CHF Flashcards
CHF definition
Clinical syndrome caused by inability of the heart to pump enough blood to maintain fluid and metabolic homeostasis.
Risk factors are CAD, HTN, cardiomyopathy, valvular heart disease, diabetes
L vs R. Systolic vs Diastolic.
Systolic dysfunction
Defined as reduced EF (less than 50%) and increased LV EDVs.
Caused by inadequate LV contractility or increased afterload.
Heart compensates for lower EF and increased preload through hypertrophy and ventricular dilation (Frank-Starling law), but compensation usually fails, leading to increased myocardial work and worsening systolic function
Most common cause of R sided heart failure
L sided heart failure
man admitted for CHF exacerbation with low EF. Patient ready for discharge and his meds include lasix and metoprolol. Next best step in management?
Add ACEi. Shown to have positive mortality benefit when used with B-blockers in NYHA class II-IV HF patients.
History and physical for systolic dysfunction
Exertional dyspnea is the earliest and most common presenting symptom and progresses to orthopnea, paroxysmal nocturnal dyspnea and finally rest dyspnea
Patients may report chronic cough, fatigue, peripheral edema, nocturia and/or abdominal fullness
Exam reveals parasternal lift, an elevated and sustained left ventricular impulse, an S3/S4 gallop, JVD and peripheral edema
Look for signs to distinguish L from R sided failure
Diagnosis of systolic dysfunction
CHF is a clinical syndrome whose diagnosis is based on signs and symptoms
CXR may show cardiomegaly, cephalization of pulmonary vessels, pleural effusions, vascular congestion, interstitial edema, and prominent hila
Echo will show low EF and ventricular dilation
Labs include BNP over 500, increased creatinine sometimes, and low sodium in later stages
ECG will usually be nondiagnostic but may help pinpoint an underlying cause like AF, an old MI, or LVH as a sign of long-standing hypertension
Acute treatment of CHF
1) Correct underlying causes such as arrhythmias, myocardial ischemia and drugs (CCBs, antiarrhythmics, NSAIDs, alcohol, thyroid and valvular disease, high-output states)
2) Diurese aggressively with loop or thiazide diuretics
3) Give ACEis to all patients who can tolerate them. Consider an ARB if patient cannot tolerate ACEi
4) B-blockers should NOT be used during decompensated CHF but should be started when patient is euvolemic
5) Treat acute pulmonary congestion with LMNOP (Lasix, Morphine, Nitrates, O2, Position - upright)
NYHA functional classification of CHF
I - no limit of activity, no sx with normal activity
II - Slight limitation of activity, comfortable at rest or with mild exertion
III - marked limitation of activity, comfortable only at rest
IV - Any physical activity brings on discomfort, symptoms present at rest
Treatment of chronic CHF
1) Control comorbid conditions and limit dietary Na and fluid intake
2) Long term B-blockers and ACEi/ARB help prevent remodeling of the heart and lower mortality for NYHA class II-IV patients. Avoid CCBs.
3) Daily ASA and a statin are recommended if the underlying cause is prior MI
4) Chronic diuretic therapy (loop plus or minus a thiazide) can prevent volume overload
5) Low dose spironolactone lowers mortality risk in patients with NYHA III-IV
6) Anticoagulate patients with a history of previous embolic events, AF, or a mobile LV thrombus
Consider an implantable biventricular cardiac defibrillator in patients with EF below 35%
CHF that is unresponsive to maximal medical therapy may require a mechanical LV assist device or cardiac transplant
Nonsystolic dysfunction definition
Defined by reduced ventricular compliance with normal systolic function. The ventricle has either impaired active relaxation (secondary to ischemia, aging, and or hypertrophy) or impaired passive filling (Scarring from prior MI; restrictive cardiomyopathy).
LV EDP increases, CO remains essentially normal and EF is normal or high.
History and physical for nonsystolic dysfunction
Associated with stable and unstable angina, SOB, dyspnea on exertion, arrhythmias, MI, HF and sudden death
Tx of nonsystolic dysfunction
1) Diuretics are first line therapy
2) Maintain rate and BP control via B-blockers, ACEis, ARBs or CCBs
3) Digoxin is not useful in these patients
Left sided CHF symptoms
1) Dyspnea***
2) L sided S3/S4 gallop
3) Bilateral basilar rales
4) Pleural effusions
5) Pulmonary edema
6) Orthopnea, PND
Right sided CHF symptoms
1) Fluid retention***
2) Right sided S3/S4 gallop
3) JVD
4) Hepatojugular reflex
5) Peripheral edema
6) Hepatomegaly, ascites
Systolic dysfunction general patient characteristics
1) Age less than 65 often
2) Comorbidities often dilated cardiomyopathy, valvular heart disease
3) Physical shows displaced PMI, S3 gallop
4) CXR shows pulmonary congestion and cardiomegaly
5) ECG/Echo shows Q waves, low EF (below 40%)
