Chamber Hypertrophy and Enlargment: Difference between revisions

In hypertrophy the heart muscle is thicker. This can have different causes. Left ventricular hypertrophy results from an increase in left ventricular workload, e.g. during hypertension or aortic valve stenosis. Right ventricular hypertrophy results from an increase in right ventricular workoad, e.g. emphysema or pulmonary embolisation.  

These causes are fundamentally different from [[Miscellaneous#Hypertrophic_Obstructive_Cardiomyopathy|hypertrophic obstructive cardiomyopathy (HCM)]], which is a congenital misallignment of cardiomyocytes resulting in hypertrophy.  

==Left ventricular hypertrophy==

[[Image:E_lvh.jpg|thumb|left|300px|LVH. R in V5 is 26mm, S in V1 in 15mm. The sum is 41 mm which is more than 35 mm and therefore LVH is present according to the Sokolow-Lyon criteria.]]

 

As the left ventricular becomes thicker, the QRS complexes become larger. This is especially true for leads V1-V6. The S wave in V1 is deep, the R wave in V4 is high. Often some ST depression can be seen in leads V5-V6, which is in this setting is called a 'strain pattern'.

The '''Sokolow-Lyon criterium'''<cite>Sokolow</cite>), this is most often used:

Other criteria:

*R >26 mm in V5 or V6;

*R >20 mm in I, II or III;

*R >12 mm in aVL (in the absence of [[Conduction delay#LAFB|left anterior fascicular block]]);

The '''Cornell-criterium''' has different values in men and women:

In the '''Romhilt-Estes Score''' LVH is ''likely'' with 4 or more points. LVH is ''present'' with 5 or more points:

* Amplitude of R or S wave in limb leads >2.0 mV, or S wave in  V1 or V2 >3.0 mV, or R wave in V5 or V6 >3.0 mV = 3 points.

* QRS duration >90 ms = 1 point.

Left ventricular hypertrophy has prognostic consequences as has been found in several studies.<cite>Levy</cite><cite>Sundstrom</cite>

===Example===

Image:LVH.jpg|ECG of patient with left ventricular hypertrophy according to the Sokolow-Lyon criteria

==Right ventricular hypertrophy==

[[Image:E_rvh.jpg|thumb|450px|Right ventricular hypertrohpy, the R wave is greater than the S wave in V1]]

==Left atrial enlargement==

:P wave with a broad (>0,04 sec or 1 small square) and deeply negative (>1 mm) terminal part in V1

:P wave duration >0,12 sec in laeds I and / or II

Left atrial enlargement is often seen in mitral valve insufficiency, resulting in backflow of blood from the left ventricle to the left atrium and subsequent incresed local pressure.  

==Right atrial enlargement==

:P >2,5 mm in II / III and / or aVF  

:P >1,5 mm in V1.

Right atrial enlargement can result from increased pressure in the pulmonary artery, e.g. after pulmonary embolisation. A positive part of the biphasic p-wave in lead V1 larger than the negative part indicates right atrial enlargement. The width of the p wave does not change.  

==Biatrial enlargement==

In biatrial enlargement is the ECG whos signs of both left and right atrial enlargement. In V1 the p wave has large peaks first in positive and later in negative direction.

#Sokolow Sokolow M, Lyon TP: ''The ventricular complex in left verntricular hypterfophy as obtained by unipolar precordial and limb leads.'' Am Heart J 37: 161, 1949