[Genetic predictors of myocardial infarction in subjects of young age]

to investigate associations of single nucleotide polymorphisms (SNP) rs499818 (6p24.1), rs619203 of ROS1 gene (6q22), rs10757278 rs1333049 (9p21.3), rs2549513 (16q23.1), rs4804611 of ZNF627 gene (19p13.2) with myocardial infarction in subjects of young age. The group of patients with MI (n=99) aged less than 45 years and the control group (n=111) did not differ significantly by sex (=0,617), age (=0.291), arterial hypertension (=0.766), diabetes mellitus (=0.395), hypercholestolemia (=0.696), excessive body mass and obesity (=0.361), abdominal obesity (=0.831) and history of smoking (=0.400). There was significant difference between groups by burdened heredity (<0.001). Genomic DNA was obtained from venous blood by phenol-chloroform extraction. Genetic testing was performed by real time polymerase chain reaction using 7900HT Fast Real-Time PCR System according to manufacturers protocol. We found significant association between rs1333049 and rs10757278 and myocardial infarction (MI). Odds ratio (OR) of development of MI in carriers of risk allele rs1333049 was 2.4 (95% confidence interval [CI] 1.24 to 4.65), in carriers of G rs10757278 allele - 2.00 (95%CI 1.05 to 3.80). Association of risk alleles rs 1333049 and G rs10757278 with MI remained significant after adjustment for burdened family history (OR 4.25, 95%CI 1.39 to 12.99, and OR 3.04, 95%CI 1.09 to 8.52, respectively). Presence in the genotype of both risk alleles rs1333049 and G rs10757278 was associated with OR of MI development 2.40 (95%CI 1.20 to 4.82) which was not different from that associated with carriage of allele rs1333049 only. Possibly in our population both SNPs belong to one linkage block and correspondingly it is sufficient to genotype one SNP. No significant associations with MI were found for variants rs4804611, rs2549513, rs499818, rs619203. SNPs rs1333049 and rs10757278 of 9p21.3 locus are predictors of MI in young individuals not dependent on both traditional risk factors and presence of burdened family history.

[Interrelationship between polymorphic markers of methylenetetrahydrofolate reductase gene and development of acute disturbance of brain circulation in families of patients with atrial fibrillation]

In the present work we for the first time on the clinic-genetic material revealed genetic predictors of development of acute disturbance of brain circulation (ADBC) in families of patients with atrial fibrillation (AF) namely polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene. Genotype CC was significantly more often found among patients with AF and ADBC compared with controls (58.1 and 35.2%, respectively, p=0.02) as well as in relatives of probands compared with the control group (59.3 and 35.2%, respectively, p=0.008). With this in relatives with revealed paroxysmal AF and ADBC we also noted presence of CC genotype. Taking into consideration the relationship obtained between polymorphysms of MTHFR gene and AF it was possible to assume that polymorphic marker CC appeared to be a predictor of ADBC in these families.

[Association of 2B-adrenergic receptor gene polymorphism with disturbances of cardiac conduction]

In this work we for the first time revealed on clinical - genetic material association between hereditary disturbances of cardiac conduction and polymorphism of 2-adrenergic receptor gene.

[Polymorphism of connexin 40 gene-- a novel genetic marker of the sick sinus node syndrome]

In this work we have demonstrated for the first time on the clinico-genetic material association between hereditary sick sinus node syndrome and connexin 40 gene polymorphism. We have revealed that heterozygous variant of connexin 40 gene variant is more frequent among patients with sick sinus node syndrome and their healthy relatives than in persons of control group.

[Polymorphisms of 2B-adrenergic receptor and endothelial NO-Synthase genes in genesis of the hereditary sick sinus node syndrome]

In this work we have demonstrated for the first time on the clinico-genetic material association between hereditary sick sinus node syndrome (SSNS) ADRA2B and eNOS genes polymorphisms. We have established predominance of homozygote genotype of more rare DD allele in patients with SSNS (28%) compared with subjects of control group (8.99%). We have found predominance of heterozygote genotype 4a/4b in patients with SSNS compared with subjects of control group (41.8 and 25.39%, respectively). The data obtained allow to suggest that eNOS gene polymorphism might be associated with SSNS.

[Ser49gly polymorphism as predictor of development of hereditary sick sinus node syndrome]

We demonstrated for the first time on clinico-genetic material an association of hereditary sick sinus node syndrome (SSNS) with polymorphism of beta-adrenorecetor gene. We found that heterozygous variant of Ser49gly of beta-adrenoreceptor gene was significantly more often met in patients with SSNS and their healthy relatives than in subjects of control group. In the group of patients with SSNS contrary to control group we noted statistically significant preponderance of carriers of mutant Gly49 allele of.

[Genetics of atrial fibrillation]

We carried out examination of 103 probands with atrial fibrillation (AF) and 301 their 1st, 2nd, and 3rd degree relatives (main group). In addition we examined 82 probands without clinical electrocardiographic signs of heart disease and 163 their 1st and 2nd degree relatives (control group). We found accumulation of AF in families of probands with this pathology. Segregation analysis of idiopathic forms of AF allowed to reveal autosomal dominant type of inheritance of this pathology. Heterozygous variant of Ser49Gly of betai-adrenoreceptor gene can be considered as one of genetic predictors of development of how primary and secondary AF.

Apoptosis of leukocytes as a marker of neutrophil-endotheliocyte interaction in coronary heart disease

We studied the mechanism of interaction of peripheral blood neutrophils with endothelial cells (expression of cell adhesion molecules and production of NO) and the role of neutrophil apoptosis in the development of endothelial dysfunction. The effects of mitochondrial dysfunction of neutrophils on the development of apoptosis of these cells after their interaction with endothelial cells were analyzed.

[Peculiarities of cardiac involvement in patients with dystrophic myotonia]

Dystrophic myotonia is a widespread hereditary disease. Pathological process touches development and functioning of various organs and tissues: smooth and skeletal muscular tissue, the heart, organ of vision, brain. Pathology of the heart serves as one of frequent manyfestations of dystrophic myotonia. Degenerative changes and fatty infiltration of myocardium not infrequently leads to dilated cardiomyopathy. Involvement of the heart in such patients is represented mainly by disturbance of cardiac rhythm and conduction. Course of the disease is progressive.

[Comparative assessment of efficacy of tissue plasminogen activator and streptokinase in the treatment of patients with acute myocardial infarction]

AIM

To compare results of treatment of patients with acute myocardial infarction with tissue plasminogen activator (TPA) and streptokinase.

MATERIAL AND METHODS

TPA (100 mg intravenously) and streptokinase (1500000 U intravenously) were used for thrombolytic therapy of acute myocardial infarction in 114 and 118 patients, respectively.

RESULTS

TPA treated compared with streptokinase treated patients were characterized by less frequent serious cardiac rhythm and conduction disturbances and hypotension during thrombolysis (p<0.05), as well as less frequent pathological Q-waves formation (p<0.001). More than 50% lowering of initially elevated ST-segment by 90-th minute occurred more often in TPA treated patients (p<0.001). Differences between TPA and streptokinase treated patients in mortality (3.5 and 7.6%, respectively), reinfarction rate during first 24 hours (3.5 and 5.1%, respectively), aneurysm formation (9.1 and 14.7%, respectively), and heart failure development (4.5 and 11.0%, respectively) were not significant.

CONCLUSION

The use of TPA for thrombolytic therapy of patients with acute myocardial infarction gave better results than the use of streptokinase.

[Angiotensin-converting enzyme gene polymorphism in patients with primary disturbances of cardiac conduction]

Increased frequencies of angiotensin-converting enzyme (ACE) D-allele and ID-genotype among patients with idiopathic atrioventricular blocks and I allele and II genotype among patients with idiopathic intraventricular blocks allow to consider these genotypes risk factors of corresponding disturbances of cardiac conduction. Decreased frequency of ACE I allele and II genotype among patients with idiopathic atrioventricular blocks is indicative of a possible protective role of II genotype against development of this type of cardiac conduction defect. Low frequency of D allele and genotype D prevents derangements of conduction in His-Purkinje system.

[Relationship between polymorphism of non-coding regions of human mitochondrial genome and primary cardiac conduction disorders]

AIM

Analysis of associations between idiopathic disturbances of cardiac conduction (DCC) and polymorphism of mitochondrial genome.

MATERIAL AND METHODS

A family examination was performed in 431 probands with various DCC and 1347 relatives of the first, second and third degree of kinship (the study group). All the examinees were divided into four subgroups. These included 158 probands with atrioventricular block (AVB) of various degree and their 518 relatives (subgroup 1); 50 probands with a complete right bundle-branch block (BBB) and their 161 relatives (subgroup 2); 108 probands with a complete left BBB and left anterior branch of the His bundle and their 152 relatives (subgroup 3); 115 probands with sick sinus syndrome (SSS) and their 327 relatives (subgroup 4). The control group consisted of 104 probands without clinical ECG manifestations of cardiac diseases and their 321 relatives. All the examinees have undergone ECG, atropin test, echocardioscopy, electrophysiological examination of the heart and mitochondrial DNA (mDNA).

RESULTS

Comparison of the incidence of mDNA D-loop restriction sites in the group of patients with idiopathic DCC and controls has found higher frequency of the Hae III 16517 site in the group of the patients (p = 0.0480). By location of the blocks (atrioventricular and intraventricular), the site occurred more frequently in patients with AVB (86.36%). The variant "+" by the site of Hae III 16517 mDNA was found to associate with disturbances of cardiac conduction, more closely in AVB.

CONCLUSION

Variability of mDNA may be an etiological factor of idiopathic DCC pathogenesis.

[New data on etiology of heart conduction disturbances]

AIM

To make a clinicogenealogical analysis of different types of heart conduction disturbances in families of Krasnoyarsk city.

MATERIALS AND METHODS

104 probands with ECG-verified idiopathic forms of atrioventricular and intraventricular blocks of different severity and 331 their close relatives (kinship degree I and II) were examined using standard clinical investigations, ECG, echocardioscopy, electrophysical investigations in some cases and coronarography.

RESULTS

All the observed 104 families were divided into 3 groups according to the type of heart conduction in proband. Group 1 consisted of 24 probands with atrioventricular block and 80 their relatives. The sick relatives had for the most part atrioventricular blocks (31.2%). 26 probands of group 2 had complete right bundle branch blocks. Of their 81 relatives, the sick ones had primarily conduction disturbances in right bundle branch (incomplete block--44.7%, a complete block--5.2%). Group 3 consisted of 54 probands with left bundle branch block and 170 relatives. The left bundle branch block was present in 27.4% of the relatives.

CONCLUSION

A definite family aggregation of heart conduction disturbances was found. This proves genetic determination of this pathology.

[Combined use of left atrial transesophageal pacing and cordarone in atrial flutter]

AIM

To investigate the effectiveness of superfrequent transesophageal left atrial stimulation (TLAS) and its combination with cordarone in management of atrial flutter (AF).

MATERIALS AND METHODS

650 patients with paroxysmal AF underwent TLAS. The paroxysm duration varied from 1 hour to 1 month. In 312 patients TLAS was performed prior to treatment with antiarrhythmic drugs (group 1), in 338 patients--after intravenous administration of cordarone (group 2).

RESULTS

Superfrequent TLAS has restored sinus rhythm (SR) in 85(27.2%) and 169(50%) patients of groups 1 and 2, respectively (p < 0.001). TLAS promoted conversion of AF in atrial fibrillation (AFi) in 185(59.3%) and 159(47.1%) patients of groups 1 and 2, respectively (p < 0.01). Moreover, SR recovered 24-48 hours after TLAS in 87(27.9%) and 64(18.9%) patients of groups 1 and 2 respectively (p < 0.01). Sinus rhythm recovered in a total of 172(55.1%) and 233(69.0%) patients, AF was converted to AFi in a total of 88(31.4%) and 95(28.1%) patients (p > 0.05) of groups 1 and 2, respectively. TLAS was uneffective in 42(13.5%) and 10(2.9%) patients of groups 1 and 2, respectively.

CONCLUSION

Superfrequent TLAS is a highly effective and non-invasive modality in the treatment of paroxysmal AF. It promotes recovery of SR. In some patients TLAS induces AFi which is more controllable by medication as regards the heart rate. Cordarone contributes to the response to TLAS in patients with paroxysmal AF.

[Use of transesophageal left atrial cardiac pacing for assessment of cordarone effectiveness in patients with atrioventricular tachycardia]

AIM

To assess by means of transesophageal left atrial pacing the effectiveness of cordarone treatment for arrhythmias caused by re-entry mechanism.

MATERIALS AND METHODS

Effectiveness of cordarone treatment was estimated in 25 patients with atrioventricular nodal tachycardia (AVNT) and in 33 patients with WPW syndrome and reciprocal atrioventricular tachycardia (RAVT) with frequent paroxysms of tachycardia 1-5 times per week. Transesophageal left atrial pacing (TELAP) was performed before antiarrhythmic treatment and on cordarone treatment day 14-18. Cordarone was given for two months in common regimen (the first 10 days--600 mg/day, the next 10 days--400 mg/day and then 200 mg/day).

RESULTS

The first TELAP induced paroxysmal AVNT or RAVT in all the patients. According to the results of the second TELAP, all the patients were divided into three groups. Group 1 included 28 patients in whom the second TELAP was unable to induce tachycardia. All these patients had increased effective refractory period (ERP) of AV node and/or of accessory pathway (AP) values and a decreased Wenkebach point (WP) < 150/min during the second TELAP in comparison with the first TELAP. All these patients had no spontaneous paroxysms of T during the 3-month follow-up. Group 2 included 18 patients in whom the second TELAP induced AVT lasting < 30 seconds. 16 of these patients had tachycardia with less heart rate during the second TELAP in comparison with the first TELAP, 153 + (-) 8 bpm vs 188 + (-) 10 bpm, p < 0.001, respectively. Also, in these 16 patients we found an increase of values of ERP of AV node and/or AP > 360 ms and a decrease of WP < 150 bmp. 14 of these 16 patients had no spontaneous paroxysms of AVT and 2 patients had short episodes of AVT during the 3-month follow-up with effects of vagal manoeuvers. From 2 other patients of group 2 one had short episodes of spontaneous T and one had long episodes of tachycardia with effect of verapamil i.v. Group 3 included 12 patients in whom the second TELAP induced the same AVT as the first TELAP. Values of ERP of AV node and/or AP and WP during the first and second TELAP were not different. All of these patients had long spontaneous paroxysms of AVT during cordarone treatment day 14-18. The treatment was discontinued in all patients of group 3.

CONCLUSION

Cordarone is effective in prevention of AVT. Negative results in provocation of AVT during TELAP after 14-18 days of cordarone treatment is a very specific predictor of cordarone treatment effectiveness. Provocation by TELAP of short episodes of AVT with reduced heart rate and higher values of ERP of AV node and AP and lowering of WP < 150 bpm may not predict ineffectiveness of cordarone in patients with AVT. Moreover, the majority of these patients had no spontaneous episodes of AVT. Provocation by TELAP during cordarone treatment of the same AVT episodes as before cordarone treatment is a very specific predictor of cordarone effectiveness.

[Chronotropic insufficiency in patients with ischemic heart disease]

A study is presented of 80 patients with ischemic heart disease (IHD): 37 patients with a low reaction of the cardiac rhythm to physical load--chronotropic insufficiency (CHI) and 43 patients with an adequate reaction of the cardiac rhythm to loads. Physical working capacity was evaluated by the strength of threshold load, pulsepressure double product, rest quotient, oxygen pulse, oxygen consumption per 1 kgm of work. Interval between the 1 and 2 examination--6.5 years. It was shown that CHI in IHD does not influence the prognosis of the disease and does not reflect the grade of its severity. They are, however, the marker of involvement of the atria. Chronic insufficiency in ischemic heart disease makes it difficult to objectively evaluate the physical working capacity.

[Comparative analysis of the significance of transesophageal stimulation of the left atrium and bicycle ergometry in the detection of residual myocardial ischemia during the early period of myocardial infarct]

The study was undertaken to compare transesophageal left atrial pacing (TLAP) and bicycle ergometry (BE) in the detection of residual myocardial ischemia (RMI) in 187 patients with myocardial infarction in the early periods of the disease (on days 20 to 26). The intensity of TLAP and BE was increased up to the threshold and submaximal levels according to the conventional criteria. Among the patients, RMI was detected in 71% with TLAP and in 55% with BE (p less than greater than 0.01). Thus, this suggests that TLAP has advantages over BE in the detection of RMI in patients with myocardial infarction in the early periods of the disease.

[The indices of spiroergometry and tetrapolar rheography in patients with ischemic heart disease]

Indices of the central hemodynamics and stroke indices were assessed by means of spiroergometry and tetrapolar chest rheography were studied in 35 practically healthy persons and 45 patients with ischemic heart disease and a direct correlation between the indices of hemodynamics and the above methods was found. Spiroergometry may be used for evaluation of the hemodynamic parameters in patients with ischemic heart disease.

[Clinico-electrocardiographic variants of combined lesions of the sinoatrial and atrioventricular nodes]

A study of 71 patients with atrioventricular blocks and 57 patients with the sick-sinus syndrome (SSS) revealed electrophysiologic evidence of sinus dysfunction in 38 (53.5%) patients with atrioventricular blocks. Sinus dysfunction was due to pathologic vegetative effects in 15 (21.1%) patients with AV blocks, and a pathology of the sinus node itself in 23 (32.4%). Impaired atrioventricular conductivity, was registered in 29 (38.7%) patients with the SSS. A disorder of atrioventricular automatism was detected in 38 patients, and was combined with impaired AV conductivity in 19 of those. Five clinico-electrocardiographic variants of binodal heart disease have been identified, and possible therapies are discussed for each of those.

[Sinus node function of ischemic heart disease patients with chronotropic incompetence]

Forty-five (17.6%) of 256 coronary patients showed inadequately small heart rate augmentation in response to rationed exercise ("chronotropic incompetence"). To assess their sinoatrial node function, esophageal atrial stimulation was done in all patients before and after drug-induced vegetative block, and the adjusted sinoatrial node function time and sinoatrial conduction time were determined. Electrophysiological evidence suggests that "chronotropic incompetence" is in most cases determined by abnormal sinoatrial rhythm. Rationed exercise testing can be used as a screening test for latent weak sinoatrial node syndrome in coronary patients.

[Auricular fibrillation in myocardial infarct]

Auricular fibrillation was observed in 17.8% of patients with large-focal myocardial infarction, mainly in females (p 0.01). The localization of myocardial infarction had no impact on the incidence of auricular fibrillation. The precursors of auricular fibrillation included atrial extrasystoli and an elevated electrolyte coefficient of the blood NaeKe. In the group of patients with myocardial infarction and auricular fibrillation mortality was more common among the females. Auricular fibrillation developing beyond the first postinfarction day worsened the prognosis considerably. The outcome of myocardial infarction did not much depend on the duration of auricular fibrillation and on the cardiac contraction frequency.