Trepopnea.

Although 3D MRA has been shown to provide excellent depiction of the pulmonary arterial tree, its clinical use has been limited due to lengthy breath-holding requirements. Employing the newest gradient generation (1.5 T MR system, amplitude of 40 mT/m and a slew rate of 200 mT/m/msec), we evaluated a technique permitting the dynamic acquisition of 3D data sets of the entire pulmonary tree in under 4 seconds. Coronal image sets were collected using a repetition time of 1.64 msec and an echo time of 0.6 msec, resulting in an acquisition time of 3.74 seconds. Three volunteers and eight dyspneic patients with known or suspected pulmonary embolism underwent MRI of the pulmonary arteries. The pulmonary arterial tree was visible to a subsegmental level in all examined subjects. Regarding the presence of pulmonary emboli in four patients, there was complete concordance between MR angiographic findings and those of corroborative studies. We conclude that diagnostic MRA of the pulmonary vasculature can be obtained even in patients with severe respiratory distress.

Dyspnea↗

PubMed2001

[Severity of dyspnea during exercise: similarities and differences between patients with COPD or pulmonary fibrosis].

To understand the mechanisms leading to dyspnea during exercise and to identify possible predictive factors, we compared dyspnea at rest (baseline)and during exercise in 27 patients with chronic obstructive pulmonary disease (COPD) and 39 pulmonary fibrosis (PF) patients. We also compared spirometry and blood gases at rest and after exercise,which consisted of a 12-minute walking test (12 WT). Heart rate and oxygen saturation (SaO2) were recorded every two minutes during the 12 WT. Distance walked was also recorded. Although dyspnea changed during the 12 WT in both groups (p < 0.001),the maximum level of dyspnea reached in the two groups was not statistically different. COPD patients walked farther than did PF patients (782 +/- 182 m vs. 618 +/- 225 m, respectively;p = 0.002) and paused less often during the 12 WT than did PF patients(0.18 +/- 0.55 vs. 0.82 +/- 1.55, respectively; p <0.05). After adjusting for diagnosis, age, sex, baseline dyspnea,distance walked and pauses during the 12 WT, we found that only SaO2 was significantly related to severity of dyspnea during exercise. We conclude that there are important differences in degree of dyspnea experienced during exercise by COPD and PF patients and that SaO2 is the only variable that predicts severity of dyspnea.

Dyspnea↗