ILE 1 Unit 2 Objectives

What equation describes the major determinants of blood pressure?

BP = CO × SVR (Blood Pressure = Cardiac Output × Systemic Vascular Resistance)

What equation determines cardiac output?

CO = HR × SV (Cardiac Output = Heart Rate × Stroke Volume)

What happens to blood pressure when cardiac output increases?

It increases

What happens to blood pressure when cardiac output decreases?

It decreases

How does vasoconstriction affect blood pressure?

Vasoconstriction causes the systemic vascular resistance (SVR) to increase resulting in an increase of blood pressure

How does vasodilation affect blood pressure?

Vasodilation decreases the systemic vascular resistance (SVR) resulting in a decrease in blood pressure

How does increased heart rate affect blood pressure?

Increased Heart Rate causes an increase in Cardiac Output which increases Blood Pressure

How does increased stroke volume affect blood pressure?

↑ Stroke Volume → ↑ Cardiac Output → ↑ Blood Pressure

How does increased sodium and water retention affect blood pressure?

↑ Na⁺ and H₂O retention → ↑ blood volume → ↑ blood pressure

How does increased sodium and water excretion affect blood pressure?

↑ Na⁺ and H₂O excretion → ↓ blood volume → ↓ blood pressure

What major physiologic factors regulate blood pressure?

Cardiac output, systemic vascular resistance, blood volume/kidney function, autonomic nervous system activity, RAAS, and vascular smooth muscle contraction

How does sympathetic nervous system activation affect blood pressure?

Sympathetic activation increases cardiac activity and vascular tone, which increases blood pressure

What is RAAS?

Renin-Angiotensin-Aldosterone System; a major system involved in regulating blood pressure and blood volume

What is the basic sequence of RAAS?

Renin → Angiotensin I → ACE → Angiotensin II

What converts Angiotensin I to Angiotensin II?

Angiotensin-Converting Enzyme (ACE)

How does Angiotensin II increase blood pressure?

It causes vasoconstriction and promotes aldosterone effects, increasing systemic vascular resistance and sodium/water retention

How does aldosterone affect blood pressure?

Aldosterone promotes Na⁺ retention; water follows sodium, increasing blood volume and contributing to increased blood pressure

What are the two major ways Angiotensin II raises blood pressure?

Vasoconstriction and aldosterone-related Na⁺/water retention

How does calcium affect vascular smooth muscle?

↑ intracellular Ca²⁺ promotes vascular smooth muscle contraction

How does increased intracellular calcium affect blood pressure?

↑ Ca²⁺ → smooth muscle contraction → vasoconstriction → ↑ SVR → ↑ blood pressure

How does decreased calcium entry into vascular smooth muscle affect blood pressure?

↓ Ca²⁺ entry → smooth muscle relaxation → vasodilation → ↓ SVR → ↓ blood pressure

What are the 3 main "knobs" that control blood pressure?

Heart/cardiac output, blood vessels/systemic vascular resistance, and blood volume

What are the two divisions of the autonomic nervous system (ANS)?

Sympathetic nervous system (SNS) and parasympathetic nervous system (PNS)

What is the general role of the sympathetic nervous system (SNS)?

"Fight or flight"

What is the general role of the parasympathetic nervous system (PNS)?

"Rest and digest"

What is the general organization of an autonomic nervous system pathway?

CNS → preganglionic neuron → ganglion → postganglionic neuron → target organ

What neurotransmitter is released by ALL preganglionic autonomic neurons?

Acetylcholine (ACh)

What receptors are found at autonomic ganglia?

Nicotinic receptors

What neurotransmitter is released by most sympathetic postganglionic neurons?

Norepinephrine (NE)

What receptors does norepinephrine primarily act on in the sympathetic nervous system?

Alpha (α) and beta (β) adrenergic receptors

What neurotransmitter is released by parasympathetic postganglionic neurons?

Acetylcholine (ACh)

What receptors does ACh act on at parasympathetic target organs?

Muscarinic receptors

What is a simple way to remember SNS vs PNS neurotransmitters?

SNS = starts with ACh —> switches to NE

PNS = starts with ACh and stays ACh

What is etiology?

The cause or origin of a disease.

What is pathophysiology?

The abnormal physiologic changes/processes that occur with a disease.

What is the etiology of essential/primary hypertension?

There is no single identifiable cause; multiple factors contribute to the development of essential/primary hypertension.

What is the basic pathophysiology of essential/primary hypertension?

Altered blood pressure regulation causes sustained ↑ cardiac output and/or ↑ systemic vascular resistance, resulting in chronically elevated blood pressure.

What major physiologic mechanisms can contribute to essential hypertension?

Increased sympathetic activity, increased RAAS activity, increased Na⁺/H₂O retention and blood volume, and increased vascular resistance.

What is the key difference between primary and secondary hypertension regarding cause?

Primary hypertension has no single identifiable cause; secondary hypertension has an identifiable underlying cause.

What nonmodifiable/patient risk factors for hypertension are listed in the course material?

Family history, age, gender, race, and chronic kidney disease (CKD).

What modifiable risk factors for hypertension are listed in the course material?

Lack of physical activity; unhealthy diet, especially high sodium; overweight/obesity; sleep apnea; high cholesterol; diabetes; smoking/tobacco use; and stress.

What dietary factor is specifically emphasized as a risk factor for hypertension?

An unhealthy diet, especially one high in sodium.

What is the difference between a hypertension risk factor and a cause of secondary hypertension?

A risk factor increases the likelihood of developing hypertension; a secondary cause is an identifiable underlying condition causing the hypertension.

What is essential/primary hypertension?

Hypertension in which a definite cause for the elevated blood pressure is not known.

What is secondary hypertension?

Hypertension caused by another medical condition.

What categories of causes can produce secondary hypertension?

Renal, endocrine, vascular, and drug-related causes.

What is the common clinical presentation of hypertension?

Hypertension is commonly asymptomatic; patients may have elevated BP without noticeable symptoms.

How is blood pressure classification determined when SBP and DBP fall into different categories?

Classify the patient in the higher blood pressure category.

How many BP measurements are used to classify/diagnose hypertension?

Use the average of ≥2 readings obtained on ≥2 occasions.

What BP is classified as normal?

SBP <120 AND DBP <80 mmHg.

What BP is classified as elevated?

SBP 120–129 AND DBP <80 mmHg.

What BP is classified as Stage 1 hypertension?

SBP 130–139 OR DBP 80–89 mmHg.

What BP is classified as Stage 2 hypertension?

SBP ≥140 OR DBP ≥90 mmHg.

What does "OR" mean when classifying Stage 1 or Stage 2 hypertension?

Only the SBP OR DBP needs to meet the higher category; classify according to the higher category.

What is white coat hypertension?

Elevated blood pressure that occurs only in a medical environment.

What is masked hypertension?

Elevated blood pressure that occurs outside of a medical environment.

What is the key difference between white coat and masked hypertension?

White coat HTN = high BP in the medical setting; masked HTN = high BP outside the medical setting.

How do you distinguish primary from secondary hypertension in a patient case?

Primary HTN has no definite known cause; secondary HTN is caused by an identifiable underlying medical condition or drug.

Why is out-of-office BP monitoring useful?

It helps determine the patient's BP outside the medical environment and can help identify patterns such as white coat or masked hypertension.

What is the minimum BP goal for adults diagnosed with hypertension in the course material?

What newer BP goal is encouraged in the 2025 guideline material?

How is hypertension described when BP is below the patient's goal?

Controlled.

How is hypertension described when BP is above the patient's goal?

Uncontrolled.

Why may BP goals need to be patient-specific?

Treatment targets should consider the patient's overall risk versus benefit rather than applying a lower target without considering the individual patient.

What major long-term cardiovascular complications can result from hypertension?

Heart attack, stroke, peripheral arterial disease (ASCVD), aneurysm, and heart failure.

What renal complication can result from long-term hypertension?

Chronic kidney disease (CKD).

What neurologic complications can result from long-term hypertension?

Memory problems and dementia.

What eye complications can result from long-term hypertension?

Thickened, torn, or broken blood vessels in the eye.

What is a major purpose of treating hypertension even when the patient has no symptoms?

To prevent long-term complications such as stroke, heart attack, and chronic kidney disease.

What four antihypertensive classes are first-line for essential hypertension in this course?

Thiazide diuretics, long-acting dihydropyridine calcium channel blockers (DHP CCBs), ACE inhibitors (ACEIs), and angiotensin receptor blockers (ARBs).

Which calcium channel blocker group is first-line for essential hypertension?

Long-acting dihydropyridine calcium channel blockers (DHP CCBs).

Are non-dihydropyridine calcium channel blockers first-line for essential hypertension?

No. They are alternative/second-line agents in the course drug table.

Are beta blockers first-line for uncomplicated essential hypertension?

No. They are alternative/second-line agents in the course material.

Are aldosterone antagonists first-line for essential hypertension?

No. They are alternative/second-line agents.

Are loop diuretics first-line for essential hypertension?

No. They are alternative/second-line agents.

Are direct vasodilators first-line for essential hypertension?

No. They are alternative/second-line agents.

Are centrally acting alpha agonists first-line for essential hypertension?

No. They are alternative/second-line agents.

Are alpha blockers first-line for essential hypertension?

No. They are alternative/second-line agents.

Why are certain antihypertensive drug classes considered first-line?

First-line therapy is based on evidence-based clinical guideline recommendations and the highest available evidence for desired patient outcomes.

What should be considered when choosing an antihypertensive for a specific patient?

Guidelines/first-line status, comorbidities, contraindications, drug interactions, and other safety and efficacy concerns.

What is the relationship between antihypertensive MOA and hypertension pathophysiology?

Antihypertensive drugs target physiologic mechanisms that contribute to elevated BP, such as RAAS activity, renal Na⁺/water handling, vascular smooth muscle tone, and sympathetic activity.

What major system do ACE inhibitors and ARBs target?

The renin-angiotensin-aldosterone system (RAAS).

What is the drug target of ACE inhibitors?

Angiotensin-converting enzyme (ACE).

What type of drug action does an ACE inhibitor have on ACE?

It inhibits the ACE enzyme.

What major organ/system is targeted by diuretics in hypertension?

The kidney, especially renal ion transporters involved in sodium and water handling.

What major tissue is targeted by calcium channel blockers in hypertension?

Vascular smooth muscle/vasculature.

What type of target do calcium channel blockers act on?

Calcium ion channels.

What system is targeted by beta blockers in hypertension?

Beta adrenergic receptors associated with sympathetic nervous system activity.

What major site is targeted by centrally acting alpha₂ agonists?

The brain/central nervous system.

What major site is targeted by alpha₁ blockers?

The vasculature.

What major site is targeted by direct vasodilators?

The vasculature.

What are example generic ACE inhibitors from the course drug table?

Captopril and enalapril.

What generic ARB is listed in the course drug table?

Valsartan.

What generic thiazide diuretics are listed in the course drug table?

Hydrochlorothiazide and chlorthalidone.

What generic DHP calcium channel blocker is listed in the course drug table?

Amlodipine.

What generic non-DHP calcium channel blockers are listed in the course drug table?

Verapamil and diltiazem.

What generic beta blocker is listed in the course drug table?

Metoprolol.

What generic aldosterone antagonists are listed in the course drug table?

Spironolactone and eplerenone.

What generic loop diuretic is listed in the course drug table?

Furosemide.

What generic direct vasodilators are listed in the course drug table?

Hydralazine and minoxidil.