heart failure Flashcards
inability of the heart to meet the body’s metabolic needs. at rest or during stress, without exceeding physiologic left and right filling pressures s
heart failure
most common primary diagnosis on admissions within the medicare population
heart failure
total cost of heart failure in US
28.8 billion
cost of HF sustainable?
nope
independent risk factors of HF
- HTN
- obesity
- diabetes
treatments for HF
- digoxin
- diuretics
- bed rest
HF prognosis
- progressive disability
2. uniform mortality
determinants of systolic performance
ejection fraction:
- myocardial mass and architecture
- contractility
- preload
- afterload
how to measure cardiac output
thermodilution
goal of managing HF
achieve adequate cardiac output while minimizing wedge P
Diastolic relaxation components (3)
- Myofibrillar dissociation
- Calcium removal from the cytoplasm against the concentration gradient
- Requires enzymatic action and energy
Diastolic passive compliance components (2)
- A tissue property (stress-strain relationship) during passive myocardial stretch
- A ventricular property related to both myocardial stretch response and to constraining effect of contiguous structures
Systolic dysfunction:
- Etiology
- Pathology components
- Pathophysiology
- Chronic volumes overload, ischemia, infectious, substance abuse or genetic
- Dilated LV and hypertrophied LV and/or RV
- Decrease in contractility and decrease resting EF (LV remodeled with dilation)
Diastolic dysfunction; HHpEF; Metabolic CV dx.:
- Etiology
- Pathology
- Pathophysiology
- HTN, Diabetes, Obesity and advanced age
- Hypertrophy, fibrosis w/out dilatation
- NI resting EF (non-dilated LV) with decrease relaxation and decrease in compliance
Increased load structure HF:
- Etiology
- Pathology
- Pathophysiology
- Valvular, congenital, obstructive, systemic shunt
- Hypertrophy and/or dilatation
- Pressure and/or volume overload
Increased load and demand HF:
- Etiology
- Pathology
- Pathophysiology
- Anemia and thyrotoxicosis
- Dilated and hypertrophied LV and RV
- Increased C.O. And increased O2 consumption or decreased O2 extraction
Restrictive/ constrictive HF:
- Etiology
- Pathology
- Pathophysiology
- Infiltration, inflammatory and neoplasticism
- Infiltrated / thickened mayo/ pericardium
- Restricted LV and RV filling
Left Heart failure HF:
- Etiology
- Manifestations
- MI, cardiomyopathy, valvular congenital, HTN
2. Pulmonary congestion and low cardiac output
Right Heart failure:
- Etiology
- Manifestations
- Left heart failure, MI, cardiomyopathy, valvular, congenital, cardiomyopathy, lung disease and pulmonary emboli
- Peripheral edema, ascites, low cardiac output
Heart failure has a maladaptive adaptation
the heart will undergo hypertrophy to normalize wall stress and systolic function but it will lead to altered contractile proteins and calcium handling, apoptosis, fibrosis and failure
function of natriuretic peptides
vasodilate and promote sodium excretion
high pulmonary venous pressure
left heart failure
high systemic venous pressure
right heart failure
NY heart association class (4)
- no symptoms
- symptoms on mod-severe exertion
- symptoms on mild exertion
- symptoms at rest
ivabradine
heart rate lowering agent acting by inhibiting the If current in the sino-atrial node
Shift trial hypothesis
addition of ivabradine to recommended therapy would be beneficial in heart failure patients with elevated heart rate
neprilysin
inhibition leads to a potentiation of vasoactive peptides that counter maladaptive mechanisms in HF
produces a positive inotropic effect through inhibition of the Na-K exchanger that results in higher intracellular sodium levels causing increased calcium transport via sodium-calcium exchange channel
digoxin
the loss of what can worsen HF?
synchronous LV contraction
most commonly used drug for suppression of ventricular arrhythmias in HF is
amiodarone
indications for implantable cardioverter defibrillators
syncope or resuscitated cardiac arrest thought ti be due to a ventricular arrhythmia
clinical assessment of hemodynamic status (2)
- thermodilution
2. swanz catheter
thermodiultion can measure _____ but there are some pitfalls in inaccuracy such as with (2)
CO
- tricuspid regurg
- fluctuation in body temp
Total uptake and release of a substance by an organ equals the blood flow to the organ and the arterio-venous concentration difference for that substance
Fick’s method
Non-invasive general assessment of atrial, ventricular and valve structure and function
TTE
Invasive and requires conscious sedation
Higher resolution imaging gives better assessment of valvular structure (e.g. infectious vegitations on valve from endocarditis)
TEE
Color-flow doppler measures blood velocity (direction and speed) by either TTE or TEE
Does not measure pressure directly, but can make inferences about pressure by converting velocity to pressure:
echo
Reflection of intravascular volume status
Estimated by pressure in the right atrium (“central venous pressure or CVP”) and/or left atrium (“pulmonary capillary wedge pressure”)
Preload: volume of blood in LV at end-diastole
Reflection of the heart’s intrinsic ability to contract and generate force during systolic
Estimated generally by the Left Ventricular Ejection Fraction
Contractility: ability of myocardium to contract
Left ventricular wall stress
Estimated by systemic vascular resistance (SVR) or mean arterial pressure
Afterload: resistance to ventricular contraction
disease modifying therapies for HF
- catecholamine pathway
- RAAS pathway
- revascularization
palliative therapies for HF
- diuretics
2. implantable defibrillator
is a life-threatening medical condition of low tissue perfusion resulting in oxygen and nutrient deficit (ischemia/infarction) the impairs tissue function
Circulatory shock
types of shock (4)
- hypovolemic
- cardiogenic
- septic
- obstructive
causes:
- Hypovolemic
- Cardiogenic
- Septic
- Obstructive
- Hypovolemic
GI bleeding, excessive diarrhea and dehydration
Cardiogenic
s/p large myocardial infarction, acute valvular disorder
Septic
Significant systemic infection
Obstructive
Pulmonary embolus
primary problem:
hypovolemic
low preload
primary problem:
cardiogenic
loss of contractility
primary problem:
septic
non-specific vasodilation and dehydration
primary problem:
obstructive
physical blockage preventing blood flow
inotropic drugs used (3)
- Beta-adrenergic agonists
- phosphodiesterase inhibitors
- digitalis glycosides
2 key components of diastolic function:
- relaxation
2. compliance
is the process of myofibrillar dissociation, an active process requiring enzymatic action and energy to remove calcium from the cytoplasm against the concentration gradient.
relaxation
is the passive property of the myocardium or of a cardiac chamber, describing (for an intact cardiac chamber) the change in volume for a given change in filling pressure, after relaxation is complete.
compliance
. A low ejection fraction is generally accompanied by
ventricular dilatation.
Systolic dysfunction is most often a consequence of
myocardial infarction (“ischemic cardiomyopathy”) or primary myocardial disease (“dilated cardiomyopathy”)
Isolated, or primary, diastolic dysfunction occurs most commonly in the _____, as a consequence of long-standing hypertension and resulting left ventricular hypertrophy.
elderly
Diastolic dysfunction may also occur as a consequence of___________, a family of genetic disorders linked to mutations of a variety of contractile proteins.
familial hypertrophic cardiomyopathy
cor pulmonale a sign of
right heart failure
long standing pressure-overload, as exemplified by hypertensive cardiomyopathy
diastolyc dysfunction
ventricular dilatation, reduced ejection fraction, commonly referred to as
“systolic dysfunction”.
hypertrophied myocyte manifests altered expression of
contractile proteins and of enzymes that regulate calcium movement,
what does the adrenergic nervous system, RAAS pathway, vasopressin and endothelin do in HF?
these systems and substances tend to vasoconstrict; augment contractility; promote hypertrophy and interstitial fibrosis; and induce sodium and water retention.
levels are elevated in heart failure.
B-type natriuretic peptide (BNP)
effective means of preventing or reversing progressive left ventricular dilatation (ventricular remodeling) in heart failure.
carvedilol
A typical regimen for such HF patients includes an
ACE inhibitor, beta blocker, digoxin, and diuretic.
These agents are useful in the management of acute exacerbations of heart failure
vasodilators
reduce pulmonary capillary (artery) wedge (PCW) pressure in patients with severe heart failure
dobutamine and milrinone
