- In an average healthy person, normal LV ejection fraction (LVEF): >50%
- Roughly 50% of those with heart failure have reduced left ventricular (LV) function (HFrEF)
- Heart cannot squeeze/contract properly, and then progressively dilates.
- The other 50% have preserved (normal contraction) LV function (HFpEF)
- Cannot relax properly, leading to high diastolic (filling) pressures.
- New heart failure – work patient up for ischemic disease (CAD) and ACS
- Coronary Artery Disease causes 67% of heart failure! #1 cause of heart failure
- Symptomatic hypotension and kidney failure can be due to cardiac output failure. Organs simply do not have sufficient blood to perfuse and stay alive.
- Etiology of HFrEF
- Drugs – cyclophosphamide, doxorubicin, trastuzumab
- Toxins – EtOH, cocaine, cobalt/lead, amphetamines
- Systemic disease – hypo- or hyperthyroidism, HIV, SLE, Neuromuscular disease (Duchenne & Becker muscular dystrophy), scleroderma
- Idiopathic (unknown cause)
- Etiology of HFpEF
- Infiltrative – amyloidosis & hemochromatosis (check ferritin)
- Clinical signs and symptoms
- Shortness of breath either with exertion or at rest
- Orthopnea (shortness of breath lying flat on one’s back)
- Paroxysmal nocturnal dyspnea (sudden bouts of shortness of breath and cough during the night/sleep hours)
- Peripheral edema (swelling of feet/legs)
- Decompensated signs/symptoms
- More pillows at nighttime
- Can’t walk up as many stairs before getting short of breath
- Increased belly size, anorexia, nausea (gut edema)
- Patients must weigh themselves daily, call the office if interval change.
- History and physical
- Paroxysmal nocturnal dyspnea leads to >2x increase in likelihood of HF
- S3 confers 11x greater chance of HF.
- If no dyspnea on exertion or crackles on lung exam, HF less likely.
- BNP level – use when cause not clear. If elevated, dyspnea is due to heart failure! If not, consider other lungs as cause.
- BNP level increases with age and bad kidneys
- BNP level decreases with high BMI.
- 12-lead EKG
- Rule out MI, tachycardia, LV hypertrophy
- Labs – BMP, CBC, UA, LFTs, lipid panel, TSH
Workup to Find A Cause
- Must think of Ischemia first –
- Serial EKGs and troponin levels to evaluate for NSTEMI/STEMI.
- Routine investigation via stress or cath no longer part of routine workup for new HF patients.
- However, if chest pain/pressure and/or risk factors are present –> proceed to cardiac cath.
- Echocardiogram is most important test in HF.
- “Wall motion abnormalities” is a clue to CAD or MI.
- Assesses valvular anatomy and function
- Left ventricular end-diastolic dimension: can aid in telling how chronic the condition is and prognosis.
- If DILATED w/acute symptoms –> chronic disease process.
- If small LV –> better shot at recovery.
- Cardiac magnetic resonance (CMR)
- Looks for wall motion abnormalities, perfusion, and VIABILITY of tissue.
- If thinking fibrosis, infiltration (amyloid/sarcoid), or iron deposition.
ACP MKSAP 17: Cardiovascular Medicine, pp. 32-34
Image obtained via Google web search.