Aim      To determine specific clinical characteristics caused by a combination of the rs397516037 pathogenic variant in the myosin-binding protein C (MTBPC3) and the rs749628307 polymorphic variant in the vinculin (VCL) gene in a Russian family of carriers and to evaluate the contribution of the rs749628307 polymorphic variant in the VCL gene to the development of hypertrophic cardiomyopathy (HCMP).Material and methods  The family under study included one healthy person and 3 patients with HCMP. A targeted analysis of proband’s exome was performed. A structural alignment for both forms of the VCL protein, the canonical form and the form with p.Arg230His substitution, was performed.Results The pathogenic rs397516037 variant and the potentially pathogenic rs749628307 variant were detected in the proband and several family members. A possibly damaging variant rs749628307 was detected in the proband and several family members evaluated in this study. The structural alignment confirmed that the rs749628307 variant did not alter the protein structure significantly and could not cause an impairment or loss of the protein function.Conclusion      This study demonstrated that apparently the rs749628307 variant in the VCL gene does not affect the protein structure in a pathogenetically significant way, neither does it affect the severity and form of the clinical manifestations of HCMP; therefore, it cannot be considered as pathogenic.

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Aim. To evaluate the relationship between the salt intake (NaCl) and the clinical and hemodynamic parameters in patients with hypertrophic cardiomyopathy (HCM).Material and methods. Forty four patients with HCM (mean age, 60,4±15,3 years) were examined. Particular attention was paid to intraventricular obstruction and hypovolemic syncope. NaCl consumption was estimated by 24-hour urine sodium test.Results. An inverse correlation was found between syncope and 24-hour natriuresis (r=-0,3, p=0,04). At 24-hour natriuresis <50 mmol/day,  syncope was more common (p=0,02): odds ratio (OR), 12,3 (95% confidence interval (CI): 1,3-121,3, p=0,03), as well as <65 mmol/day (p=0,04): OR, 8,3 (95% CI: 1,13-60,3; p=0,04). At higher 24-hour urine sodium values, no reduction in syncope risk was recorded. A correlation was found between low values of left ventricular (LV) stroke volume index (SVI) (<26 ml/m2) and 24-hour urine sodium (<50 mmol/day) (r=0,5, p=0,01). An inverse correlation was observed between LV SVI and syncope at 24-hour natriuresis <50 mmol/day (r=-0,9; p=0,05). An inverse relationship was found between the intraventricular obstruction and 24-hour urine sodium (r=-0,4, p=0,01). The prevalence of obstruction increased as natriuresis decreased: at 120 mmol/day, OR was 4,3 (95% CI: 1,01-18,6, p=0,048), at 110 mmol/day, OR — 4,6 (95% CI: 1,218,1, p=0,03), and at 100 mmol/day, OR — 4,0 (95% CI: 1,1-11,7, p=0,04). An increase in 24-hour urine sodium >130 mmol/day was not followed by a further decrease in obstruction prevalence.Conclusion. To reduce the obstruction risk, the optimal 24-hour urine sodium level is ≥130 mmol/day (NaCl, 7,5 g/day). To reduce the syncope risk, regardless of obstruction presence, the optimal level of 24-hour natriuresis is ≥65 mmol/day (NaCl, 3,8 g/day).

Funding Acknowledgements Type of funding sources: None. Background Patients with hypertrophic cardiomyopathy (HCM) are advised to avoid dehydration and drink enough fluids to maintain circulating blood volume (BV) when LV volume is reduced. Salt (NaCl) intake is one of the main factors affecting BV and hemodynamics. At the same time, there have been no studies to find the optimal level of salt intake and identify its effect on hemodynamics in HCM patients. Purpouse To estimate the effect of salt (NaCl) intake on the clinical course and hemodynamics in hypertrophic cardiomyopathy patients (HCM). Material and methods: 54 HCM patients aged between 18 and 81 (average age 60.1 ± 15.2 years), were examined. Medical history and complaints were mainly focused on the shortness of breath, dizziness, and nonarrhythmogenic syncope. ECG, Holter ECG monitoring and EchoCG were performed. The NT-proBNP level and the 24-hour urine sodium tests were taken. Results The average level of Na+ in the 24-hour urine sample was 128.2 ± 84.1 mmol/day; an inverse correlation was found between this parameter and syncope (r=-0.4, p = 0.03) and also with LV outflow tract obstruction (r=-0.3, p = 0.04). NT-proBNP level was found to be 1449 [444; 3807] ng/L, with a positive relationship between NT-proBNP and functional class of chronic heart failure by NYHA (r = 0.4; p = 0.009). In patients with daily natriuresis &lt;50 mmol/day, syncope was more common (60% vs 8%, p = 0.01), a lower LV stroke volume index (LV SVI) was revealed (19.8 ± 3.6 vs 27.1 ± 4, 8 ml/m², p = 0.006); daily natriuresis &gt;65 mmol/day corresponded to a higher right atrium volume index (21.7 ± 7.3 vs 29.1 ± 11.1 ml/m², p = 0.01),  higher left atrium volume index (36.0 ± 13.8 vs 47.6 ± 13.8 ml/m², p = 0.01) and higher systolic pulmonary artery pressure (28.4 ± 6.3 vs 35.1 ± 7.9 mm Hg, p = 0.02). An increase in natriuresis &gt; 100 mmol/day was followed by a decrease in the frequency of obstruction (52% vs 22%, р=0.04), which persisted at natriuresis &gt; 110 mmol/day (58% vs 29%, р=0.03). Daily natriuresis &lt;50 mmol/day folowed by increased of syncope with OR 16.9 (95% CI: 2.2-132.5, p = 0.007), and &lt;65 mmol/day - OR 7.6 (95% CI: 1.4-41.7; p = 0.02). Obstruction frequency decreased with natriuresis &gt; 90 mmol/day - OR 3.7 (95% CI: 1.2-12.1, p = 0.03), with natriuresis &gt;100 mmol/day OR 3.9 (95% CI: 1.3-12.3, p = 0.02), with natriuresis &gt;110 mmol/day OR 5.2 (95% CI: 1.6-16.9, p = 0.007).  Conclusions Low salt intake in the observed cohort of HCM patients was accompanied by a lower LV SVI and higher incidents of syncope. As salt intake in patients with HCM increases, the atria volume and the pressure in the pulmonary artery increase also. Frequency of obstruction was reduced with sodium levels in daily natriuresis &gt; 90 mmol/day.

Aim. To assess the relationship between the level of salt (NaCl) consumption and clinical and hemodynamic parameters in patients with hypertrophic cardiomyopathy (HCM) of different age groups.Material and methods. We examined 57 patients with HCM (mean age, 59,2±16,2 years). The patients were divided into groups according to the World Health Organization (WHO): I — young age (≤44 years old) — 12,4% of patients; II — middle (45-59 years old) — 37,2%; III — elderly (60–74 years old) — 36%; IV — senile (≥75 years old old) — 14,4%. The clinical status of patients was assessed, during which special attention was paid to syncope not related to cardiac arrhythmias. NaCl intake was assessed by the 24-hour urine sodium (Na+) level.Results. In the general cohort, in Na+ level <50 mmol/day, the lowest left ventricular stroke volume (LVSV) index was observed, which were associated with syncope (r=-0,9, p=0,03). With the urinary sodium level of 50-70 mmol/day, an increase in LVSV index was observed and the absence of syncope. At Na+ level more than 70 mmol/day, no increase in LVSV index was observed. In this regard, a predictive model was created, as a result of which it was found that with an increase in Na+ consumption by 1 mmol/day, an increase in LVSV index by 0,3 ml/m2 should be expected. There were no significant differences in the effect of NaCl intake on the studied parameters in patients with HCM of different ages. At the same time, low NaCl intake in elderly patients was associated with syncope.Conclusion. Minimal values of Na+ intake (<50 mmol/day or NaCl 3 g/day) were found, which are unfavorable for patients with HCM due to the risk syncope. The 24-hour urine sodium level to maintain a hemodynamically safe level of LVSV index in patients with HCM should be more than 70 mmol/day (NaCl 4,1 g/day). Monitoring of Na+ consumption level is especially important in elderly people with HCM.