Valsalva Manœuvre in the Diagnosis of Left Ventricular Failure in Chronic Obstructive Pulmonary Disease Exacerbation

Inclusion Criteria * We included in this group, patients with a history (previous history) of COPD who consulted the emergency room for an exacerbation of COPD defined by a respiratory rate\> 25c/min and a pH \<7.35 and a PaCO2 \>6 KPa. * This group is also divided into two groups according to clinical expert assessment and the BNP value: Group1 : BNP\> 400pg/ml, Group2 : BNP \<400PG / ml Exclusion Criteria: * We excluded from this study patients with Prominent cardiac arrest * Rhythm disorders including severe tachycardia arrhythmia * Auricular fibrillation * Hemodynamic instability requiring the use of vasoactive drugs and a contre indications of non invasive ventilation such us consciousness disorders with a Glasgow score \<12/15,a swallowing disorder * A significant bronchial obstruction ,the upper airway obstruction , in upper gastrointestinal bleeding in progress, an extreme obesity and Cirrhosis or cancer. * We are also excluded patients who did not cooperate and those who refused the study.