Module 7

Question 1

Cardiac Output

Answer 1

volume of blood pumped out of a ventricle in one minute.

CO= SVxHR

Question 2

Systolic Dysfunction

Answer 2

The heart is unable to eject blood from the ventricle due to impaired myocardial contractility (MI, ischemia, dilated cardiomypathy) or pressure overload (stenosis, hypertension)

Question 3

Dilated cardiomypathy

Answer 3

condition where the left ventricle of the heart is unable to pump blood properly due to it being enlarged and weakened.

Question 4

Diastolic dysfunction

Answer 4

The heart is unable to relax (left ventricular hypertrophy, hypertrophic cardiomyopathy, restrictive cardiomypathy) or fill normally (tamponade, MS) due to stiffness

Question 5

Restrictive cardiomypathy

Answer 5

Walls of the heart are rigid so the heart is unable to stretch and fill normally

Question 6

hypertrophic cardiomypathy

Answer 6

a primary disease of the myocardium where the wall is thickened without obvious cause. The cardiac muscle is functionally impaired. (leading cause of sudden cardiac death in young athletes)

Question 7

Ventricular hypertrophy

Answer 7

thickening of ventricular walls

Question 8

Right heart failure

Answer 8

most commonly associated with left heart failure. However on its own it is usually the result of lung diseases (parenchymal pulmonary disease or pulmonary vascular disease)
Right ventricle is vulnerable to failure as a result of acute pulmonary embolism

Question 9

Compensatory mechanisms to preserve CO when increased work is put on the heart

Answer 9

Frank-Starling mechanism, neurohormonal alterations, ventricular hypertrophy and remodelling.

Question 10

Frank-Starling mechanism

Answer 10

Cardiac fiber will contract with greater force if stretched prior to contracting producing greater stroke volume to preserve CO

Question 11

Neurohormonal transmitters

Answer 11

mechanisms that maintain cardiac output include: Adrenergic nervous system, renin-angiotensin-aldosterone system and increased production of ADH.

Question 12

Ventricular hypertrophy and remodelling

Answer 12

occurs over a period of time. The heart muscle thickens as a result of the heart pumping against high pressures and dilates due to volume overload.

Question 13

What factors precipitate symptoms of heart failure

Answer 13

1) Increased afterload (increasing resistance to ejecting of blood from Ventricles)
2) Increased preload (increasing volume of blood to be pumped)
3) Impaired atrial emptying
4) Impaired systolic function (reducing myocardial contractility)
5) Increased metabolic demands (for blood by peripheral tissues)

Question 14

Signs of left heart failure

Answer 14

diaphoretic (sweating)
tachypnea (rapid breathing)
tachycardia
pulmonary rales
loud P2, S3 gallop

Question 15

Signs of right heart failure

Answer 15

jugular venous distention
hepatomegaly (enlarged liver)
peripheral edema

Question 16

Left heart failure symptoms

Answer 16

dyspnea(laboured breathing)
orthopnea (shortness of breath while lying flat)
Paroxysmal nocturnal dyspnea(attacks of shortness of breath usually happening at night)
Fatigue

Question 17

Right heart failure symptoms

Answer 17

Peripheral edema

Upper right quadrant discomfort

Question 18

What attributes to the rising prevalence of heart failure?

Answer 18

1. An aging population- heart failure usually happens in people who are over 50 years old.
2. Revascularization and thrombolytic therapy- because of these therapies individuals can now survive an acute event, they are left with some myocardial damage which can attribute to heart failure later.

Question 19

Methods to diagnose heart failure

Answer 19

Chest X-ray
BNP- B type natriuretic peptide- produced when ventricular myocardium is subject to hemodynamic stress
History
Echocardiogram- calculate ejection fraction and visualize systolic and diastolic function

Question 20

what is that goal of chronic heart failure treatment?

Answer 20

identify and correct underlying etiology
eliminate the precipitating cause of symptoms
manage heart failure symptoms
modulate the neurohormonal response
improve long term survival

Question 21

Phamacological treatment of chronic heart failure

Answer 21

ACE inhibitors- effect on remodeling
Beta blockers- enhance relaxation, lower HR, longer diastole filling time
Coumadin- cause anticoagulation
Cardiac inotropes- enhance force of ventricular contraction
Diuretics- promotes elimination of sodium and water(D. venous return)
Digoxin- enhances contractility

Question 22

Pharmacological treatment of diastolic dysfunction

Answer 22

ACE inhibitors
calcium channel blockers
diuretics

Question 23

Lifestyle modification (CHF)

Answer 23

Reduced sodium diet
limited fluid intake
Regular exercise tailored to patients tolerance level

Question 24

Heart transplant and mechanical treatments for CHF include:

Answer 24

Heart transplant
Implantable cardiac defibrillator (ICD)
Cardiac resynchronization
Left Ventricular Assist Device (LVAD)

Question 25

Treatment of acute heart failure

Answer 25

Goal: increase oxygenation and reduce left heart filling pressures
Treatment: Vasodilators (nitroglycerine), upright position, oxygen, morphine, loop diuretics (furosemide, bumetanide, torsemide), inotropic drugs (dopamine, dubutamine), and nitroprusside in patients with severe MR or AR

Question 26

What can cause increased afterload?

Answer 26

arterial hypertension
aortic stenosis
pulmonary valve stenosis

Question 27

What can cause increased preload?

Answer 27

left to right shunt

severe valvular regurgitation

Question 28

impaired atrial emptying can be caused by

Answer 28

mitral stenosis

tricuspid valve stenosis

Question 29

Impaired systolic function can be caused by

Answer 29

myocardial ischemia
myocardial infarction
dilated cardiomypathy

Question 30

What causes increased metabolic demand

Answer 30

pregnancy
hyperthyroidism
tachycardia
anemia