Materials and methods. 225 patients were examined: 67 patients with a combination of CHD and gastroesophageal reflux disease (GERD) - the main group, and two groups of comparison: 72 CHD patients and 86 GERD ones.
According to sex-age composition the patients were commeasured: in the group of patients with the combined nosology the average age made 59±11,4 years old, there were 33 (49,3%) women there; in the patients´ group with CHD the average age made 59±11,0 years old, 34 (47,2%) women; in the group of patients with GERD the average age made 56±10,6years old, 40 (46,5%) women.
The inclusion criteria: CHD (unstable angina, exertional angina of II-IV functional class, old myocardial infarction in the anamnesis), endoscopically positive GERD.
The exclusion criteria: clear rhythm or capacity disorders (atrial fibrillation, paroxysmal forms of tachyarrhythmia, frequent extrasystole, pulse generator availability, etc.), acute myocardial infarction during last two months and noncoronarogenic forms of the cardiac muscle damage, cardiac failures, signs of progression of acute or a chronic infectious disease recrudescence, cardiac decompensation of IV functional class according to NYHA, malignant neoplasms, endoscopically negative GERD.
The CHD was verified by the presence of old cardiac infarction or typical clinical presentation together with a positive take of stress-test (cycle ergometry), or together with the acknowledged episodes of myocardial ischemia at days ECG monitoring (SM ECG).
The diagnostics of endoscopically positive GERD was mediated by fibroesogastroduodenoscopy (FEGDS). The esophagus inflammatory-destructive processes´ depth was carried out at total morphological investigation of biopsy materials of esophageal mucosa, the GERD with reflux esophagitis (RE) catarrhal and erosive forms was found.
As myocardium electrical instability markers the duration and asynchronism of repolarization processes, heart rate variability factors (HRV) were defined. In the standard ECG tested in generally accepted derivations the QT interval duration, QT interval dispersion (QTd) and QT corrected interval (QTc), which was computed using the formula of H.Bazett modified by L.Taran и N.Szilagyi, were calculated. The SM ECG was carried out with the help of Cardiotechniques-4000 system; standard factors of HRV were taken into account: high frequency waves capacity within the limits of 0,4 - 0,15 Hz, Рдв (HF), low frequency waves capacity within the limits of 0,15 - 0,04 Hz, Рмв1 (LF), average value of NN-intervals´ standard deviations calculated on 5-minutes periods during the whole record (SDNNi), the initial value of the most commonly occurring R-R intervals (MODA), relative high frequency waves´ capacity value expressed in normalized units (HF in n.u.), relative low frequency waves´ capacity value expressed in normalized units (LF in n.u.), total power of the spectrum (TP), percentage of the sequential intervals´ diversity more than 50 mc (PNN50).
The statistic analysis of the findings was carried out with the help of standard statistic packages of programs Statgraphics, 6,0 version Statistica.
Results. A range of myocardium electrical instability markers´ state features was found out, thus, CHD patients authentically (р<0,05) differed from GERD patients with normal QT, QTс and QTd excess incidence; in the CHD patients a more significant asynchronity of repolarization processes compared to the GERD patients was found authentically (р<0,05). At comparison of the showings of the patients with CHD and GERD combination and patients with "isolated" CHD it is found that the average QTc, QTd in the group of patients with the combined pathology were authentically (р<0,05) higher than in the patients with CHD. The investigation of features of repolarization processes depending on the degree of RE testified that in the group of patients with the combined pathology an authentic increase (р<0,05) of the duration and repolarization processes asynchronity with an erosive variant of GERD unlike the patients with catarrhal RE is registered.
At the analysis of HRV factors authentically lower (р<0,05) values of HF, LF, MODA, TP, SDNNi and PNN50 compared to the group of patients with "isolated" CHD have been detected in the patients of the main group. The combined pathology patients authentically differed (р<0,05) from the GERD patients on all investigated factors of HRV. The HRV factors comparison in the group of patients with the combination of CHD and GERD depending on the degree of RE allows speaking on an authentic decrease (р<0,05) of HF, LF, HF in n.u., LF in n.u., MODA and TP with erosive changes of the lower third of the esophagus. No similar tendency was detected in the GERD patients group.
A multivariate regression analysis of the findings was carried out, and it testified that the intensity of RE exerts an independent authentic (р<0,05) influence on both myocardium inhomogeneity (QTd) and HRV factors.
Conclusions. The characteristics of coronary heart disease in the aspect of transnosologic co-morbidity with gastroesophageal reflux disease are: 1. the decrease of the cardiovascular system adaptative capacities, lower stress tolerance of the body and greater probability of the myocardium electrical instability; 2. the depth of the esophagus structural changes - the independent factor of the myocardium electrical instability risk in the given class of patients.
The article is admitted to the International Scientific Conference " Fundamental and applied problems of medicine and biology" ; Italy (Sicily), July 15-22, 2007.; came to the editorial office on 25.06.07