A 74-year-old man has experienced substernal chest pain for the past 3 hours. The pain is constant. He is now becoming short of breath. In the emergency department his vital signs include temperature 37.1 C, pulse 108/min, respiratory rate 29/min, and blood pressure 90/70 mm Hg. He is unable to lie supine. Auscultation of the chest reveals bilateral crackles in lower lung fields. He has a summation (S3 and S4) gallop. A chest radiograph shows prominent bilateral perihilar infiltrates.

Example 1:

Example 2:

Example 3:

Questions:

4.1 What is suggested by these findings?

Acute myocardial infarction with pulmonary edema

4.2 What tests would help confirm the diagnosis?

His total CK is 332 U/L with CK-MB fraction of 8%. His troponin I is 10 ng/mL.

Additional history:

He is admitted to the hospital. He receives thrombolytic therapy with tPA. His condition is stable. He receives pharmacologic therapy with an anticoagulant, probably a low moleculart weight heparin analogue. Other possible therapies include an anti-platelet agent or a beta-blocker.

He now has the following hemodynamic pressures:

4.3 What do these findings indicate?

Acute pulmonary edema.

4.4 If his left chamber volume at end of diastole = 0.11 L, chamber volume at end of systole = 0.08 L, and he is an average-sized person with a body surface area of 1.62 m2, calculate his cardiac output, cardiac index, and ejection fraction.

Stroke Volume = ((Chamber Volume at End Diastole) - (Chamber Volume at End Systole)) = 0.03 L

Cardiac Output = (Stroke Volume) X (Heart Rate) = 3.45 L/min

Cardiac Index = (Cardiac Output) / (Body Surface Area) = 2.13 L/min/m2

Ejection Fraction = ((Stroke Volume) / (Chamber Volume at End Diastole)) * 100 = 27%