against long-standing AI. Again, the electrocardiographic findings of left atria1 enlargement and left ventricular hypertrophy do not aid in the diagnosis.

The patient in this case thus appears to have acute mitral regurgitation, apparently secondary to ruptured chordae tendineae from acute valvular endocarditis. There may well be aortic valvular involvement as well.

Such patients are difficult to treat. In this case, pul- monary edema and hypotension should be initally treated with diuretics to decrease the preload and do-

MARTIN ET AL W CARDIOGENIC SHOCK AND PULMONARY EDEMA

pamine to increase cardiac contractility. Sodium nitro- prusside, a direct vasodilator, has proved beneficial in the treatment of severe mitral regurgitation.32933 The systemic vascular resistance is increased in these pa- tients and augments the regurgitation. Reduction of aortic impedance to left ventricular ejection by nitro- prusside decreases the regurgitant flow and increases the forward cardiac output. Norepinephrine, a strong vasoconstrictor that therefore increases the afterload, is contraindicated because it serves only to increase the regurgitant fraction. There was no change in blood pressure after discontinuation of the norepinephrine infusion-further evidence of its ineffectiveness in this case.

An intra-aortic balloon pump (IABP) has proven useful in the treatment of intractible hypotension and pulmonary edema secondary to acute mitral regurgi- tation.34p35 Although the cited studies included patients with papillary muscle rupture secondary to acute MI, the basis of the beneficial effect of the IABP is similar to that in patients with rupture of the chordae tendi- neae. The obvious difference between the groups is the associated myocardial damage in patients with papillary muscle rupture.

In systole, the balloon deflates just prior to aortic valve opening and abruptly reduces aortic pressure, thereby allowing the left ventricle to eject against a greatly reduced arterial impedance. This reduces the regurgitant flow across the mitral valve. By inflating in diastole, the balloon displaces a volume of blood equal to its own volume, thereby raising aortic dia- stolic pressure and increasing the regurgitant flow across an incompetent aortic valve. Thus, the use of an IABP in the present of aortic insufficiency is con- traindicated .

Urgent cardiac catheterization with left ventricular angiography is indicated in this case to confirm the diagnosis and to assess the severity of valvular and left ventricular dysfunction. Once the diagnosis of acute mitral regurgitation secondary to ruptured chordae tendineae is made, the therapeutic options are prosthetic valve replacement or repair of the ruptured chordae. Although favorable long-term results after valvuloplasty have been reported, these studies have involved patients with spontaneous chordae tendineae rupture, involving primarily the posterior cusp.36737 Most authorities agree that mitral valve replacement is currently the treatment of choice for ruptured chordae tendineae secondary to bacterial endocarditis, particularly if it involves the anterior cusp.

Correct timing is the essence of surgical manage- ment of endocarditis. If the operation can be safely delayed, antibiotic therapy should eradicate or at least greatly reduce the population of organisms on the valve, thus decreasing the chance of infection of the

prosthetic valve. If surgery is delayed too long, the patient may die suddenly or the hemodynamic status may deteriorate so much that operation is no longer feasible. The hemodynamic status of the patient in this case makes her a candidate for urgent mitral valve replacement after the diagnosis is confirmed.

It must be mentioned that left atria1 myxomas are notoriously difficult to diagnose clinically and must also be considered in this patient. In 1951, Prichard3* commented on the belief of many that “the diagnosis of cardiac tumors is either impossible or a matter of chance.” Since widespread use of noninvasive cardiac imaging with echocardiography and radionuclide scan- ning, diagnosis has improved but remains difftcult if not impossible on the basis of clinical findings alone. In a recent review from the Mayo Clinic,39 only five of 40 atria1 myxomas were diagnosed on the basis of history, physical examination, chest radiograph, or electrocardiogram. In three of the five, a calcified intra-atria1 mass was seen on chest radiograph, while in the remaining two patients, the diagnosis was made by histologic examination of a specimen from an acutely ischemic limb. Myxomas should be considered in the differential diagnosis of any patient with sus- pected mitral valvular disease who is in sinus rhythm with congestive heart failure or constitutional symp- toms. The Mayo Clinic study found fever present in 30%, anemia in 40%, congestive heart failure in 70%, and syncope in 23% of patients with myxomas. Other authors have reported similar findings.40-42 The vast majority of clinical diagnoses included mitral valvular disease, acute rheumatic carditis, and bacterial endo- carditis .

Although atria1 myxomas have been regarded as classic simulators of mitral stenosis, recent reviews have reported findings of mitral stenosis in only 20% to 40% of patients. Apical systolic murmurs were present in 40% to 50%. Wise43 reported a patient with severe mitral regurgitation secondary to ruptured chordae tendineae from a calcified atrial myxoma vis- ible only on fluoroscopy, not routine chest radiograph.

In view of the findings in this case and the difficulty in diagnosing atria1 myxomas clinically, this tumor must be suspected. Echocardiography has proven to be an effective noninvasive diagnostic aid, particularly in patients with less severe symptoms not warranting catheterization. The patient’s hemodynamic status in this case is an indication for catheterization and an- giography emergently. Direct left atria1 catheterization is best avoided in this situation because of the risk of dislodging tumor tissue. Instead, injection of contrast material into the pulmonary artery and delayed filming to show the left atrium is the best diagnostic proce- dure .

Dr. Nowak: Dr. Babbs, given your expertise in

237

AMERICAN JOURNAL OF EMERGENCY MEDICINE W Volume 2, Number 3 n May 1984

FIGURE 3. Simultaneous left ventricular and radial arterial pressure tracings in a patient with obstructive hypertrophic cardiomyopathy show the Brockenbrough response to a ventricular premature beat (VPB). The gradient across the left ventricular outflow tract is about 80 mm Hg. Following the VPB (indicated by arrows on the ECG and the LV pressure tracing), there is a compensatory pause. In the beat following the compensatory pause, the arterial pressure falls despite an increase in the left ventricular systolic pressure, and the radial pulse pressure narrows. (Reproduced from DeSanctis RW. Cardiomyopathies. In: Rubenstein E (ed). SCIENTIFIC AMERICAN Medicine. New York: Scientific American, Inc. 0 1984 SCIENTIFIC AMERICAN Mrdicine. All rights reserved.)

CPR, if this woman with presumably acute valvular disease had experienced cardiac arrest, what specifi- cally would you do during CPR to optimize blood flow?

Dr. Charles F. Babbs (Purdue University, West La- fayette, Indiana): It’s interesting that in a case of valvular insufficiency, if one believes in the thoracic pump mechanism of CPR, it may not matter whether the mitral valve is competent. However, in valvular stenosis there may be impairment of flow. Further, this is one diagnosis that may not be completely ruled out in this case. I agree that sick sinus syndrome does not explain the pulmonary edema with normal sinus rhythm. I also agree that there is no evidence for acute myocaridal infarction or ischemic heart disease. Idio- pathic hypertrophic subaortic stenosis (IHSS) is an interesting possibility that cannot be totally ruled out. There is a clinical bedside test for IHSS that entails listening to the murmur during leg elevation. Most murmurs due to valvular stenosis will become louder with this maneuver because there is increased venous return to the heart and greater flow through the ste- notic region. However, the murmur of IHSS will be- come softer because the stenosis caused by the hy- pertrophic muscle is decreased when the left ventricle dilates. This would have been an interesting test to perform on this patient.

Dr. Dennis C. Whitehead (Marquette General Hos- 238

pital, Marquette, Michigan): It’s interesting that the diastolic murmur was not recorded until after the pa- tient had been receiving morepinephrine, which, as Dr. Martin has noted, is contraindicated in a case of suspected aortic insufficiency. If the patient had suf- fered only minor damage to the aortic leaflets during her childhood episode of rheumatic fever, a soft murmur of aortic insufficiency could have been easily missed. Thus, norepinephrine would be the perfect way to accentuate that murmur-in exactly the way you wouldn’t want to, since it would exacerbate the insufficiency.

I’d like to make one other point. Here’s a patient with poor color who has pulmonary edema, and someone has determined arterial blood gases with the patient breathing room air. I would not have withheld oxygen therapy when she was acutely ill in order to obtain a baseline set of arterial blood gases.

Clinical Diagnoses

Brady-tachy syndrome, rheumatic mitral valve dis- ease.

Dr. Martin’s Diagnoses

Acute valvular endocarditis, acute chordae tendi- neae rupture, acute mitral regurgitation, possible acute aortic insufficiency.

MARTIN ET AL n CARDIOGENIC SHOCK AND PULMONARY EDEMA

CLINICAL COURSE

The patient was admitted to the coronary care unit and a Swan-Ganz catheter was inserted. The pulmonary artery pressure was 55730 mm Hg (n = 40), and the capillary wedge pressure was 25 mm Hg. (No comment was made regarding the V wave.) An echocardiogram demonstrated a normal septum and a calcified mitral ring. Blood cultures were neg- ative for pathogenic organisms.

Cardiac catheterization revealed a cardiac output of 6.0 Y min, with a normal cardiac index. Right atrial, right ventric- ular, and pulmonary capillary wedge pressures all showed moderate elevation. Careful pullback across the left ventric- ular outflow tract demonstrated a definite gradient between the left ventricular apex (225/30 mm Hg) and the subaortic valvular region (85/30 mm Hg); a simultaneous radial artery pressure was 85/55 mm Hg. After premature ventricular con- tractions, the gradient increased, a classic finding in IHSS (Fig. 3).

A left ventricular angiogram and coronary arteriogram re- vealed three plus mitral insufficiency, severe stenosis at the right coronary artery, and moderate stenosis of the left an- terior descending artery. There was poor left ventricular function.

The patient was later taken to the operating room, where her mitral valve was resected and a Bjork-Shiley prostetic valve was inserted. The ventricular septum was not touched. The left anterior descending artery was bypassed, but the surgeon was unable to bypass the right coronary artery. A permanent pacemaker was inserted.

Postoperatively, the systolic blood pressure promptly rose to 120 mm Hg. No vasopressors were required. The patient made an uneventful recovery and was discharged one month later.

Final Diagnoses

Hypertrophic cardiomyopathy with subaortic stenosis, coronary atherosclerosis, and mitral regurgitation.

REFERENCES

1. Goodwin JF, Roberts WC, Wenger NK. Cardiomyopathy. In

Hurst JW, Logue RB, Rackley CE, et al (eds). The Heart,

Arteries, and Veins. New York: McGraw-Hill Book Com-

pany, 1982.

2. Braunwald E, Lambrew CT, Morrow AG, et al. Idiopathic

hypertrophic subaortic stenosis. Circulation 1964; 29/30

(Suppl IV):1 -213. 3. Lown 8. Electrical reversion of cardiac arrhythmias. Br

Heart J 1967;29:469-489.

4. Gupta PK. Sick sinus syndrome: Clinical features, diagnosis and treatment. Comprh Ther 1979;5:21-27.

5. Moss AJ, Davis RJ. Brady-tachy syndrome. Prog Cardiovasc Dis 1974;16:439-454.

6. Engel TR, Meister SG, Feitosa GS, et al. Appraisal of sinus node artery disease. Circulation 1975;52:286-291.

7. Shaw DB: The etiology of sinoatrial disorder (sick sinus syn- drome). Am Heart J 1976;92:539-546.

8. Davies MJ, Pomerance A. Quantitative study of ageing changes in human sinoatrial node and internodal tracts. Br Heart J 1972;34:150-157.

9. Rubenstein JJ, Schulman CL, Yurchak PM, et al. Clinical spectrum of sick sinus syndrome. Circulation 1972;46:

5-13.

10. Fowler ND. High cardiac output states. In Hurst JW, Logue

RB, Rackley CE, et al (eds). The Heart, Arteries, and Veins.

New York: McGraw-Hill Book Company, 1982.

11. Wagner GS, Roe CR, Limbird LE, et al. The importance of

identification of the myocardial-specific isoenzyme of creatine phosphokinase (MB form) in the diagnosis of

acute myocardial infarction. Circulation 1973;47:

263-269.

12. Vlodaver Z, Edwards JE. Rupture of ventricular septum or

papillary muscle complicating myocardial infarction. Cir-

culation 1977;55:815-822.

13. Swan DA, Bell 8, Oakley CM, et al. Analysis of symptomatic

course and prognosis and treatment of hypertrophic ob- structive cardiomyopathy. Br Heart J 1971;33:671-685.

14. Simpson PC, Bristow JD. Recognition and management of

emergencies in valvular heart disease. Med Clin North Am

1979;63:155-172.

15. Sanders CA, Armstrong PW, Willerson JT, et al. Etiology and

differential diagnosis of acute mitral regurgitation. Prog

Cardiovasc Dis 1971;14:129-152.

16. Walsh RA, O’Rourke RA. Diagnosis and management of

acute left-sided valvular regurgitation. Curr Prob Cardiol

1979;4:4-34.

17. Brody W, Criley JM. Intermittent severe mitral regurgitation.

N Engl J Med 1970;283:673-676.

18. Dinsmore RE, Sanders CA, Harthorne JW. Mitral regurgita-

tion in idiopathic hypertrophic subaortic stenosis. N Engl J Med 1966;275:1225-1228.

19. Sanders CA, Austen WG, Harthorne JW, et al. Diagnosis and

surgical treatment of mitral regurgitation secondary to

ruptured chordae tendineae. N Engl J Med 1967;276:

943-948.

20. Luther RR, Meyers SW. Acute mitral insufficiency secondary

to ruptured chordae tendineae. Arch Intern Med

1974;134:568-578.

21. Childress RH, Maroon JD, Genovese PD. Mitral insufficiency

secondary to ruptured chordae tendineae. Ann Intern

Med 1966;65:232-234.

22. Osmundson PJ, Callahan JA, Edwards JE. Ruptured mitral

chordae tendineae. Circulation 1961;23:42-54.

23. Roberts WC, Braunwald E, Morrow AG. Acute severe mitral regurgitation secondary to ruptured chordae tendineae:

Clinical, hemodynamic, and pathologic considerations.

Circulation 1966;33:58-70.

24. Sanders CA, Scannell JG, Harthorne JW, et al. Severe mitral

regurgitation secondary to ruptured chordae tendineae.

Circulation 1965;31:506-516.

25. Selzer A, Kelly JJ, Vannitamby M, et al. The syndrome of

mitral insufficiency due to isolated ruptured of the

chordae tendineae. Am J Med 1967;43:822-836.

26. Hepper NG, Burchall HB, Edwards JE. Cardiac clinic CXLVI:

Mitral insufficiency in healed unrecognized bacterial en- docarditis. Proc Staff Meet Mayo Clin 1956;31:659-664.

27. Rackley CE, Edwards JE, Karp RB, et al. Mitral valve disease. In Hurst JW, Logue RB, Rackley CE, et al (eds). The Heart, Arteries, and Veins. New York: McGraw-Hill Book Com-

pany, 1982. 28. Manhas DR, Hessel EA, Winterscheid LC, et al. Repair of

mitral incompetence secondary to ruptured chordae ten- dineae. Circulation 1971;43:688-697.

29. Cohen LS, Mason DT, Braunwald E. Significance of an atrial gallop sound in mitral regurgitation: A clue to the diag- nosis of ruptured chordae tendineae. Circulation

1967;35:112-118. 30. Edwards JE. Mitral insufficiency secondary to aortic valvular

bacterial endocarditis. Circulation 1972;46:623-626.

31. Morganroth J, Perloff JK, Zeldis SM, et al. Acute severe aortic regurgitation: Pathophysiology, clinical recogni-

239

AMERICAN JOURNAL OF EMERGENCY MEDICINE n Volume 2, Number 3 n May 1984

tion, and management. Ann Intern Med 1977;87:223- 232.

37.

32. Chatterjee K, Parmley WW, Swan HJC, et al. Beneficial ef-

fects of vasodilator agents in severe mitral regurgitation

due to dysfunction of subvalvular apparatus. Circulation

1973;48:684-690. 38.

33. Goodman DJ, Rossen RM, Holloway EL, et al. Effect of ni-

troprusside on left ventricular dynamics in mitral regur- gitation. Circulation 1974;50:1025-1032.

34. McEnany MT, Kay HR, Buckley MJ, et al. Clinical experience

with intraaortic balloon pump support in 728 patients. Cir-

culation 1978;58 (Suppl 1):124-132.

35. Gold HK, Leinbach RC, Sander CA, et al. lntraaortic balloon

pumping for ventricular septal defect or mitral regurgi-

tation complicating acute myocardial infarction. Circula- tion 1973;47:1191-1196.

36. Selzer A, Kelly JJ, Kerth WJ, et al. Immediate and long range

results of valvuloplasty for mitral regurgitation due to rup-

tured chordae tendineae. Circulation 1972;45, 46 (Suppl

l):l52-56.

39.

40.

41.

42.

43.

Ross BA, Fox C, Brown AH, et al. Late results of valvulo-

plasty for mitral regurgitation due to rupture of chordae

of the posterior (mural) cusp. J Thorac Cardiovasc Surg 1976;71:533-536.

Prichard RW. Tumors of the heart: Review of the subject

and report of one hundred fifty cases. Arch Pathol

1951;51:98-105.

Sutton MG, Mercier LA, Giuliani ER, et al. Atrial myxomas:

A review of clinical experience in forty patients. Mayo Clin

Proc 1980;55:371-376.

Buckley BH, Hutchins GM. Atrial myxomas: A fifty year re-

view. Am Heart J 1979;97:639-643.

Zitnik RS, Giuliani ER. Clinical recognition of atrial myxoma.

Am Heart J 1970;80:889-700.

Greenwood WF: Profile of atrial myxoma. Am J Cardiol

1968;21:367-375.

Wise JR. Mitral Regurgitation due to rupture of chordae

tendineae by calcified atrial myxoma. Br Med J 1974; 2:95-96.

240