Transcript Update in Heart Failure

Heart Failure: medication
Types of Heart Failure
• Systolic (or squeezing) heart failure
– Decreased pumping function of the heart, which
results in fluid back up in the lungs and heart failure
• Diastolic (or relaxation) heart failure
– Involves a thickened and stiff heart muscle
– As a result, the heart does not fill with blood properly
– This results in fluid backup in the lungs and heart
failure
Classification of HF: Comparison
Between ACC/AHA HF Stage and
NYHA Functional Class
ACC/AHA HF Stage1
NYHA Functional Class2
None
A At high risk for heart failure but without
structural heart disease or symptoms
of heart failure (eg, patients with
hypertension or coronary artery disease)
B Structural heart disease but without
symptoms of heart failure
C Structural heart disease with prior or
current symptoms of heart failure
D Refractory heart failure requiring
specialized interventions
I
Asymptomatic
II
Symptomatic with moderate exertion
III Symptomatic with minimal exertion
IV Symptomatic at rest
1Hunt
SA et al. J Am Coll Cardiol. 2001;38:2101–2113.
2New
York Heart Association/Little Brown and Company, 1964. Adapted from: Farrell MH et al. JAMA. 2002;287:890–897.
Compensatory Mechanisms:
Renin-Angiotensin-Aldosterone System
Beta
Stimulation
• CO
• Na+
Renin + Angiotensinogen
Angiotensin I
ACE
Angiotensin II
Peripheral
Vasoconstriction
Kaliuresis
Aldosterone Secretion
Salt & Water Retention
 Plasma Volume
 Afterload
 Cardiac Output
 Preload
 Cardiac Workload
Heart Failure
Fibrosis
Edema
Drug Therapy
Heart Failure Treatments:
Medication Types
Type
What it does
•ACE inhibitor
(angiotensin-converting
enzyme)
•Expands blood vessels which lowers
blood pressure, neurohormonal
blockade
•ARB (angiotensin receptor
blockers)
•Similar to ACE inhibitor—lowers
•Beta-blocker
•Reduces the action of stress
blood pressure
hormones and slows the heart rate
•Digoxin
•Slows the heart rate and improves the
heart’s pumping function (EF)
•Diuretic
•Filters sodium and excess fluid from the
blood to reduce the heart’s workload
•Aldosterone
blockade
•Blocks neurohormal activation and controls
volume
Rational for Medications
(Why does my doctor have me on
so many pills??)
• Improve Symptoms
– Diuretics (water pills)
– digoxin
• Improve Survival
–
–
–
–
Betablockers
ACE-inhibitors
Aldosterone blockers
Angiotensin receptor
blockers (ARB’s)
Lifestyle Changes
What
Why
•Eat a low-sodium, low-fat
diet
•Sodium is bad for high blood pressure,
causes fluid retention
•Lose weight
•Extra weight can put a strain on
the heart
•Stay physically active
•Exercise can help reduce stress
and blood pressure
•Quit Smoking
•Smoking can damage blood vessels and
make the heart beat faster
1. АСЕ inhibitors
Angiotensin
Renin
Angiotensin I
()
receptor
AT2-
receptor
Kinins
Angiotensin II
AT1-
ACE
inhibitors
ACE
(kininase II)
Breakdown
ACE
()
ACE inhibitors reduce pre- and afterload.
They are administered in lower doses alone
or together with diuretics, cardiac glycoside,
antiischemic agents, etc. in all stages of CHF,
due to systolic dysfunction.
2. Thiazides and loop diuretics
They increase salt and water loss,
reduce blood volume
and lower excessive venous filling pressure,
reduce circulating blood volume and preload.
The congestive features of oedema, in the lungs
and periphery, are alleviated,
cardiac output is also increased.
Hydrochlorothiazide
Chlorthalidone
5%
20–30%
3. Cardiac glycosides (CGs)
France, UK
Nativelle
(1869)
•Digitoxin
Digitalis purpurea (Foxglove)
W. Withering (1785)
Ex
3Na+
Na+/K+
ATP-ase
(–)
2K+
3Na+
Na+/Ca2+
exchange
Ca2+
In
DIGOXIN
Digoxin:
•Positive inotropic effect
•Negative chronotropic effect
•Negative dromotropic effect
ARs: bradycardia, AV block,
Extrasystoles arrhythmias,
accumulation and intoxication.
Potassium and calcium have antagonistic action.
Hypokalemia and hypercalcemia potentiate
the action of CGs.
CGs are effective in CHF, occuring with
normal or accelerated heart rhythm,
especially in cases of atrial fibrillation.
Digoxin (t1/2 40 h): p.o. or i.v.
4. Aldosterone antagonists
In cases of severe heart failure low
doses of Spironolactone are added to the
therapy while regularly checking creatinine
and electrolyte levels. Spironolactone
is a weak diuretic. It blocks aldosterone
receptors in the distal renal tubules
and reduces increased aldosterone
levels in CHF.
In low doses (25 mg/24 h) Spironolactone
potentiates the effects of ACE inhibitors.
It also saves K+ and Mg2+ and has antiarrhythmic activity. Spironolactone
prevents myocardial fibrosis, caused by
aldosterone, and in this way increases
myocardial contractility.
Similar to spironolactone is another
aldosterone antagonist – Eplerenone.
5. Beta- and alpha-blocking agents
Carvedilol is a blocker of β- and αreceptors. It also has antioxidant, vasodilating
and cardioprotective effects. It decreases
cardiac output, peripheral vascular resistance
and afterload. Carvedilol lowers mortality
with 25–67%, but it is contraindicated in CHF,
occuring with cor pulmonale. The treatment
begins with low doses (3.125 mg/12 h).
6. Beta-blocking agents
Cardioselective beta-blocker Metoprolol decrease
with 31% mortality in
patients with CHF, if used in combination with
diuretics, ACE inhibitors and Digoxin.
In congestive left-ventricular
heart failure Isosorbide dinitrate
and Isosorbide-5-mononitrate are
prescribed.
To prevent tolerance
development are necessary
8–12 hours intervals without nitrates.
Modern medicine often
disproves this saying.
“The heart never stops. When it stops, it stops
forever”. Leonardo da Vinci