Assessment of right ventricular function by strain rate imaging in chronic obstructive pulmonary disease.

The purpose of the current study was to compare right ventricular (RV) myocardial wall velocities (tissue Doppler imaging) and strain rate imaging (SRI) parameters with conventional echocardiographic indices evaluating RV function in chronic obstructive pulmonary disease (COPD) patients. In total, 39 patients with COPD and 22 healthy subjects were included in the current study. Seventeen patients had pulmonary artery pressure <35 mmHg (group I) and 22 patients had pulmonary artery pressure >35 mmHg (group II). Tissue Doppler imaging, strain and strain rate (SR) values were obtained from RV free wall (FW) and interventricular septum. Respiratory function tests were performed (forced expiratory volume in one second/vital capacity (FEV(1)/VC) and carbon monoxide diffusion lung capacity per unit of alveolar volume (D(L,CO)/V(A))). Strain/SR values were reduced in all segments of group II patients compared with group I patients and controls with lowest values at basal FW site. A significant relationship was shown between peak systolic SR at basal FW site and radionuclide RV ejection fraction. A significant relationship was shown between peak systolic SR at basal FW site and D(L,CO)/V(A) and FEV(1)/VC. In conclusion, in chronic obstructive pulmonary disease patients, strain rate imaging parameters can determine right ventricular dysfunction that is complementary to conventional echocardiographic indices and is correlated with pulmonary hypertension and respiratory function tests.

Early protective effects of tiotropium bromide in patients with airways hyperresponsiveness.

Tiotropium is an anticholinergic drug for Chronic Obstructive Pulmonary Disease (COPD) patients, with a peak bronchodilator effect observed after 1.5 to 2 hours and a long duration of action. The aim of our study was to quantify the early protection of a single dose of inhaled tiotropium against methacholine-induced bronchoconstriction in asthmatic patients with airway hyperresponsiveness. Ten subjects (7M, 3F), with history of asthma and a baseline FEV(1) (Forced Expiratory Volume 1 sec) > 80% of predicted, were enrolled in the study. Each subject performed three methacholine challenge tests, with a time of 72 hours between each challenge: Test A (methacholine challenge test), and successively, at random, Test B (methacholine 30 minutes after inhaled Tiotropium) and Test C (methacholine 30 minutes after inhaled Placebo). PD20 (Provocative Dose causing a 20% decrease in basal FEV(1) value) was reached to assess airways responsiveness. All the subjects showed in Test A and Test C a mild-moderate airway hyperresponsiveness. In Test B no PD20 was reached at the inhaled maximum dose of methacholine (1600 microg), FEV(1) before tiotropium was 88.6% +/- 4.4, beginning test FEV(1) 92.6% +/- 4.3, end test FEV(1) 85.7% +/- 4.6. Inhaled tiotropium bromide 18 microg has shown a protective effect against methacholine-induced bronchoconstriction in asthmatic patients, with mild-moderate airways hyperresponsiveness, already 30 minutes after its administration.

High resolution computed tomography (HRCT) assessment of beta 2-agonist induced bronchodilation in chronic obstructive pulmonary disease patients.

The evaluation of airway obstruction reversibility in chronic obstructive pulmonary disease (COPD) patients is currently performed by means of an indirect assessment of drug inducing variations in pulmonary function tests. Imaging techniques, especially high resolution computed tomography (HRCT), usually provide a complete evaluation of lung parenchyma (bronchial and vascular structures), but so far they have never been applied to visualize the effects on the bronchopulmonary tree of some pharmacologic stimuli (beta 2 adrenergic agonist), currently used in clinical practice to disclose the presence of airway reversibility. In order to assess the possible role of HRCT in this setting, five COPD patients have been subjected to a double functional radiologic evaluation before and after salbutamol-induced broncho-dilation, with a rigorous assessment of bronchial diameter changes by means of "bronchus-vessel" ratio, currently used for diagnosing bronchiectasis in COPD patients. The results of this experimental study enable us to visualize drug induced broncho-dilation, with a direct assessment of airway reversibility in these patients, and to show a good correlation between functional and HRCT findings, raising the possibility of evaluation COPD patients with abnormal spirometric results or with early signs of lung involvement.