CHF

it means the heart has an abnormal shape or isn't working properly, which causes specific symptoms.

What Exactly is Heart Failure?

Blood tests, congestion

To officially diagnose heart failure, doctors look for proof in one of two ways

Myocardium, pericardium, heart valves

it is the end result of many other heart problems. These problems might involve:

HFrEF (Heart Failure with reduced Ejection Fraction)

The heart muscle is too weak to squeeze properly. Because it's weak, the percentage of blood it manages to pump out with each beat (the "ejection fraction") is lower than normal.

HFpEF (Heart Failure with preserved Ejection Fraction)

The heart is strong enough to pump, but the muscle has become stiff. It can't relax (which the text calls "lusitropic properties") enough to let a normal amount of blood fill the chamber in the first place.

Fatigue, Dyspnea, Volume overload

Symptoms of heart failure

Elderly, people with comorbidities, racial and ethnic disparities

Who gets most of heart failure

HFrEF
HFpEF
HFmrEF

HFimpEF

The Four Categories of Heart Failure

Clogged arteries, heart attacks, dilated cardiomyopathy, overworked hearts, high bp

Main causes of heart failure

Amyloidosis, cancer therapies

Two Emerging Causes Doctors are also seeing more heart failure caused by two specific things

Heart Rate (HR) x Stroke Volume (SV)

CO formula

Cardiac output

is the total amount of blood your heart pumps in one minute.

• increased natriuretic peptide plasma concentrations

• objective evidence of pulmonary or systemic congestion of cardiogenic origin.

Heart failure (HF) is a clinical syndrome associated with symptoms signs due to abnormalities in cardiac structure and/or function substantiated by the presence of

The left ventricular ejection fraction (LVEF)

is used to classify patients into four different types of HF

Cardiac Output (CO) x Systemic Vascular Resistance (SVR)

Mean Arterial Pressure (MAP) formula

obesity, diabetes, and high blood pressure

Patients with HFpEF frequently suffer from

Tachycardia & increased contractility, Fluid retention & increased preload, Vasoconstriction & increased afterload, Ventricular hypertrophy & remodeling

four main tactics the body uses in reduced EF

Concentric Hypertrophy

Pumping against high blood pressure causes the walls to get extremely thick and stiff (common in stiff-heart HFpEF)

Eccentric Hypertrophy

A weak, over-filled heart stretches out. The muscle walls become thin, and the main chamber turns from a healthy, football-like ellipse into a bloated, basketball-like sphere.

Angiotensin II, NE, ET, aldosterone, vasopressin, and numerous inflammatory cytokines

Responsible for ventricular remodeling by initiating the signal transduction cascade.

Amyloidosis

is a disease where abnormal, misfolded proteins don't get broken down. Instead, they act like sticky gunk or trash that builds up in your body’s tissues.

Amyloid Cardiomyopathy

When this sticky protein gunk builds up in the spaces between your heart muscle cells, it’s called

AL Amyloidosis (Light Chain)

This is caused by a problem in the bone marrow, where abnormal "light chain" proteins are pumped into the blood and get stuck in the organs.

ATTR Amyloidosis (Transthyretin)

this protein becomes unstable, falls apart, and forms the sticky gunk.

transthyretin

which normally helps carry vitamins and hormones in your blood.

Hypertrophic Cardiomyopathy (HCM)

is a condition where the muscle of the heart grows abnormally thick.

Neurohormonal Model

It explains that heart failure is a chain reaction

Autocrine, paracrine factors

Nuerohormones

Angiotensin II

• Severe Squeezing: It locks into specific receptors (AT1) in your blood vessels, acting as a potent "vasoconstrictor." This narrows the blood vessels, making it much harder for the weak heart to push blood through them.

• Releasing More Stressors: It triggers the release of other stress chemicals, like AVP (vasopressin) and ET-1 (endothelin-1), and forces nerves to dump more adrenaline-like chemicals (Norepinephrine) into the system.

• Salt Hoarding: It tells the kidneys to hold onto salt (sodium) directly, and indirectly by releasing another hormone called aldosterone.

• Kidney Pressure: It squeezes specific blood vessels in the kidneys to artificially keep pressure high enough so the kidneys don't fail.

• Direct Heart Destruction: It directly attacks the heart, causing it to grow abnormally thick (hypertrophy), change shape (remodeling), kill off its own cells (apoptosis), and create inflammation and scarring.

Norepinephrine

• Heart Exhaustion: It forces the heart to beat faster (tachycardia) and squeeze harder, while narrowing blood vessels.

• Burned-Out Receptors: Because the heart is constantly bombarded by NE, its chemical receivers (beta-1 receptors) get exhausted and shut down (downregulation), making the heart lose sensitivity to normal signals.

• Lethal Rhythms and Cell Death: Too much of this chemical increases the risk of dangerous, irregular heartbeats (arrhythmias) and literally kills heart muscle cells through cell death (apoptosis and necrosis).

• Shape Changes: Like Angiotensin II, it forces the heart to remodel and thicken.

Aldosterone

• Severe Swelling: Aldosterone levels spike because Angiotensin II triggers its release, and because the failing heart isn't pumping enough blood to the liver for the liver to filter it out. This excess hormone forces the body to retain salt and water, causing classic swelling (edema) and fluid overload.

• Heart Scarring (Fibrosis): The text points out that its direct effect on the heart might be even worse than the swelling. Aldosterone creates tough scar tissue (collagen) inside the heart muscle.

• Stiff Pump: This scar tissue makes the heart stiff and rigid. A stiff heart can't squeeze properly (systolic function) and can't relax to fill up with blood properly (diastolic function). It also causes system-wide inflammation and muscle/bone wasting.

Natriuretic Peptides

• The Relief Valve: When the heart is stretched from too much pressure or fluid, it releases these peptides. They act as a natural defense system, making you pee out salt and water (diuresis) and fighting back against the harmful stress chemicals (RAAS and SNS).

• A Crucial Blood Test: Because the heart releases BNP when it's stressed, doctors use BNP blood tests as a primary tool to diagnose heart failure. If a patient comes into urgent care short of breath, a high BNP level tells the doctor the shortness of breath is due to heart failure, not just a lung problem.

• Limitations: While great for diagnosis and predicting how bad the disease is (prognosis), constantly checking BNP levels to guide daily medication doses hasn't proven to be consistently helpful, and things like obesity can falsely lower the test results.

AVP (Vasopressin)

This hormone tells the kidneys to hold onto pure water. In heart failure, it's elevated, causing fluid overload, dangerously low sodium levels in the blood, and narrowed blood vessels.

SGLT2 Inhibitors

They do this by reducing inflammation, stress, and improving how the heart uses energy, further proving that heart failure is a complex, whole-body disease.

Dyspnea and fatigue leading to exercise intolerance and fluid overload resulting in peripheral edema and pulmonary congestion

signs and symptoms

Bulging neck veins, peripheral edema, rapid weight gain

Sign of systemic congestion

Worsening kidneys, cold hand and feet, confusion, fast heart rate, low bp

Signs of Low Cardiac Output

• Improve the patient’s overall quality of life.

• Relieve or reduce uncomfortable symptoms (like shortness of breath or swelling).

• Keep the patient out of the hospital.

• Slow down the disease so it doesn't get worse quickly.

• Help the patient live longer.

The main goals of treatment are to:

Prevention

Main tx goal for stage A HF

ACE Is/ARBs, SGLT2 Is, Statins

Medications Used for Prevention

Stage B

there is now actual physical evidence that your heart is damaged or struggling.

• Structural Heart disease

• Abnormal cardia function

• High blood test markers

Doctors diagnose Stage B if you meet any of these criteria:

• LV Hypertrophy

• MI

• Valvular disease

• LVEF < 40%

Common Conditions Found in Stage B

• medications are maxed

• High risk

• frequent hospital visits

Doctors classify you as Stage D if

Patients with an ejection fraction (LVEF) under 35%

Who gets ICD

ARNI

BETA BLOCKER

ALDOSTERONE ANTAGONIST

SGLT2 INHIBITOR

In class C, the guidelines state these patients need a combination of four powerful medication classes:

• Hydralazine-nitrates (a combo that widens blood vessels, often used for African American patients).

• Digoxin (helps the heart squeeze a little harder).

• Ivabradine (slows down a heart rate that is still too fast despite beta-blockers).

• Vericiguat (a newer drug that helps relax blood vessels and improve heart function after a recent hospital stay).

If the "Core Four" aren't working well enough, doctors have a backup toolkit of very specific add-on medications they can consider for certain patients. These include:

ACE Inhibitors, ARBs, and Beta-Blockers

Pharmacologic Therapy for HFrEF

Calcium Channel Blockers (CCBs)

Drugs Unique to the "Stiff Pump"

ARNIs and SGLT2

doctors now prescribe _____ inhibitors for HFpEF using the exact same doses and monitoring rules as they do for HFrEF

ACE inhibitors

also stop the breakdown of a different chemical called bradykinin

ACE inhibitor

every single patient with a weak pump (HFrEF) must be on an

dry, nagging, tickly cough

This is the most common reason people quit taking the ACEi. Up to 20% of patients develop a

Bradykinin

Cough happens in ACEi because of the buildup of that chemical

Hypotendion, renal dysfunction, hyperkalemia, cough, angioedema

ACEi AE

ACE inhibitors, ARBs, ARNI

are strictly forbidden during pregnancy. They can cause severe birth defects, stunted growth, and fetal kidney failure.

ARBs

If a patient has a weak pumping heart, they are usually the backup plan.

candesartan, valsartan, and losartan

While there are many ARBs on the market, the heart failure guidelines only recommend three specific ones:

Kidney strain, hypotension, hyperkalemia

ARBs adverse effects

sacubitril/valsartan

Currently, there is only one ARNI drug approved for heart failure

36 hours

If you are switching from an ACE inhibitor to an ARNI, you must wait a full

Carvedilol

This drug blocks multiple types of receptors and acts as an antioxidant. Because it also widens blood vessels, it drops blood pressure more than the others. It is the best choice if a patient has poorly controlled high blood pressure.

Fatigue, bradycardia

b-blockers AE

β-blockers

should be used in all stable patients with Stages B-D HFrEF

ARNI or an SGLT2 inhibitor

taking the newer heart medications like ______ actually helps lower the risk of your potassium spiking.

Loop Diuretics

These drugs attack a specific pump in the kidneys (the Na-K-2Cl transporter) to stop the body from absorbing salt. Where salt goes, water follows—so the patient pees it all out.

Furosemide, Bumetanide, and Torsemide

There are three main loop diuretics:

thiazide (HCTZ, Metolazone)

However, if a patient has hit the "ceiling" with their strong loop diuretic and is still swollen, a doctor will add a

thiazides

are great at lowering blood pressure, they are also highly useful for patients with mild fluid buildup and high blood pressure (which is very common in patients with the "stiff pump" HFpEF)

Nitrates

These drugs release nitric oxide, a chemical that relaxes your veins. By widening the veins, more blood pools in your body instead of rushing into the heart all at once. This reduces the fluid pressure stretching the heart (known as preload).

Hydralazine

This drug specifically targets and relaxes your arteries (the pipes carrying blood away from the heart). By widening these pipes, the resistance drops (reducing afterload), making it much easier for the weak heart to pump blood forward to the rest of the body.

BiDil® (which contains both a nitrate and hydralazine)

drug specifically for treating heart failure in African Americans.

Nitrates

are actually harmful to patients with a stiff pump. Studies show that giving this to these patients severely reduces their ability to exercise, ruins their quality of life, and causes them to feel faint or actually pass out (syncope).

Ivabradine

targets and blocks this specific electrical current. By doing so, it slows down how often the pacemaker fires, which gently lowers your heart rate.

Ivabradine

only affects the heart rate. It does not lower your blood pressure, it does not change how electrical signals travel through the rest of the heart, and it does not weaken the heart's physical pumping squeeze.

Ivabradine

However, if a patient is on their maximum beta-blocker dose and their heart rate is still stubbornly sitting above 70 beats per minute, doctors will add

Atrial Fibrillation, bradycardia, visual disturbances

Ivabradine AE

Digoxin

It increases the "rest-and-digest" signals. This naturally slows the heart rate down, giving the heart chambers more time to fully fill with blood between beats.

Vericiguat

It is an "sGC activator." It directly grabs onto that middle receptor (sGC) and forces it to pump out that final, healthy, relaxing chemical (cGMP), even if the body isn't making enough of its own Nitric Oxide.

Anemia

Vericiguat AE

verapamil and diltiazem

Drugs like ____ are absolutely forbidden (contraindicated) for patients with a weak pump. This is because they have a "negative inotropic effect"—a medical term meaning they physically weaken the squeezing power of the heart muscle.

Tafamidis

It acts like molecular superglue. The drug physically binds to specific spots on the TTR protein (the thyroxine-binding sites) and locks the 4-piece puzzle together.

Prevention

Main goal tx for class A HF

CAD, HTN, Weight & blood sugar

Key risks in Class A

MI, Valvular disease, LVH, LVEF <40%

Common condition found in stage B

spironolactone and eplerenone.

Aldosterone antagonist

Aldosterone

causes the heart to build up stiff scar tissue (fibrosis) and dangerously change shape (remodeling). Blocking the hormone stops this scarring process.

ACE Inhibitors, ARBs, and Beta-Blockers

In a "weak pump" (HFrEF), these drugs are mandatory to save the failing heart. But for a "stiff pump" (HFpEF), studies show these drugs don't actually fix the stiff heart muscle itself.

diltiazem, amlodipine, and verapamil

are generally dangerous (contraindicated) for patients with a weak pump (HFrEF) because they can make the pumping action even weaker.

ARBs

If a patient has a weak pumping heart, ___ are usually the backup plan.

ARNI

It was much better at preventing heart-related deaths and keeping people out of the hospital. While it did cause more low blood pressure, it actually caused less of the nagging cough and high potassium than the older drug.

Low dose aldosterone antagonist

Aldosterone antagonist for px with weak pump

Hyperkalemia, hormonal change

Side effect of aldosterone antagonist

Spironolactone

In men, this can cause impotence or the growth of breast tissue (gynecomastia). In women, it can cause irregular periods.

Dapagliflozin, Empagliflozin

SGLT2 inhibitors

SGLT2 inhibitors

Because of these trials, _____ are now a foundational, must-have treatment for nearly all heart failure patients.

Dehydration, Urinary infections, Fournier’s gangrene, ketocidosis

SGLT2 Is side effects

Torsemide & Bumetanide

These are lopp diuretics that are incredibly reliable. If you swallow a pill, nearly 100% of the drug makes it into your bloodstream. Therefore, an IV dose in the hospital is the exact same strength as the pill you take at home.

Furosemide

Loop diuretic that is highly unpredictable. Depending on the person, anywhere from 10% to 100% of the pill might actually make it into the bloodstream (the average is about 50%). Also, eating food or having a swollen, fluid-filled gut from heart failure severely slows down furosemide absorption. Because of this, an IV dose of furosemide is usually twice as strong as the pill form.

Torsemide

A loop diuretic that doesn't interact with food, lasts longer, and might even help heal the heart muscle