Left ventricular hypertrophy

Left ventricular hypertrophy
Classification and external resources
A heart with left ventricular hypertrophy in short-axis view
ICD-10	I51.7
ICD-9	429.3
DiseasesDB	7659
MeSH	D017379

Left ventricular hypertrophy (LVH) is the thickening of the myocardium (muscle) of the left ventricle of the heart.

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.^[1]

While LVH itself is not a disease, it is usually a marker for disease involving the heart.^[2] 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.

Diagnosis

The principal method to diagnose LVH is echocardiography, 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. Normal thickness of the left ventricular myocardium is from 0.6 to 1.1 cm (as measured at the very end of diastole. If the myocardium is more than 1.1 cm thick, the diagnosis of LVH can be made.

ECG criteria for LVH

There are several sets of criteria used to diagnose LVH via electrocardiography.^[3] None of them is perfect, though by using multiple criteria sets, the sensitivity and specificity are increased.

The Sokolow-Lyon index^[4][5]:

• 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^[6] 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):

ECG Criteria	Points
Voltage Criteria (any of): R or S in limb leads ≥20 mm S in V1 or V2 ≥30 mm R in V5 or V6 ≥30 mm	3
ST-T Abnormalities: ST-T vector opposite to QRS without digitalis ST-T vector opposite to QRS with digitalis	3 1
Negative terminal P mode in V1 1 mm in depth and 0.04 sec in duration (indicates left atrial enlargement)	3
Left axis deviation (QRS of -30° or more)	2
QRS duration ≥0.09 sec	1
Delayed intrinsicoid deflection in V5 or V6 (>0.05 sec)	1

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

Treatment

The enlargement is not permanent in all cases, and in some cases the growth can regress with the reduction of blood pressure and controlling excitements/emotions strictly.^[7]

Associated genes

• OGN, osteoglycin

See also

• Cardiomegaly
• Ventricular hypertrophy
• Primary hyperparathyroidism

References

1. ^ "Ask the doctor: Left Ventricular Hypertrophy". http://www.clevelandclinic.org/heartcenter/pub/guide/askdoctor/lvh.htm. Retrieved 2007-12-07. 
2. ^ Meijs MF, Bots ML, Vonken EJ, et al. (2007). "Rationale and design of the SMART Heart study: A prediction model for left ventricular hypertrophy in hypertension". Neth Heart J 15 (9): 295–8. doi:10.1007/BF03086003. PMC 1995099. PMID 18030317. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1995099. 
3. ^ "Lesson VIII - Ventricular Hypertrophy". http://library.med.utah.edu/kw/ecg/ecg_outline/Lesson8/index.html#LVH. Retrieved 2009-01-07. 
4. ^ Sokolow M, Lyon TP. The ventricular complex in left ventricular hypertrophy as obtained by unipolar precordial and limb leads. Am Heart J. 1949;37:161–186.
5. ^ "Time-Voltage QRS Area of the 12-Lead Electrocardiogram : Detection of Left Ventricular Hypertrophy -- Okin et al. 31 (4): 937 -- Hypertension". http://hyper.ahajournals.org/cgi/content/full/31/4/937#R10. Retrieved 2007-12-07. 
6. ^ Casale PN, Devereux RB, Alonso DR, Campo E, Kligfield P (1987). "Improved sex-specific criteria of left ventricular hypertrophy for clinical and computer interpretation of electrocardiograms: validation with autopsy findings". Circulation 75 (3): 565–72. doi:10.1161/01.CIR.75.3.565. PMID 2949887. 
7. ^ Gradman AH, Alfayoumi F (2006). "From left ventricular hypertrophy to congestive heart failure: management of hypertensive heart disease". Prog Cardiovasc Dis 48 (5): 326–41. doi:10.1016/j.pcad.2006.02.001. PMID 16627048.