Clinical Treatment of Heart Failure Flashcards
What are the major goals of therapy?
↑ quantity of life (improve survival)
↑ quality of life (reduce symptoms)
Decrease societal / financial burden of disease
How to therapeutically approach HF?
-Correction of the underlying cause of HF
-Elimination of precipitating factors (infection, anemia, etc)
-Reduction of congestion
-Improve blood flow:
Modulate neurohormal activation
Devices / transplantation
What lab studies could rule out reversible causes of HF?
- Vitals BP / HR (hypertension)
- EKG (tachyarrhythmia, AFib, PVCs)
- CMP, CBC (renal failure, liver dysfunction, anemia, infxn)
- CXR (coexistant lung disease, for future comparison)
- BNP / NT-proBNP, troponin (prognosis)
- Echo (dilation, LV function, wall motion, PHTN, prognosis)
- Coronary angiogram v. CTA, stress testing, MRI (ischemia, scar)
- Thyroid function tests
- Iron studies (hemochromatosis, iron deficiency)
How do you reduce congestion?
Diuretics, Reverses fluid retention (Na loss)
The most common HF therapy
Diuretics
Pharmacokinetics of diuretics
Can be used chronically and acutely
Typically PO dose at baseline
Often use IV in the hospital (PO not absorbed, worsening renal function, also need higher dose)
Side effects: dehydration, hypokalemia, sulfa, tinnitis
Diuretics method of action
increase Salt (+Water) Excretion->decrease Intravasc Fluid Vol->decrease Venous Congestion->decrease dyspnea/edema
What are ACE inhibitors?
- …prils (lisinopril, enalapril, benazepril)
- Block conversion of ATI to ATII
Effects of ACEIs
Direct vasodilation
Decreased aldosterone activation
Side effects of ACEIs
Hypotension
Worsening renal function (afferent vasocontraction)
Hyperkalemia
Cough (kinin potentiation): ~20%
Angioedema: <1%, can occur after months of use
What are ARBs?
- …sartans (e.g. valsartan, candesartan, losartan)
- Effect: Block the receptor of angiotensin II
Clinical use of ARBs
- In studies have been equivalent to ACEI
- Controversial whether use in combination (ARB + ACEI) provides added benefit
- Generally used when patients develop cough to ACEI
Side effects of ARBs
ARBs do not produce kinin potentiation (no cough)
Otherwise side effects are similar to ACEI
What are Mineralocorticoid Receptor Antagonists (MRA)?
-Spironolactone and eplerenone
-Effect: Block mineralocorticoid receptor
Kidney: ACEI/ARB aldosterone block is incomplete
Produces additional sodium loss (diuretic), Antifibrotic
Side effects of MRAs
Hyperkalemia (requires close monitoring)
Gynecomastia (spiro only)
What are beta-blockers?
- olols (metoprolol, carvedilol, bisoprolol)
- Effect: Antagonize effect of sypathetic system (epinephrine/norepinephrine)
- β1 blockade:
- Negative chronotrope (slow heart rate, less arrhythmia)
- Negative inotrope (decreased metabolic demand)
- [α1 blockade: vasodilation]
Side effects of beta-blockers
Negative inotrope: short-term loss for long-term gain
Fluid retention
Hypotension
Decreased cardiac output, even cardiogenic shock
Bronchoconstriction
End result of Adrenergic and RAAS blockers?
-Anti-Remodeling Decreased: Hypertrophy Fibrosis Apoptosis -All 3 REDUCE MORBIDITYAND IMPROVE SURVIVAL
What are the different Vasodilators for HF?
Arterial vasodilation (antihypertensives) Venous vasodilation (venodilators) Pulmonary arterial vasodilation
Effect of pulmonary arterial vasodilation
Decrease in RV afterload
Effect of Venous vasodilation (venodilators)
Decrease in preload
Benefits of arterial vasodilatation
Decrease in LV afterload
Reduced cardiac work
Less mitral regurgitation
Use of Hydralazine / isosorbide dinitrate in HFREF
Hyd/ISDN < ACEI (V-HeFT II)
Hyd/ISDN+ACEI/BB in blacks good (A-HeFT)
What is an ICD?
Implanted Cardioverter Defibrillators
Patients with LVEF <=35% or prior dangerous heart rhythms
Abort sudden cardiac death from ventricular tachycardia / fibrillation
What is CRT therapy?
Cardiac Resynchronization Therapy
Biventricular pacemakers (CRT or BiV)
LV lead placed through the coronary sinus
Indication for CRT use
For patients with QRS duration > 120 msec (bundle brank block)
CRT mechanism of action
Cause the LV lateral wall and septal wall to contract together, which produces a more efficient contraction / ↑ stroke volume
Usually placed with ICD
Rx options for chronic (stable) HFrEF
BB ACEI/ARB Aldosterone antagonist Hydralazine / ISDN \+/-Digoxin ICD/CRT
Rx options for Acute decompensated HF
IV diuretics
IV vasodilators (nitrates / nitroprusside, if BP allows)
Positive pressure ventilation (CPAP/BiPAP, intubation) for hypoxia
May also reduce preload
IV inotropes for shock only
May need to cut back on beta-blockers (only in severe cases)
Types of Positive Inotropic Agents
Digoxin (PO) - K/Na exchange
Dobutamine (IV) – β agonist (opposite of BB)
Milrinone (IV) – phosphodiesterase inhibitor (effect is similar to dobutamine)
Clinical use of positive inotropic agents
ACUTE: IV agents used short term to reverse shock
Long-term they worsen remodeling
CHRONIC: Digoxin has no effect on mortality but may reduce symptoms and hospitalization (also some decrease in heart rate in AFib)
In high doses causes dig toxicity (mostly arrhythmias)
T or F: inotropic agents Improve symptoms short-term
Long-term HF is worsened
True
Beta-Agonism v. Antagonism:
ACUTE v. CHRONIC, respectively
Stages of HF
Asymptomatic HF (late “prevention”)
Chronic stable HF (ambulatory)
Acute decompensated HF (hospitalized)
End-stage heart failure (advanced)
What is LVAD?
Left Ventricular Assistance Device mechanical circulatory device that is used to partially or completely replace the function of a failing heart, can be used in CHF
Options for end-stage HFrEF
Transplant
LVAD
Inotrope infusion
Hospice
What can you do to improve Sx in HFrEF?
Diuretics (furosemide) Digitalis PO (HFrEF with shock - dobutamine, milronone)
What can you do to prolong survival in HFrEF?
ACE Inhibitors / Angiotensin Receptor Blockers
Beta Blockers
Aldosterone Receptor Antagonists
Other Vasodilators (hydralazine + nitrates)
Cardiac Resynchronization Therapy (biventricular pacing)
Implantable Cardioverter Defibrillator (ICD)
Therapy for HFpEF
- treating the underlying disorder (hypertension, diabetes, kidney dysfunction)
- Diuretics are used to keep volume normal (sodium retention is common)
- Vasodilators are used to maintain normal blood pressure
- neurohormonal antagonists (e.g. ACEI, ARB) not successful
