[Permanent cardiac pacing in vasovagal syncope and carotid sinus syndrome].

Vasovagal syncope and carotid sinus syndrome are common conditions in young and elderly people, respectively, mostly with benign prognosis. Nevertheless, severe or "malignant" syncopal attacks in some patients may be associated with life-threatening injury. Unfortunately, up to now almost all drug trials have failed to demonstrate any benefit in preventing syncope and interventional approach (pacemaker) may be appropriate. This article contains literature review and discussion of indications for pacing in vasovagal syncope and carotid sinus syndrome.

[Wall motion abnormalities and hemodynamic parameters in patients with left bundle branch block during exercise echocardiography].

Study aim was to investigate dynamics of local contractility and hemodynamic parameters during exercise stress echocardiography (EEcho) in patients with left bundle branch block (LBBB). We examined 23 patients (15 men, 8 women) aged 48-65 years (mean age 53.9+/-8.1 years). Bicycle EEcho was accomplished according to standard protocol. Patients without clinical signs of ischemic heart disease (n=11) comprised group 1, patients after myocardial infarction (n=12) - group 2 (subgroup 2A - with negative test result, subgroup 2B - with worsening of local left ventricular contractility during EEcho). At baseline group 1 patients had significantly better hemodynamic parameters (ejection fraction - EF, left ventricular end diastolic volume - LVEDV) and no abnormalities of local contractility. Exercise tolerance was also the highest in this group. Insignificant worsening of postexercise EF occurred in patients of subgroup 2B (from 46+/-10.5 to 44,2+/-9.4%). In group 1 EF significantly increased (from 56.8+/-10.5% to 64.7+/-15.4%, <0.05), in subgroup 2A tendency to EF increase up to 48.7+/-9.9% was registered. Lowering of local contractility abnormalities index was noted also only in patients of subgroup 2B (from 1.54+/-0.4 to 2.17+/-0.37 (p<0.01). LVEDV compared with initial values tended to decrease in both groups (however differences between groups were not significant). Positive echocardiographic response was associated with significant changes of transmitral blood flow. Angiographically clean coronary arteries were found in 8 of 10 patients in group 1. Six group 2 patients with history of typical clinical picture of angina and myocardial infarction) had multivessel lesions in coronary vascular bed. EEcho result was positive in 5 of 6 group 2 patients. Thus EEcho possesses high potential for diagnosis of coronary atherosclerosis in patients with LBBB. This allows recommending it as a first line method in patients with this pathology.

[Localization of accessory atrioventricular pathways in patients with manifest premature ventricular excitation syndrome by three-dimensional vector electrocardiography].

Distribution of excitation via ventricular myocardium in patients with accessory atrioventricular pathways (AAVP) was studied using three-dimensional vector ECG. Analysis of the ECGs obtained during the study formed new views on the excitation process in the myocardium in the presence of AAVP, and made it possible to formulate vector ECG (VECG) criteria of AAVP localization. In 30 cases out of 33 it was possible to correctly localize AAVP. Information obtained as a result of VECG analysis made it possible to localize AAVP preoperatively within the limits of 1/14th atrioventricular sulcus with 97.1% accuracy, which is substantially higher than the accuracy of conventional electrocardiographic algorithms. Thus, the study found that in some cases three-dimensional vector ECG allows for substantial increase in the validity of AAVP localization, while in others it is the only sensitive non-invasive method of topical diagnostics of manifest premature ventricular excitation syndrome. Knowledge of the character of intervector interaction during ventricular electric systole makes it possible to predict the character of changes in the trajectory of QRS vector loop in any AAVP localization, i.e. to model the vector loop.