Flashcards in Chronic Heart Failure (CHF) Deck (66):
Define heart failure
Syndrome that occurs when the heart is unable to pump sufficient blood to meet the metabolic demands of the body
Characterized by dyspnea and abnormal retention of water and sodium
What changes can cause heart failure?
4. Heart rate
1. Stretching of muscle fibers in (L) ventricle @ end of diastole
2. Affected by systemic BP & rate of venous return
1. Amount of pressure (L) ventricle must work against to pump blood into circulation
Ability of muscle cells to contract after depolarization
1. Volume in ventricle during diastole
2. Approx 110-120 ml
Define stroke volume
1. Volume of blood that empties out of ventricle during systole
2. Approx 70 ml
1. Remaining volume in each ventricle after systole
2. Approx 40-50 ml
Define Ejection fraction
1. End diastolic volume that is ejected
2. Approx 60%
What demographic group has heart failure?
Primarily a disease of elderly
75% of cases occur in pts > 65 yrs of age
What is the etiology of CHF?
1. Abnormal cardiac function
C. Cardiac arrhythmia
2. Abnormal left ventricular volume
A. Diseases with high metabolic rate
3. Abnormal ventricular pressure
B. Pulmonary HTN
D. Aortic or pulmonic valve stenosis
4. Abnormal ventricular filling
A. Mitral / tricuspid stenosis
B. Atrial fibrillation
Define Class I heart failure
Patients with cardiac disease but resulting in no limitation of physical activity. Ordinary physical activity does not cause undue fatigue, palpitation, dyspnea or anginal pain.
Define Class II heart failure
Patients with cardiac disease resulting in slight limitation of physical activity. They are comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnea or anginal pain.
Define Class III heart failure
Patients with cardiac disease resulting in marked limitation of physical activity. They are comfortable at rest. Less than ordinary activity causes fatigue, palpitation, dyspnea or anginal pain. t
Define Class IV heart failure
Patients with cardiac disease resulting in inability to carry on any physical activity without discomfort. Symptoms of heart failure or the anginal syndrome may be present even at rest. If any physical activity is undertaken, discomfort increases.
Hwo can heart failure be classified?
Sides or cardiac cycle involved
Define right sided heart failure
Right sided heart failure (Cor Pulmonale)
Usually 2° to left sided heart failure
Also occurs 2° to COPD & Pulm HTN
What is the most common cause of systolic heart failure?
Most common cause is ischemic heart disease
What is the most common cause of diastolic heart failure?
Most common cause is HTN
What is Stage A of heart failure?
1. No objective evidence of CV disease. No symptoms and no limitation in ordinary physical activity.
2. High risk for HF but without structural heart disease or sx’s of HF
A. HTN, Ischemic heart disease
What is stage B of Heart failure?
1. Objective evidence of minimal cardiovascular disease. Mild symptoms and slight limitation during ordinary activity. Comfortable at rest.
2. Structural heart disease but without signs/sx’s of HF
A. Previous MI, LVH, asymptomatic valvular disease
What is stage c of Heart failure?
1. Objective evidence of moderately severe cardiovascular disease. Marked limitation in activity due to symptoms, even during less-than-ordinary activity. Comfortable only at rest.
2. Structural heart disease with prior or current sx’s of HF
What is stage D of heart failure?
1. Objective evidence of severe cardiovascular disease. Severe limitations. Experiences symptoms even while at rest.
2. Refractory HF requiring specialized interventions
What is the pathophys of left sided heart failure?
1. ↓ Contractility of left ventricle
2. Leads to dec CO -> blood backs up into left atrium and then into lungs -> Pulmonary edema
What is the pathophys of right sided heart failure?
1. ↓ Contractility of right ventricle
2. Blood backs up into right atrium and then into peripheral circulation -> Peripheral edema
What is the pathophys of systolic heart failure?
1. Pumping disorder
2. Left ventricle is unable to pump enough blood out into systemic circulation during systole -> ↓ EF -> ↓ CO
3. Blood backs up into pulmonary circulation -> pulmonary pressure rises -> can lead to right HF (Cor Pulmonale)
What is the pathophys of diastolic heart failure?
1. Filling disorder
2. Left ventricle is stiff --> unable to relax & fill during diastole --> ↓ stroke volume
define Cor pulmonale
1. Cause must originate in the pulmonary circulation system
2. Blood vessels in lungs ↓ in number (2° to lung tissue destruction) &/or chronic constriction (2° to poor alveolar ventilation)
RV no longer able to push blood into the lungs effectively → chronic overload eventually → HF
What are acute causes of cor pulmonale?
What are chronic causes of cor pulmonale?
What do all forms of heart failure decrease? What is the general pathophys of heart failure?
1. All forms of HF ↓ CO and trigger compensatory mechanisms that improve CO
A. Leads to ↑ ventricular workload
2. ↑ Sympathetic activity → ↑ PVR, ↑ contractility, ↑ heart rate & ↑ venous return
3. ↓ CO → ↓ blood flow to kidneys
A. → RAAS activated
1. ↓ BP → renin secretion by kidneys
2. Renin stimulates conversion of angiotensionogen to angiotensin I
3. Angiotensin I converts to angiotensin II in lungs
4. Angiotensin II → vasoconstriction of arteries/arterioles → ↓ water excretion
5. Angiotensin II stimulates release of ADH (vasopressin) & aldosterone by adrenal cortex
6. ADH/aldosterone ↓ urine output by ↑ H2O & Na retention
7. ↑ End diastolic volume (overoad) → ↑ workload on heart --> LVH --> ↓ CO
What are the sxs of left sided heart failure?
1, Exertional dyspnea
A. 1st sx usually
2. Nonproductive cough
A. Accompanies exertional dyspnea
5. Paroxysmal nocturnal dyspnea (PND)
6. Bibasilar rales
7. S3 gallup
What are the sxs of right sided heart failure?
1. Weight gain
2. Distended neck veins
5. Dependent pitting edema
6. Hepatojugular reflux
7. S3 gallup
What are the dx studies for suspected heart failure?
8. Cardiac catheterization
What are the BNP results in heart failure?
1. ↑ When ventricular filling pressures are high
2. Used as biochemical marker when diagnosing and treating decompensated CHF
What are the CBC results in heart failure? Why is it performed?
What are the BMP results in heart failure? Why is it performed?
1. R/O Renal insufficiency
2. R/O Electrolyte disturbances
4. Hypo or hyperkalemia
What are the ECHO results in heart failure? Why is it performed?
1. Reveals size and function of both atria & ventricles
2. Detects pericardial effusions, valvular abnormalities, intracardiac shunts, and segmental wall motion abnormalities
What are the EKG results in heart failure?
May indicate underlying or secondary arrhythmia, LVH, MI or ischemia
What are the CXR results in heart failure?
2. Pleural effusions: kerley B lines
3. Pulmonary edema
When is a cardiac cath indicated?
1. Symptomatic HF + angina
2. Symptomatic HF + positive nuclear stress test
What are the classes of treatment options for a CHF pt?
2. RAAS Inhibitors
3. Beta blockers
4. Digitalis glycosides
What is the most effective means of treating CHF symptoms?
When are thiazide diuretics used in CHF? what are the se?
1. Used to treat mild fluid retention
2. S/E: Intravascular volume depletion, hypokalemia, prerenal azotemia, hyperkalemia in CKD
When are loop diuretics used in CHF? what are the se?
1. Rapid onset and relatively short duration of action
2. Used to treat mod-severe CHF
3. S/E: hypotension, intravascular volume depletion, hypokalemia, prerenal azotemia
When are K sparing diuretics used in CHF? what are the se?
1. Often given with loop diuretics
2. Inhibit aldosterone which is elevated in CHF
3. Diuretic potency minimal, but helps to minimize hypokalemia secondary to loop diuretics
4. S/E: hyperkalemia
What is the 1st line Tx (w/diuretics) for pt’s w/LV systolic dysfunction OR asymptomatic low EF ?
ACEI & ARBs
What is the moa and se of arbs and aceis?
1. Inhibit ACE and formation of angiotensin II -> causing vasodilation
2. ↓ Aldosterone secretion from adrenal cortex
3. ↑ CO
4. Slows ventricular remodeling
5. Increases survival in HF
6. S/E: hypotension, hyperkalemia, dizziness, ↑ serum Cr, cough (ACEI)
What class of drugs is recommended in long term management of chronic CHF?
What class of drug is avoided in acute HF? Why?
1. Avoid in acute HF
2. Can cause an initial drop in EF due to its acute negative inotropic effect
What effect do beta blockers have on ejection fraction?
1. Over period 3-6 months, beta blockers produce rise in EF slows hr and allows for better filling time
A. ≈ 10% ↑ EF & reduction in LV size and mass
What is the moa of beta blockers? What are the se?
1. ↓ HR and contractility
2. Dose must be slowly titrated up
3. S/E: fatigue, impotence
What do you do if a CHF pt develops decompensation while on a beta blocker in an OP setting?
1. ↑ Diuretics to re-establish euvolemia ASAP (24-72 hr) w/out change in β-blocker dosing
Don't want to abruptly stop beta blocker
What do you do if a CHF pt develops decompensation while on a beta blocker in an IP setting?
IP Tx (failed intensive OP Tx)
1. ↓ β-blocker dose if the patient is unresponsive to diuretic and/or vasodilator therapy
2. ↓ Dose increases risk
What are the indications for digitalis?
1. Symptomatic CHF in pt’s on diuretics and RAAS inhibitors
2. Pt’s with CHF & atrial fibrillation who require rate control
What is the moa of digitalis? What are the se?
1. Positive inotrope
A. ↑ Force and velocity of myocardial contraction
2. Narrow therapeutic to toxic ratio
3. Dig toxicity: nausea, blurred vision, yellow halos
What is the physiologic effect of vasodilators? When are they used?
1. ↓ Preload and improve CO
2. Added to previous meds in severe or refractory CHF
When are IV Nitrates (NTG, hydralazine, nitroprusside) indicated?
Indicated for acute or severely decompensated CHF, esp in setting of myocardial ischemia or HTN
What is the effect of IV Nesitiride/Natrecor?
Potent vasodilator ↓ ventricular filling pressures
What are the indications for anticoag therapy?
PT/INR target range 2 - 3.0
When is an Implantable Cardioverter Defibrillator (ICD) indicated?
Pt’s with HF at risk of fatal arrhythmias (EF < 35%)
When is an biventricular pacing indicated? How does it help CHF pts?
1. HF 2° to systolic dysfunction have abnormal intraventricular conduction results in dyssynchronous and inefficient contractions
2. Reduces mortality and hospitalization
Mod-severe HF, EF < 35%, prolonged QRS duration
What lifestyle changes are indicated for CHF pts?
1. Case Management
A. 2 gm Na diet
B. Daily weights
C. Exercise training program
2. Cardiac transplantation
A. 1 yr survival rates > 80-90%
B. 5 yr survival rate > 70%
3. Palliative care
What is the prognosis for CHF pts?
1. Heart failure carries poor prognosis
2. Even with modern treatment, 5 year mortality rate is approx 50%