A 32-year-old nurse who had rheumatic fever as a child noticed a persistent tach

Question

A 32-year-old nurse who had rheumatic fever as a child noticed a persistent tachycardia and light-headedness. Upon examination, chest x-rays showed an enlarged left atrium and left ventricle. ECG analysis showed atrial fibrillation. There was also mild pulmonary congestion. Cardiac evaluation resulted in the following information: Cardiac output (CO) 3.4 L/min Blood pressure (BP) 100/58 mm Hg Left atrial pressure (LAP) 16 mm Hg Right ventricular pressure (RVP) 44/8 mm Hg Heart sounds revealed valvular regurgitation.

1. Based on the information provided, which A-V valve is incompetent, allowing the regurgitation?

2. Which heart sound would be pronounced and lengthened?

3. Describe, using surface anatomy, the location at which this valvular disorder could best be heard.

4. If the other A-V valve were incompetent instead of this one, would the CO, BP, LAP, and RVP be different? If so, how?

5. What are the causes of the tachycardia, light-headedness, and mild pulmonary congestion?

6 Calculate the pulse pressure (PP) and mean arterial pressure (MABP) for this individual. a. PP = b. MABP =

Explanation / Answer

Answers:

1) Regurgitation is the name for leaking heart valves.A leaking mitral valve allows blood to flow in two directions during the contraction.
So the mitral valve is incompetent here.
Physiological consequences in this case are:
-Atrial fibrillation
-Mild pulmonary congestion
-Mitral valve stenosis
-Low cardiac output
Right ventricle pumps harder= increased pressure
Right Atrium:Pressure: normal, Volume: normal

Left Atrium:Pressure: high,Volume: high

Right Ventricle:Pressure: high,Volume: high

Left Ventricle:Pressure: low,Volume: low

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2)The first heart sound is prolonged and lengthened.

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3) This mitral valvular disorder sound could best be heard at the left midclavicular line at the fifth intercostal space.
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4) Aortic stenosis is a narrowing of the aortic valve opening. Aortic stenosis restricts the blood flow from the left ventricle to the aorta and may also affect the pressure in the left atrium.
Aortic valve stenosis is characterized by the left ventricular pressure being much greater than aortic pressure during left ventricular (LV) ejection (see figure at right). In this example, LV peak systolic pressure during ejection is 200 mmHg (normally ~120 mmHg) and the aortic pressure is slightly reduced to from 120 to 110 mmHg.
Pulmonic valve stenosis is analogous to aortic valve stenosis except that the changes in pressure are on the right side of the heart. A pressure gradient occurs across the pulmonic valve during right ventricular ejection. Compensatory increases in right ventricular end-diastolic pressure as well as right atrial pressure and volume occur. If it is tricuspid stenosis:

Specific findings
Mean pressure gradient    5 mmHg
Inflow time-velocity integral    >60 cm

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