PATH - Heart Pt. 1 (HF, Congenital & Ischemic Heart Dz)

Question 1

What does cardiac hypertrophy mean?

Answer 1

Increase in ventricular thickness

Allows heart to pump harder to overcome higher mean arterial pressures

Question 2

What is cardiac dilation?

Answer 2

Enlarged chamber sizes

Allows greater blood volume load

Question 3

What is cardiomegaly?

Answer 3

Increased cardiac weight

Question 4

What is the myocardium?

Answer 4

Muscle tissue of the heart that is made up of atrial myocytes

Atrial myocytes have storage granules that contain Atrial Natriuretic Peptide (ANP)

Question 5

What is ANP?

Answer 5

Atrial Natriuretic Peptide

Hormone that promotes arterial vasodilation and stimulates renal salt and water elimination (Natriuresis and diuresis) which is beneficial in the setting of HTN and Congestive Heart Failure (CHF)

ANP Lowers Blood Pressure and blood volume

Question 6

What are the 3 types of damage that can occur to cardiac valves?

Answer 6

Collagen
- Mitral Prolapse

Nodular Calcification
- Calcific aortic stenosis

Fibrotic Thickening
- Rheumatic Heart Disease

Question 7

When does blood flow to the myocardium?

Answer 7

During ventricular diastole

- When the aortic valve closes, blood flow into the cardiac vessels from the aorta

Question 8

Why can’t the heart recover its myocardium very well?

Answer 8

Bone marrow derived precursors and stem cells present in the myocardium only replaces 1% of its tissue each year, too slow to recover from any serious pathologies

Question 9

What happens to myocardium and chambers with aging?

Answer 9

• Left ventricle chamber size increases
• Increase amount of epicardial fat
• Mycardium accumulates Lipofuscin
• Myocardium accumulates areas of basophilic degeneration

Question 10

What is lipofuscin?

Answer 10

Lipofuscin is a marker of stress and aging

It is a yellow, grainy pigment that accumulates in the myocardium as the heart ages

Question 11

What changes occur to the cardiac valves with aging?

Answer 11

• Aortic Valve and Mitral Valve undergo annular calcification (can cause electrical issues)
• Fibrous thickening of the valves
• Mitral leaflets buckle towards Lt atrium –> increase in left atrium size
• Lambl excrescences - small filiform processes form on the closure lines of aortic and mitral valves, probably resulting from the organization of small thrombi

Question 12

What vascular changes occur with age?

Answer 12

Coronary atherosclerosis

Dilated ascending aorta with rightward shift

Stiffening of the aorta

Question 13

What does it mean for the heart to have pump failure?

Answer 13

In some conditions the myocardium contracts weakly during systole and there is inadequate cardiac output.

Conversely, myocardium may relax insufficiently during diastole to permit adequate ventricular filling

Question 14

What is flow obstruction?

Answer 14

Lesions can obstruct blood flow through a vessel (atherosclerotic plaque) or prevent valve opening or otherwise cause increased ventricular chamber pressure (e.g., aortic valvular stenosis, systemic hypertension. aortic coarctation).

In the case of a valvular blockage the increased pressure verloads the chamber that pmps against the obstruction

Question 15

What is regurgitant flow?

Answer 15

A portion of the output from each contraction flows backward through an incompetant valve, adding a volume overload tot he affected atria or ventricles (eg left ventriacl in aortic regurgitation; left atrium and left ventricle in mitral regurg

Question 16

What is shunted flow?

Answer 16

Blood can be diverted from one part of the ehart to another (eg from left ventricle to right ventrical) through defects that can be congenital or acquired (eg following myocardial infarction)

Shunted flow can also occur between blood vessels as in patent ductus arteriosus (PDA)

Question 17

Waht are disorders of cardiac conduction

Answer 17

Conduction defects or arrhythmias due to uncoordinated generation r transmission of impulses (eg atrial or ventricular fibrillation) lead to nnonuniform and inefficient myocardial contractions, and may in fact be lethal.

Question 18

What is a rupture of the heart or major vessel?

Answer 18

In such circumstances (eg gunshot to left ventricle or oartic dissection and rupture), there is cataclysmic exsanguination, either into body cavities or externally

Question 19

What is CHF?

Answer 19

Congested Heart Failure

Occurs when the heart is unable to pump blood at a rate to meet peripheral demand, or can only do so with increased filling pressure

May result from:

• loss of myocardial contractile function (systolic dysfunction)
• Loss of ability to fill the ventricles during diastole (diastolic dysfuntion)

CHF quickly leads to cardiac hypertrophy

Question 20

What is cardiac hypertrophy?

Answer 20

Cardiac myocytes become hypertrophic when sustained pressure or volume overload (sysemic HTN or aortic steonisis) or sustained trophic signals (beta-adrenergic stimulation)

Two types:

• Pressure overload hypertrophy
• Volume overload hypertoprhy