[ECG changes in patients with type I diabetes mellitus as a function of disease duration]. / Izmenenie na EKG bol'nykh sakharnym diabetom I tipa v zavisimosti ot prodolzhitel'nosti bolezni.

A study of changes on additionally intensified (I mV-50 mm) ECG of 137 patients with diabetes mellitus without clinical signs of heart involvement with a disease of various duration has shown that time and total amplitude ECG values had no statistically significant differences in several groups (with duration of disease 0-4, 5-9, 10 and more years--1st, 2nd, and 3rd groups, respectively). The results obtained were interpreted as a sign of an increased hemodynamic load of atrial myocardium, resulting from augmenting diabetic dystrophic changes in the myocardium associated with diabetes mellitus progress.

[The detection of changes in intra-atrial conductivity (based on enhanced ECG data)]. / Vyiavlenie izmenenii vnutripredserdnoi provodimosti (po dannym usilennoi EKG).

The 20-fold enhanced ECG (without frequency filtration of the signal) was recorded in 30 normal men aged 18 to 36 years. A study was made of the constancy of the P wave forms on the ECG. The P wave form underwent changes in 8 test subjects: in 5 during breathing retention on expiration and in 3 during superficial breathing. The changes indicated are viewed as a manifestation of intraatrial conduction disorders. It is assumed that the changes in the tone of the autonomic nervous system and myocardial hypoxia may contribute to the detection of latent disorders in the cardiac activity.

[The low-amplitude elements of the ECG in diabetic patients]. / Izuchenie nizkoamplitudnykh élementov EKG u bol'nykh sakharnym diabetom.

To estimate the rate of changes in low-amplitude elements of the ECG (P wave greater than or equal to 120 ms, distance between its bifurcate peaks greater than 30 ms, P of the terminal index greater than 1.5 microV/s, corrected according to Bazett's formula, PQ interval greater than 200.0 ms, T-U segment displaced downwards from the isoline, negative, biphasic U wave), the additionally enhanced ECGs (1 mV = 50 mm) were recorded in 137 patients suffering from type I diabetes mellitus (DM) without the clinical signs of heart damage (CSHD), in 35 patients with type II DM, in 83 with diabetic myocardiodystrophy (DMD) associated with type I DM and 115 in association with type II DM, in 19 patients with coronary heart disease (CHD) in the presence of type I DM, and in 83 patients suffering from CHD and type II DM. It has been established that changes in low-amplitude elements of the ECG may occur in 55-60% of patients suffering from DM without CSHD, 79-80% of patients with DMD, and in 90-100% of patients with CHD in the presence of DM versus 18.2% in the control group of normals (110 test subjects). In most cases, the changes in the atrial complex of the ECG are not coupled with those seen in the TU-U complex in patients suffering from DM without CSHD and DMD and may be coupled in patients suffering from CHD and DM. The increasing rate of the changes in the P complex together with those in TU-U was ascertained in patients suffering from DM without CSHD, DMD, CHD in the presence of both type I and type II DM. The DM type did not exert any appreciable effect on the characteristics or the rate of changes in low-amplitude elements of the ECG.

[Characteristics of the U wave on the electrocardiogram of patients with diabetes mellitus type 1 without clinical signs of cardiac damage]. / Kharakteristika zubtsa U na EKG bol'nykh sakharnym diabetom I tipa bez klinicheskikh priznakov porazheniia serdtsa.

Additionally increased (1 mB = 50 mm) ECG recorded in 137 patients with diabetes mellitus without clinical signs of cardiac damage and 66 healthy subjects revealed that the incidence of positive U wave was less in the patients than in the healthy subjects. The negative U wave was found in leads aVR, III, aVL, and V1 in healthy subjects. In patients with diabetes mellitus, the negative and diphasic U waves were found in all the ECG leads. The amplitude of a positive U wave on a ECG strip of the patients was significantly lower in leads V1 and V2 than that of the healthy subjects. The findings are regarded as manifestations of metabolic and dystrophic myocardial changes of diabetic origin.