Congestive Heart Failure

History

DCM presents with slowly progressing signs and symptoms of congestive heart failure, including shortness of breath, easy fatigue, and poor exercise tolerance.

Congestive heart failure can have a profound impact on the way people feel and function, causing:

• easy fatigue
• shortness of breath and tachypnea
• poor exercise capacity
• diaphoresis and pallor (a serious sign - SNS activated to increase cardiac output. Beta-block.)

Left heart failure can lead to pulmonary congestion:

• cough, crackles, pleural effusion
• paroxysmal nocturnal dyspnea
• orthopnea

Advanced CHF can lead to hypoxic encephalopathy, with irritability, restlessness, and loss of attention span, potentially progressing into stupor and coma.

NYHA Classifications

• Class I - no symptoms with ordinary physical activity

• Class II - slight limitation. Comfortable at rest, but ordinary exertion results in palpitations, fatigue, dyspnea, or angina.

• Class III - Comfortable at rest, but marked limitiations otherwise. Likely can't work for a living because of fatigue.

• Class IV - symptoms of cardiac insufficiency at rest or with minimal activity. likely needs institutionalization. Symptoms of cardiac insufficiancy at rest.

Frail elderly present atypically

Physical Exam

Clinical accuracy rate is 75-80% in cases of acute decompensation.

Cardiovascular

• tachycardia (100-120 is common)
• soft heart sounds (in systolic people)
• S3

Right heart failure can lead to systemic congestion and its symptoms:

• edema (ascites more in older folks, pitting edema in younger)
• weight gain
• elevated jugular venous pressure
• hepatomegaly
• pleural effusions

Lab Investigations

• low O2 sats
• low Na+ (poor prognosticator)
• azotemia (renal hypoperfusion)

BNP - B-type natriuretic peptide

• increases with age
• <100 means CHF is unlikely; >400 pg/ml strongly suggests it
• secreted by ventricles of heart in response to stress or excessive stretching by myocytes
• I heard it causes vasoconstriction and diuresis
• elevated levels in blood can be helpful, but there are false +ves
• pricey
• over 90% when combining clinical impression with BNP
• if its obvious, don't use it. Use in cases of uncertainty

Diagnostic Imaging

ECG

Chest X Ray

Extracardiac effects of left-sided failure are most prominent in the lungs. Increased pressure backs up into pulmonary capillaries and arteries, resulting in pulmonary edema. Perivascular and interstitial transudate forms, particularly in the interlobular septa. This is responsible for Kerley's B lines, or septal lines. Progressive widening of alveolar septa eveltually leads to accumulation of fluid in the alveolar air spaces themselves.

Peribronchial cuffing - fluid extravasation around bronchi (online image)

Vascular redistribution (cephalization of flow) - increased flow to the apices of the lung as a result of increased pulmonary venous pressure.

Echocardiography

Ejection fraction is a useful feature.

Infants and Children

cardinal findings

• tachypnea
• tachcardia
• cardiomegaly

other findings

• hepatomegaly
• failure to thrive
• cyanosis, especially during feeding or exertion

Medication

Treatments improving mortality target neurohormonal mediators of heart function. Treatment protocol depends on functional class, ability to come for blood testing, and other reasons.

diuretics, especially loop diuretics and K+ sparing diuretics, unload the heart

• not so many clincial trials
• loop diuretics (ie furosemide) recommended for people with congestive symptoms. Once acute congesiton is dealt with, use lowest dose
• in pts with refractory failure, a 2nd diuretic (thiazides or low-dose metozalone) can be added cautiously
• edema is substantial in gut. absorption drops. don't use oral pills - use IV at first.
• thaizides don't work well by themselves. why?

ACE inhibitors

• together with beta blockers, are standard therapy
• provide ~20-25% improvement in many regards - hypertrophy, hospitalizations, stroke
• contra: hypokalemia, severe renal insufficiency, severe hypotension
• long term mortality benefit - up to 12 years
• reduce TPR and therefore preload and afterload
• decrease aldosterone leading to lowered preload
• decreased NE release
• decreased bradykinin breakdown
• decreased ventricular remodeling
• ARBs can be considered as an alternative in pts with AMI with acute HF or LVEF <40%
  • can be used in addition to ACEIs and further drops in negative outcomes
• additional cost, effort, side effects

cardiac glycosides - digoxin

• increased contractility, leading to increased CO
• anti-arrhythmic
• Na/H exchange inhibitor
• neutral effect on mortality, improves exercise, symptoms, hospitalizations
• reserved for pts with many symptoms

beta blockers (carvedilol, bisoprolol, metoprolol tartrate): block SNS activity

• metoprolol blocks signs and symptoms of CHF; decreases HR
• carvedilol (a nonselective SNS antagonist) reduces signs and symptoms, slows progression, and decreases mortality
  • β1 antagonism decreases HR
• α1 antagonism blocks vasoconstriction and decreases afterload

reduce mortality by 30-40%,most pronounced in sickest patients.

we think it antagonizes toxic neurohormonal effects, but we don't know

• perhaps bb's lower concentration of recpetors
• airplane headphones analogy

 

as bb's reduce HR and contractility, too much too soon can decrease EF and make them very sick. Therefore, titrate slowly upwards to avoid initial deterioiration and to then build clincial beenfits.

• side effects: hypotension, fluid retention, braducardia/heart block

vasodilators, ie nitroglycerin, used acutely

ionotropic agents, ie dobutamine, used acutely.

low dose dopamine: vasodilator in renal beds, allowing diuretics to penetrate

Aldosterone Blockers

ie spironolactone

• reserve for pts who have failed other treatments

minimal impact on BP, but major effect on creatinine and potassium

learn more about this...

nitrates + hydralazines

• strict vasodilator
• use in in people unable to tolerate ACEis and ARBs
• appear particulary useful in black folks

anticoagulation

• only use in ppl with arrhythmias or people with clots

Avoid:

• Ca²⁺ channel blockers
• NSAIDs
• some antipsychotics
• corticosteroids

Nutrition

Sodium intake should be limited to 2000 mg daily, and total fluid intake should also be controlled.

Weight should be used to assess this, and should be kept within +/- 2lb.

Exercise

Regular mild exercise promotes efficient blood flow.

Education

people with heart failure often have complex comorbidities and can't learn well.

5% of pts with CHF can explain what CHF is (get ref for this!)

Many therapies aren't taken.

• aggressive risk factor reduction
• lifestyle
• fluid/salt vigilance

Pediatric Treatments

fix underlying cause

medication

• reduce preload: diuretics
• inotropics: digoxin, dopamine, dobutamine
• reduce afterload: ACE inhibitors

nutrition

anemia

measure success by growth

Frail Elderly

CCS 2006 recommendations for elderly HF patients, with the focus on symptoms and quality of life, rather than

ACE inhibitors (monitor renal function and electrolytes) and beta-blockers are first line recommendations

beta blocker uptitration is less frequently successful due to postural hypotension

Assess for relevant co-morbidities: depression, dementia

Acute Decompensation

Acute decomensation may be treated as effectively in home as in hospital, providing adequate care is delivered, and at less cost (Tibaldi et al, 2009).