Abstract 2954: Monitoring of Breathing Patterns in Heart Failure Patients Using Pressure-Derived Respiration
Background: Dyspnea is a common symptom of worsening heart failure (HF). Patients (pts) may not recognize their abnormal breathing patterns until the symptom becomes more frequent and severe. Thus, ambulatory monitoring of respiration in pts could be important for timely management of HF. Continuously recorded right ventricular pressure (RVP) from the Chronicle implantable hemodynamic monitor (IHM) can be used to detect changes in respiration. This study evaluated the feasibility of pressure-derived respiration detection for dyspnea monitoring.
Methods: Data were analyzed from 14 cardiopulmonary exercise (CPX) tests performed in six HF patients (62 ± 7 years, 6 males, LVEF = 23 ± 5%) implanted with an IHM. Pts rested for 10 minutes before undergoing a sub-maximal bike exercise test. Continuous RVP waveforms from the IHM were recorded simultaneously with respiration data from the CPX system. A respiration signal and corresponding rate were derived from the RVP waveform. The pressure-derived respiration rate was compared with that from the CPX system for all one-minute time intervals.
Results: The peak-to-peak excursion of the RVP waveform associated with inspiration and expiration was approximately 15% of pulse pressure at rest (5.4 ± 1.9 and 35.0 ± 16.2 mmHg, respectively), and at peak exercise (8.4 ± 3.7 and 54.3 ± 19.8 mmHg). Linear regression of respiration rates showed a Pearson’s correlation coefficient of 0.97 with p < 0.001.
Conclusions: In pts with chronic HF, pressure-derived respiration rate from the IHM demonstrated an excellent correlation to respiration rate measured by the CPX system. Monitoring of pressure-derived respiration for HF pts is feasible using the IHM.