Adenosine vs. regadenoson for stress induction in dynamic CT perfusion scan of the myocardium: A single­center retrospective comparison.

Cardiac computed tomography (CT) angiography offers several approaches to determine the hemodynamic severity of coronary artery obstruction. Dynamic myocardial perfusion is based on serial CT imaging of contrast flow into the myocardium and calculation of absolute myocardial perfusion rates. East-Slovak Institute of Cardiovascular Diseases has been the first center in Slovakia intensively using this modern technique to increase the quality level of non-invasive diagnosis of symptomatic patients with a low to moderate pre-test probability of ischemic heart disease. The present study included 46 patients with a mean age of 64 years (33 men and 13 women). Prior to the CT study, myocardial stress was pharmacologically (adenosine, n=15 and regadenoson, n=31) induced by vasodilatation of the coronary arteries. Hemodynamic parameters (myocardial blood flow) were evaluated in all patients following successful CT perfusion without complications, allergic reaction or other severe side effects. The present study revealed that regadenoson increased the heart rate following infusion with a higher magnitude compared with adenosine. Moreover, the effect of regadenoson was independent of patient's body mass index and was associated with a lower incidence of mild adverse effects. The present study provided further clinical evidence for a more wider use of regadenoson over adenosine.

Allergic sensitization pattern as a marker of bronchial hyperresponsiveness in allergic rhinitis patients living in temperate continental climate zone.

BACKGROUND: Bronchial hyperresponsiveness (BHR) is a key feature of asthma, but it may also appear in allergic rhinitis. The type of allergen, as well as regional characteristics, play an important role in the development of BHR. The aim of our study was to analyze allergen sensitization patterns and the factors that affect BHR in allergic rhinitis patients living in temperate continental climate zone. METHODS: This study retrospectively analyzed allergic rhinitis patients from Eastern Slovakia who underwent skin-prick tests to aeroallergens, spirometry, histamine and methacholine bronchial provocation tests for evaluation of lower airway symptoms. We analyzed the associations between BHR and the pattern of aeroallergen sensitization, lung function parameters, and the total IgE and eosinophil levels. RESULTS: Out of 365 allergic rhinitis patients (age range 16-64 years), 114 showed BHR. Sensitization to house dust mites (HDMs) and grass were the most common. BHR was significantly associated with sensitization to dogs (odds ratio, OR = 2.15, 95% confidence interval, CI: 1.13-4.11) and Alternaria (OR = 2.15, 95% CI: 1.06-4.35); however, BHR did not show a relationship with HDMs sensitization. The levels of total IgE and eosinophils were higher in the BHR-positive group. Sensitization to more than six allergens significantly increased the probability of BHR (p < 0.01). CONCLUSION: Dogs and Alternaria, but not HDMs, were the sensitizing agents most closely associated with BHR. High-grade sensitization and increased total IgE and eosinophil levels were characteristic clinical signs in BHR-positive allergic rhinitis patients in the temperate continental climatic zone.

Gene Polymorphism of the Adenosine A2a Receptor in Patients with Vasovagal Syncope.

BACKGROUND: Adenosine may play a role in the pathogenesis of vasovagal syncope (VVS). The aim of the study was to evaluate the adenosine A(2A) receptor gene 1083 T > C polymorphism in patients with syncope and its possible association with results of head-up tilt test (HUT). METHODS: Three hundred and forty-seven consecutive patients (mean age 47.3 ± 18.5 years, 132 men, 215 women) with one or more syncopal episodes underwent HUT as part of standardized diagnostic evaluation. HUT was positive in 207 patients (75 males, mean age 44.7 ± 18.6 years) and negative in 140 patients (58 males, mean age 48.17 ± 18.8 years). One thousand and eighty-three T > C single nucleotide polymorphism in the adenosine A(2A) receptor gene (rs5751876) was evaluated in 347 patients with syncope and in 85 subjects without history of syncope (54 men, mean age 41.7 ± 16.3). RESULTS: Adenosine A(2A) receptor 1083 T > C polymorphism was not associated with the positivity of HUT. Blood pressure and heart rate response to tilting was similar in all genotypes. Low frequency (LF) power was significantly lower in CC genotype compared to CT genotype in early phase of tilt (log LF 2.69 ± 0.61 vs 3.20 ± 0.60; P = 0.01) and at the time of syncope (log LF 2.60 ± 0.63 vs 2.77 ± 0.48; P = 0.04). CONCLUSIONS: Adenosine A(2A) receptor 1083 T > C polymorphism is not associated with the positivity of HUT and its proposed role in predisposition to VVS was not confirmed. CC genotype may be associated with lower sympathetic activity during HUT.

Global myocardial contractile reserve assessed by high-dose dobutamine stress echocardiography predicts response to the cardiac resynchronization therapy.

BACKGROUND: Myocardial contractile reserve (CR) is a strong prognostic factor in patients with heart failure. The presence of significant myocardial fibrosis can lead to a reduced response to cardiac resynchronization therapy (CRT). We assumed that myocardial CR assessed by high-dose dobutamine stress echocardiography (DSE) would predict response to CRT. METHODS: Fifty-two consecutive symptomatic patients with heart failure (New York Heart Association [NYHA] class III), with depressed ejection fraction (EF) of the left ventricle (26.3 ± 6.9%) and dyssynchronous contractions (QRS duration 149.8 ± 23.8 msec) underwent DSE before CRT implantation. The difference in EF at rest and at peak (40 µg/kg per minute) DSE indicated global CR. Responders to CRT were defined by a decrease in left ventricular end-systolic volume of ≥15% and/or an increase in EF of ≥5% after 6 months of CRT. RESULTS: During high-dose dobutamine infusion, responders (28 patients, 54%) showed a greater increase in EF compared with nonresponders (Δ 11 ± 7% vs. Δ 2 ± 9%, P = 0.007). CR correlated moderately with an improvement in EF after 6 months of CRT (r = 0.50, P = 0.0009). Furthermore, responders showed significant improvement in clinical status, evaluated by a reduction in NYHA functional class (-0.8 ± 0.6 vs. 0.1 ± 0.4, P = 0.02), compared with nonresponders. A 7% exercise-induced increase in EF yielded sensitivity of 79% and specificity of 87% in predicting the response to CRT after 6 months. CONCLUSIONS: Myocardial CR assessed by high-dose DSE can play a potentially important role in identifying responders to CRT.

[Importance of EKG in patients wuth resynchronization therapy]. / Význam EKG u pacientov s resynchronizacnou liecbou.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves symptoms and survival in patients with chronic heart failure. The presence of electrocardiographic (ECG) signs of electrical dyssynchrony during ventricular contractions are an essential criterion for the implantation of CRT. Nevertheless, 1/3 proportion of patients who undergo CRT do not seem to respond favorably. Aim of study was to investigate the relevant ECG parameters prior to CRT (as well as their postimplantation changes) and to determine their relation to predicting favorable response to CRT. METHODS: 52 symptomatic patients (age 62.2 ± 10.5 years, 39 men) with severe left ventricular (LV) systolic dysfunction (ejection fraction 26.3% ± 6.9%) with QRS 120 ms underwent CRT implantation. In early pre- and postimplantation CRT period the following ECG parameters were recorded: QRS complex width and morphology (complete and atypical left bundle branch block, nonspecific intraventricular conduction delay), the size of R and S wave. After 6 months of CRT, responders were definied by improvement of LV ejection fraction > 5 % and/or reduction of end-systolic LV volume > 15 %. RESULTS: The incidence of left bundle branch block (complete or atypical) prior to CRT implantation was higher in responders compared to non-responders group (64% vs 35%, p = 0.036). After implantation of CRT, responders showed significant narrowing of the QRS complex, while non-responder`s QRS complex width remained unchanged (QRS -18 ± 22 ms vs 1 ± 27 ms, p = 0.018). Furthermore QRS complex reduction led to increase in LV ejection fraction (r = 0.47, p = 0.001) and to reduction of LV end-systolic volume (r = 0.42, p = 0.004). R and S changes between responders and non-responders did not differ (p = 0.598 respectively, P = 0.685). CONCLUSION: The presence of complete left bundle branch block before CRT implantation is associated with a better response to CRT compared to other myocardial intraventricular conduction disturbances. Post-implantation narrowing of QRS complex appears to be an early predictor of favorable response to CRT.

Effects of partially ionised medical oxygen, especially with O2•-, in vibration white finger patients.

A major symptom of hand-arm vibration syndrome is a secondary Raynaud's phenomenon-vibration white finger (VWF)-which results from a vasospasm of the digital arteries caused by work with vibration devices leading to occupational disease. Pharmacotherapy of VWF is often ineffective or has adverse effects. The aim of this work was to verify the influence of inhalation of partially ionized oxygen (O2•-) on peripheral blood vessels in the hands of patients with VWF. Ninety one (91)patients with VWF underwent four-finger adsorption plethysmography, and the pulse wave amplitude was recorded expressed in numeric parameters-called the native record. Next, a cold water test was conducted following with second plethysmography. The patients were divided in to the three groups. First and second inhaled 20-min of ionized oxygen O2•- or oxygen O2 respectively. Thirth group was control without treatment. All three groups a follow-up third plethysmography-the post-therapy record. Changes in the pulse wave amplitudes were evaluated. Inpatients group inhaling O2•- a modest increase of pulse wave amplitude was observed compared to the native record; patients inhaling medical oxygen O2 and the control showed a undesirable decline of pulse wave amplitude in VWF fingers. Strong vasodilatation were more frequent in the group inhaling O2•- compare to O2 (p < 0.05). Peripheral vasodilatation achieved by inhalation of O2•- could be used for VWF treatment without undesirable side effect in hospital as well as at home environment.

Regional myocardial contractile reserve assessed by strain echocardiography and the response to cardiac resynchronization therapy.

BACKGROUND: Overall response rate to cardiac resynchronization therapy (CRT) is still not optimal. The aim of the study was to evaluate the influence of the regional myocardial contractile reserve during dobutamine infusion in the area of left ventricular (LV) electrode on the response rate and reverse remodeling LV in patients receiving CRT. METHODS: Biventricular pacemaker was implanted in 41 consecutive patients (33 men, mean age 62 ± 10 years) with LV ejection fraction (LVEF) ≤ 35%, New York Heart Association class III and QRS duration ≥ 120 ms. Myocardial contractile reserve was assessed by LV strain during dobutamine infusion (20 µg/kg/min) using speckle tracking echocardiography. Patients were classified as responders if an increase in LVEF ≥ 5% or decrease in end-systolic volume ≥ 15% was observed after 6 months of CRT. RESULTS: Twenty-four patients were responders and 17 were non-responders. During dobutamine infusion at a rate of 20 µg/kg/min, responders showed significant increase in regional deformation (Δ strain) when compared to non-responders (2.14 ± 2.9 vs. - 0.94 ± 1.74, p = 0.042). Patients with increased deformation in the LV lead area during dobutamine stimulation were more likely to be responders to CRT compared to patients without increased deformation in this area (81% vs. 20%, p = 0.0002). They exhibited significant increase in LVEF (8.8% ± 10.3% vs. 0.3% ± 6.4%, p = 0.01). LV electrode localization in viable myocardium was a good predictor of response to CRT (AUC 0.852, p < 0.0001). CONCLUSIONS: Regional contractile reserve assessed by strain rate echocardiography during dobutamine infusion predicts the response to CRT.

Clinical history in the diagnosis of the cardiac syncope­the predictive scoring system.

BACKGROUND: Cardiac syncope represents clinical situation with serious prognosis. The aim of the present study was to develop the diagnostic scoring system based on the clinical history allowing to distinguish between cardiac and noncardiac syncope. METHODS: Clinical history was obtained in the form of the structured questionnaire in 60 patients with cardiac syncope (mean age 70 ± 10 years, 33 men) an in 140 patients with noncardiac syncope (mean age 45 ± 20 years, 44 men). Multivariate regression analysis identified seven variables that were included in the final regression model. RESULTS: The age above 55 years, presence of structural heart disease, syncope in supine position, absence of prodromal symptoms, and chest pain before syncope were predictive of cardiac syncope. Predictors of noncardiac syncope were recovery duration of more than 1 minute and syncope occurring immediately after standing up. A diagnostic point score was derived from the regression coefficients. The sum of the points identified patients with cardiac syncope if the diagnostic point score was ≤2. Diagnostic performance of the score was assessed on the validation group of 67 patients with syncope (21 patients with cardiac syncope and 46 patients with noncardiac syncope). Sensitivity was 81%, specificity 84.8%, positive predictive value 70.8%, and negative predictive value 90.7%. CONCLUSION: Predictive model based on parameters form clinical history of the patients may help to distinguish between cardiac and other causes of syncope.

A prospective study of the standardized diagnostic evaluation of syncope.

AIMS: To evaluate the aetiology and the diagnostic yield of the standardized diagnostic work-up based on European Society of Cardiology guidelines in the syncope unit. METHODS AND RESULTS: A total of 501 patients (191 men and 310 women), mean age 65 years (44-75 years), were prospectively evaluated. They underwent initial evaluation (history, physical evaluation, and a 12-lead electrocardiogram) and subsequently targeted tests that differed according to suspected aetiology. Initial evaluation resulted in diagnosis in 155 patients--reflex syncope (93), arrhythmogenic syncope (62), and pacemaker malfunction (7). In 22 patients with solitary syncope, a diagnostic algorithm was stopped after initial evaluation. In 139 patients with organic heart disease, cardiac syncope was found in 83 patients and reflex syncope in 30 patients. In 185 patients without organic heart disease, reflex syncope was diagnosed in 127 patients, cardiac syncope in 30 patients, and vascular syncope in 2 patients. Vasovagal syncope was the most common type of syncope (43%), followed by bradyarrhythmias (25%), tachyarrhythmias (9%), and orthostatic hypotension (5%). Aetiology of syncope remained unknown in 11% of patients. Diagnostic yield of specific examinations was as follows: head-up tilt 52%, implantable loop recorder 51%, electrophysiologic study 33%, initial evaluation 31%, EKG Holter 12%, orthostatic test 10%, transoesophageal stimulation 9%, carotid sinus massage 4%, and echocardiography 2%. CONCLUSION: Standardized diagnostic evaluation determined the aetiology of syncope in 89% of patients. Diagnostic yield of specific diagnostic procedures was different. Initial evaluation resulted in diagnosis in one-third of patients.