SM 138a - Heart Failure Physiology Flashcards
This graph represents grade _____ diastolic dysfunction.
How do you know?
What other indications might be present?
This graph represents grade I (mild) diastolic dysfunction.
-
Small E wave (E/A ration <1)
- Impaired ventricular relaxation = slow early filling
- E’ velocity is decreased
- In addition, LA size and pressure will be normal to increased
Describe the symptoms of left-sided heart failure
- Dyspnea
- Orthopnea
- Paroxysmal nocturnal dyspnea
- Fatigue
- Diaphoresis
- Tachycardia
- S3 (Systolic)
- S4 (Diastolic)
A patient with symptoms and underlying structural heart disease has stage ___ heart failure
A patient with symptoms and underlying structural heart disease has stage C heart failure
Eccentric hypertrophy is associated with ______ heart failure,
while concentric hypertrophy is associated with ________ heart failure
Eccentric hypertrophy is associated with systolic heart failure,
while concentric hypertrophy is associated with diastolic heart failure
HF_EF is associated with systolic dysfunction,
while HF_EF is associated with diastolic dysfunction
HF_r_EF is associated with systolic dysfunction,
while HF_p_EF is associated with diastolic dysfunction
Describe key features of eccentric hypertrophy
Cause:
Organization of sarcomeres:
Effect:
-
Cause
- Volume overload
-
Organization of sarcomeres
- New sarcomeres are created in series with existing sarcomeres
- Myocyte elongation
-
Effect
- Dilation of the ventricle
- Increased wall stress
- Systolic dysfunction
- Mitral regurgitation
Describe Class I heart failure (NYHA)
No symptoms
How would you expect wall thickness to change in systolic heart failure?
Diastolic heart failure?
Systolic: Decreased wall thickness
Diastolic: Increased wall thickness
A patient with no symptoms has class ___ heart failure (NYHA)
A patient with no symptoms has class I heart failure (NYHA)
How would you expect end diastolic volume to change in systolic heart failure?
Diastolic heart failure?
Systolic: EDV increases
Diastolic: Normal EDV (but most likely with increased pressure)
Initially, neurohormonal activation helps patients with heart failure compensate for low CO by increasing BP.
In general, how can these compensatory mechanisms cause heart failure to worsen?
- Vasoconstriction (initially compensatory)
- Causes increased afterload
- Worse cardiac output
- Causes increased afterload
- Angiotensin II, Alsosterone
(initially compensatory to retain fluid)- Leads to cardiac fibrosis
- Adverse remodeling
- Eccentric hypertrophy -> Dilation of LV
- Concentric hypertropy -> Increased LV wall thickness
Which extra heart sound is likely present if there is diastolic dysfunction?
S4
A patient who gets symptoms with major exertion has class ____ heart failure (NYHA)
A patient who gets symptoms with major exertion has class II heart failure (NYHA)
Patients with ejection fraction less than ____ most likley have HFrEF
Patients with ejection fraction less than 40-45% most likley have HFrEF
Describe key features of eccentric hypertrophy
Cause:
Organization of sarcomeres:
Effect:
-
Cause
- Volume overload
-
Organization of sarcomeres
- New sarcomeres are created in series with existing sarcomeres
- Myocyte elongation
-
Effect
- Dilation of the ventricle
- Increased wall stress
- Systolic dysfunction
- Mitral regurgitation
A patient who has symptoms at rest has class ___ heart failure (NYHA)
A patient who has symptoms at rest has class IV heart failure (NYHA)
A patient experiencing heart failure has an initial compensatory neurohormonal response, initiated by the activation of ___________
A patient experiencing heart failure has an initial compensatory neurohormonal response, initiated by the activation of Baroreceptors
A patient with no symptoms but increased risk factors has stage ___ heart failure
A patient with no symptoms but increased risk factors has stage A heart failure
Describe Class IV heart failure (NYHA)
Symptoms with rest
What is the main difference in patients with HFpEF and HFrEF?
Anatomical structure of the myocardium and myocytes
Describe Stage B heart failure
No symptoms
Has structural heart disease and/or functional heart abnormalities strongly sassociated with heart failure
(ex: Previous MI, Asymptomatic LV systolic dysfunction, LV hypertrophy)
This graph represents grade _____ diastolic dysfunction.
How do you know?
What other indications might be present?
This graph represents grade II (moderate) diastolic dysfunction.
-
E velocity is normal: E/A >1
- Looks about the same as the normal graph, but this is because increased atrial pressure is present in addition to impaired ventricular relaxation
- Increased LA size and pressure
- Decreased E’ velocity
A patient with advanced structural heart disease and markded symptoms of heart failure despite maximum medical therapy has stage ___ heart failure
A patient with advanced structural heart disease and markded symptoms of heart failure despite maximum medical therapy has stage D heart failure
Describe the symptoms of right-sided heart failure
- Peripheral edema
- Right upper quadrant discomfort (Due to hepatic enlargement)
- Hepatomegaly
- Jugular venous distension
A normal heart meets most of its energy needs by metabolizing __________, but a heart in failure prefers __________ instead
A normal heart meets most of its energy needs by metabolizing fatty acids ,
but a heart in failure prefers glucose instead
Heart failure occurs when the heart….
a) ____________________
b) _________________
or both
Heart failure occurs when the heart….
a) Cannot produce enough cardiac output to meet metabolic demands
b) Can only produce sufficient cardiac output at the expense of high filling pressures
or both a) and b)
Describe key features of concentric hypertrophy
Cause:
Organization of sarcomeres:
Effect:
-
Cause
- Pressure overload
-
Organization of sarcomeres
- New sarcomeres are created in parallel with existing sarcomeres
- Myocyte thickening
-
Effect
- Decreased chamber compliance
- Increased wall thickness
- __But cavity size remains the same
- Increased ventricular filling pressure
- Diastolic dysfunction
Which extra heart sound is likely present if there is systolic dysfunction?
S3
Ejection fraction is a function of _________, ___________, and ____________.
Ejection fraction is a function of preload, afterload** and **contractility.
A patient with no symptoms but sructural heart disease and or functional heart abnormalities that are associated with heart failure has stage ___ heart failure
A patient with no symptoms but sructural heart disease and or functional heart abnormalities that are associated with heart failure has stage B heart failure
_________ hypertrophy causes dilation of the left ventricle,
while ________ hypertropy causes increased LV wall thickness
Eccentric hypertrophy causes dilation of the left ventricle,
while concentric hypertropy causes increased LV wall thickness
In the setting of heart failure, what causes increased ventricular filling pressures?
Impaired relaxation (decreased compliance), obstruction to filling, fluid overload, or a combintion of all of the above
A patient who gets symptoms with minimal exertion has class ____ heart failure (NYHA)
A patient who gets symptoms with minimal exertion has class III heart failure (NYHA)
What are the 3 common types of electrical problems seen in heart failure?
-
Atrial fibrilation/Atrial flutter
- Due to atrial fibrosis
-
Ventricular tachycardia
- Due to focal reentry around a scar or fibrosis
- Seen in systolic HF (HFrEF), especially if the patient has a previous MI
-
Interventricular and intraventricular electical dyssynchrony
- Due to ventricle enlargement
- Leads to mechanical dyssynchrony
A patient with normal ejection fraction but _______ may have reduced cardiac output
A patient with normal ejection fraction but a stiff heart may have reduced cardiac output
(Note: low cardiac output is more often caused by reduced ejection fraction)
What are the three phases of diastole?
Early: Ventricular relaxation with passive filing fo the ventricle due to pressure gradient
Mid: Diastasis, when ventricular P = atrial P
Late: Atrial contraction
Describe Stage D heart failure
Advanced structural heart disease
Marked symptoms of heart failure despite maximum medical therapy
Describe Class II heart failure (NYHA)
Symptoms with major exertion
In the setting of heart failure, what causes the heart to generate insufficient cardiac output?
Contractility is impaired, resulting in chronic volume overload.
- Impaired contractility may be due to…
- Dilated cardiomyopathy
- Coronary artery disease (MI, ischemia)
- Mitral or aortic regurgitation
Describe Stage A heart failure
No symptoms, but has risk factors (like hypertension)
What signal in the body triggers the release of natiruetic peptides?
In general, what is the effect?
Hemodynamic stress on the myocardium
- ANP: Atrial
- BNP: Ventricles
- CNP: Branches of the Aorta
Natiruetic peptices counteract the effects of the sympathetic nervous system, RAAS, and AVP (aka ADH)
Doppler echocardiography is used to determine diastolic dysfunction presence and severity.
What do the E and A waves represent in these graphs?
E wave: Early transluminal flow velocity (during ventricular relaxation with passive filling due to pressure gradient)
A wave: Late transluminal flow velocity (due to atrial contraction)
Not shown: E’: Early myocardial relaxation velocity
Describe Class III heart failure (NYHA)
Symptoms with minimal exertion
What is the general cause of electrical problems in heart failure?
The normal pattern of conduction is disrupted due to ventricular and atrial remodeling
A patient presents with dyspnea, and lab tests reveal elevated BNP levels.
What does this tell you about the cause of the patient’s dyspnea?
Elevated BNP increases the likelihood that the dyspnea has a cardiac cause.
In addition to heart failure, BNP is also elevated in Pulmonary Embolism (Due to RV stress) and Acute Coronary Syndrome (Due to LV stres)
This graph represents grade _____ diastolic dysfunction.
How do you know?
What other indications might be present?
This graph represents grade III (severe) diastolic dysfunction.
- Increased E velocity (E/A >1)
- Despite impaired relaxation, due to very high atrial pressures
- E wave is narrow
- Early diastole is very short due to decreased ventricular compliance
- Very slow E’
- Increased atrial size and pressure
What is the most common cause of right heart failure?
Left heart failure
Describe Stage C heart failure
Symptomatic heart failure wiht underlying structural heart disease
What imaging technique would you use to quantify diastolic dysfunction?
Doppler echocardiography
