#9 - Heart Failure (Dr. Bbrown) Flashcards
Define heart failure
A pathophysiologic state when the heart cannot deliver the cardiac output that matches the the metabolic demands of the tissues OR can do so only by resorting to elevated diastolic filling pressures.
By the Fick equation, what are the two determinants of Blood Pressure (and their determinates)?
Fick’s law is derived from Ohm’s law. E=IR becomes BP = CO * R
CO is determined by stroke volume (SV) and heart rate, HR.
Therefore BP = SVHRR
Heart failure symptoms are due to 2 major processes, which are?
1) decreased forward flow (cardiac output) - leads to exertional fatigue in exercising muscles, and hypotension.
2) Elevated filling pressures
Elevated filling pressures on the left side of the heart lead to ?
dyspnea (infiltrate in lung)
Dependent edema =
edema in the extremities
Elevated filling pressures on the right side of the heart lead to ?
edema in the extremities, sometimes ascites (fluid in the peritoneal cavity)
Describe the 4 New York Heart Association (NYHA) classes? Who do they apply to?
NYHA classes refer to patients with heart failure or angina. Class 1: Ordinary physical activity = no symptoms class 2 - ordinary physical activity = symptoms class 3- less than ordinary physical activity causes symptoms class 4 = symptoms at rest, increased symptoms with activity.
Can New York Heart Association (NYHA) classes change?
Yes. it is a level of function, and function can change. Heart failure stages can’t change, though.
Describe the common physical exam findings (other than vital signs) for left sided heart failure
- pulmonary crackles at the base and posteriorly (due to pulmonary congestion)
- sometimes an apical S3 gallop
Describe vital signs findings in heart failure - 3
- narrowed pulse pressure
- tachycardia at rest
- elevated respiratory rate
Describe the common physical exam findings (other than vital signs) for right sided heart failure
- edema in the extremities (dependent edema)
- sometimes ascites.
- NOTE: untreated edema in the legs or abdomen should always be accompanied by elevated jugular venous distention or positive hepatojugular reflux sign (pressing on right upper quadrant, positive exam causes elevation of jugular venous pressure). If it is not accompanied by this, consider other causes.
You have a patient with edema in the legs, you think she has heart failure. What physical exam test could you do to make the diagnosis more likely ?
Jugular venous distension (should be elevated or positive hepatojugular reflux sign. These should always be present with edema due to heart failure.
-NOTE: untreated edema in the legs or abdomen should always be accompanied by elevated jugular venous distention or positive hepatojugular reflux sign (pressing on right upper quadrant, positive exam causes elevation of jugular venous pressure). If it is not accompanied by this, consider other causes.
chest x ray findings for heart failure
cardiomegaly may or may not be present.
There may be normal heart size and lots of pulmonary congestion
T/F: in heart failure, cardiomegaly will always be present.
False.
Describe the function of pro-BNP / BNP testing. What are they used for, how do they affect the diagnosis?
Useful for heart failure.
—low levels - 500 - consistent with heart failure as the cause of dyspnea (but not specific!! eg pulmonary embolism can cause elevated BNP)
Serial BNP testing can be useful in tracking treatment of heart failure.
T/F: echocardiography is very useful for heart failure diagnosis.
True. It can show diastolic/systolic dysfunction without valve abnormality. It should be part of the workup for all cases of heart failure!
What are the 3 basic cardiac causes of heart failure
- Arrhythmia
- Myocardial disease
- Mechanical
What are the ways arrhythmia can cause heart failure?
there’s 1 he covered.
3rd degree AV block - electrical stimulations don’t reach the left ventricle. This can cause HF all on its own.
What are the 2 myocardial causes of heart failure?
- systolic dysfunction
- diastolic dysfunction.
What are the similarities and differences b/t systolic dysfunction and diastolic dysfunction as causes of heart failure. Define in terms of : -elevated diastolic filling pressure -cardiomegaly -ejection fraction -wall thickness -wall compliance -heart sounds present
Similar: They both have elevated diastolic filling pressure, which causes symptoms.
Systolic:
- cardiomegaly
- reduced ejection fraction
- normal wall thickness
- wall compliance normal
- S3 gallop = hallmark
Diastolic
- x ray normal heart size
- ejection fraction normal
- increased wall thickness
- wall compliance reduced (stiff walls)
- S4 (atrial gallop) = hallmark
An individual has heart failure due to weak contractility in his left ventricle. His heart failure is (diastolic / systolic)
systolic.
Describe the process of systolic heart failure.
Starts with an individual whose strength of contraction is subpar (SYSTOLIC DYSFUNCTION). They cannot raise CO by increasing contractility, so they increase filling pressure. The ventricular chambers are usually dilated.
diastolic dysfunction heart failure is also known as?
Heart failure with preserved ejection fraction
What are the 3 main mechanical causes of heart failure
- increased afterload (valve stenosis, arterial hypertension)
- volume overload
- pericardial disease
What are the three categories of precipitating causes of heart failure (ie, things that make it worse)
- high output states
- new direct insults to the heart
- indirect stresses to the heart (non-high output)
4 common high output states, which increase demand on the heart, making heart failure worse.
- fever/infection
- anemia
- pregnancy
- hyperthyroidism.
3 direct cardiac causes that can precipitate (make worse) pre-existing heart failure.
valvular (eg, endocarditis)
- myocardial damage
- arrhythmia (eg, afib)
3 indirect stresses to the heart (non high output states) that can make heart failure worse.
- excess exercising and salt
- hypertension
- pulmonary embolism (changes the pulmonary pressure)
What labs should be done for newly diagnosed heart failure?
- Chest x ray
- EKG
- CBC
- kidney / liver function tests
- TSH (for hyperthyroid)
- echocardiogram
What are the 4 components of drug therapy for NON-hypotensive pulmonary edema (due to left heart failure)
- oxygen
- diuretic (lots)
- morphine (venous dilation, increasing filling pressures, leading to better output
- vasodilator - eg sublingual nitroglycerin
Which 2 drugs should almost never be used for NON-hypotensive pulmonary edema (due to left heart failure)
aminophylline
digoxin
Define stage A of heart failure
Stage A: at high risk for heart failure but without structural heart disease or symptoms of heart failure (eg, hypertensive patient, hyperlipidemia. Treat underlying risks)
Define stage B of heart failure
Structural heart disease but without signs or symptoms of heart failure.
(eg, left ventricular hypertrophy, but no symptoms due to it yet.)
Define stage C of heart failure
Structural heart disease with prior or current symptoms of heart failure.
Define stage D of heart failure.
Refractory heart failure, requiring specialized interventions (heart transplant, etc)
Can stages of heart failure change for a particular patient?
Nope. Once you’re at a stage, you can only get worse. Never go to better stage.
Recommended therapy for stage A of heart failure.
Treat hypertension and thyroid disease, and diabetes
- exercise and weigh reduction
- reduce alcohol and nicotine use.
Name 3 classes of drugs that should be avoided in heart failure patients.
- anti-arrhythmic drugs (with the exception of amiodarone and dofetilide.
- bradycardic calcium channel blockers - verapamil and diltiazem=bad
- NSAIDs (except aspirin)
Recommended for stage C heart failure.
- all the therapies for stage A
- dietary salf restriction
- diuretics AS NEEDED for fluid reduction
For stage C with reduced LV ejection fraction or history of MI:
- ACE-inhibitors (or ARBs)
- Beta blockers.
What two drug classes should be used for stage C heart failure patients with reduced LV ejection fraction or past history of MI.??
- ACE-inhibitors (or ARBs)
- Beta blockers.
Short acting ACE inhibitor
captopril
How should ACE - inhibitors be used in heart failure patients? (how often can you titrate up, etc)
Start low, go slow.
titrate up after 4 or more half-lives (usually 2 days).
What should be done if potassium is high with ACEinhibitor treatment?
add a small dose of thiazide diuretic.
3 main side effects which need to be monitored with ACE inhibitor therapy. & 2 lesser concerns.
- orthostatic hypotension (BP drops when you stand)
- hyperkalemia (high K+)
- increased BUN/ Creatinine (due to effects on the arterioles in the glomerulus
angioedema and cough are also a concern. - better with ARBs
How do ACE Inhibitors impact heart failure symptoms and longevity?
They improve both!
How do vasodilators impact heart failure symptoms and longevity?
improve survival, but only in patients with heart failure and decreased systolic function, when combined with ACE inhibitors, ARBS or hydralazine!!
You have a African American patient with heart failure due to decreased systolic function. What combination of vasodilator drugs is recommended for him?
Isosorbide Dinitrate and hydralazine
-this combination of vasodilators work especially well in african americans. Also an alternative to vasodilator treatment with ACE inhibitors.
How do vasodilators impact heart failure symptoms and longevity?
They improve both.
T/F: beta blockers are only useful for patients with systolic dysfunction, they shouldn’t be used with diastolic dysfunction.
False. They are useful for both.
Which 2 beta blockers are probably the best for heart failure?
- carvedilol
- metoprolol
When should aldosterone antagonists (spironolactone) be used for heart failure?
in severe cases where LV ejection fraction is reduced.. With extreme caution - can cause hyperkalemia (high K+) - must monitor closely and frequently.
When should implantable cardioverter - defribillators be used for heart failure?
In patients with LV ejection fraction less than 30-35%, even with other treatment.
When should biventricular electronic pacing therapy be used for heart failure?
Patients with
-LV ejection fraction
When should digoxin be used?
NOT a first line drug. It should be used if treatment with diuretics, vasodilators, and beta blockers, have not eliminated symptoms
how does digoxin impact symptoms and survival?
helps symptoms
does not help survival.
Treatment for stage D heart failure.
Heart transplant/ hospice
How do beta blockers impact symptoms and survival in heart failure patients?
they improve both!
Which two drugs are the cornerstones of therapy for heart failure?
- ACE inhibitors
- Beta blockers
How do diuretics impact symptoms and survival in heart failure?
Improve symptoms but not survival.
List the structural characteristics of heart failure due to systolic dysfunction, in terms of
- diastolic filling pressure
- cardiomegaly
- ejection fraction
- wall thickness
- wall compliance
- heart sounds present
Systolic:
- cardiomegaly
- reduced ejection fraction
- normal wall thickness
- wall compliance normal
- S3 gallop = hallmark
List the structural characteristics of heart failure due to diastolic dysfunction, in terms of
- diastolic filling pressure
- cardiomegaly
- ejection fraction
- wall thickness
- wall compliance
- heart sounds present
Diastolic
- x ray normal heart size
- ejection fraction normal
- increased wall thickness
- wall compliance reduced (stiff walls)
- S4 (atrial gallop) = hallmark
You see a patient with severe left systolic dysfunction, with a LV ejection fraction of 20%. Which drug wouldn't help symptoms or survival? -ACEI -ARB Implantable cardioverter-defibrillartor -isosorbide dinitrate -digoxin
digoxin
You see a patient: BP 180/110 LV ejection fraction 70% Hypertrophy of the LV Dyspnea on exertion.
What is the diagnosis?
Heart failure secondary to systemic hypertension, due to diastolic dysfunction. Treat with hypertensive drugs.
(diastolic = preserved ejection fraction)