8 Cardiovascular Disease

What is cardiovascular disease, and what major process contributes to many cardiovascular disorders?

• Cardiovascular disease (CVD): Any disease involving the heart or blood vessels.

• It is the leading cause of death in the United States.

• Lipid disorders and atherosclerosis are major contributing factors.

Major manifestations include:

• Coronary artery disease

• Carotid artery disease

• Cerebrovascular disease

• Peripheral arterial disease

• Congestive heart failure

• Cardiomyopathy

• Cardiac arrhythmias

What is atherosclerosis, and why can it affect multiple organ systems?

• Atherosclerosis is the buildup of lipid plaques within arterial walls.

• It involves progressive inflammation and degeneration of the intima of medium and large arteries.

• Plaques narrow or obstruct arteries, reducing oxygen and nutrient delivery.

• Because arteries supply the entire body, atherosclerosis can damage the heart, brain, eyes, kidneys, and extremities

What are the major modifiable risk factors for atherosclerosis?

• Hypertension

• Dyslipidemia

• Diabetes mellitus

• Obesity

• Smoking

• Poor diet

• Physical inactivity

Common grouping: Hypertension, dyslipidemia, diabetes, and obesity are strongly associated with metabolic syndrome and accelerate atherosclerosis.

What is coronary artery disease, and what are its major risk factors?

• Coronary artery disease (CAD): Atherosclerotic disease of the coronary arteries that supply oxygenated blood to the myocardium.

• It is the leading cause of death worldwide.

Major risk factors:

• Diabetes

• Hypertension

• Dyslipidemia

• Smoking

• Positive family histor

What is the pathophysiology of coronary artery disease?

• Atherosclerotic plaque develops within a coronary artery.

• The plaque narrows or occludes the artery.

• Coronary blood flow and myocardial oxygen supply decrease.

• Symptoms develop when myocardial oxygen demand exceeds oxygen supply.

• Complete obstruction can cause myocardial infarction and myocardial tissue death

What are the classic and associated symptoms of coronary artery disease?

• Angina: Chest pain or pressure, often described as an “elephant sitting on the chest.”

• May radiate to the:

  • Left arm

  • Jaw

  • Back

Associated symptoms:

• Diaphoresis

• Nausea

• Lightheadedness

• Shortness of breath

• Fatigue

Women may experience less chest pressure and more arm or jaw symptoms, vague symptoms, or no obvious symptoms

What are the major complications of coronary artery disease?

• Myocardial infarction: Complete coronary artery blockage

• Arrhythmias: Abnormal cardiac rhythm

• Heart failure: Weakened pumping ability

• Sudden cardiac death

These complications reflect myocardial ischemia, infarction, or loss of effective cardiac function

How is coronary artery disease diagnosed?

• Clinical history and cardiovascular risk factors

• ECG: Quick, noninvasive assessment

• Troponins: Detect myocardial injury

• Cardiac imaging and stress testing

• Coronary angiography: Gold-standard test for defining coronary obstruction

What are the major components of coronary artery disease management?

• Lifestyle and risk-factor modification

• Treatment of:

  • Hypertension

  • Diabetes

  • Dyslipidemia

• Selected medications:

  • Aspirin: Reduces platelet aggregation

  • Beta-blockers: Reduce cardiac workload and oxygen demand

  • Nitrates: Produce vasodilation and relieve angina

What structures do the carotid arteries supply, and how do they branch?

The carotid arteries supply the brain, face, and eyes.

The common carotid artery divides into:

• External carotid artery: Primarily supplies the face and external head structures.

• Internal carotid artery: Supplies the brain and gives rise to the ophthalmic artery, which supplies the eye

What is the pathophysiology and clinical importance of carotid artery disease?

• Atherosclerotic plaques develop within the carotid arteries.

• These plaques can reduce blood flow or generate emboli.

• Circulation to the brain and eyes may become compromised.

• Carotid artery disease is a major cause of:

  • Ischemic stroke

  • Transient ischemic attack

  • Ocular ischemia

Its risk factors are similar to those for coronary artery disease

What is a transient ischemic attack, and what symptoms may occur with carotid artery disease?

A transient ischemic attack (TIA) is a sudden, temporary neurologic deficit caused by transient cerebral ischemia.

Possible symptoms:

• Weakness

• Numbness

• Speech difficulty

• Amaurosis fugax: Transient monocular vision loss

A TIA is a warning sign for a possible future stroke

How do TIA and stroke differ?

• TIA: Produces a sudden but temporary neurologic deficit without permanent brain infarction.

• Stroke: Produces permanent brain infarction and potentially lasting neurologic dysfunction.

Stroke mechanisms include:

• Embolism

• Thrombosis

• Hypoperfusion

What is a carotid bruit, and what does it suggest?

• A carotid bruit is a whooshing sound heard over the carotid artery during auscultation.

• It results from turbulent blood flow.

• It may indicate carotid artery narrowing from atherosclerotic disease.

• Its presence should prompt further vascular evaluation when clinically appropriate

How is carotid artery disease diagnosed?

• Carotid duplex ultrasound

  • First-line and noninvasive

  • Evaluates flow velocity and degree of stenosis

  • A 60%–99% blockage raises concern for stroke risk

• CTA or MRA

  • Provides more detailed vascular imaging

• Cerebral angiography

  • Gold standard

  • Invasive

How is carotid artery disease managed?

• Lifestyle and cardiovascular risk-factor modification

• Treatment of hypertension, diabetes, and dyslipidemia

• Aspirin: Reduces thrombotic risk

• Statins: Reduce lipid burden and vascular risk

• Revascularization procedures:

  • Carotid endarterectomy

  • Carotid artery stenting

When is carotid endarterectomy useful according to the lecture?

• Carotid endarterectomy may be appropriate for clinically significant stenosis, especially ≥70%.

• It is generally not useful for:

  • Complete carotid stenosis

  • Stenosis below 50%

The procedure physically removes atherosclerotic plaque from the affected carotid artery

What ocular complications can result from carotid artery disease?

Because the ophthalmic artery is the first major branch of the internal carotid artery, carotid disease may present as:

• Ocular ischemic syndrome

• Retinal artery occlusion

• Hollenhorst plaques

• Amaurosis fugax

These ocular findings may be the first indication of serious systemic vascular disease

What causes ocular ischemic syndrome, and what patients are most likely to develop it?

• Ocular ischemic syndrome (OIS) results from chronic ocular hypoperfusion caused by severe carotid stenosis, typically greater than 90%.

• It usually occurs in patients ages 50–80 with systemic vascular disease.

• Common associations:

  • Diabetes

  • Hypertension

  • Atherosclerotic disease

• Men are affected more often than women

What are the typical symptoms of ocular ischemic syndrome?

• Unilateral, gradual reduction in vision

• Ocular or periorbital pain

• Possible history of amaurosis fugax

Key distinction: OIS usually causes gradual visual loss from chronic hypoperfusion, whereas retinal artery occlusion typically causes sudden, painless visual loss

What are the characteristic ocular signs of ocular ischemic syndrome?

• Dilated but non-tortuous retinal veins

• Narrowed retinal arteries

• Midperipheral dot-and-blot hemorrhages

• Neovascularization involving:

  • Iris, or rubeosis

  • Anterior chamber angle

  • Optic disc

  • Retina

High-yield pattern: Narrow arteries + dilated non-tortuous veins + midperipheral hemorrhages.

How should ocular ischemic syndrome be managed?

OIS requires urgent systemic and ophthalmic evaluation:

• Urgent carotid duplex ultrasound

• CTA or MRA

• Cardiac evaluation

• Referral to primary care or a vascular specialist

• Aggressive management of systemic vascular risk factors

• Ophthalmology co-management

• PRP and/or anti-VEGF treatment for neovascularization

OIS is an emergency because it signals a high risk of stroke

What systemic conditions increase the risk of retinal artery occlusion?

• Hypertension

• Dyslipidemia

• Diabetes

• Smoking

• Carotid artery disease

• Previous cerebrovascular accident

• Previous TIA

These conditions promote atherosclerosis, embolism, thrombosis, or vascular insufficiency.

Why is symptomatic retinal artery occlusion considered a medical emergency?

• Symptomatic retinal artery occlusion is an ischemic event and a stroke warning sign.

• It may reflect active embolic disease from the carotid arteries or heart.

• The patient requires immediate emergency referral for a complete stroke evaluation.

• The ocular event may precede a cerebral ischemic event

How should an asymptomatic Hollenhorst plaque be managed compared with symptomatic retinal artery occlusion?

• Symptomatic RAO: Emergency referral for an immediate stroke workup.

• Asymptomatic Hollenhorst plaque: Lower stroke risk than symptomatic RAO, but still requires:

  • Evaluation of cardiovascular and stroke risk factors

  • Carotid artery imaging

  • Outpatient systemic evaluation

Key principle: Symptoms determine the urgency, but both findings require systemic investigation.

How do central and branch retinal artery occlusions differ anatomically?

• CRAO: Obstruction of the central retinal artery before or near its major retinal branching, producing diffuse retinal ischemia.

• BRAO: Obstruction of one of the central retinal artery’s branch vessels, producing sectoral ischemia within the affected retinal quadrant.

The central retinal artery arises from the ophthalmic artery, which branches from the internal carotid artery

What are the four subtypes of central retinal artery occlusion?

1. Nonarteritic CRAO

2. Transient nonarteritic CRAO

3. Nonarteritic CRAO with cilioretinal artery sparing

4. Arteritic CRAO due to giant cell arteritis

Critical distinction: Arteritic CRAO requires immediate evaluation and management for giant cell arteritis

What are the major embolic sources of retinal artery occlusion?

• Ipsilateral carotid atherosclerosis

• Cardiac sources, including:

  • Atrial fibrillation

  • Valvular disease

  • Endocarditis

This is why RAO evaluation requires both carotid imaging and cardiac assessment.

What are the characteristic symptoms and retinal findings of retinal artery occlusion?

• Sudden, painless, monocular vision loss

• Possible preceding amaurosis fugax

• Ischemic pale or white retina:

  • Diffuse in CRAO

  • Sectoral in BRAO

• Narrowed retinal arterioles

• Possible optic disc edema or pallor

• Possible visible retinal embolus or Hollenhorst plaque

What findings are most characteristic of central retinal artery occlusion?

• Sudden, severe, painless monocular vision loss

• Visual acuity frequently reduced to counting fingers or light perception

• Diffuse retinal whitening

• Cherry-red spot at the fovea

• Narrowed retinal arterioles

• Intact choroidal circulation

The cherry-red spot appears because the ischemic retina becomes opaque while the thinner fovea continues to reveal the underlying choroidal circulation

How do the fundus findings of BRAO differ from those of CRAO?

• BRAO: Sectoral retinal whitening corresponding to the obstructed arterial branch.

• CRAO: Diffuse retinal whitening involving most of the retina, often with a cherry-red spot.

• Visual loss in BRAO usually corresponds to the affected retinal area, while CRAO generally causes much more profound visual impairment

What immediate ocular interventions may be attempted for a very recent retinal artery occlusion?

If symptom onset was within approximately 90–120 minutes, attempted interventions may include:

• Ocular massage

• IOP-lowering medication

• Anterior chamber paracentesis

• Inhaled carbogen or hyperbaric oxygen

These interventions attempt to restore retinal perfusion or move an embolus, but they must not delay emergency referral for stroke evaluation

What systemic workup is required for retinal artery occlusion?

Immediate actions:

• Check blood pressure.

• Send the patient to the emergency department for a stroke workup.

• Obtain ESR, CRP, and platelet count immediately to evaluate for giant cell arteritis.

Additional testing:

• Fasting blood glucose

• HbA1c

• CBC with differential

• PT/PTT

• Lipid profile

• Carotid duplex or CTA/MRA

• Cardiac evaluation, including ECG

What follow-up is required after CRAO versus BRAO?

CRAO

• Follow systemic recommendations from neurology or internal medicine.

• Dilated examination in 1–4 weeks to monitor for neovascularization.

• Neovascularization occurs in approximately 20% according to the lecture.

• Treat neovascularization with PRP and/or anti-VEGF.

• Monitor for neovascular glaucoma.

BRAO

• Dilated examination every 3–6 months.

• Neovascularization is rare but remains possible

What are the highest-yield cardiovascular and retinal vascular associations to memorize?

• Atherosclerosis: Lipid plaques plus progressive inflammation of the arterial intima

• CAD: Myocardial oxygen demand exceeds coronary oxygen supply

• Coronary angiography: Gold standard for CAD

• Carotid duplex: First-line test for carotid stenosis

• Cerebral angiography: Gold standard but invasive

• Amaurosis fugax: Transient monocular vision loss

• Carotid endarterectomy: Consider for clinically significant stenosis, especially ≥70%

• OIS: Usually severe carotid stenosis >90% with chronic ocular hypoperfusion

• OIS fundus: Narrow arteries, dilated non-tortuous veins, and midperipheral hemorrhages

• RAO: Sudden, painless monocular vision loss and a stroke warning sign

• CRAO: Diffuse retinal whitening plus cherry-red spot

• BRAO: Sectoral retinal whitening

• RAO sources: Ipsilateral carotid disease or cardiac emboli

• ESR + CRP + platelets: Immediately rule out giant cell arteritis

• CRAO follow-up: Watch for neovascularization and neovascular glaucoma

• Hollenhorst plaque without symptoms: Outpatient vascular evaluation

• Symptomatic RAO: Immediate emergency department stroke workup