INSTRUCTORS ONLY

Cardiovascular Laboratory 3
HEART FAILURE AND ITS CONSEQUENCES

Areas of Concentration

• Pathogenesis of congestive heart failure and the pathologic changes
  of organs affected by congestive heart failure

In particular:

1. Understand the pathogenesis of acute edema and chronic passive congestion, and be able to describe the clinical manifestations of these conditions.

2. Understand how the liver is affected by cardiac failure.

3. Understand how failing cardiac output affects extracardiac organs besides the liver. Be able to describe the pathologic features of ischemic colitis.

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

Slide 30 [WebScope] [ImageScope] and Slide 32 [WebScope] [ImageScope]

A 55-year-old man complaining of chest pain was admitted to the hospital. His clinical evaluation quickly led to the diagnosis of myocardial infarction, primarily involving the left ventricle. The patient appeared restless, anxious, and markedly dyspneic. He appeared pale and his extremities were cool to the touch. Bradycardia was present and the patient was hypotensive. Shortly after admission, the patient developed pulmonary edema.

Blood chemistries revealed a markedly elevated cardiac-specific troponin T level as well as an elevated creatinine phosphokinase (MB isoenzyme). The liver enzymes were also elevated. An electrocardiogram manifested abnormal Q waves in the inferior leads. The patient developed lethal arrhythmias and died 5 days after admission. Slides 30 and 32 were prepared from his lungs and liver, respectively.

1. What pathologic features are manifested by the lung?

2. Why do some of the alveoli contain blood? Why do some of the alveoli also contain neutrophils?

3. Why did the patient develop pulmonary edema and elevated liver enzymes?

4. What signs and symptoms are associated with the pulmonary abnormalities?

5. Plates of viable hepatocytes surround zones of blood largely devoid of liver cells. What has happened to the missing hepatocytes? (Hint: these hepatocytes were located about the central veins.)

6. What diseases or other insults could lead to this type of liver damage?

7. Give several examples of other disorders that may be associated with chest pain.

Slide 31 [WebScope] [ImageScope] and Slide 88 [WebScope] [ImageScope]

A 47-year-old woman had long complained of shortness of breath. She had first noticed becoming dyspneic several years ago when she would walk to work, a distance of 2 miles. Recently, she had become dyspneic when lying down. She felt fatigued and no longer had any energy. On several occasions over the last month, she had become exceedingly short of breath and had expectorated blood-tinged fluid. Her most recent visit to her physician had been prompted by the onset of bloody diarrhea. These slides unfortunately did not come from her lungs or colon, but they do illustrate the pathology involved.

1. What pathologic features are evident in the lung? Identify the pigment and explain its presence. Is the pigment found within the cells or is it extracellular?

2. What kind of injury has affected the bowel mucosa? In what sort of clinical settings might this injury be encountered?

3. In most of the histologic sections, neutrophils have accumulated beneath the injured mucosa. What has attracted the neutrophils and what complication(s) might develop?

4. How does congestive heart failure account for the pathologic features found in the lung and colon?

5. What other symptoms and signs might have been caused by the congestive heart failure?

6. What pathologic lesions or conditions could have led to this patient’s heart failure?

Slide 37 [WebScope] [ImageScope]

A 60-year-old man sought medical attention because of dizziness, palpitations, and impotence. The patient suffered from diabetes mellitus and had smoked cigarettes for the last 35 years. Among several abnormal physical findings were the downward and lateral displacement of the left ventricular apex impulse and an elevation in the patient’s diastolic blood pressure. Slide 37 was prepared from the heart of a patient with the same disorder.

1. Based on the pathologic features of slide 37, what cardiac condition was present?

2. What would have been the gross appearance of the heart?

3. What histologic features distinguish the myocardial fibers?

4. What conditions can lead to left ventricular myocardial hypertrophy? What conditions can lead to right ventricular hypertrophy?

5. What other pathologic features might have been observed in this person’s heart?

Slide 9 [WebScope] [ImageScope]

A 69-year-old man enters the E.R. complaining of fever and shaking chills. The intern quickly notices the patient’s bandaged, malodorous leg and summons the medical student to attend to the leg. Slide 9 was prepared from the skin and subcutis of a similar patient’s leg.

1. What will the medical student find as she unwraps the bandages? Why did the patient have fever and chills?

2. Describe the pathologic features illustrated by Slide 9. What is happening in the zone between the living and dead tissues? Bacteria often cause a secondary infection. Where did the bacteria come from?

3. What vascular abnormalities might lead to gangrene in an extremity? Other than gangrene, what other effects might peripheral vascular abnormalities have on the leg?

4. How might ischemia or gangrene develop in abdominal organs?

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'