Biventricular hypertrophic cardiomyopathy with ACTC1 and LDB3 mutations, results of primary prevention of sudden cardiac death: а case report

Introduction. Hypertrophic cardiomyopathy (HCM) significantly increases the risk of sudden cardiac death (SCD), especially in young patients. Familial HCM requires an individual approach to risk stratification and determining indications for primary prevention of SCD.

Brief description. This case describes a patient with a rare genetic anomaly (a combination of ACTC1 and LDB3 mutations). Thanks to timely diagnosis, indications for a cardioverter-defibrillator implantation were determined, which made it possible to stop an episode of ventricular fibrillation (VF). The case describes the changes of the patient's echocardiographic parameters, morphological features (biventricular myocardial hypertrophy, myocardial bridge), as well as the disease course, therapeutic approaches and 6-year treatment outcomes.

Discussion. Careful stratification of SCD risk, including assessment of family history, constant monitoring with dynamic echocardiography and Holter monitoring, allowed timely implantation of a cardioverter-defibrillator and stopping VF. Preventive measures, continuity between the inpatient and outpatient stages saved the patient's life, improved the prognosis and slowed the progression of left ventricular hypertrophy. A rare genetic variant of HCM with mutations in the ACTC1 and LDB3 genes has been described in only three cases over 5 years, which emphasizes the scientific significance of this case. The combination of biventricular hypertrophy, myocardial bridge, and episodes of ventricular tachycardia and VF may be associated with this genotype, which requires further study to improve SCD risk management strategies.

1. Czimbalmos C, Csecs I, Toth A, et al. The demanding grey zone: Sport indices by cardiac magnetic resonance imaging differentiate hypertrophic cardiomyopathy from athlete's heart. PLoS One. 2019;14(2):e0211624. doi:10.1371/journal.pone.0211624.

2. Maron BJ, Rowin EJ, Maron MS. Global Burden of Hypertrophic Cardiomyopathy. JACC Heart Fail. 2018;6(5):376-8. doi:10.1016/j.jchf.2018.03.004.

3. Patel N, Shetty NS, Pampana A, et al. Sex-Associated Differences in Clinical Outcomes After Septal Reduction Therapies in Hypertrophic Cardiomyopathy. Mayo Clin Proc. 2024;99(12):1933-44. doi:10.1016/j.mayocp.2024.05.026.

4. Engel TR. Diagnosis of Hypertrophic Cardiomyopathy: Who Is in Charge Here-The Physician or the Computer? J Am Coll Cardiol. 2020;75(7):734-5. doi:10.1016/j.jacc.2019.12.028.

5. Liu Q, Li D, Berger AE, et al. Survival and prognostic factors in hypertrophic cardiomyopathy: a meta-analysis. Sci Rep. 2017;7(1):11957. doi:10.1038/s41598-017-12289-4.

6. Salakhov RR, Golubenko MV, Pavlukova EN, et al. Experience in genetic testing of hypertrophic cardiomyopathy using nanopore DNA sequencing. Russian Journal of Cardiology. 2021;26(10):4673. (In Russ.)

7. Gabrusenko SA, Gudkova AYa, Koziolova NA, et al. 2020 Clinical practice guidelines for Hypertrophic cardiomyopathy. Russian Journal of Cardiology. 2021;26(5):4541. (In Russ.)

8. Davydova VG, Gudkova AYa, Krutikov AN, et al. Clinical, morphological and genetic characteristics of young patients with hypertrophic cardiomyopathy with indications for implantable cardioverter-defibrillator. Russian Journal of Cardiology. 2024; 29(11):5994. (In Russ.)

9. Andreeva SE, Marusova MO, Bortsova MA, et al. Familial hypertrophic cardiomyopathy with midventricular obstruction associated with MYH7, FHOD3 and BAG3 gene variants: a case report. Russian Journal of Cardiology. 2024;29(10S):6146. (In Russ.)