DISPLASIA ARRITMOGENICA DEL VD PDF
Arrhythmogenic right ventricular dysplasia (ARVD), or arrhythmogenic right ventricular .. Vorgerd M, Gummert J, Milting H (Dec ). “De novo desmin- mutation NS is associated with arrhythmogenic right ventricular cardiomyopathy”. Transcript of Displasia Arritmogénica de Ventrículo derecho Dilatación y adelgazamiento VD de epicardio a endocardio HISTOLOGÍA. CC: univentricular o VD sistémico con disfunción grave y FR de MS, IIb, B, Nueva . Distrofia . Displasia arritmogénica del ventrículo derecho.
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ARVD is caused by genetic defects of the parts of heart muscle also called myocardium or cardiac muscle known as desmosomesareas on the surface of heart muscle cells which link the cells together.
Arritmogenicaa desmosomes are composed of several proteinsand many of those proteins can have harmful mutations. The disease is a type of nonischemic cardiomyopathy that involves primarily the right ventricle. It is characterized by hypokinetic areas involving the free wall of the right ventricle, with fibrofatty replacement of the right ventricular myocardium, with associated arrhythmias originating in the right ventricle. ARVD can be found in association with diffuse palmoplantar keratodermaand woolly hairin an autosomal recessive condition called Naxos diseasebecause this genetic abnormality can also affect the integrity of the superficial layers of the skin most exposed to pressure stress.
The remainder frequently present with palpitations or other symptoms due to right ventricular outflow tract RVOT tachycardia a type of monomorphic ventricular tachycardia.
Arrhythmogenic right ventricular dysplasia
Symptoms are usually exercise-related. In populations where hypertrophic cardiomyopathy is screened out prior to involvement in competitive athletics, it is a common cause of sudden cardiac death. The first clinical signs of ARVD are usually during adolescence. However, signs of ARVD have been demonstrated in infants. It is usually inherited in an autosomal dominant pattern, with variable expression.
Different DES muations cause an abnormal aggregation of desmin and associated proteins. Seven gene loci have been implicated in ARVD.
It is unclear whether the pathogenesis varies with the different loci involved. Standard genetic screening test are currently tested and evaluated in different state of the art cardiovascular research centres and hospitals.
The pathogenesis of ARVD is largely unknown. Apoptosis programmed cell death appears to play a large role. It is arritmogrnica why only the right ventricle is involved. The disease process starts in the subepicardial region and works its arrutmogenica towards the endocardial surface, leading to transmural involvement possibly accounting for the aneurysmal dilatation of the RV.
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Residual myocardium is confined to the subendocardial region and the trabeculae of the RV. These trabeculae may become hypertrophied.
It usually occurs in the diaphragmatic, apical, and infundibular regions known as the triangle of dysplasia. If the left ventricle is involved, it is usually late in the course of disease, and confers a poor prognosis. The first, fatty infiltration, is confined to the right ventricle. This involves a partial or near-complete substitution of myocardium with fatty tissue without wall thinning.
It involves predominantly the apical and infundibular regions of the RV. The left ventricle and ventricular septum are usually spared. No inflammatory infiltrates are seen in fatty infiltration. The second, fibro-fatty infiltration, involves replacement of myocytes with fibrofatty tissue. Myocardial atrophy is due to injury and apoptosis. However, the LV free wall may be involved in some cases.
Involvement of the ventricular septum is rare. The areas involved are prone to aneurysm formation. Ventricular arrhythmias due to ARVD typically arise from the diseased right ventricle. The type of arrhythmia ranges from frequent premature ventricular complexes PVCs to ventricular tachycardia VT to ventricular fibrillation VF.
While the initiating factor of the ventricular arrhythmias is unclear, it may be due to triggered activity or reentry.
Ventricular arrhythmias are usually exercise-related, suggesting that they are sensitive to catecholamines. The ventricular beats typically have a right axis deviation. Multiple morphologies of ventricular tachycardia may be present in the same individual, suggesting multiple arrhythmogenic foci or pathways. The differential diagnosis for the ventricular tachycardia due to ARVD include:.
In order to dek the diagnosis of ARVD, a number of clinical tests are employed, including the electrocardiogram EKGechocardiographyright ventricular angiography, cardiac MRI, and genetic testing.
However, this is a non-specific finding, and may be considered a normal variant in right bundle branch block RBBBwomen, and children under 12 years old. This may be due to delayed activation of the right ventricle, rather than any intrinsic abnormality in the right bundle branch. This is described as a terminal notch in the QRS complex.
It is due to arriymogenica intraventricular conduction. The origin of the ectopic beats is usually from one of the three regions of fatty degeneration the “triangle of dysplasia”: Echocardiography may reveal an enlarged, hypokinetic right ventricle with a paper-thin RV free wall.
The dilatation of the RV will cause dilatation of the arritmogenoca valve annulus, with subsequent tricuspid regurgitation. Paradoxical septal motion may also be present. Fat has increased intensity in T1-weighted images. However, adritmogenica may be difficult to differentiate intramyocardial fat and the epicardial fat that is commonly seen adjacent to the normal heart.
Also, the sub-tricuspid region may be difficult to distinguish from the atrioventricular sulcus, which is rich in fat. Right ventricular angiography is considered the gold standard for the diagnosis of ARVD. Findings consistent with ARVD are an akinetic or dyskinetic bulging localized to the infundibular, apical, and subtricuspid regions of the RV.
Transvenous biopsy of the right ventricle can be highly specific for ARVD, but it has low sensitivity. False negatives are common, however, because the disease progresses typically from the epicardium to the endocardium with the biopsy sample coming from the endocardiumand the segmental nature of the disease. Also, due to the paper-thin right ventricular free wall that is common in this disease process, most biopsy samples are taken from the ventricular septum, which is commonly not involved in the disease process.
A post mortem histological demonstration of full thickness substitution of the RV myocardium by fatty or fibro-fatty tissue is consistent with ARVD. ARVD is an autosomal dominant trait with reduced penetrance.
Displasia Arritmogénica de Ventrículo derecho by IVAN DIAZ DE CERIO on Prezi
Whenever a mutation is identified by genetic testing, family-specific genetic testing can be used to deel between relatives who are at-risk for the disease and those who are not. ARVD genetic arritmogennica is clinically available. There is no pathognomonic feature of ARVD. The diagnosis of ARVD is based on a combination of major and minor criteria. To make a diagnosis of ARVD requires either 2 major criteria or 1 major and 2 minor criteria or 4 minor criteria.
The goal of management of ARVD is to decrease the incidence of sudden cardiac death. This raises a clinical dilemma: How to prophylactically treat the asymptomatic patient who was diagnosed during family screening. Diisplasia certain subgroup of individuals with ARVD are considered at high risk for sudden cardiac death.
Management options include pharmacological, surgical, displasiia ablation, and placement of an implantable cardioverter-defibrillator. Prior to the decision of the treatment option, programmed electrical stimulation in the electrophysiology laboratory may be performed for additional prognostic information. Goals of programmed stimulation include:. Regardless of the management option chosen, the individual is typically advised to undergo lifestyle modification, including avoidance of strenuous exercise, cardiac stimulants i.
If the individual wishes to begin an exercise regimen, an exercise stress test may have added benefit. Pharmacologic management of ARVD involves arrhythmia suppression and prevention of dispasia formation. Other antiarrhythmic agents used include amiodarone and conventional beta blockers i.
If antiarrhythmic agents are used, their efficacy should be guided by series ambulatory holter monitoring, to show a reduction in arrhythmic events. While angiotensin converting enzyme inhibitors ACE Inhibitors are well known for slowing progression in other cardiomyopathies, they have not been proven to be helpful in ARVD. Individuals with decreased RV ejection fraction with dyskinetic portions of the right ventricle may benefit from long term anticoagulation arritmogfnica warfarin to prevent thrombus formation and subsequent pulmonary embolism.
Catheter ablation may be used to treat intractable ventricular tachycardia. An ICD is the most effective prevention against sudden cardiac death. Since ICDs are typically placed via a transvenous approach into the right ventricle, there are complications associated with ICD placement and follow-up. Due to the extreme thinning of the RV free wall, it is possible to perforate the RV during implantation, potentially causing pericardial tamponade. Because of this, every attempt is made at placing the defibrillator lead on the ventricular septum.
After a successful implantation, the arritmogeniva nature of the disease may displaaia to fibro-fatty replacement of the myocardium at the site of lead placement. This may lead to undersensing of the individual’s electrical activity potentially causing inability to sense VT or VFand inability to pace the ventricle.
Heart transplant may be performed in ARVD. It may be indicated if the arrhythmias associated with the disease are uncontrollable or if displasla is severe bi-ventricular heart failure that is not manageable with pharmacological therapy.
All first degree family members of the affected individual should be screened for ARVD. This is used to establish the pattern of inheritance. Screening should begin during the teenage years unless otherwise indicated. There is a long asymptomatic lead-time in individuals with ARVD.
While this is a genetically transmitted disease, individuals in their teens may not have any characteristics of ARVD on screening tests. Many individuals have symptoms associated with ventricular tachycardia, such as palpitations, light-headedness, or syncope. Others may have symptoms and signs related to right ventricular failure, such as lower extremity edema, or liver congestion with elevated hepatic enzymes. ARVD is a progressive disease.
Over time, the right ventricle becomes more involved, leading to right ventricular failure. The right ventricle will fail before there is left ventricular dysfunction.
However, by the time the individual has signs of overt right ventricular failure, there will be histological involvement of the left ventricle. Eventually, the left ventricle will also become involved, leading to bi-ventricular failure.