Chest
Volume 131, Issue 4, April 2007, Pages 1050-1057
Journal home page for Chest

Original Research
COPD
Reduced Intrathoracic Blood Volume and Left and Right Ventricular Dimensions in Patients With Severe Emphysema: An MRI Study

https://doi.org/10.1378/chest.06-2245Get rights and content

Background

Left ventricular (LV) filling is impaired in patients with severe emphysema manifesting in small end-diastolic dimensions. We hypothesized that the hyperinflated lungs of these patients with high intrinsic positive end-expiratory pressure will decrease intrathoracic blood volume (ITBV) and ventricular preload. We therefore measured ITBV, and LV and right ventricular (RV) dimensions and function using MRI techniques in patients with severe emphysema.

Methods

Patients with severe emphysema (n = 13) and matched healthy volunteers (n = 11) were included. The magnetic resonance (MR) examination consisted of three parts: (1) evaluation of RV and LV dimensions and function and interventricular septum curvature using cine MRI; (2) quantification of aortic flow using MR phase velocity mapping; and (3) calculation of the cardiopulmonary peak transit time (PTT) from the pulmonary artery to the ascending aorta using contrast-enhanced, time-resolved, two-dimensional MR angiography.

Results

There were no differences between the groups regarding age, height, or weight. In the emphysema patients, ITBV index (− 35%), LV end-diastolic volume index (LVEDVI) [− 21%], RV end-diastolic volume index (− 20%), cardiac index (− 22%), and stroke volume index (SVI) [− 40%] were lower compared to control subjects. LV and RV end-systolic volumes, LV wall mass, septal curvature, and PTT did not differ between the groups. LVEDVI (r = 0.83) as well as SVI (r = 0.82) correlated closely to ITBV index. SVI correlated closely to LVEDVI (r = 0.84).

Conclusions

LV and RV performance is impaired in patients with severe emphysema because of small end-diastolic dimensions. One possible explanation for the decreased biventricular preload in these patients is intrathoracic hypovolemia caused by hyperinflated lungs.

Section snippets

Materials and Methods

The local Ethics Committee of the Medical Faculty of Göteborg University approved the study protocol, written informed consent was obtained from all subjects, and the study complied with the recommendations found in the Declaration of Helsinki.6 Criteria for inclusion in the emphysema group (n = 13) were a history of lung emphysema based on physical examination, chest radiography, and pulmonary function test results: FEV1 from 15 to 30% of predicted value; total lung capacity > 120% of

Results

There were no differences between the groups regarding age, height, or weight (Table 1). The emphysema patients had the typical functional features of severe pulmonary emphysema: severe obstruction to expiratory airflow and considerable hyperinflation (Table 1).

Discussion

The main findings of this study were that cardiac performance was compromised in patients with severe pulmonary emphysema, as demonstrated by a lower SVI, when compared to control subjects matched for gender, age, and BSA. Although we have not proven a cause-effect relationship, the close relationship between ITBVI and LVEDVI and between LVEDVI and SVI (Fig 5, 6) strongly suggest that a low preload, caused by intrathoracic hypovolemia, contributes to the impaired LV performance seen in patients

References (32)

  • World Medical Association declaration of Helsinki

    Recommendations guiding physicians in biomedical research involving human subjects

    JAMA

    (1997)
  • The American Society for Transplant Physicians (ASTP)/American Thoracic Society(ATS)/European Respiratory Society(ERS)/International Society for Heart and Lung Transplantation(ISHLT)

    International guidelines for the selection of lung transplant candidates

    Am J Respir Crit Care Med

    (1998)
  • PennellDJ

    Ventricular volume and mass by CMR

    J Cardiovasc Magn Reson

    (2002)
  • RajappanK et al.

    The role of cardiovascular magnetic resonance in heart failure

    Eur J Heart Fail

    (2000)
  • SieversB et al.

    Impact of papillary muscles in ventricular volume and ejection fraction assessment by cardiovascular magnetic resonance

    J Cardiovasc Magn Reson

    (2004)
  • RoeleveldRJ et al.

    Interventricular septal configuration at MR imaging and pulmonary arterial pressure in pulmonary hypertension

    Radiology

    (2005)
  • Cited by (0)

    This study was supported by the Swedish Medical Research Council, No. 13156 and the Medical Faculty of Gothenburg.

    No financial or other potential conflicts of interest exist for any of the authors.

    View full text