Systolic time intervals combined with Valsalva maneuver for the diagnosis of left ventricular dysfunction in COPD exacerbations

BACKGROUND: The goal of this study was to determine the value of systolic time intervals and their change during Valsalva maneuver (VM) in the diagnosis of left ventricular dysfunction (LVD) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). METHODS: We included 166 patients admitted to the emergency department for AECOPD. Measurement of systolic time intervals included electromechanical activation time (EMAT), left ventricular ejection time (LVET), and EMAT/LVET ratio. These were performed at baseline and during the first strain phase of the VM using a computerized phonoelectrocardiographic method. The diagnosis of LVD was determined on the basis of clinical examination, echocardiography, and brain natriuretic peptide. The values of systolic time intervals were compared between patients with and without LVD; their diagnostic performance was assessed using the area under receiver operating characteristic (ROC) curve. RESULTS: Patients with LVD (n=95) had a significantly higher EMAT and lower LVET and EMAT/LVET ratio compared to patients without LVD (n=71); the area under ROC curve was 0.79, 0.88, and 0.90, respectively, for EMAT, LVET, and EMAT/LVET ratio. All baseline systolic time intervals changed significantly during VM in patients without LVD but they did not change in patients with LVD. The area under ROC curve increased to 0.84 and 0.93, respectively, for EMAT and EMAT/LVET ratio but did not change for LVET. CONCLUSION: Simple and noninvasive measurements of systolic time intervals combined with VM could be helpful to detect or rule out LVD in patients admitted to the emergency room for COPD excacerbation. The EMAT/LVET ratio seems to have the best diagnostic value.