Lipid Disorder

By what mechanism does the specialized probe in Transesophageal echocardiography (TEE) achieve high-resolution imaging of cardiac structures?

The probe is passed into the esophagus to sit in close proximity to the posterior heart.

Identify the specific posterior cardiac structures for which TEE provides superior visualization compared to TTE.

The left atrium, left atrial appendage (LAA), mitral valve, and thoracic aorta.

Which imaging modality looks for Infective Endocarditis and evaluates cardioembolic sources of a stroke like a left atrial appendage thrombus

TEE (Transesophageal Echo)

Which specific condition involving valvular vegetations or abscesses makes TEE the preferred diagnostic tool over TTE?

Infective endocarditis.

In the context of a stroke workup, what two cardioembolic sources is TEE primarily used to identify?

Left atrial appendage thrombus and atrial septal defects (or patent foramen ovale).

Limiations of a TEE (Transesophageal Echo)

Esophageal damage (perforation, aspiration, dysphagia

Requires sedation (esophageal intubation)

What anatomical limitation of TTE is circumvented by TEE when imaging patients with obesity or lung disease?

Interference from body habitus and chest wall anatomy is minimized by the posterior esophageal location.

List the primary esophageal contraindications for performing a TEE procedure.

Strictures, tumors, varices, or recent esophageal surgery.

Why is sedation typically required for a TEE, and how does this affect patient risk?

Esophageal intubation is invasive, and sedation increases risk in unstable or elderly patients.

Contrast the typical clinical role of TTE versus TEE.

TTE is used for first-line cardiac imaging, while TEE is used for detailed evaluation when TTE is inadequate like for Infective Endocarditis or a left atrial appendage thrombus

Which imaging modality looks at Left atrium, LAA, mitral valve, aorta, TEE or TTE?

TEE

Which imaging modality looks at Ventricles, valve function, pericardium, TEE or TTE?

TTE

Which imaging modality, TEE or TTE, is the more sensitive for detection of thrombus and vegetations?

TTE

What is the difference between LDL and HDL?

LDL delivers cholesterol to the the tissues and HDL is involved in reverse cholesterol transport

Which lipoprotein component is characterized as the primary driver of atherosclerosis?

Low-density lipoprotein cholesterol (LDL-C).

What is the physiological function of Very-low-density lipoprotein (VLDL)?

It transports triglycerides from the liver to peripheral tissues and contributes to plaque formation.

Explain the clinical significance of measuring Apolipoprotein B (ApoB).

It represents the total number of atherogenic particles and serves as the most accurate risk indicator

At what serum level do triglycerides significantly increase the risk for acute pancreatitis?

> 500 mg/dL.

Provide the formula for calculating Non-HDL cholesterol.

Total Cholesterol - HDL-C.

In which patient population is Non-HDL-C considered a better risk predictor than LDL-C?

Patients with elevated triglycerides, specifically > 150 mg/dL.

Normal endothelial cells maintain vascular tone primarily through the production of which molecule?

Nitric oxide (NO).

What is the hallmark of endothelial dysfunction ?

Impaired vasodilation and heightened oxidative stress.

Chronic inflammation and hyperpermeability.

Identify the molecule cited as the 'KEY trigger' of the atherosclerotic cascade.

Oxidized LDL (ox-LDL).

Cause of endothelial injury

hypertension, tobacco exposure, diabetes, and Oxidized LDL (ox-LDL). Ox-LDL is the key trigger of the process.

Describe the cellular transition that occurs during Step 2 (Inflammation) of the atherosclerotic cascade.

Monocytes differentiate into macrophages, which then become foam cells after ingesting lipids.

What constitutes the 'fatty streak' seen in early atherosclerosis?

The accumulation of lipid-laden foam cells within the vessel wall.

How does smooth muscle cell (SMC) proliferation contribute to plaque development?

SMCs migrate from the media into the subintimal space, contributing to plaque growth and vascular remodeling.

Overview of the atherosclerotic cascade

1. endothelial injury from oxidized LDL leads to

2. macrophages becoem foam cells which form a fatty streak

3. a fibrous cap is formed and its rupture leads to MI or stoke

Which substance is released upon plaque rupture to initiate the coagulation cascade?

Tissue factor which leads to thrombin formation

Exposure of subendothelial collagen during plaque rupture leads directly to which thrombotic process?

Platelet adhesion.

Plaque rupture exposes tissue factor and subendothelial collagen, leading to thrombin generation and platelet adhesion. This results in ________

acute coronary syndromes, MI, or stroke.

What is the inheritance pattern and general prevalence of Familial Hypercholesterolemia (FH)?

It is an autosomal dominant disorder

Mutations in which gene account for over 90% of Familial Hypercholesterolemia cases?

The LDLR gene (LDL receptor defects).

Results of Familial Hypercholesterolemia

results in lifelong elevated LDL-C and a 2-4 fold higher risk of premature ASCVD.

What is the effect in the risk of ASCVD in pts with Familial Hypercholesterolemia

2-4 fold higher risk of premature ASCVD.

Differentiate between Familial Hypercholesterolemia and Polygenic Hypercholesterolemia.

FH is a monogenic mutation, while polygenic involves the contribution of multiple common LDL-C-raising genetic variants.

Familial Hyperlipidemia: results from an inheritance pattern + _______ to manifest

environmental triggers

Familial Combined Hyperlipidemia has elevated levels of:

elevated LDL-C, triglycerides, and increased ApoB production.

Which endocrine disorder is the most common secondary cause of dyslipidemia?

Hypothyroidism.

Secondary causes of dyslipidemia

Dietary: High saturated/trans-fat intake, excessive alcohol (critical TG trigger). Hypothyroidism, Diabetes (most important for TG), Cushing syndrome, Obesity.

The body doesn’t feel like you have enough so it ↑ the uptake, Chronic kidney disease, nephrotic syndrome, obstructive liver disease.

Medications, Pregnancy, menopausal transition.

Identify the 'most important' disease state associated with secondary hypertriglyceridemia.

Poorly controlled diabetes mellitus.

Which lifestyle factor is described as a 'critical trigger' for secondary hypertriglyceridemia and why?

Alcohol abuse or excess.

because it damages the liver which is critical for processing lipids

What is the recommended lipid screening frequency for young adults without cardiovascular risk factors?

Start at 19 then every 5 years.

At what age range is it recommended to perform initial pediatric lipid screening to identify FH?

Between 9 and 11 years of age.

Under what condition is 'cascade screening' recommended for children as young as 2 years old?

If there is a first- or second-degree relative with premature ASCVD, severe hypercholesterolemia, or FH.

Standard Lipid Profile: Includes

Total Cholesterol (TC), LDL-C, HDL-C, Triglycerides, and Non-HDL-C.

Should a pt be fasting or non fasting for a lipid panel?

generally fasting

When is a fasting lipid sample mandatory rather than a nonfasting one?

When nonfasting triglycerides are > 400 text mg/dL, there is a family history of genetic lipid disorders, or when identifying pancreatitis risk (TG >500 mg/dL).

What are the three components used to estimate Total Cholesterol in the direct measurement formula?

the sum of LDL, HDL, and VLDL

Why is Low HDL-C clinically significant in the 2026 ACC guidance?

It is considered a risk-enhancing factor, even if it is not a direct treatment target.

How is the value of HDL-C typically determined in a standard lipid panel?

It is measured directly.

Which two lipoproteins contribute to the measurement of Triglycerides (TG)?

VLDL and Chylomicrons.

At what threshold does serum Triglyceride (TG) concentration significantly increase the risk for pancreatitis?

> 500 mg/dL.

What is the formula used to calculate Non-HDL-C?

Non-HDL-C = Total Cholesterol - HDL-C.

Which specific atherogenic lipoproteins are included in the Non-HDL-C value?

LDL, VLDL, IDL, and Lp(a).

According to 2026 ACC guidance, when is the use of Non-HDL-C particularly emphasized?

When Triglycerides are > 150 mg/dL.

What is the 'Desirable' threshold for Total Cholesterol (TC)?

< 200 mg/dL.

What is the 'Desirable' threshold for LDL-C?

< 100 mg/dL.

What is the low HDL-C threshold for men that is considered a risk-enhancing factor?

< 40 mg/dL.

What is the low HDL-C threshold for women that is considered a risk-enhancing factor?

< 50 mg/dL.

What is the threshold for 'Very High' Triglycerides (TG)?

> 500 mg/dL.

What is the 'Desirable' value for Non-HDL-C?

< 130 mg/dL.

Which lipid is the primary target for therapy

LDL-C

low HDL = risk ____

enhancer

Lipid Pattern 1 (Isolated Elevated LDL-C) is characterized by LDL-C > 160 mg/dL with normal TG and normal HDL-C; what are three common causes?

Familial hypercholesterolemia (FH), dietary factors, and hypothyroidism.

If a patient presents with isolated LDL-C > 190 mg/dL, what specific screening is indicated?

Screening for Familial Hypercholesterolemia (FH) and TSH to rule out hypothyroidism

Pattern 2 (Low HDL-C with Normal LDL-C) is strongly associated with which syndrome?

Metabolic syndrome and , smoking, and sedentary lifestyle.

Pattern 2 (Low HDL-C with Normal LDL-C)what action should be taken?

Assess lifestyle and metabolic syndrome components.

What clinical conditions should be suspected in Pattern 3 (Elevated TG with Low HDL-C)?

Insulin resistance, diabetes, and metabolic syndrome.

Pattern 3 (Elevated TG with Low HDL-C) what action should be taken?

Evaluate for secondary causes; aggressive lifestyle modification.

What defines Lipid Pattern 4: Mixed Dyslipidemia?

Elevated LDL-C combined with elevated Triglycerides (TG).

Lipid Pattern 4: Mixed Dyslipidemia(↑ LDL + ↑ TG): Seen in

familial combined hyperlipidemia and diabetes

In Lipid Pattern 5 (Severe Hypertriglyceridemia, TG > 500 mg/dL), what is the most urgent clinical assessment required?

Assessment of pancreatitis risk.

Which lipid parameter is described as a better predictor of ASCVD risk than LDL-C, especially when TG > 150 mg/dL?

Non-HDL-C.

List the two NEW variables included in the 2026 PREVENT-ASCVD equations that were not in the PCE.

Estimated glomerular filtration rate (eGFR) and statin use.

Which variable was intentionally removed from the PREVENT-ASCVD equations to reduce potential bias?

Race.

Under the 2026 guidelines, what percentage range defines 'Low risk' for 10-year ASCVD?

< 3%.

What 10-year ASCVD risk range is classified as 'Borderline risk' in the 2026 update?

3% to < 5%.

What 10-year ASCVD risk range is classified as 'Intermediate risk' in the 2026 update?

5% to < 10%.

What 10-year ASCVD risk percentage defines the 'High risk' category in the 2026 guidelines?

> 10%.

In the 2026 ASCVD risk guidelines, what clinical diagnosis automatically places a patient in the high-risk category?

Diabetes.

For risk-enhancing factors, what age thresholds define 'premature ASCVD' in family history?

Men < 55 years and Women < 65 years.

What range of primary hypercholesterolemia (LDL-C) is considered a risk-enhancing factor?

LDL- C = 160-189 mg/dL.

What range of GFR is considered a risk-enhancing factor?

15-59

Which chronic inflammatory conditions are listed as traditional risk enhancers?

Psoriasis, rheumatoid arthritis, and HIV/AIDS.

Women-specific risk enhancers related to the timing of hormonal changes.

Early menarche, early menopause (before age 45), PCOS, adverse pregnancy outcomes (preeclampsia, gestational diabetes, preterm delivery).

What level of nonfasting Triglycerides (TG) is considered a risk enhancer if persistently elevated?

> 175 mg/dL.

At what concentration does Apolipoprotein B (ApoB) become a risk-enhancing factor?

> 130 mg/dL.

What is the risk-enhancing threshold for Lipoprotein(a) [Lp(a)]?

> 125 nmol/L

Lp(a) should be measured at least once to identify those individuals at higher risk of ASCVD. It is considered as a risk-enhancing factor at levels ≥125 nmol/L (50 mg/dL)"

What level of high-sensitivity C-reactive protein (hsCRP) is considered a risk-enhancing factor?

> 2.0 mg/L.

When is Coronary Artery Calcium (CAC) scoring typically utilized in lipid management?

When the decision about statin therapy is uncertain in borderline or intermediate risk patients.

CAC score is 0 indicates

Statin therapy may be withheld or delayed (unless the patient is a smoker, has diabetes, or a strong family history of premature ASCVD).

What CAC score range favors statin therapy, particularly in adults > 55 years of age?

1-99.

Statin therapy is generally indicated for what CAC score thresholds?

CAC > 100

What is the Class I recommended dietary pattern to decrease LDL-C and reduce ASCVD risk?

A diet emphasizing fruits, vegetables, nuts, legumes, whole grains, and fiber.

What is the recommended daily limit for saturated fat as a percentage of total calories for LDL-C reduction?

< 7%.

What is the daily goal for dietary fiber intake (25-30 g) for managing lipid levels?

25-30 g/day.

How much can plant sterols/stanols (2 g/day) typically lower LDL-C levels?

6-15%.

What is the expected LDL-C reduction from dietary modification alone?

5-10%.

For moderate TG elevation (150-499 mg/dL), added sugars should be limited to what percentage of total calories?

< 6%.