INSTRUCTORS ONLY

Cardiovascular Laboratory 4
INFLAMMATORY DISORDERS OF THE HEART

Areas of Concentration

• Rheumatic heart disease

• Endocarditis, infective and non-infective

• Myocarditis

• Pericarditis

In particular:

1. Recognize the pathologic features of acute rheumatic carditis and understand how the acute lesions lead to chronic rheumatic heart disease.

2. Recognize the pathologic features of infective endocarditis, and distinguish them from non-infective valve lesions. Explain how the pathology leads to clinical features.

3. Recognize the pathologic features of myocarditis and explain their distinction from those of ischemic injury.

4. Recognize the pathologic features of acute and chronic pericarditis.

PC USERS: Drive mapping is no long needed. Use the ImageScope links.

Slide 50 [WebScope] [ImageScope]

A 19-year-old student presented to the campus health service complaining of transient knee and hip joint pains of one week’s duration. He had become febrile 2 days prior to seeking medical attention. Physical examination revealed swollen knee joints and small painless subcutaneous swellings located in the scalp and over the elbows. One week later, a heart murmur thought to be due to mitral regurgitation was detected. Congestive heart failure soon developed and the patient succumbed despite aggressive medical treatment. Slide 50 is prepared from the autopsy material.

1. What epicardial abnormality is present and how might this have been clinically manifested in the living patient?

2. Valvular endocardial fibrin deposits (excrescences) are present in the slide. What would these deposits have looked like grossly? If the patient had survived, what would be the clinical significance of these endocardial fibrin deposits?

3. What myocardial abnormalities are present? How would they have resolved if the patient had survived?

4. How could the lesions illustrated in Slide 50 lead to chronic heart disease? What other organs and tissues might well have been abnormal in this patient?

Slide 51 [WebScope] [ImageScope]

Assume the patient presented in the previous case had survived, graduated from college, and had done well for two decades. He then developed malaise and a low-grade fever. When joint pains ensued, the patient sought medical attention, fearful that his rheumatic fever had recurred. Physical examination revealed a heart murmur (the patient had been told of a persistent murmur over the last several years), splenomegaly, and subungual splinter hemorrhages. Laboratory evaluation revealed a normocytic normochromic anemia and a leukocytosis with neutrophilic left shift. Proteinuria was detected. Blood cultures were obtained. Slide 51 came from another patient with the same disease, but in whom a timely diagnosis had not been made.

1. Please describe the pathologic features illustrated by your slide.

2. What is the pathogenesis of the valvular lesions? What are several likely etiologic agents?

3. What local and systemic complications might have arisen secondary to the valvular lesions?

4. What other clinical signs and symptoms might have been present?

5. What cardiac and non-cardiac conditions predispose to this disorder?

6. What other disorders may produce excrescences or vegetations on cardiac valves? How would these lesions differ histologically from those found in the present case?

Slide 58 [WebScope] [ImageScope]

A 20-year-old college student suddenly collapsed while walking to class. He could not be resuscitated and a medical examiner subsequently performed an autopsy. The student had been previously well though his roommate mentioned that the deceased student had had a flu-like illness several weeks earlier. A histologic section prepared from his heart is presented to you.

1. Characterize the myocardial cellular infiltrate.

2. What is your diagnosis? Mention several causes for this disease.

3. How do the pathologic features differ from those of ischemic myocardial disease?

4. How might this disease present clinically?

5. In addition to sudden cardiac death, what are other sequelae of this disorder?

6. Cardiac arrest and sudden cardiac death often have underlying structural causes, such as myocardial infarction. What are some other structural causes of sudden cardiac death?

Slide 21 [WebScope] [ImageScope] and Slide 194 [WebScope] [ImageScope]

At low power, notice the inflamed epicardium. The exudate which covers the epicardial surface contains fibrin and bacterial colonies. Underneath the exudate layer are large numbers of neutrophils. Beneath the neutrophils are delicate blood vessels (mainly capillaries) and cells with spindle-shaped nuclei (primarily fibroblasts). These vessels and the fibroblasts are components of granulation tissue. Notice that some of the granulation tissue has become scar or fibrous tissue that partially involves the underlying myocardium.

1. Notice the inflammatory cells within the granulation tissue. Are these the same types of inflammatory cells that are found within the exudate layer on the surface of the epicardium?

2. For how long has the epicardium been inflamed? How would the bacteria have reached the epicardium?

3. Based on the pathologic features, construct a clinical presentation for this patient, including both signs and symptoms.

4. What might be a late sequel to the intense inflammation noted in Slide 21?

5. Slide 194 is an example of an epicarditis/pericarditis secondary to a connective tissue disorder. How do the pathologic features manifested in this slide differ from those features present in Slide 21?

CASE PRESENTATION (no slides)

A 33-year-old woman was evaluated for suspected mitral stenosis. Although she manifested signs and symptoms characteristic of mitral stenosis, she had also complained of weight loss and two episodes of syncope.

Pertinent physical findings were limited to pallor and a holosystolic murmur that was loudest at the apex. An electrocardiogram was normal. Subsequent evaluation led to an echocardiograph that demonstrated a pedunculated tumor located in the left atrium. A follow-up angiography study confirmed the presence of the tumor.

The patient underwent a left atriotomy and a sessile, gelatinous friable mass was removed from the atrium. The mass was attached by a stalk to the atrium in the region of the fossa ovalis. Histologically, the mass was composed of cells with round, elongated, or polyhedral shapes embedded in a myxoid stroma rich in glycosaminoglycans. The cells were arranged in cords and rings as well as in irregular clusters. Hemosiderophages, lymphocytes, and plasma cells were variably present. A diagnosis of atrial myxoma was made. After examining the images shown to you by your instructor, please answer the following questions.

1. This patient manifested signs and symptoms characteristic of mitral stenosis. What signs and symptoms might have been evident?

2. Are weight loss, syncope, and pallor usually associated with mitral stenosis?

3. Myxomas are notorious for their varied clinical manifestations. What signs and symptoms can you enumerate?

4. What are atrial myxomas?

5. Mention at least two other examples of benign cardiac neoplasms.

The answers to the path lab questions will be posted approximately 48-72 hours after the lab sessions. These are abbreviated answers, not a full discussion of the topics. You can find them in the M2 CTools site resources. In the folder for each sequence the will be a folder called 'Path Lab Resources'