science

Left ventricular hypertrophy

Left ventricular hypertrophy is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Left ventricular hypertrophy rather than just read about it. In short: Left ventricular hypertrophy (LVH) is thickening of the heart muscle of the left ventricle of the heart, that is, left-sided ventricular hypertrophy and resulting increased left ventricular mass. Causes While ventricular hypertrophy occurs naturally as a reaction to aerobic exercise and strength training, it is most frequently referred to as a pathological reaction to cardiovascular disease, or high blood pressure.

Key takeaways

Left ventricular hypertrophy belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Left ventricular hypertrophy to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Left ventricular hypertrophy from memory before moving on to harder problems.

Reference excerpt

Left ventricular hypertrophy (LVH) is thickening of the heart muscle of the left ventricle of the heart, that is, left-sided ventricular hypertrophy and resulting increased left ventricular mass.

Causes While ventricular hypertrophy occurs naturally as a reaction to aerobic exercise and strength training, it is most frequently referred to as a pathological reaction to cardiovascular disease, or high blood pressure. It is one aspect of ventricular remodeling. While LVH itself is not a disease, it is usually a marker for disease involving the heart. Disease processes that can cause LVH include any disease that increases the afterload that the heart has to contract against, and some primary diseases of the muscle of the heart. Causes of increased afterload that can cause LVH include aortic stenosis, aortic insufficiency and hypertension. Primary disease of the muscle of the heart that cause LVH are known as hypertrophic cardiomyopathies, which can lead into heart failure. Long-standing mitral insufficiency also leads to LVH as a compensatory mechanism. LV mass increases with ageing. Associated genes include OGN (osteoglycin).

Diagnosis The commonly used method to diagnose LVH is echocardiography, with which the thickness of the muscle of the heart can be measured. The electrocardiogram (ECG) often shows signs of increased voltage from the heart in individuals with LVH, so this is often used as a screening test to determine who should undergo further testing.

Echocardiography

Two dimensional echocardiography can produce images of the left ventricle. The thickness of the left ventricle as visualized on echocardiography correlates with its actual mass. Left ventricular mass can be further estimated based on geometric assumptions of ventricular shape using the measured wall thickness and internal diameter. Average thickness of the left ventricle, with numbers given as 95% prediction interval for the short axis images at the mid-cavity level are:

Women: 4 – 8 mm Men: 5 – 9 mm

CT & MRI CT and MRI-based measurement can be used to measure the left ventricle in three dimensions and calculate left ventricular mass directly. MRI based measurement is considered the "gold standard" for left ventricular mass, though is usually not readily available for common practice. In older individuals, age related remodeling of the left ventricle's geometry can lead to a discordancy between CT and echocardiographic based measurements of left ventricular mass.

ECG criteria

There are several sets of criteria used to diagnose LVH via electrocardiography. None of them are perfect, though by using multiple criteria sets, the sensitivity and specificity are increased. The Sokolow-Lyon index:

S in V1 + R in V5 or V6 (whichever is larger) ≥ 35 mm (≥ 7 large squares) R in aVL ≥ 11 mm The Cornell voltage criteria for the ECG diagnosis of LVH involve measurement of the sum of the R wave in lead aVL and the S wave in lead V3. The Cornell criteria for LVH are:

S in V3 + R in aVL > 28 mm (men) S in V3 + R in aVL > 20 mm (women) The Romhilt-Estes point score system ("diagnostic" >5 points; "probable" 4 points):

Other voltage-based criteria for LVH include:

Lead I: R wave > 14 mm Lead aVR: S wave > 15 mm Lead aVL: R wave > 12 mm Lead aVF: R wave > 21 mm Lead V5: R wave > 26 mm Lead V6: R wave > 20 mm Diagnostic accuracy of electrocardiography in left ventricular hypertrophy can be enhanced with artificial intelligence analysis.

Treatment Treatment is typically focused on resolving the cause of the LVH with the enlargement not permanent in all cases. In some cases the growth can regress with the reduction of blood pressure. LVH may be a factor in determining treatment or diagnosis for other conditions, for example, LVH is used in the staging and risk stratification of Non-ischemic cardiomyopathies such as Fabry's Disease. Patients with LVH may have to participate in more complicated and precise diagnostic procedures, such as echocardiography or cardiac MRI.

See also Cardiomegaly Primary hyperparathyroidism Ventricular hypertrophy

References

External links

Illustrations

Worked examples

Example 1 — a first encounter with Left ventricular hypertrophy

Start with the simplest possible case. Write down what Left ventricular hypertrophy claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Left ventricular hypertrophy before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Left ventricular hypertrophy ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Left ventricular hypertrophy

In research: Left ventricular hypertrophy appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Left ventricular hypertrophy in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Left ventricular hypertrophy is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cardiomegaly, so understanding it makes those chapters shorter.
In everyday life: Look for Left ventricular hypertrophy outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Left ventricular hypertrophy in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Left ventricular hypertrophy means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Left ventricular hypertrophy out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Left ventricular hypertrophy in simple terms?

Left ventricular hypertrophy (LVH) is thickening of the heart muscle of the left ventricle of the heart, that is, left-sided ventricular hypertrophy and resulting increased left ventricular mass. Causes While ventricular hypertrophy occurs naturally as a reaction to aerobic exercise and strength tr…

Why does Left ventricular hypertrophy matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Left ventricular hypertrophy?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Left ventricular hypertrophy.