Effects of lung volume reduction surgery on left ventricular diastolic filling and dimensions in patients with severe emphysema

Abstract

Study objectives: Data on the influence of lung volume reduction surgery (LVRS) on cardiac function and hemodynamics are scarce and controversial. Previous studies have focused mainly on right ventricular function and pulmonary hemodynamics. Here, we evaluated the effects of LVRS on left ventricular (LV) end-diastolic filling pattern, dimensions, stiffness, and performance, as well as pulmonary and systemic hemodynamics.

Design: A prospective, open, controlled study.

Patients: Patients with severe emphysema undergoing LVRS (10 patients). Patients scheduled for pulmonary lobectomy due to carcinoma (ie, the lobectomy group) served as control subjects (10 patients).

Measurements: LV dimensions and mitral flow velocities were measured by transesophageal, two-dimensional, Doppler echocardiography, and central hemodynamics were measured by a pulmonary artery thermodilution catheter. Measurements were performed during anesthesia in the supine position, before and after surgery, without and with passive leg elevation.

Results: Baseline cardiac index (CI) [- 21%], stroke volume index (SVI) [- 31%], stroke work index (SWI) [- 26%], and LV end-diastolic area index (EDAI) [- 15%] were significantly (p < 0.001) lower, whereas LV end-diastolic stiffness (LVEDS) did not differ in the LVRS group compared to the lobectomy group. The time from peak early diastolic filling to zero flow (E-dec time) [58%] and the deceleration slope of early diastolic filling (E-dec slope) [45%] were significantly higher (p < 0.01), whereas peak early diastolic filling velocity (E-max) [- 31%; p < 0.01] and the proportion of E-max vs peak late diastolic filling velocity (A-max) [ie, the E/A ratio] (- 27%; p < 0.001) were significantly lower compared to the lobectomy group. LVRS significantly increased CI (40%; p < 0.001), SVI (34%; p < 0.001), SWI (58%; p < 0.001), LV EDAI (18%; p < 0.001), E-max (44%; p < 0.01), A-max (15%; p < 0.05) and E/A ratio (28%; p < 0.01), decreased E-dec time (- 31%; p < 0.05) and E-dec slope (- 98%; p < 0.01), and had no effect on LVEDS. In the lobectomy group, surgery affected none of these variables.

Conclusions: LV function is impaired in patients with severe emphysema due to small end-diastolic dimensions. LVRS increases LV end-diastolic dimensions and filling, and improves LV function.