Effects of sympatholytic therapy on insulin sensitivity indices in hypertensive postmenopausal women.

Cardiovascular risk factors are often ineffectively controlled in hypertensive postmenopausal women, and moreover, some antihypertensive drugs may increase particular risk factors such as insulin resistance. In a multicenter, multinational (Finland, Sweden, Lithuania), double-blind, prospectively randomized study hypertensive obese postmenopausal women without hormone therapy (n = 98) were randomly assigned to receive treatment with either the centrally acting agent moxonidine, 0.6 mg/day, or with the peripherally acting atenolol, 50 mg/day, for 8 weeks. In addition to blood pressure measurements, insulin sensitivity was estimated by the quantitative insulin sensitivity check index (QUICKI) and by the insulin sensitivity index (ISI-Matsuda). Subgroup analysis in insulin-resistant women (fasting P-insulin > or = 10 mU/l) and blood pressure responders (diastolic blood pressure < or = 90 mmHg and/or reduction of blood pressure > or = 10 mmHg) were also carried out. Both atenolol and moxonidine led to a significant reduction in diastolic blood pressure of 9.5 mmHg and 6.2 mmHg, respectively. Among insulin-resistant women, an increase in the insulin sensitivity assessed by ISI was improved with moxonidine treatment (p = 0.025). A decrease in insulin sensitivity assessed by QUICKI was observed with atenolol treatment in women with fasting insulin level < 10 mU/l. In patients, in whom blood pressure was reduced, an improvement in insulin sensitivity (ISI) was associated with moxonidine treatment (p = 0.019), but not with atenolol treatment. The centrally acting sympatholytic agent moxonidine did reduce blood pressure somewhat less than atenolol, but it was associated with an improved metabolic profile in terms of decreased insulin resistance both in insulin-resistant postmenopausal women and in women with a significant blood pressure response.

[Significance of a differentially amplified ECG in the diagnosis of paroxysmal tachycardias]. / Znachenie differentsial'no usilennoi EKG v diagnostike paroksizmal'nykh takhikardii.

For differentiation of tachycardias the authors offer a method of recording the curves of differentially increased spike potentials (DISP) of atriae from the surface of the chest wall, based on the recording of the electrical activity of the atriae in the shape of a high amplitude atrial spike complex. The DISP curves have been recorded in 36 patients with tachycardias, in whom by usual ECG it was difficult to determine the tachycardia type, in some cases it was impossible, for instance in confluence of the P wave with the QRS complex or the T wave. The typical and constant form of the atrial spike complex on the DISP curve in the sinus rhythm permits determining the sequence of the stimulations of atriae and the type of disorders of the cardiac rhythm. The recording of the DISP of atriae as to complexity does not differ from the recording of the usual ECG.

[New diagnostic method in arrhythmias and heart conduction disorders]. / Novyi sposob diagnostiki nekotorykh aritmii i narushenii provodimosti serdtsa.

The authors developed a method for recording spike potentials of the heart conduction system from the body surface on a curve of differentially intensified spike potential (DISP). They examined 187 patients and 60 healthy persons. The spike potentials of the sinoatrial node, atria and the bundle of His recorded on the DISP curves coincide exactly in time with spike potentials on intracardiac ECG recorded by microcatheterization of the heart through the subclavian vein, which makes it possible to distinguish on the DISP curve reference points for determining conductivity on definite areas of the heart conduction system. DISP recording allows the diagnosis of conductivity disorders and atrial overloading, arrhythmias of the heart, the diagnosis of which cannot be made from the ordinary ECG. In some cases this method can substitute for intracardiac ECG.

[A new method of recording spike potentials of the atria from the body surface]. / Eine neue Registriermethode von Spike-Potentialen der Vorhöfe von der Körperoberfläche.

A new method of recording spike potentials (rapid deflections) of the heart conductive system (sinus node, atrial conductive tracts, His' bundle)from the body surface was developed using differential magnifying 50 to 250 times and yielding frequencies 30-110 Hz with special filters. The curves with differentially amplified spike potentials (DASP) of the heart conductive system were recorded in 249 patients with various cardiac arrhythmias; the control group consisted of 60 healthy persons. By means of synchronous recording of intracardiac ECG and DASP curves on the latter well recognizable points for the determination of the excitation spreading rate in certain areas of the conductive system were distinguished. The recording of DASP-curves allowed the determination of intraatrial conduction disturbances, atrial overloading and distinguishing of retrograde conduction in atria, sinoventricular conduction, ectopic prefibrillatory activity and differentiation of paroxysmal tachycardias. The new method of recording of spike potentials of the atria from the body surface allows the diagnosis of the conduction disturbances and cardiac arrhythmias, including life threatening ones, which were previously determined using exclusively intracardiac ECG. The application of our method enables to increase the possibilities of the investigation of cardiac arrhythmias and conductive disturbances and allows a multiple examination and evaluation of the influence of drugs on the heart conductive system.