[Evaluation of the signal-to-noise ratio--"Kullback information"--in the spectrum of cardiointervals in arterial hypertension patients depending on cosmophysical factors]. / Otsenka sootnosheniia signal/shum--"informatsii Kul'baka"--v spektrakh kardiointervalov u bol'nykh arterial'noi gipertenziei v zavisimosti ot kosmofizicheskikh faktorov.

It was shown that Kullback information (In) that is registered in a cardiogram, for example, during the arterial hypertension crisis can be used in medicinal diagnostics. Periods of In fluctuations from 2 to 12 days were revealed; some factors that influence In are shown to have a cosmophysical nature.

[The use of a new method for determining the ratio of the glomerular filtration rate to circulating plasma volume in patients with arterial hypertension]. / Primenenie novogo metoda opredeleniia otnosheniia skorosti klubochkovoi fil'tratsii k ob''emu tsirkuliruiushchei plazmy u bol'nykh arterial'noi gipertoniei.

Renal scintigrams with 99Tc-DTPA were analysed retrospectively in 19 patients with essential hypertension. Glomerular filtration rate (GFR) was measured by Gates technique. Ratio GFR to plasma volume (PV) was quantified by A. M. Peters' technique (1994). PV was calculated as the relation of these two indices. Total GFR in hypertensive patients widely ranged (from 76.8 ml/min to 165.7 ml/min). Three groups were selected taking into account hypertension duration: patients with decreased, normal and increased values of basal GFR. The severity of hypertension did not affect the GFR, but showed positive and strong correlation with PV (r = 0.91; p < 0.05). GFR/PV was decreased in hypertensive patients. Factors affecting the GFR in hypertensive subjects are discussed.

[Silent myocardial ischemia in patients with essential hypertension]. / "Nemaia" ishemiia u bol'nykh gipertonicheskoi bolezn'iu.

Holter monitoring was performed in 61 patients with essential hypertension. Painless, silent ST segment depression was found in 34 patients. Exercise myocardial scintigraphy indicated the occurrence of transient perfusion defects without abnormal clearance (Group 1) and those with abnormal clearance (Group 2). The patients from Group 1 showed more severe myocardial hypertrophy, higher platelet aggregation, coronary atherosclerosis was detected in 1 case. The patients from Group 2 exhibited less myocardial hypertrophy, lower platelet aggregation. Coronary atherosclerosis was revealed in 4 cases. The patients from the two groups had elevated plasma norepinephrine levels at the onset of silent myocardial ischemia.

[Hypertension and "silent" myocardial ischemia. I. The results of stress scintigraphy of the myocardium in patients]. / Gipertonicheskaia bolezn' i "nemaia" ishemiia miokarda. Soobshchenie I. Rezul'taty nagruzochnoi stsintigrafii miokarda u bol'nykh.

As many as 24 patients suffering from essential hypertension (EH) were examined. The patients were subjected to Holter ECG monitoring, echocardiography, coronary angiography, exercise scintigraphy of the myocardium with transesophageal pacing of the atria and the dipyridamole test. The patients manifested defects of thallium accumulation during exercise scintigraphy of the myocardium. They were transitory defects of accumulation with clearance impairment recorded in EH patients with atherosclerosis of the coronary arteries; transitory defects of accumulation without clearance impairment recorded in EH patients with the angiographically unchanged coronary arteries. In Holter ECG monitoring, the patients with a silent depression of the ST segment demonstrated transitory defects of thallium accumulation by the myocardium in all the cases during exercise scintigraphy of the myocardium.

["Silent" myocardial ischemia and the activity of the sympathetic-adrenal system in hypertension patients]. / "Nemaia" ishemiia miokarda i aktivnost' simpatiko-adrenalovoi sistemy u bol'nykh gipertonicheskoi bolezn'iu.

The aim of the study was to assess the sympathoadrenal activity at the time of silent ischemia event in hypertensive patients. In 15 hospitalized hypertensive patients having silent ischemia event during Holter ECG monitoring while walking, blood samples for catecholamines were taken at the time of silent ischemia event, pointed with alarm by the real time ECG "Q Med" monitor (USA). Control blood samples were taken under the same conditions without ST-segment depression. Plasma noradrenaline (NA) during silent ischemia was significantly higher than the control level without ischemia (458 +/- 71 ng/l vs 717 +/- 95 ng/l) (p less than 0.01). The changes in plasma NA correlated with left ventricular mass assessed by echocardiography (r = 0.70, p less than 0.01). The role of sympathoadrenal hyperactivity in the genesis of silent myocardial ischemia in patients with essential hypertension is discussed.

[A painless decrease in the ST segment during the 24-hour ECG monitoring of hypertensive patients]. / Bezbolevoe snizhenie segmenta ST pri sutochnom monitorirovanii EKG u bol'nykh gipertonicheskoi bolezn'iu.

The daily Holter ECG monitoring and echocardiography were conducted in 61 men aged on the average 50.5...1.2 years with a diagnosis of stage II essential hypertension. 55.7% of the patients manifested episodes of painless depression of the ST segment. Such parameters as the patients' age, duration and intensity of arterial hypertension, the painful syndrome pattern did not afford revealing persons at high risk for instability of the ST segment of the ECG. Only initial disorders of the repolarization phase of the ECG at rest, so-called ECG with the signs of left ventricle hypertrophy with "strain" were in this respect of prognostic importance. 2/3 of the patients with the left ventricle mass exceeding 200 g manifested episodes of "silent" depression of the ST segment, with those episodes being encountered more frequently in left ventricle hypertrophy with an asymmetry index greater than or equal to 1.5.

[A comparative evaluation of loading tests for the diagnosis of ischemic heart disease at the prehospital stage]. / Sravnitel'naia tsennost' prob s nagruzkoi dlia diagnostiki ishemicheskoi bolezni serdtsa na dogospital'nom étape.

Bicycle ergometry, the treadmill test, transesophageal pacing of the left atrium and 24-h monitoring of the ECG were performed on an outpatient basis in 82 persons (all men) with angina pectoris of effort and stenosing atherosclerosis of the coronary arteries verified with the aid of selective coronarography and in 17 men with intact coronary arteries. Transesophageal pacing and the treadmill test exhibited the highest sensitivity (94 and 89%, respectively) in the diagnosis of the latent forms of coronary failure. The sensitivity of bicycle ergometry (77%) was significantly lower which was caused by a considerable number (21%) of tests completed before the appearance of diagnostic criteria. Meanwhile the results of 24-h monitoring of the ECG (65% sensitivity) depended on the degree of the patients' physical activity and way of life. All the four methods did not significantly differ in the specificity. Proceeding from the data obtained it is recommended that the treadmill test and transesophageal pacing of the heart may be widely used on an outpatient basis to diagnose coronary disease.

"Silent" myocardial ischaemia in essential hypertension.

During 16-h electrocardiographic monitoring of 29 patients with stage II (WHO) essential hypertension and left ventricular hypertrophy, the episodes of painless "silent" myocardial ischaemia were registered in 12. In these patients a bicycle ergometry test, transoesophageal atrial pacing, isotope ventriculography at rest and during isometric exercise, and coronary angiography in 3 cases, were performed. A comprehensive evaluation of findings revealed the presence of coronary insufficiency not accompanied by pain syndrome. Absence of angiographic signs of coronary stenosis in 3 patients subjected to coronary angiography suggests the presence of relative coronary insufficiency at least in these patients.

[Prevalence of ischemic heart disease and its risk factors among Tuva cattle-breeders]. / Rasprostranennost' ishemicheskoi bolezni serdtsa i faktorov ee riska sredi zhivotnovodov Tuvy.

A simultaneous comprehensive epidemiological survey of 1198 cattle-breeders was conducted in central and southern Tuva. CHD in men was diagnosed in 11.1%, in women in 24.0% (all of them aged 20 to 69). Changes in the end part of the ventricular complex were more common, particularly in women. Arrhythmia and angina of effort were very rare. Functional ECG tests (including propranolol, piridamole, bicycle ergometry) brought about negative results with relation to CHD. Positive correlation was shown between CHD prevalence and AH frequency, negative correlation--between CHD prevalence and smoking frequency. Rare excessive body mass and fat metabolic derangements probably accounted for the absence of correlation of these indices with CHD frequency. A high AH frequency was revealed in men (12.3%) and women (28.8%). Left ventricular hypertrophy was noted in 25.8% of men, of them raised BP was noted in 36.6% only; in women these figures were 12.7 and over 50%, respectively. Some peculiarities of the epidemiology of CHD and its risk factors in Tuva indicated a high frequency of noncoronarogenic myocardial pathology, rare occurrence of CHD, and low specificity of the Minnesota code criteria for the detection of this disease in the population under study.