pathophys of CHF

Question 1

forward heart failure

Answer 1

The inability of the heart to pump blood forward at a sufficient rate to meet the metabolic demands of the body

Question 2

backward heart failure

Answer 2

the ability to pump blood forward at a sufficient rate only if the cardiac filling pressures are abnormally high

Question 3

what is heart failure?

Answer 3

Syndrome, not a Disease!

At some time during the course of the illness, CHF is a principal manifestation of nearly every form of cardiac disease

can be forward, backward or both
can be acute or chronic

Question 4

what are the 4 major determinants of cardiac performance

Answer 4

heart rate
preload
afterload
contractility

Question 5

Role of Ca2+ in Cardiomyocyte Contractility

Answer 5

Calcium induced calcium release. the amount of calcium released from the SR determines the ionotrophy/contractility

Question 6

how do you calculate ejection fraction

Answer 6

SV/EDV x 100

(SV = EDV-ESV) normal is greater than 50%

Question 7

Frank-starling law

Answer 7

the stroke volume of the heart increases in response to an increase in the volume of blood filling the heart (the end diastolic volume) when all other factors remain constant

Question 8

disorders of impaired contractility

Answer 8

Myocardial Infarction/Ischemic Cardiomyopathy
Chronic Mitral Regurgitation
Dilated Cardiomyopathy

Question 9

disorders of increased afterload

Answer 9

Severe Aortic Stenosis

Uncontrolled Hypertension

Question 10

Disorders with Impaired Ventricular Relaxation/Decreased Filling

Answer 10

Restrictive Cardiomyopathy
Acquired or Familial Hypertrophic Cardiomyopathy
Constrictive Pericarditis

Question 11

Systolic Heart Failure’s affect on ejection fraction

Answer 11

reduces the ejection fraction

decreased contractility = decreased stroke volume

Question 12

diastolic heart failures affect on ejection fraction

Answer 12

remains relatively the same - due to decreased compliance, EDV is decreased

Question 13

differences of the RV compared to the LV

Answer 13

RV is much more “compliant” than LV
Wall Thickness
RV Developed Pressure

Question 14

cardiac causes of right sided heart failure

Answer 14

LV Failure of any cause
Mitral Stenosis/Regurgitation
Acute MI with RV Infarction
Pulmonic Stenosis

Question 15

pulmonary causes of right sided heart failure

Answer 15

Pulmonary Parenchymal Diseases
•COPD
• Interstitial Lung Diseases (silicosis, pulmonary fibrosis, etc.)
• ARDS

Pulmonary Vascular Diseases
• Pulmonary Embolism
• Primary Pulmonary Hypertension

Question 16

compensation mechanisms to maintain CO in CHF

Answer 16

1. Frank-Starling Mechanism - seconds (Length-Dependent Activation)
2. Autonomic Nervous System - second (Baroreceptor Response)
3. Renal Compensation – seconds to hours (Renin-Angiotensin-Aldosterone System)
4. ` Ventricular Remodeling – weeks to years

all are acutely beneficial but can lead to worsening ventricular preformance

Question 17

Post-MI Ventricular Remodeling definitions

Answer 17

LV enlargement and distortion of regional and global ventricular geometry occurring after myocardial infarction

or

Any architectural or structural change that occurs after myocardial infarction in either the infarcted or noninfarcted regions of the heart.”

Question 18

Ventricular Remodeling in other forms of Heart Disease

Answer 18

Pre- and Post-Natal Cardiac Growth ( Cardiac Eutrophy)

Pressure-Overload LVH (Concentric LVH)
• Aortic Stenosis
• Systemic Hypertension

Volume-Overload LVH (Eccentric LVH)
• Mitral Regurgitation
• AV Fistula
• Hyperthyroidism

Question 19

concentric hypertrophy vs. eccentric hypertrophy

Answer 19

Concentric hypertrophy is due to pressure overload (really thick walls), while eccentric hypertrophy is due to volume overload ( really big size)

Question 20

what contributes to systolic and diastolic wall stress

Answer 20

volume overload
pressure overload
post-MI segmental dysfunction
myocardial dysfunction
myocardial hypertrophy

Question 21

what does systolic and diastolic wall stress lead to

Answer 21

myocardial dysfunction

myocardial hypertrophy

Question 22

wall stress equations

Answer 22

(pressure x radius)/ wall thickness

Question 23

risk factors for developing post-MI ventricular remodeling

Answer 23

large infarct
anterior is greater risk than posterior
reduced EF 4 days after MI
vessel is occluded after the MI

Question 24

when does remodeling occur

Answer 24

months to years before symptoms of CHF

Question 25

how can congestive heart failure be prevented

Answer 25

by preventing or slowing the progression of ventricular remodeling

Question 26

what causes remodeling

Answer 26

Remodeling is predominantly a growth-mediated response, and results from an interplay between mechanical factors, and systemic and locally derived neurohormonal factors.

Structural changes in the ventricular myocardium represent the disease process

Question 27

drugs to prevent ventricular remodeling

Answer 27

ACE Inhibitors/ARBs/LCZ696
Beta Blockers
Aldosterone Antagonists

Question 28

drugs to prolong survival with CHF

Answer 28

ACE Inhibitors/ARBs/LCZ696
Hydralazine + Nitrates
Beta Blockers (carvedilol, metoprolol, bucindolol)
Aldosterone antagonists (spironolactone,
eplerenone)

Question 29

symptoms and clinical findings of right sided HF

Answer 29

peripheral edema
RUQ discomfort
JVD
hepatomegaly

Question 30

symptoms of left-sided HF

Answer 30

dyspnea
orthopnea (cannot lie flat)
paroxysmal nocturnal dyspnea (shortness of breath while sleeping) 
cough
fatigue

Question 31

physical findings of left sided HR

Answer 31

diaphoresis
tachycardia
tachypnea
pulmonary rales
loud P2
*S3 gallop (systolic dysfunction)
*S4 gallop (diastolic dysfunction)