| Left ventricular hypertrophy | |
|---|---|
 | |
| A heart with left ventricular hypertrophy in short-axis view | |
| Specialty | Cardiology |
| Complications | Hypertrophic cardiomyopathy, Heart failure [1] |
| Diagnostic method | Echocardiography, cardiovascular MRI [1] |
| Differential diagnosis | Athletic heart syndrome |
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.
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. [2] It is one aspect of ventricular remodeling.
While LVH itself is not a disease, it is usually a marker for disease involving the heart. [3] 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.[ citation needed ] 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.[ citation needed ]
Long-standing mitral insufficiency also leads to LVH as a compensatory mechanism.[ citation needed ]
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.[ citation needed ]
| Mild | 12 to 13 mm |
| Moderate | >13 to 17 mm |
| Severe | >17 mm |
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. [6] Average thickness of the left ventricle, with numbers given as 95% prediction interval for the short axis images at the mid-cavity level are: [7]
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, [8] 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. [9]
There are several sets of criteria used to diagnose LVH via electrocardiography. [10] None of them are perfect, though by using multiple criteria sets, the sensitivity and specificity are increased.
The Sokolow-Lyon index: [11] [12]
The Cornell voltage criteria [13] 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:
The Romhilt-Estes point score system ("diagnostic" >5 points; "probable" 4 points):
| ECG Criteria | Points |
Voltage Criteria (any of):
| 3 |
ST-T Abnormalities:
| 3 |
| 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:
Diagnostic accuracy of electrocardiography in left ventricular hypertrophy can be enhanced with artificial intelligence analysis. [14]
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. [15]
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. [16] Patients with LVH may have to participate in more complicated and precise diagnostic procedures, such as Echocardiography or Cardiac MRI. [17] [18]
Cardiology is the study of the heart. Cardiology is a branch of medicine that deals with disorders of the heart and the cardiovascular system. The field includes medical diagnosis and treatment of congenital heart defects, coronary artery disease, heart failure, valvular heart disease, and electrophysiology. Physicians who specialize in this field of medicine are called cardiologists, a specialty of internal medicine. Pediatric cardiologists are pediatricians who specialize in cardiology. Physicians who specialize in cardiac surgery are called cardiothoracic surgeons or cardiac surgeons, a specialty of general surgery.
Electrocardiography is the process of producing an electrocardiogram, a recording of the heart's electrical activity through repeated cardiac cycles. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the heart using electrodes placed on the skin. These electrodes detect the small electrical changes that are a consequence of cardiac muscle depolarization followed by repolarization during each cardiac cycle (heartbeat). Changes in the normal ECG pattern occur in numerous cardiac abnormalities, including cardiac rhythm disturbances, inadequate coronary artery blood flow, and electrolyte disturbances.
Aortic stenosis is the narrowing of the exit of the left ventricle of the heart, such that problems result. It may occur at the aortic valve as well as above and below this level. It typically gets worse over time. Symptoms often come on gradually with a decreased ability to exercise often occurring first. If heart failure, loss of consciousness, or heart related chest pain occur due to AS the outcomes are worse. Loss of consciousness typically occurs with standing or exercising. Signs of heart failure include shortness of breath especially when lying down, at night, or with exercise, and swelling of the legs. Thickening of the valve without narrowing is known as aortic sclerosis.
The mitral valve, also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valves. It has two cusps or flaps and lies between the left atrium and the left ventricle of the heart. The heart valves are all one-way valves allowing blood flow in just one direction. The mitral valve and the tricuspid valve are known as the atrioventricular valves because they lie between the atria and the ventricles.
A ventricle is one of two large chambers toward the bottom of the heart that collect and expel blood towards the peripheral beds within the body and lungs. The blood pumped by a ventricle is supplied by an atrium, an adjacent chamber in the upper heart that is smaller than a ventricle. Interventricular means between the ventricles, while intraventricular means within one ventricle.
Afterload is the pressure that the heart must work against to eject blood during systole. Afterload is proportional to the average arterial pressure. As aortic and pulmonary pressures increase, the afterload increases on the left and right ventricles respectively. Afterload changes to adapt to the continually changing demands on an animal's cardiovascular system. Afterload is proportional to mean systolic blood pressure and is measured in millimeters of mercury.
Arrhythmogenic cardiomyopathy (ACM), arrhythmogenic right ventricular dysplasia (ARVD), or arrhythmogenic right ventricular cardiomyopathy (ARVC), most commonly is an inherited heart disease.
Hypertrophic cardiomyopathy is a condition in which muscle tissues of the heart become thickened without an obvious cause. The parts of the heart most commonly affected are the interventricular septum and the ventricles. This results in the heart being less able to pump blood effectively and also may cause electrical conduction problems. Specifically, within the bundle branches that conduct impulses through the interventricular septum and into the Purkinje fibers, as these are responsible for the depolarization of contractile cells of both ventricles.
Aortic regurgitation (AR), also known as aortic insufficiency (AI), is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle. As a consequence, the cardiac muscle is forced to work harder than normal.
A right bundle branch block (RBBB) is a heart block in the right bundle branch of the electrical conduction system.
Ventricular hypertrophy (VH) is thickening of the walls of a ventricle of the heart. Although left ventricular hypertrophy (LVH) is more common, right ventricular hypertrophy (RVH), as well as concurrent hypertrophy of both ventricles can also occur.
Left bundle branch block (LBBB) is a conduction abnormality in the heart that can be seen on an electrocardiogram (ECG). In this condition, activation of the left ventricle of the heart is delayed, which causes the left ventricle to contract later than the right ventricle.
Right ventricular hypertrophy (RVH) is a condition defined by an abnormal enlargement of the cardiac muscle surrounding the right ventricle. The right ventricle is one of the four chambers of the heart. It is located towards the lower-end of the heart and it receives blood from the right atrium and pumps blood into the lungs.
Athletic heart syndrome (AHS) is a non-pathological condition commonly seen in sports medicine in which the human heart is enlarged, and the resting heart rate is lower than normal.
Vectorcardiography (VCG) is a method of recording the magnitude and direction of the electrical forces that are generated by the heart by means of a continuous series of vectors that form curving lines around a central point.
ST depression refers to a finding on an electrocardiogram, wherein the trace in the ST segment is abnormally low below the baseline.
In electrocardiography, left axis deviation (LAD) is a condition wherein the mean electrical axis of ventricular contraction of the heart lies in a frontal plane direction between −30° and −90°. This is reflected by a QRS complex positive in lead I and negative in leads aVF and II.
Heart failure with preserved ejection fraction (HFpEF) is a form of heart failure in which the ejection fraction – the percentage of the volume of blood ejected from the left ventricle with each heartbeat divided by the volume of blood when the left ventricle is maximally filled – is normal, defined as greater than 50%; this may be measured by echocardiography or cardiac catheterization. Approximately half of people with heart failure have preserved ejection fraction, while the other half have a reduction in ejection fraction, called heart failure with reduced ejection fraction (HFrEF).
Tissue Doppler echocardiography (TDE) is a medical ultrasound technology, specifically a form of echocardiography that measures the velocity of the heart muscle (myocardium) through the phases of one or more heartbeats by the Doppler effect of the reflected ultrasound. The technique is the same as for flow Doppler echocardiography measuring flow velocities. Tissue signals, however, have higher amplitude and lower velocities, and the signals are extracted by using different filter and gain settings. The terms tissue Doppler imaging (TDI) and tissue velocity imaging (TVI) are usually synonymous with TDE because echocardiography is the main use of tissue Doppler.
In electrocardiography, a strain pattern is a well-recognized marker for the presence of anatomic left ventricular hypertrophy (LVH) in the form of ST depression and T wave inversion on a resting ECG. It is an abnormality of repolarization and it has been associated with an adverse prognosis in a variety heart disease patients. It has been important in refining the role of ECG LVH criteria in cardiac risk stratification. It is thought that a strain pattern could also reflect underlying coronary heart disease.
| Authority control databases: National |
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