The purpose of this study is to explore the feasibility of monitoring hemodynamic changes, which result from heart failure exacerbations, by recording the respiratory effort, chest wall dynamics and quantifying the development of dyspnea by using miniature mechanical sensors that are attaches to the chest.

Pulmonary veins congestion and fine changes in alveolar transudative effusion accumulation affect lung mechanics (compliance) and the respiratory effort. Moreover, the associated state of oxygen de-saturation is compensated by an increase in the respiratory effort. These changes in the respiratory effort are reflected in chest wall dynamics and may provide the earliest non-invasive sign for lung congestion and deterioration in the heart failure.

The research system comprises of patches attached to the patients' thorax that include motion sensors (Accelerometers) that measure the chest wall dynamics and the mechanics of lung inflation and deflation. The signals are acquired by a miniaturized device that amplifies and samples the signals, stores and analyzes the data and displays the trends on the screen.

Inclusion Criteria:

• Acute decompensated HF
• Decompensated chronic HF in patients with NYHA class III-IV symptoms
• Age over 20 years
• Ejection fraction reduced below 35% OR doppler evidence of impaired left ventricular diastolic filling

Exclusion Criteria:

• Inability or unwillingness to follow the study protocol