Heart Failure Flashcards
Define Heart Failure
Usually progressive clinical syndrome that develops when the heart is unable to pump blood at a rate sufficient to meet the metabolic demands of the tissues or can do so only at elevated filling pressures
Heart failure starts out
As an outcome of multiple disease
It begins only when you put your heart under some type of stress (exercise, etc)
Acute HF is caused by:
hemodynamic stress
- Fluid overload
- Acute valvular dysfunction
- A large MI
Chronic HF is caused by:
Ischemic Heart Disease
Chronic work overload (hypertension, valve disease)
Intrinsic cardiac mechanisms include
Specifically occur with the heart
- Frank-Starling and strecth of the right atrial wall
Extrinsic cardiac mechanisms include:
Things that occur outside the body that causes changes to the heart (rate and contraction)
- Autonomic Nervous System
IHD leads to
cardiac function impairment
HTN leads to
Increased wrokload
IHD and HTN both lead to
activation of compensatory mechanisms to amintain arterial pressure and perfusion of vital organs
Define Frank-Starling mechanism
Increased filling volumes dilate the heart and increase cross-bridge formation within the sarcomeres which leads to enhanced contractility
Define Myocardial adaptations
Hypertrophy and ventricular remodeling (caused by hypertrophy)
What promotes ventricular remodeling?
IHD due to fibrosis production in the heart where the dead tissues is
Define Activation of neurohumoral systems
Release of NE causes increased HR and augments myocardial contractility and resistance
Activation of RAAS
Release of atrial natiuretic peptide
Compensatory mechanisms are:
initially adequate to maintain normal cardiac output but later they become overwhelmed leading to cardiac dysfucn
Pathological changes that occur as a result of adaptive changes cause:
Functional and structural problems such as myocyte apoptosis, cytoskeletal alterations, and fibrosis
Frank Starling Mechanisms Limitations
There is only so much increase in right atrial pressure or end diastolic volume that will increase the cardiac output and for a while this is linear but eventually it will plateau
Define Myocardial Hypertrophy
Myocyte size increase Protein synthesis increase Enlarged nuclei Numerous mitochondria (need more energy) Increase in DNA ploidy
What can cause Myocardial Hypertrophy?
Increased hydrostatic pressure
Volume overload
Activation of beta adrenergic receptors (catecholamine stimulation)
Pressure Overload hypertrophy + Myocardial Hypertrophy
Cause increase in wall thickness
New sarcomeres are assembled in parallel
- Thicker
Volume Overload hypertrophy + Myocardial Hypertrophy
Ventricular dilation occurs
New sarcomeres assemble in response to volume and are in series with current ones
-Heavier
HTN =
Pressure overload
Valvular disease =
Pressure and/or volume overload
MI =
Regional dysfunction with volume overload
Cardiac dysfunction occurs via
Abnormal myocardial metabolism
Alteration of intracellular Ca
Apoptosis of myocytes
Reprogramming of gene expression (miRNA)
Why are miRNA important
They regulate the expression of other genes
Myocardial Hypertrophy prognosis
Increased heart mass is correlated with increase cardiac mortality and morbidity
- Usually involves increased mass but not increased vessels so there is a lack of perfusion
More catecholamines produced leads to
More stimulation of beta adrenergic receptors in the heart which leads to vasoconstriction and reduced blood flow to the limbs
Define Systolic Dysfunction
Progressive deterioration of myocardial contractile function
- IHD
Diastolic dysfunction
Incapability of the heart chamber to expand and fill sufficiently during diastole
- Pericarditis
HF with a depressed ejection fraction =
Systolic failure
HF with a preserved ejection fraction =
Diastolic failure
Define Forward Failure
Decreased cardiac output and tissue perfusion
Define Backward failure
Congestion in the venous system
Left ventricular dysfunction leads to
Tissue hypoperfusion
Right ventricular dysfunction leads to
Venous congestion so low blood oxygenation bc the blood cannot get to the lungs and out to the tissues
LSHF symptoms
May be quite subtle and often related to pulmonary congestion and edema (cough and dyspnea)
Fatigue
Decreased kidney perfusion (increased RAAS)
Pre-renal azotemia
Define Orthopnea
Dyspnea occuring when laying down or leaning back
Redistribution of fluids from the splanchnic circulation and lower extremities into the central circulation
Increase in pulmonary capillary pressure seen with orthopnea is bad because:
It will lead to leakage of the fluid to other parts of the body
Define Paroxysmal Nocturnal Dyspnea
Acute episodes of severe SOB and coughing
Occurs at night and awakens the patient from sleep
Paroxysmal Nocturnal Dyspnea Patho
Increased pressure in the bronchial arteries leading to airway compression, along with interstitial pulmonary edema that increases airway resistance
Afib =
Arrhythmia characterized by uncoordinated, chaotic contraction of the atrium
Stasis increases risk of thrombosis and TE stroke
RSHF shows as
Hepatosplenomegaly Peripheral edema Pleural effusion Ascites Venous congestion (kidney azotemia, brain encepthalopathy)
Define Ascites
Accumulation of flluid in the peripheral cavity caused by congestion in the venous system which leads to increased hydrostatic pressure and fluid being pushed into open cavities of the body (edema)
Pleural effusion leads to
Dyspnea bc the fluid accumulation leads to compression of the lung parenchyma
Define Jugular venous pulsation
RSHF
Push on the abdomen and there will be increased pressure in the neck which leads to elevation of this muscle
GI Symptoms of HF
Anorexia, nausea, early satiety bc ab pain
Right upper quadrant pain
Edema of bowel wall or congested liver
Cerebral symptoms of HF
Confusion
Disorientation
Sleep and mood distrubances
Nocturia and insomnia
Cheyne-Stokes Respiration
Associated with low cardiac output
Caused by diminished sensitivity of the repiratory center to PCo2
- This means the patient is about to die and shows as phases of intense breathing, rest, and repeat
Physical Exam findings for HF patients
Reduced systolic BP due to LV dysfunction
Reduced pulse pressure due to reduced stroke volume
Sinus tachycardia (adrenergic activity)
Cool extremities and peripheral cyanosis (adrenergic activity)
Pulmonary crackles
Plural effusion
Cardiomegaly
Murmurs of bi and tricuspid valvues
Hepatomegaly
Ascites, Jaundice, peripheral edema and pigmented skin
LSHF Symptoms
Coughing SOB Tiredness Pulmonary congestion and pressure Pulmonary edema
RSHF
Pleural effusion
Ascites
Enlarged veins in the abdomen
Peripheral edema
Cardiogenic Shock and Cardiogenic PE
Severe LV dysfunction leading to congestion and hypoperfusion
Decreased cardiac index and systolic hypotension
CS and Cardiogenic PE Causes
Acute MI/ischemia bc of LV failure, papillary muscle/chordal rupture with severe mitral regurgitation Wall rupture + tamponade Acute myocarditis PE (RSHF) Severe Valvular HD
Define Tamponade
Blood accumulates in the pericardium which causes acute LSHF bc the heart cannot expand (diastolic)
Systolic Myocardial Dysfunction leads to
Decreased cardiac output
Decreased stroke volume which can lead to (1) hypotension which decreases coronary perfusion pressure and causes ischemic or (2) decreased systemic perfusion which leads to compensatory vasoconstriction (both then lead to progessive myocardial dysfunction and death)
Diastolic myocardial dysfunction leads to
Increase LVEDP and pulmonary congestion which leads to hypoxemia which ultimately causes ischemia –> progressive dysfunction and death
HF + MI
There is already ischemia from the MI so now if they have systolic/diastolic dysfunction then there is even more ischemia
