Lecture 6 Key Points - Hypertension & Hypotension

Hypertension ranges

Elevated blood pressure, often above 130/80 mmHg.

Hypotension ranges

Abnormally low blood pressure, typically below 90/60 mmHg.

Cardiovascular System

System comprising heart, blood, and vessels.

Systolic Pressure

Pressure during peak ventricular contraction.

Diastolic Pressure

Pressure during heart's resting phase.

Systemic Vascular Resistance (SVR)

Total resistance in arterial system.

Pulse Pressure

Difference between systolic and diastolic pressures.

Cardiac Output

Volume of blood pumped by the heart per minute.

Stroke Volume

Blood volume ejected per heartbeat, ~70 mL.

Heart Rate

Number of heartbeats per minute, average ~80 bpm.

Renin-Angiotensin-Aldosterone System

Hormonal system regulating blood pressure and fluid balance.

Angiotensin II

Potent vasoconstrictor increasing blood pressure.

Aldosterone

Hormone increasing sodium retention, affecting blood volume.

Vasopressin (ADH)

Hormone promoting water retention, increasing blood volume.

Primary Hypertension

90-95% of cases, cause unknown.

Secondary Hypertension

5-10% of cases, identifiable underlying causes.

Diuretics

First-line hypertension treatment, targets kidneys.

Vascular Resistance

Force opposing blood flow in vessels.

Autonomic Nervous System

Controls involuntary bodily functions, including blood pressure.

Short-term Regulation of blood pressure

Immediate adjustments via autonomic nervous system.

Intermediate Regulation of blood pressure

Involves hormonal responses to blood pressure changes.

Long-term Regulation of blood pressure

Endocrine adjustments affecting blood volume and pressure.

Thiazides

Most common diuretic class, mild effects.

Hydrochlorothiazide

Common thiazide diuretic, few side effects.

Loop Diuretics

Strong diuretics, potassium-wasting effects.

Furosemide

Loop diuretic, impairs Na+/K+/Cl- cotransporters.

Potassium-Sparing Diuretics

Inhibit Na+/K+ pump, retain potassium.

Spironolactone

Aldosterone antagonist, used in hypertension.

Triamterene

K+ sparing diuretic, often combined with thiazide.

Beta Blockers

Reduce heart rate, blood pressure, cardiac output.

Propranolol

Nonselective beta blocker, used for migraines.

Selective Beta Blockers

Atenolol and Metoprolol, once daily dosing.

ACE Inhibitors

Inhibit RAA system, prevent AT1 to AT2 conversion.

Lisinopril

Common ACE inhibitor, ideal for long-term therapy.

Angiotensin Receptor Antagonists

Inhibit AT2 effects, fewer side effects than ACE.

Losartan

Inhibits AT2 effects, less potent than ACE inhibitors.

Calcium Channel Blockers

Act on vascular smooth muscle, treat hypertension.

Dihydropyridines

Vascular selective CCBs, end in -ipine.

Gingival Hyperplasia

Common in CCB users, resolves after stopping.

Malignant Hypertension

BP > 180/120, medical emergency.

Hypertensive Urgency

> 180/120, asymptomatic, refer to PCP.

Hypertensive Emergency

> 180/120, symptomatic, signs of organ damage.

NSAID Interaction with beta blockers

Prolonged use reduces beta blocker effectiveness.

Rebound Tachycardia

Abrupt cessation of beta blockers causes increased heart rate.

White Coat Hypertension

Elevated BP only in healthcare settings.

Normal BP

Blood pressure outside healthcare settings is normal.

Prevalence of white coat hypertension

Occurs in 15% to 30% of patients.

Dental Appointment Protocol

Measure BP and pulse at every appointment.

Stressful Appointments

Avoid long or stressful dental procedures.

Potential Causes of Hypertension

Includes pain, stress, and anxiety.

Postural hypotension

Drop in BP due to position change.

Vasoconstrictors

Drugs that narrow blood vessels.

Hypertension prevalence

Affects 28% of US population.

Primary diagnosis visits

35 million yearly office visits for hypertension.

Controlled hypertension

Only 35% of patients manage their condition.

Smoking effects

Damages vascular endothelium, increasing hypertension risk.

Atherosclerotic plaques

Cholesterol deposits damaging blood vessels.

Alcohol impact

Contributes to vascular endothelium damage.

Target organ effects of hypertension

Hypertension affects organs like heart and kidneys.

Left ventricular hypertrophy

Heart muscle thickening due to high BP.

Nephrosclerosis

Kidney damage from prolonged hypertension.

Encephalopathy

Brain dysfunction caused by severe hypertension.

Orthostatic hypotension

BP drop upon standing from sitting.

Neurogenic causes of orthostatic hypotension

Blood pressure regulation impairment due to neural issues.

Non-neurogenic causes of orthostatic hypotension

Inadequate BP response despite normal neural function.

Vasovagal syncope

Fainting due to excessive vagal stimulation.

Shock

Life-threatening condition with organ under-perfusion.

Supine hypotensive syndrome

Hypotension in pregnant women due to vena cava compression.

Hemorrhagic shock

Life-threatening condition from significant blood loss.

Acute congestive heart failure

Heart fails to meet metabolic demands.

Acute adrenal insufficiency

Inadequate stress response leading to hypotension.