A-5

The analysis of structure of the valvular heart diseases

Sophia M. Shakhnabieva
Scientific-Research Institute of Heart Surgery and Organ Transplantation

Objective: The most frequent causes of VHD are degenerative disease,  rheumatic fever and infectious endocarditis.

Research objective: to study the structure of the valvular heart diseases (VHD) in Bishkek.

Methods:  For studying of structure of the VHD among inhabitants of Bishkek referred to the  Scientific Research Institute of Heart Surgery and Organ Transplantation, the retrospective analysis of out-patient cards of the patients observed  from 2005 to 2018 was carried out. In total, the analysis included 472 patient cards. For the specified period of observation (2005-2018) 472 patients with VHD living in Bishkek were examined.

Results:  Among patients with VHD the females were 312 (66.1%) patients, males – 160 (33.9%). The adult and middle age (from 18 to 60 years) prevailed among patients – 441 patients (93.4%), there were only 20 children, preadolescents, adolescents (4.2%).  Overall, 217 (45.9%) the patients underwent hospital treatment.  

VHD developed as a result of a chronic rheumatic fever in most of patients – 386 (81.8%), and due to  primary infectious endocarditis in 9 (1.9%) patients, and  secondary – in 19 (4.0%) patients. Other reasons of VHD (atherosclerosis, heart injuries, syphilis, etc.) made 58 (12.3%) patients.

By the number of the involved valves the combined VHD prevailed (372 (78.8%)), isolated or local were seen in 65 (13.8%) patients, combination of several valves met less often (36 (7.4%)). Distribution of VHD by the type of the valve was as following: aortic valve (216), mitral valve (307), tricuspid valve (196), the valve of pulmonary artery (4).

Among patients the compensated heart diseases were detected in 190 (40.3%) patients, subcompensated – 221 (46.8%), decompensated – 61 (12.9%) patients.

In total, 147 (31.1%) patients were operated, repair of the valve or replacement. Valve replacement with  mechanical valves were done in 91.8% patients or bioprosthetic valves -8.2% patients. The type of valve replacement depended on the patient’s age, condition, and the specific valve affected.

Closed mitral commissurotomy  was performed in 22 (4.7%) cases, mitral valve replacement in 77 (16.3%) patients, mitral and aortic valve replacements were carried out in 20 (4.2%) patients, mitral, aortic  and tricuspid valves replacement were carried out in 4 (0.8%) patients, mitral and tricuspid valves replacements -  18 (3.8%) of patients, aortic valve replacement  – 1 (0.2%) the patient, tricuspid valve replacement  – 1 (0.2%) the patient, secondary infectious endocarditis – 4 (0.8%) patients.

Conclusion: In our patients cohort, females and the adult and middle aged (from 18 to 60) patients prevailed. The most common  cause of VHD was chronic rheumatic fever. By the number of the involved valves the combined VHD  prevailed.

A-6

Association of heart rate variability parameters with sinus rhythm maintenance

Elmira N. Tukusheva
Scientific-research institute of heart surgery and organs transplantation

Objective: The relative hypersympathicotonia due to the suppression of the parasympathetic division of the autonomic nervous system (ANS) in combination with signs of baroreflex insufficiency prevents the maintenance of sinus rhythm in various structural heart diseases. In this paper, we analyzed the modulating effect of the ANS on the sinus rhythm control in patients operated due to acquired valvular heart disease.

Methods: A total of 42 patients with atrial fibrillation and 30 patients with normal sinus rhythm who were subjected to mitral valve replacement for rheumatic isolated mitral insufficiency from 2007 to 2015 in the Department of Surgery of Acquired Heart Diseases of the Scientific-Research Institute of Heart Surgery and Organs Transplantation were included in the study. The temporal and spectral indices of HRV of the 24h electrocardiographic (ECG) monitoring in the preoperative period were evaluated. In the early postoperative period, the association of HRV  parameters according to the ECG monitoring data with the sinus rhythm maintenance was retrospectively studied. An active orthostatic test (tilt-test) was carried out in order to reveal heart rhythm regulation abnormalities.

Results: In the postoperative period, rhythm maintenance was observed in 14 patients from the main group of patients (hereafter AF1 group), whereas in 28 patients rhythm control was not  achieved (hereafter AF2 group). Sex distribution in the main group (AF) was: 26 women and 16 men, and in the control group (hereafter NSR): 20 women and 10 men. The age of the examined patients ranged from 14 to 48 years (mean age 38.1 ± 5.9 years). The duration of the underlying disease ranged from 7-21 years, an average of 14.3 ± 7.8 years.

  The indices of both the temporal and spectral parameters in patients of the AF1 group did not significantly differ from the values ​​of the analogous indices in patients with sinus rhythm (NSR). The SDNN was 140.1 ± 26.5 ms. vs 150.2 ± 28.4 ms, (p> 0.05). Parasympathetic indicators of RMSSD and p-NN50% also showed no difference (p> 0.05). The VLF (index of subcortical structures), LF (index of the sympathetic system) and HF (index of the parasympathetic system) of the AF1 group were 2364 ± 1089 ms, 857 ± 354 ms, 301 ± 109 ms, respectively, did not significantly differ from the values ​​of similar indicators in the group NSR (2489 ± 1254 ms, 975 ± 367 ms, 338 ± 121 ms; p> 0.05). The values ​​of sympathetic-parasympathetic balance in both groups were also comparable (3.8 ± 1.1 units in the NSR group and 3.5 ± 1.3 units in the AF1 group, p> 0.05).

   A comparative analysis of HRV indicators between the AF1 and AF2 groups showed statistically significant differences in both temporal and spectral parameters. The SDNN of the MA2 group was 124.2 ± 16.4 ms compared to 140.1 ± 26.5 ms of the AF1 group, p <0.05, the RMSSD and p-NN50% also showed a significant difference: p <0.01. Similar data were obtained when analyzing the frequency spectrum data. The power of the HF range in patients of the AF2 group turned out to be significantly lower than the values of the same indicator in the group of patients with AF1 (175 ± 98 ms2 vs. 301 ± 109 ms, p> 0.05). Naturally, against the background of suppression of the parasympathetic division of the ANS in patients of the AF2 group, a shift in the autonomic balance towards a relative predominance of sympathetic influences was noted. Thus, the indicator of sympathovagal balance (LF / HF) was significantly higher in AF2 than that in the AF1 group (5.2 ± 1.0 units versus 3.8 ± 1.1 units, p <0.01).

In the NSR group, the tilt test resulted in a significant increase in the activity of sympathetic LF oscillations (from 975±367 ms² to 1150±328 ms², p <0.01) and a decrease in the power of parasympathetic influences (HF drop from 338±121 ms² to 192±85 ms², p <0.01). The sympato-vagal balance increased from 3.5±1.3 units. to 5.6±1.4 units (p <0.01).

  In the AF1 group, the tilt test also led to an increase in the LF oscillations (from 857±354 ms2 to 951±345 ms2, p <0.05). The dynamical reaction of the LF trend noted, however, the degree of the reaction was slightly lower compared with the NSR group (+ 11.0% and 17.9%, respectively). The reaction of the parasympathetic component in AF1 group also consisted in reducing its power from 301±109 ms2 to 184±90 ms2 (p <0.01), which led to an increase in sympatho-vagal balance (from 3.8±1.1 units up to 5.1±1.2 units, p <0.01).

   In the AF2 group, the tilt-test did not lead to an increase, but. on the contrary, in the drop in the power of the sympathetic component of the spectrum (from 801±305 ms² to 611±285 ms², p <0.01). Thus, the fall in power of the LF trend was 23.7%, showing a disadaptive (pathological) picture. A decrease in the power of HF modulations from 175–98 ms² to 121–54 ms² (p <0.01) was noted. However, the sympathetic-parasympathetic balance in this group of patients did not undergo significant dynamics in the course of the tilt test (before the test: 5.1±1.2 units, after the test: 5.2 ± 1.0 units, p> 0.05 ).

 

Conclusion: So, the ability to maintaining of sinus rhythm in patients operated on for mitral insufficiency depended on the ANS state. It’s explained by the impact of relative hypersympathicotonia due to the suppression of the parasympathetic division of the ANS in combination with signs of baroreflex insufficiency on the prevention of sinus rhythm maintenance in this category of patients.