Congestive Heart Failure Summary
What is paroxysmal nocturnal dyspnea and what causes it?
-Acute severe dyspnea and coughing that occur 1-3 hours into sleep, awaking the patient suddenly -Associated with cardiac asthma, or wheezing due to bronchospasm from interstitial pulmonary edema
What gastrointestinal changes manifest as a result of right ventricle failure (5)?
-Anorexia -Nausea -Early satiety -Abdominal pain (All are probably related to edema of the bowel wall and/or liver congestion) -Liver congestion may cause stretching of the liver capsule and right-upper quadrant pain
What are the causes increased afterload resistance (2)?
-Aortic stenosis -Uncontrolled hypertension
Which vasodilatory molecules are activated by left ventricle failure (3)?
-Atrial and brain natriuretic peptides (ANP and BNP) -Prostaglandins (PGE2 and PGI2) -Nitric oxide (NO)
Which parenchymal pulmonary diseases cause right ventricle failure (3)?
-COPD -Interstitial lung disease -Acute respiratory distress syndrome
What are the main roots of the etiologies of right ventricle failure?
-Cardiac -Parenchymal pulmonary disease -Pulmonary vascular disease
What is left ventricle remodeling and what induces it?
-Changes in size, shape, structure and physiology of the heart after injury to the myocardium -Collective neurohormonal, adrenergic and cytokine systems lead to adaptive changes in the myocardium
Which disorders of rhythm and rate cause systolic heart failure (2)?
-Chronic bradyarrhythmias -Chronic tachyarrhythmias
Which symptoms present in left ventricle failure due to reduced cerebral perfusion (2)?
-Confusion -Disorientation
Which complications of pulmonary heart disease lead to heart failure (2)?
-Cor pulmonale -Pulmonary vascular diseases
What are the etiologies of systolic heart failure (5)?
-Coronary artery disease -Chronic pressure overload -Chronic volume overload -Nonischemic cardiomyopathy -Disorders of rate and rhythm
What is Cheyne-Stokes respiration and what causes it?
-Cyclic hyperventilation and apnea associated with advanced heart failure -Low cardiac output and diminished sensitivity of the respiratory center to arterial pCO2
Review: what should you associate S4 with (2)?
-Diastolic dysfunction -Stiffness of myocardium
Which types of nonischemic cardiomyopathies cause systolic heart failure (6)?
-Familial/genetic disorders -Infiltrative disorders -Toxic/drug induced damage -Metabolic disorders -Viral -Chaga's disease
What are the cardinal symptoms of left ventricle failure (2)?
-Fatigue -Shortness of breath: In the early stages, dyspnea is noted only during exertion, but ultimately may occur even at rest as the disease progresses
Which systems show the effects of right ventricle failure (4)?
-Gastrointestinal -Urinary -Jugular venous pressure -Abdomen and extremities
What abdomen and extremity changes manifest as a result of right ventricle failure (2)?
-Hepatomegaly, or liver enlargement, is an important sign of right ventricle failure; it may be tender to palpation and may pulsate with systole, pressing on the liver may increase JVD -Peripheral edema is a cardinal sign of right ventricle failure; it is usually symmetric and occurs mostly in the ankles and pretibial region, although moves over the sacrum in bedridden patients
Which complications of chronic pressure overload cause systolic heart failure (2)?
-Hypertension -Obstructive valvular disease
Which conditions lead to systolic heart failure (2)?
-Impaired contractility -Very increased afterload resistance
Which conditions lead to diastolic heart failure (2)?
-Impaired ventricular relaxation -Obstructed left ventricle filling
What are the causes of acute decompensation in chronic heart failure (4)?
-Increased metabolic demand -Increased circulating volume (preload) -Increased afterload -Impaired contractility
Which types restrictive cardiomyopathy cause diastolic heart failure?
-Infiltrative disorders: amyloidosis and sarcoidosis -Storage diseases: hemochromatosis
Describe how ventricular remodeling contributes to diastolic dysfunction/failure (2).
-Ischemia and other events can reduce ATP concentration, ultimately slowing myocardial relaxation -Alternatively, hypertrophy and fibrosis can reduce left ventricle compliance, resulting in wall stiffening and elevated left ventricle filling pressures
Summarize the major etiologies of left ventricle failure (4).
-Ischemic heart disease due to coronary artery disease -Hypertension -Aortic and mitral valve diseases -Primary diseases of the myocardium
Summarize the major etiologies of right ventricle failure (3).
-Left ventricle failure -Cor pulmonale: chronic due to COPD or acute due to pulmonary embolism -All causes of right ventricle failure promote pulmonary hypertension
Which cardiac conditions cause right ventricle failure (3)?
-Left ventricle failure (most common) -Right ventricle MI -Pulmonary valve stenosis (uncommon)
What are the causes of impaired ventricular relaxation (4)?
-Left ventricle hypertrophy from hypertension -Hypertrophic cardiomyopathy -Restricted cardiomyopathy -Ischemia
What are the causes of impaired contractility of the heart (4)?
-MI -Ischemia -Chronic volume overload from aortic or mitral regurgitation -Dilated cardiomyopathy
Which conditions that produce a high out-put state cause heart failure
-Metabolic disorders: thyrotoxicosis and nutritional disorders -Excessive blood flow requirements: systemic arteriovenous shunting and chronic anemia
What are the causes of obstructed left ventricle filling (3)?
-Mitral stenosis -Pericardial constriction or tamponade -Tachyarrhythmia
Which complications of coronary artery disease cause systolic heart failure (2)?
-Myocardial infarction -Myocardial ischemia
Describe the steps involved in left ventricle remodeling (5).
-Myocyte hypertrophy -Progressive loss of myocytes through necrosis, apoptosis and autophagic cell death -Altered genetic expression of contractility proteins and ion channels -Alteration in the metabolism of the myocardium with decreased ability to maintain calcium homeostasis -Abnormal reorganization of the extracellular matrix with decreased structural support
In addition to fatigue and dyspnea, what are the other symptoms of left ventricle failure (9)?
-Orthopnea -Paroxysmal nocturnal dyspnea (PND) -Cheyne-Stokes respiration (periodic breathing) -Reduced cerebral perfusion -Pulmonary edema -Pulmonary effusion -Extra cardiac sounds -Cardiomegaly -Cardiac cachexia
What are the etiologies of diastolic heart failure (5)?
-Pathological hypertrophy -Aging -Restrictive cardiomyopathy -Fibrosis -Endomyocardial disorders
Which types of pathological hypertrophy cause diastolic heart failure (2)?
-Primary: hypertrophic cardiomyopathies -Secondary: hypertension
Which pulmonary vascular diseases cause right ventricle failure (2)?
-Pulmonary embolism -Primary pulmonary hypertension
What are the other etiologies of heart failure (2)?
-Pulmonary heart disease -High out-put states
Besides pulmonary congestion, what other factors contribute to the dyspnea of left ventricle failure (4)?
-Reduced pulmonary compliance -Increased airway resistance -Respiratory muscle fatigue -Anemia
Which complications of chronic volume overload cause systolic heart failure (3)?
-Regurgitant valvular disease -Intracardiac (left to right) shunting -Extracardiac shunting
Describe the extra cardiac heart sounds that come with left ventricle failure (2).
-Some patients may have a 3rd heart sound (S3), which usually signifies volume overload. -A 4th heart sound (S4) is usually associated with diastolic dysfunction and stiffness of the myocardium
What results from an index event (2)?
-Structural damage to the myocardium -Disruption of the myocardium's ability to contract normally
Which types of cardiac dysfunction lead to left ventricle failure (2)?
-Systolic failure -Diastolic failure
What are the consequences of right ventricle failure?
-The resulting increase in diastolic pressure transmits to the right atrium and then to the systemic veins -There will also be decreased preload to the left ventricle -Left ventricle stroke volume will fall
When evaluating a patient for congestive heart failure, what are the important components for making a diagnosis (6)?
-Thorough history and physical -Routine blood work -Biomarkers -12 lead ECG -Chest x-ray -Echocardiogram with doppler
What is acute decompensation in chronic heart failure?
A sudden and dramatic worsening, especially in patients with a reduced ejection fraction.
What is BNP?
B-type natriuretic peptide, a 32-amino-acid polypeptide containing a 17-amino-acid ring structure common to all natriuretic peptides. The major source of plasma BNP is the cardiac ventricles.
What is the number one cause of heart failure?
Coronary artery disease.
A 65-year old female presents complaining of swelling in her legs. She also has occasional dyspnea. Findings include elevated jugulo-venous pulsation, hepatomegaly, and EF of 48%. Which of the following best accounts for this situation? Cor pulmonale Left systolic dysfunction Left diastolic dysfunction LV and RV failure Decompensated RV failure
Decompensated right ventricle heart failure is most likely, left ventricular and right ventricular failure would be the second best choice.
Useful definitions: Forward failure.
Decreased cardiac output plus increased metabolic demand, resulting in decreased tissue perfusion.
What type of heart failure does a preserved ejection fraction represent?
Diastolic failure.
Useful definitions: Preload.
Ventricular wall tension at the end of diastole, as approximated by end-diastolic volume or pressure.
Useful definitions: Afterload.
Ventricular wall tension during contraction, as approximated by arterial pressure.
Useful definitions: Stroke volume.
Volume of blood ejected from the ventricle during systole.
Useful definitions: Cardiac output.
Volume of blood ejected per minute (CO = stroke volume x heart rate).
Review: what should you associate S3 with?
Volume overload.
What causes orthopnea in left ventricle failure?
Dyspnea while recumbant, which increases pulmonary capillary pressures. Relieved by elevating the upper body with pillows, etc.
What jugular venous pressure changes manifest as a result of right ventricle failure (1)?
Elevated jugular venous pressure. Blood pools in the venous system, and one of the major signs is distention of the right jugular vein (JVD), which approximates the pressure in the right atrium.
Describe how pulmonary congestion causes dyspnea.
Fluid builds in the lung interstitium and/or alveoli, activating receptors that stimulate rapid, shallow breathing (cardiac dyspnea).
Useful definitions: Ejection fraction.
Fraction of end-diastolic volume ejected during systole; range of normal is 55-75%.
What is the definition of heart failure?
Heart failure is the inability of the heart to pump blood forward at a sufficient rate to meet the metabolic demands of the body, OR the ability to do so only if cardiac filling pressures are sufficiently high, OR both.
Describe the character of an index event.
It can be acute (MI) or gradual (years of hypertension). The common feature is that each index event causes a decline in the pumping capacity of the heart. Depending on the situation, symptoms may occur immediately or take years to surface.
What role does ADH play in the compensatory mechanism of adrenergic nervous system stimulation?
It increases the permeability of the renal collecting ducts, leading to the reabsorption of free water.
What causes cardiac cachexia?
It is thought to be due to an elevated metabolic rate and secondary malnutrition.
What is the result of activation of the renon-angiotensin-aldosterone system?
It leads to vasoconstriction of the peripheral vasculature, myocyte hypertrophy, myocyte cell death, and myocardial fibrosis.
Which of the following is most likely to initially result in left systolic dysfunction? Pulmonary embolism Myocardial infarction Concentric hypertrophy from hypertension Mitral stenosis Acute volume overload
Myocardial infarction, none of the other options will not immediately cause heart failure.
What urinary changes manifest as a result of right ventricle failure (1)?
Nocturia develops. Redistribution of fluid from the splanchnic circulation and lower extremities into the central circulation while recumbant promotes increased urination. May occur in left and/or right ventricular failure.
Which type of heart failure will pulmonary embolism produce?
Right heart failure.
Describe how ventricular remodeling contributes to systolic dysfunction/failure.
Sustained activation of the neurohormones described previously results in gene and protein alteration that impairs excitation-contraction and cross-bridge interaction. Over time, these collective changes impair myocyte contractility.
What type of heart failure does a depressed ejection fraction represent?
Systolic failure.
Describe in more detail the compensatory mechanism of activating the adrenergic nervous system.
The decreased cardiac output in HF patients results in an "unloading" of high-pressure baroceptors (circles) in the left ventricle, carotid sinus, and aortic arch. This unloading of the peripheral baroreceptors leads to a loss of inhibitory parasympathetic tone to the central nervous system (CNS), with a resultant generalized increase in efferent sympathetic tone, and non-osmotic release of arginine vasopressin (AVP) from the pituitary.
What is the cause of dyspnea?
The most important mechanism is pulmonary congestion.
What information can you glean from BNP levels?
The release of BNP appears to be in direct proportion to ventricular volume and pressure overload. BNP is an independent predictor of high left ventricle end-diastolic pressure.
What condition produces right ventricle failure?
The right ventricle is not equipped to handle a significant increase of afterload. Left ventricle failure presents this exact problem.
Why is the right ventricle less prone to failing than the left ventricle?
The right ventricle normally has more compliance than the left ventricle and ejects blood against a relatively low pulmonary vascular resistance. This enables the right ventricle to cope with a wide range of filling pressures.
What is the prognosis for heart failure patients with symptoms at rest?
They have a 30-70% annual mortality rate.
What is the prognosis for heart failure patients with symptoms only with moderate activity?
They have an annual mortality rate of 5-10%.
What is the purpose of activating the renin-angiotensin-aldosterone and adrenergic nervous systems in left ventricle failure?
They maintain cardiac output by increasing retention of salt and water and myocardial contractility.
What is the purpose of obtaining routine blood work for a patient you suspect has congestive heart failure?
To look for anemia, renal disease, thyroid disease, etc.
What is the purpose of obtaining a chest x-ray for a patient you suspect has congestive heart failure?
To look for cardiomegaly, pulmonary edema or pleural effusion.
Following the index event, which compensatory mechanisms become activated (2)?
-Activation of the renin-angiotensin-aldosterone and adrenergic nervous systems -Activation of vasodilatory molecules
What is a clinical diagnosis?
A diagnosis based solely on history and physical.
What is cardiac cachexia indicative of?
A poor prognosis, it is usually found in those with both left and right ventricular failure.
What is the general prognosis for congestive heart failure (3)?
-30-40% of patients die within 1 year of diagnosis -60-70% die within 5 years of diagnosis -They either die from gradually worsening heart failure or a sudden event, such as MI or a ventricular arrhythmia
What qualifies as a depressed ejection fraction?
40% or less.
Can BNP levels distinguish between heart failure with preserved ejection fraction or reduced ejection fraction?
Although BNP has been determined to be the strongest predictor of systolic versus nonsystolic heart failure, it does not reliably differentiate between preserved ejection fraction and reduced ejection fraction.
Why is remodeling disadvantageous in the long run?
Although these neurohormonal mechanisms facilitate short-term adaptation by maintaining blood pressure, and hence perfusion to vital organs, the same neurohormonal mechanisms are believed to contribute to end-organ changes in the heart and the circulation and to the excessive salt and water retention in advanced heart failure.
What initiates the pathogenesis of heart failure?
An index event:
What is the etiology of heart failure?
Any condition that leads to an alteration in left and/or right ventricle structure or function can lead to HF.
What is the purpose of obtaining an echocardiogram with doppler for a patient you suspect has congestive heart failure?
Assesses ventricular size and function and provides a good estimate of ejection fraction.
What is the purpose of obtaining an evaluation of biomarkers for a patient you suspect has congestive heart failure?
BNP markers are relatively sensitive for the presence of heart failure.
What is the purpose of obtaining a 12 lead ECG for a patient you suspect has congestive heart failure?
Can screen for arrhythmias, ventricular enlargement, prior MI, etc.
Which condition augments the risk of developing heart failure?
Hypertension contributes to HF development in 75% of cases.
What effect does cardiomegaly have on heart sounds?
If the heart is enlarged, the palpable heart impulse may be displaced and/or enlarged.
What does it mean to say that heart failure is a clinical diagnosis?
Occurs in patients who develop a constellation of clinical symptoms (dyspnea & fatigue) and signs (pulmonary edema and other edema) that lead to frequent hospitalizations, a poor quality of life, and a shortened life expectancy.
Useful definitions: Backward failure.
Pooling of blood in the venous system (lungs, SVC, IVC, liver, extremities).
What is cor pulmonale?
Right ventricle failure due to a primary pulmonary process.
Describe pulmonary effusion.
Signifies fluid collecting in the pleural spaces and is usually found during chest imaging.
Describe the presentation of pulmonary edema in left ventricle failure.
Signifies presence of fluid in the interstitium and is found by hearing crackles in the lungs during auscultation. Tends to be most prominent in the lung bases when the patient is upright. Also seen in chest imaging.
When is an assessment of BNP levels indicated?
Whenever the diagnosis of heart failure is uncertain or when the clinical presentation is ambiguous.
