HF Flashcards
What COMPENSATORY RESPONSES BECOME MALADAPTIVE LONG TERM
• Myocyte dysfunction • Ventricular remodeling • Hypertrophy, fibrosis • Myocyte death
HF treatment
Preload, afterload, contractility> SV>CO
^ preload + ^ afterload = decreased SV } decreased
Decreased contractility= decreased SV }. CO
Therefore we want to reduce preload+ afterload
AND INCREASE Contractility
HF + tx aims to
Causes breathlessness and distress
Treatment aims to:
Prolong life
Relieve symptoms
Improve quality of life
ACEIs/ARBs
(Afterload, preload)
Reduce cardiac afterload
Reduce cardiac preload
Delay progression of the disease
Prolong life
ACEIs may be used
as first-line treatment
ARBs are a reasonable alternative
in case of ACEI intolerance
Angiotensin Receptor-Neprilysin Inhibitor (ARNI)
Examples
Some patients may be candidates for initial
therapy with an ARNI
—> (sacubitril-valsartan)
ARNI MoA
•Neprilysin degrades natriuretic peptides and ATII •Natriuretic peptides (B-type natriuretic peptide-
BNP): hormones released in HF to counteract the
effects of compensation:
-Natriuresis (counteracts NA retention)
-Vasodilation (counteracts Vasoconstriction)
-Inhibition of renin, ATII, aldosterone, ADH release
and action RAAS pathway
Eligibility criteria for initial therapy with an ARNI
Current or prior elevated B-type natriuretic
peptide (BNP) level or N-terminal proBNP
Hemodynamic stability (BP ≥100 mmHg)
No history of angioedema
Access to medication
Adverse effects of ARNI
-Hypotension
-hyperkalemia (RAAS pathway)
-cough
-dizziness (from hypotension)
β-BLOCKERS IN HF
Considered first line treatment in combination with ACEIs, ARBs or ARNI
But NOT in acute, decompensated HF
β-BLOCKERS IN HF
Examples
Metoprolol, carvedilol, bisoprolol
EFFECTS OF β-BLOCKERS IN HF
SA node: Decrease heart rate
Myocardium: Decrease contractility
Renal: Decrease renin release, decrease RAAS
activation, reverse vasoconstriction, prevent fluid
retention —> Decrease blood pressure
Save energy and oxygen demand
Reduce Ca cycling and propensity for arrhythmias Halt progression of the disease
Improved survival
DIURETICS
Chronic tx and combination + monitor
Chronic treatment with ACEIs leads to ‘aldosterone escape’’
—Circulating aldosterone concentrations return towards pre-treatment values
Combining ACEIs/β-blockers with aldosterone antagonists (spironolactone, eplerenone) further reduces mortality in more advanced HF
Monitor K+ levels with ACEIs/ARBs/ARNI in combination with aldosterone antagonist
Other diuretics e.g. loop/thiazide diuretics used to treat congestion but do not prolong life
ALDOSTERONE ANTAGONISTS MoA
Aldosterone
↑Na+ & H2O retention —->↑ Preload & BP
Myocardial fibrosis
Endothelial dysfunction
Promotes arrhythmias
Aldosterone antagonists in HF
Decrease preload
Improve prognosis
OTHER DRUGS FOR SECONDARY TREATMENT OF HF
1.Hydralazine plus nitrate (isosorbide nitrate)
• Hydralazine reduces afterload, while nitrates
reduce preload
• Addition to HF regimen, especially in black patients, improves survival
Reduces TPR
OTHER DRUGS FOR SECONDARY TREATMENT OF HF
- Digoxin
- Ivabradine
2.
• Does not reverse/retard progression of HF
• Reduces hospitalization (in combination with
other HF drugs)
