Aritmogenny cardiomyopathy of a right ventricle

Description:

The right ventricular aritmogenny cardiomyopathy – the disease which is characterized by progressive substitution of a myocardium of a right ventricle connecting or fatty tissue with rare involvement in process of a myocardium of a left ventricle, as a rule, does not strike an interventricular partition". The term "aritmogenny dysplasia of a right ventricle" is offered G. Fontaine in 1977 therefore this disease is often called Fontaine's disease. In 1982 Marcus offered the term "aritmogenny right ventricular cardiomyopathy, or aritmogenny disease of a right ventricle". Many authors consider PKMP as a myocardial phenomenon, however, according to Fontaine, PKMP is display of a dysplasia. D. Corrado and соавт. consider that the left ventricle (LV) also is involved in 76% of cases of PKMP in process. And according to C. McRae and соавт., LZh is surprised in 50% of cases of PKMP that it is followed by existence of the expressed dilatatsionny cardiomyopathy.

Symptoms of the Aritmogenny cardiomyopathy of a right ventricle:

The isolated PZh dysplasia
1. PKMP pure form: the macroscopic sample comprises PZh dilatation with protrusions in the field of "a dysplasia triangle" (fibrous and zhkhzirovy fabric shroud PZh in the form of spots, extending to area of a top, funnel and tricuspid area in the form of a triangle. The most part of mass of a myocardium is replaced with fat. The typical histologic sample gives the chance to reveal substitution of an average and periblast of a myocardium of PZh (less myocardium of LZh) fatty tissue and fibrous restriction. The reinforced mussel of a distal part of coronary arteries explains emergence in such patients of atypical pain in a thorax which belongs to markers of a syndrome of X.
2. The disease of Naxos – the PKMP unique autosomal and recessive form, is often presented in the form of malignant ventricular arrhythmias. Statistically: 25 patients from 12 families, penetrance – 90%. Such patients have a characteristic phenotype: a palmar and-foot keratosis as pemphigoid, woolly hair. The clinical signs given to an electrocardiography (ECG) and results of a biopsy are similar to those at PKMP.
3. The Venetian cardiomyopathy represents the greatest symptom complex of PKMP. At this LZh form it is involved more often than at previous. Family penetrance makes 50%. The lethal outcome at the age of 7 years is registered.
4. Smoke a disease, histologically the corresponding PKMP, it is described in Southeast Asia, Japan. Not coronary precardiac elevation of a segment of ST in the field of PZh is revealed at teenagers who or rest had during sleep a risk of emergence of sudden death. At some patients are revealed typical by PKMP ECG signs.
5. The isolated tachycardia proceeding from PZh: the data received when performing a nuclear magnetic and resonant research and an angiokontrastirovaniya confirm existence of PKMP localized in the field of a funnel.
6. High-quality extrasystoles.
Assume that they come from the area of a funnel. Histologically the considerable distribution of fibrous fabric in the field of a funnel associated with an inflammation was defined. According to authors, a cause of death of such patients – myocardites.
7. Ul's anomaly – seldom met pathology leading to heart failure at young age and within several days/weeks – by death. A cause of death of such patients – a heart overload, heart failure and/or arrhythmias. In such cases the myocardium is characterized by total absence of muscle fibers, and the endocardium and an epicardium are opposed. Macroscopically at Ul's disease "pergament" heart is defined. Ul's disease is result of extensive and complete apoptotic destruction of a myocardium of PZh, unlike PKMP. At the moment Ul's anomaly and PKMP are considered as pathogenetic similar diseases.
8. The PKMP Nearitmogenny forms according to the new WHO classification are considered as the PKMP form. In this case availability of aritmogenny substrate in "the sleeping state" which comes to light at special invasive/noninvasive researches is supposed.

Dysplasia with involvement of LZh
1. The Biventrikulyarny dysplasia is characterized by defeat of both ventricles. Typical histologic structure of LZh: substitution by fatty tissue, fibrous restriction. This state leads to heart failure in connection with excessive reduction of a myocardium of LZh and can be mistakenly diagnosed as an idiopathic dilatatsionny cardiomyopathy. Differential and diagnostic criterion is existence of fatty infiltration of a myocardium.
2. The dysplasia complicated by myocarditis – both ventricles, the forecast adverse are in that case involved. In most cases in a structural basis of PKMP myocarditis is genetically predetermined. At myocarditis with involvement of both ventricles there is heart failure leading to death, claiming the lives of 1% of patients a year.
Diagnosis in cases of the nearitmogenny forms complicated by myocarditis is difficult.

Reasons of the Aritmogenny cardiomyopathy of a right ventricle:

The etiology of a right ventricular aritmogenny dysplasia is studied insufficiently now. Most often the disease has idiopathic or hereditary character. It is shown that from the genetic point of view the cohort of patients is enough geterogenn, both autosomal and dominant, and recessive modes of inheritance are revealed. Besides, 6 genes and 9 independent loci responsible for development of a right ventricular dysplasia / cardiomyopathy are identified. The mutant genes associated with a right ventricular cardiomyopathy are revealed in 14 [q23-24] and 17, 12, 18 [q21] chromosomes. They include intermediate filaments, десмоплакин, плакофиллин, плакоглобин, a kernel – factors of protection of a myocardium against influence of a mechanical stress at the cellular level. In addition, desmosomes are included into structure of an inserted cordial disk and participate in intracellular alarm networks which are precisely studied by in vitro now. Manifestation of these mutations is dysfunction of sokratitelny proteins and their interaction.
Besides, allocate also other options of PKMP:
1. Congenital anomaly of development of a myocardium of PZh with clinical manifestation – sudden death.
2. A consequence of the dysplasia caused by the metabolic disturbances striking PZh and causing the progressing substitution of myocytes.
3. Inflammatory genesis: a dysplasia as result of myocarditis when the infection does not leave marks of primary inflammation. According to F. Calabrese and соавт., in PKMP cases often found myocarditis in this connection consider the etiological agent of a disease in the form of group of kardiotropny viruses. E. Nurmukhametova considers the most frequent reason of myocarditis defeat by Koksaki's virus of group B. At the same time involvement as the carrying-out system of heart, and directly a myocardium is possible. But Fontaine adheres to other point of view: patients with PKMP are inclined to developing of infectious myocardites, that is interpretation of relationship of cause and effect is changed. According to Peters, acute/chronic myocarditis leads the left departments of heart to involvement in process that is predictively an adverse sign. In view of contradictory data the role of infectious myocarditis at PKMP demands further studying.
4. According to Turrini, Corrado, PKMP is a consequence of dystrophy of a myocardium with a myocardium degrowth, its dysfunction, electric instability and heart failure.
5. Morgera and соавт. noted associations of blockade of the left leg of a ventriculonector with arrhythmias and idiopathic ventricular tachyarrhythmias.
6. According to Folino, there is a correlation dependence between decrease in vagal influence and severity of a disease.

Treatment of the Aritmogenny cardiomyopathy of a right ventricle:

At PKMP apply drug, noninvasive and operational treatment.
Drug treatment is carried out only as symptomatic therapy and provides elimination and prevention of zhizneugrozhayushchy arrhythmias, is more rare – displays of congestive heart failure. The best results are received when using a sotalol (83%) in comparison with verapamil which efficiency made 50%, Amiodaronum (25%) and beta-blockers (29%). In hard cases at good tolerance with observance of precautionary measures it is possible to use combinations of drugs, for example Amiodaronum with beta adrenoblockers or Amiodaronum with flekainidy or other antiarrhytmic means of a class 1C. In the first case it is considered positive pharmakodinamichesky, and in the second – pharmacokinetic interaction of the combined medicines. Flekainid it is possible to combine also with beta adrenoblockers. At the insufficient efficiency estimated with use of data of holterovsky monitoring of an ECG, it is reasonable to carry out selection of methods of antiarrhytmic therapy by means of an electrophysiologic research.
Treatment of congestive heart failure is carried out by the standard methods. Also APF inhibitors are especially effective карведилол.
At bradycardia including the induced antiarrhytmic therapy, recommends installation of an electrocardiostimulator.
In refrakternost cases to therapy and at high risk of development of a syndrome of a sudden cardiac death resort to noninvasive methods of treatment: implantations of a defibrillator cardioverter or radio-frequency ablation. According to Gatzoulis, on the lake of Naxos automatic defibrillators are implanted to two patients with malignant ventricular arrhythmias. According to S. Peter, ablation is carried out only at angiographic confirmation of a focal dysplasia. According to Masedo, at lipomatous infiltration PZh6 the mm (according to results of a magnetic and resonant research) without local or widespread dysfunction of PZh should carry out carefully implantation of a kardioverteradefibrillyator and to use medicines. Implantation of a cardioverter defibrillator is, as a rule, transferred without complications and allows to reduce mortality.
At patients with persistent potentially fatal ventricular arrhythmias, especially in combination with dysfunction of LZh and congestive heart failure, effectively surgical treatment – the ventrikulotomiya providing interruption of circulation of a pathological excitation wave in PZh.
Among methods of an operative measure by the most effective transplantation of heart is. However, in view of many reasons, it is made extremely seldom, and data on this occasion in literature meet infrequently.
That in studying of PKMP certain results are achieved presence of "white spots" at an etiology of this disease testifies to need of carrying out further researches on this subject.