Abstract 14551: Müller Maneuver as a Tool for Stress Echocardiography in Evaluation of Exercise Capacity in Patients With Dilated Cardiomyopathy
Introduction: Müller maneuver (MM), which is a forced inspiration against a closed airway, has been incorporated as one of the physiologic, non-invasive stress tests. Increasing negative intrathoracic pressure during MM results in an increase of LV transmural pressure (TMP), which acts as an elevated left ventricular (LV) afterload.
Hypothesis: Changes in LV end-systolic volume (ESV) during MM may be different between heathy subjects and patients with dilated cardiomyopathy (DCM) (Figures A and B), and may be associated with LV end-systolic elastane (Ees) and exercise capacity.
Purpose: To measure LV ESV during MM in healthy subjects and patients with DCM, and to compare the results of MM stress echocardiography with estimated Ees and exercise capacity evaluated by cardiopulmonary exercise test (CPX).
Methods: In 20 patients with DCM and 15 healthy subjects, MM was repeated 5 times. Each MM was performed for 10 seconds with intraoral pressure to generate a steady level of -20 to -40 mmHg. Simultaneous biplane echocardiography was performed to measure LV ESV before and 1 or 2 beats after the onset of MM. TMP was calculated as (systolic blood pressure х 0.9 + intraoral pressure). TMP and LV ESV in each MM was plotted in individuals (Figures A and B). Peak O2 was measured by CPX.
Results: The slope between TMP and LV ESV was significantly different between healthy subjects and DCM patients (4.5±2.3 vs 9.7±2.6 mmHg/ml/BSA, p<0.001) (Figure C). The slope significantly correlated with estimated Ees (r=0.77) and peak O2 (r=0.82) (both p<0.001), which was independent determinant of peak O2 in multivariate analysis (β=0.61, p<0.001).
Conclusions: Stress echocardiography with MM is useful to estimate Ees and to evaluate exercise capacity in patients with DCM. Because of its non-invasive, physiologic, easily reversible nature, MM stress echocardiography has potential as an alternative and complementary method in patients with incapable or unwilling to standard exercise testing.
Author Disclosures: T. Onoue: None. S. Fukuda: None. A. Hayashi: None. S. Hei: None. Y. Kado: None. M. Iwataki: None. K. Otani: None. R. Kohno: None. Y. Oginosawa: None. M. Araki: None. S. Sonoda: None. M. Takeuchi: None. H. Abe: None. Y. Otsuji: None.
- © 2016 by American Heart Association, Inc.