Lecture 29: Heart Failure

Question 1

When a failing ventricle is unable to pump all of the blood returned to it, the veins behind the failing ventricle

Answer 1

become congested with blood

Question 2

Two most common causes of heart failure

Answer 2

1. Damage to the heart muscle as a result of impaired circulation to the cardiac muscle
2. Prolonged pumping against a chronically increased afterload, as with a stenoic semilunar valve or a sustained elevation in blood pressure

Question 3

Three reasons that are the cause of heart failure

Answer 3

1. Impaired contractility
2. Increased afterload
3. Impaired ventricular filling

Question 4

Systolic dysfunction

Answer 4

Heart failure caused by an abnormality of ventricular emptying, due to impaired contractility or excessive afterload

Question 5

Diastolic dysfunction

Answer 5

Heart failure caused by abnormalities of diastolic relaxation or ventricular filling

Question 6

Impaired myocardial contractility (Systolic dysfunction) may result from

Answer 6

. Destruction of myocytse

2. Abnormal myocyte function
3. Fibrosis

Question 7

Dilated cardiomyopathy (systolic dysfunction) may result from

Answer 7

Cardiac enlargement due to ventricular dilation with only minor hypertrophy

Question 8

Pressure overload impairs ventricular ejection by

Answer 8

significantly increasing resistance to flow

Question 9

Consequences of systolic dysfunction

Answer 9

• During diastole, the persistently elevated left ventricular pressure is transmitted to the left atrium and to the pulmonary veins and capillaries
• An elevated pulmonary hydrostatic pressure leads to transudation of fluid in the pulmonary interstitium and symptoms of pulmonary congestion

Question 10

Approx. ____ of patients with heart failure demonstrate abnormalities of diastolic function; either

Answer 10

• Impaired diastolic relaxation (active, energy-dependent process)
• Increased stiffness of the ventricular walls
• Both

Question 11

In diastolic dysfunction, the walls of the left ventricle becomes chronically stiff, thus

Answer 11

In diastole, filling of the ventricle occurs at higher than normal pressure

Question 12

Consequences of diastolic dysfunction

Answer 12

Patients often present with signs of vascular congestion because the elevated diastolic pressure is transmitted retrograde to the systemic and pulmonary veins