Heart Failure (edited) Flashcards
What causes HF?
HF is most commonly caused Reduced ability of the heart to eject blood, known AD low-output heart failure
Types of heart failure?
HF with Reduced ejection fraction (HFrEF)/Systolic dysfunction - impaired ability to eject blood during systole
HF with preserved ejection fraction (HFpEF)/ Diastolic dysfunction - impaired ventricular relaxation and filling during diastole
What characterizes systolic dysfxn of HF?
Left ventricle ejection fraction < 40%
HFrEF
What characterizes mixed dysfxn of HF?
mid-range reduction of EF (40-49%)
mixed diastolic and systolic dysfunction
What sometimes xterizes diastolic HF?
HF with preserved EF (HFpEF)
EF 50-54%
Normal EF is 55-70%
T/F? HF is one of the most important conditions to include lifestyle counseling and the requirements for strict medication adherence?
True
What does Ischemic cardiomyopathy result from?
Ischemic=from decreased blood supply
From myocardial damage sustained during an acute myocardial infarction, resulting in loss of contractile function
What does Non-Ischemic cardiomyopathy encompass?
A variety of conditions that ultimately increase the workload of cardiomyocytes, accelerating cell death and lead to a thin-walled dilated left ventricle with reduced contractile function
long standing HTN valvular disease excessive alcohol illicit drugs congenital heart defects viral infections diabetes cardiotoxic drugs chest radiation
What are the most common causes of HF in North America?
myocardial infarction
And
HTN
List drugs that cause or worsen HF
DI NATION
Dipeptidyl peptidase 4 inhibitors (DPP-4 ———-inhibitors)
–alogliptin, sitagliptin
Immunosuppressants (TNF inhibitors)
–etanercept, rituximab and interferons
Nondihydropyridine CCBs
–diltiazem and verapamil (specifically in ————systolic HF)
Antiarrhythmics (avoid class I agents in HF)
–amiodarone and dofetilide have LESS risk of —worsening HF
Thiazolidinediones (increase risk of edema)
Itraconazole
Oncology Agents (anthracyclines-doxorubicin, —daunorubicin)
NSAIDs (all including celecoxib)
What’s cardiac output? (CO)
Vol of blood (in L) pumped by the heart in 1 min
It’s a fxn of HR and stroke vol.
CO = HR x SV
What’s stroke vol?
Amt of blood ejected from the left ventricle during 1 cardiac cycle (one heartbeat)
What determines stroke volume?
SV is determined by vol of blood in ventricle (preload), the resistance to forward flow in arterial vessels (afterload), and how hard the ventricle squeezes during systole (contractility)
So, SV is determine by preload, afterload and contractility
What’s preload?
Volume of blood in the ventricle
What’s afterload?
Resistance to forward flow in the arterial vessels
What’s contractility?
How hard the ventricle squeezes during systole
What’s cardiac index?
CO/BSA
It relates the CO to the size of the patient
HF is a progressive syndrome, what does that mean?
During low CO state (main problem in HFrEF), neurohormones try to compensate by increasing volume, or increasing force or speed of contractions
may temporarily increase CO
BUT chronic neurohormonal activation causes damage to myocytes and produces changes in size, composition and shape of heart CARDIAC REMODELING
One of the ways the heart tries to compensate during HF is by activating RAAS? Implication of this?
In response to low CO, neurohormones are released to compensate by increasing volume of blood, or increasing force or speed of heart contraction
RAAS results in Ang II which causes VASOCONSTRICTION as well as Ang II stimulates the adrenal gland to release aldosterone which increases NA and H20 retention, K excretion. Ang II also stimulates adrenal release of vasopressin which cause vasoconstriction and water retention
What other compensation by the heart increases HR and contractility? (T4 augmenting CO)
Sympathetic (adrenergic) activation
SNS activation results in NE and EPI release which causes increased HR and contractility (+ inotrope) and vasoconstriction
While the RAAS activation in HF is useful (maintains BP and adequate perfusion), what’s not so good abt it?
Na and water retention => edema
Excess fluid causes body to be congested and the classic sx of “congestive” HF is seen
General HF S/Sx
Dyspnea (SOB)
Cough
Fatigue, Weakness
Reduction of exercise capacity
Labs to distinguish between cardiac causes of SOB or other issues
Increased BNP (B-type Natriuretic Peptide): normal < 100 pg/ml
Increased NT-proBNP (N-terminal pro B-type Natriuretic Peptide) normal < 300 pg/ml
S/sx of left-sided HF?
Orthopnea-SOB when laying flat
S3 gallop-abnormal heart sound
hypo perfusion-renal impairment, cool extremities
Bibasilar rales-crackling lung sounds
Paroxysmal nocturnal dyspnea (PND) or nocturnal cough and SOB