Quiz 7: Biomedical Sciences

What is the definition of heart failure?

a clinical syndrome resulting from any structural or functional cardiac disorder that impairs the ability of the ventricle to fill or eject blood

What are the 3 major etiologies of HF?

CAD, long-standing hypertension, and cardiomyopathies

What are examples of cardiomyopathy causes?

familial/genetic, diabetic, or infectious myocarditis

What are some drug-related causes of heart failure?

- direct cardiotoxic anti-cancer drugs

- negative inotropes (non-DHP CCBs, beta-blockers, some anti-arrhythmics)

- drugs that cause Na⁺/water retention (NSAIDs, corticosteroids)

Preload

venous return that fills the left ventricle, stretching the muscle prior to contraction

What does the Frank-Starling law state?

within physiological limits, increased LV filling increases stroke volume

How does preload-stroke volume response differ in compensated HF vs normal?

Reduced strove volume with same given preload compared to normal.

What happens in decompensated heart failure regarding preload?

increasing LV filling no longer increases stroke volume; symptoms persist

Afterload

the resistance the heart must pump against, represented by systemic vascular resistance

What is cardiac output?

stroke volume × heart rate

Why is extremely high heart rate harmful in HF?

it reduces diastolic filling time, decreasing stroke volume

Contractility

the intrinsic strength of the cardiac muscle

What two major consequences occur when the heart pump fails?

increased venous congestion and decreased cardiac output

What symptoms result from venous congestion?

pulmonary edema and peripheral edema

What symptoms result from decreased cardiac output?

fatigue, weakness, reduced organ perfusion

What neurohormonal systems activate in response to low cardiac output?

RAAS and the sympathetic nervous system

What are key mediators released due to RAAS/SNS activation in HF?

angiotensin II, aldosterone, norepinephrine, epinephrine

How does Ang II and aldosterone worsen HF?

increase afterload, preload, sodium/water retention, and direct myocardial remodeling

Why is HF described as a "vicious cycle"?

compensatory responses worsen cardiac workload and structural damage over time

All the following are maladaptive responses to heart failure,

EXCEPT:

improved renal blood flow

3 multiple choice options

What are the four primary drug therapy pillars for HFrEF?

Beta-blockers, RAAS inhibitors (ARNi > ACEI > ARB), SGLT2 inhibitors, MRAs

Which beta-blockers reduce mortality in HF?

bisoprolol, carvedilol, metoprolol succinate (SR)

How do beta-blockers benefit HF?

reduce catecholamine toxicity, decrease remodeling, reduce workload

How do ACE inhibitors benefit HF?

reduce preload, afterload, and long-term cardiac remodeling; improve survival

When are ARBs used in HF?

when ACE inhibitors are not tolerated (e.g., cough, angioedema)

Why is combining NSAIDs with ACEI/ARB dangerous in HF?

loss of afferent vasodilation + efferent vasoconstriction → ↓ GFR → acute kidney injury

What is the major benefit of SGLT2 inhibitors in HF?

reduce HF worsening and CV death regardless of diabetes status

What is the primary role of loop diuretics in HF?

reduce fluid (water and salt) overload and improve symptoms

What extra benefit do MRAs (spironolactone/eplerenone) provide in HF?

reduce morbidity and mortality by blocking aldosterone-mediated remodeling

Venodilators

long-acting nitrates (ISDN, ISMN, nitroglycerin)

Arteriodilators

hydralazine

Which vasodilator combination reduces mortality in African Americans with HF?

isosorbide dinitrate + hydralazine

When is the nitrate/hydralazine combo used instead of ACEI/ARB?

pregnancy, intolerance, or renal insufficiency.

What is ejection fraction (EF)?

stroke volume ÷ end-diastolic volume

HFrEF

systolic dysfunction (reduced contraction)

HFpEF

diastolic dysfunction (impaired filling)

Are positive inotropes used in HFpEF?

No, because contractility is not the primary problem

Mr. A.A. is a 58-year-old patient who is recently diagnosed with heart failure with reduced ejection fraction (HFrEF).

His past medical history includes hypertension, IHD, dyslipidemia, and

bronchial asthma. His medication list includes HCTZ, verapamil, atorvastatin,

aspirin, clopidogrel, and occasional terbutaline inhaler for his mild asthma.

Which of these medications should be

discontinued after the recent diagnosis

of HFrEF?

Verapamil

3 multiple choice options

Which of these medications should be

prescribed to Mr. A.A.?

Ramipril

3 multiple choice options

If the cardiologist prescribes bisoprolol to Mr. A.A., you should educate the patient that

bisoprolol may worsen his asthma

3 multiple choice options