Heart Failure
Causes of HF: CAD (MC), HTN, DM, valvular dz, infilitration (amyloidosis), arrhythmias
RF: Smoking/COPD, etOH, obesity
The Basics
Left Ventricular End Diastolic Volume (LVEDV)
How much blood is in LV after diastolic filling
Stroke Volume
How much blood ejected
Determinants of SV
Preload - LVEDV or LVEDP
Stretch of heart fibers at end-diastole
Contractility
Force generated with a given preload
Afterload
Impedance of ejection
Ejection fraction (LV)
Fraction of EDV ejected end of systole
Stroke V olume/End diastolic volume
Systolic dysfunction
↓ in myocardial contractility
Less blood gets out (↓ SV)
More gets left behind (↑ end systolic volume/LVEDP)
Leftover blood ➔ eccentric remodeling
Causes of systolic dysfunction:
HF, arrhythmia, dilated cardiomyopathy, myocarditis
Diastolic dysfunction
Abnormality with relaxation/compliance
Can be from concentric remodeling (AS/HTN)
➔ impaired filling ➔ ↓ EDV ➔ ↓ SV
If less comes in less goes out
Causes of diastolic dysfunction:
HFrEF vs HFpEF
HF with reduced EF (HFrEF)
Greatly reduced EF (40% or 35%)
HF with preserved EF (HFpEF):
SSX of HF & LV diastolic dysfunction but with "normal" EF
"Normal" heart
"Normal" EDV = 120ml
"Normal" SV = 70 ml
70/120 = 0.58 (EF = 58%)
Systolic dysfunction ➔ ↑ EDV & ↓ SV
EDV = 150ml
SV = 50ml
50/150 = 0.33 (EF = 33%)
HF with reduced EF
Diastolic dysfunction ➔ ↓ EDV & ↓ SV
EDV = 80ml
SV= 40ml
40/80 = 0.50 (EF = 50%)
HF with preserved EF
Systolic dysfunction means less blood gets out and more blood is left behind ➔ ESV ➔ ↑ EDV
More left behind ➔ eccentric remodeling
Diastolic dysfunction means you start with less
Less when you start ➔ concentric remodeling (or EDV was low to start)
Feeling extra: Frank-Starling curve
SSX: RHF vs LHF
HF SSX: Congestion... it's a circuit... but some ssx are classically associated more with LHF than RHF
Left HF
Pulmonary congestion
Dyspnea on exertion, paroxysmal nocturnal dyspnea, orthopnea, crackles/rales
CXR: Prominent pulmonary vessels, perihilar alveolar edema
Cephalization - ↑ pulmonary vessel prominence in upper lobes
Peribronchial cuffing
Septal/Kerley B lines and effusions can be seen with bedside US
Syncope/presyncope - ↓ SV ➔ ↓ perfusion to brain ➔
Right HF
Systemic congestion ➔ ↑ venous pressure
↑ JVP (volume overload) (not engorged external jugular vein)
Kussmaul's sign: ↓ compliance of RV ➔ ↑ JVP with inspiration
Normally inspiration ➔ ↑ right sided preload ➔ ↓ JVP
Peripheral edema
Hepatic congestion ➔ ascites, jaundice, nausea
Generally, DOE in HF is attributed to ↓ CO
If you're feeling extra:
Paroxysmal nocturnal dyspnea is typically attributed to ↑ venous return
Edema that stayed peripheral makes it to heart when pt goes supine all night
Displaced Point of Maximum Impulse (PMI): ↓ EF by 10%: laterally displaced
High output HF
High output state ➔ normal cardiac function with ↓ systemic vascular resistance (arteriolar dilation or bypass of arterioles and capillary beds)
Causes include cirrhosis, hyperthyroid, AV fistulas, B1 (thiamine) deficiency, sepsis