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3 . 2021

Manifestation of hypertrophic cardiomyopathy in children: phenotype, genotype and features of surgical treatment

Abstract

Background. Hypertrophic cardiomyopathy (HCM) is the most common genetically determined pathology of the myocardium, manifesting at any age. Despite the high prevalence and intensive research, the relationship between the genotype, phenotype and prognosis of this disease has not been sufficiently studied. There are several generations of guidelines discussing risk assessment and milestones of treatment of HCM, but most of them are validated in adult patients. Pediatric manifestation of HCM always means a particularly high risk of sudden cardiac death and rapid progression of pathology. However, the possibility of surgical treatment HCM in early age and indications for such a surgery in children are still not discussed enough, especially in the Russian medical journals.

Aim - to present the results of diagnosis and surgical treatment in children operated for HCM at the age of 13-18 years.

Material and methods. Preoperative examination had included family history collection, general and biochemical blood analysis, resting and 24-hours ECG monitoring, transthoracic and transesophageal (intraoperative) EchoCG, cardiac MRI with a gadolinium. Genetic testing was performed by whole-exome sequencing (WES) on the Illumina platform. Confirmation of all identified genetic variants was performed by capillary Sanger sequencing.

Results. From 2016 to 2021, an extended myectomy HCM was performed in 10 children diagnosed with HCM at the age of 13-18 years. All operated children underwent surgery successfully, and all were discharged from the clinic. The time of postoperative follow-up was from 1 to 5 years (with an annual examination after surgery). The phenotype of myocardial hypertrophy in 9 out of 10 children was determined as a submitral (diffuse-generalized) phenotype. The thickness of the interventricular septum ranged from 25 to 55 mm. A cardioverter-defibrillator was implanted before the main operation in 8 patients, and two of them had appropriate shocks during the postoperative follow-up period. The family history was affected in 7 cases. Causative genetic variants were identified in 6 probands.

Conclusion. HCM in children is a special variant of the pathology, characterized by rapidly progression and severe anatomical and functional dysfunction of the myocardium. Surgical remodeling performed by an experienced team of specialists can prevent severe diastolic heart dysfunction. It is an effective surgical technic with a good medium-term result.

Keywords:hypertrophic cardiomyopathy, septal myectomy, MYH7, MyBPC3, RASopathy, sudden cardiac death

Funding. The study had no sponsor support.
Conflict of interest. The authors declare no conflict of interest.
For citation: Dzemeshkevich S.L., Motreva A.P., Kalachanova E.P., Nikityuk T.G., Martyanova Yu.B., Kalmykova O.V., Leontieva I.V., Miklashevich I.M., Dombrovskaya A.V., Polyak M.E., Zaklyazminskaya E.V. Manifestation of hypertrophic cardiomyopathy in children: phenotype, genotype and features of surgical treatment. Clinical and Experimental Surgery. Petrovsky Journal. 2021; 9 (3): 16-24. DOI: https://doi.org/10.33029/2308-1198-2021-9-3-16-24 (in Russian)

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CHIEF EDITOR
CHIEF EDITOR
Sergey L. Dzemeshkevich
MD, Professor (Moscow, Russia)

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