Abstract 17525: Activity-contextualized Wearable Ballistocardiogram Measurements Can Classify Decompensated versus Compensated Heart Failure Patients
Introduction: Wearable technology may allow continuous home monitoring of heart failure (HF) patients (pts) to predict its worsening and guide treatment in order to prevent hospitalization. Most current wearable devices only measure heart rate (HR), rhythm (ECG) or thoracic impedance, which have limited predictive value in HF pts. We have shown that ballistocardiography (BCG) - the measurement of body vibrations in response to cardiac ejection - can quantify cardiac output and contractility [pre-ejection period (PEP)] changes using a small wearable patch (Fig 1a).
Hypothesis: HR and PEP recovery following 6 minute walk test (6MWT) is significantly slower for pts with compensated (C) vs decompensated (D) HF.
Methods: We enrolled 15 pts hospitalized for D HF [46 ± 14 years, 26% women, 95% New York Heart Association (NYHA) class IV symptoms, ejection fraction (EF) 0.24 ± 0.11] and 19 stable outpatients with C HF [58 ± 13 years, 23% women, 77% NYHA class I/II symptoms, EF 0.44 ± 0.14]. Pts wore a custom chest patch that measured BCG and ECG and performed a 6MWT, after which pts stood still for 5 min in recovery. We measured HR and RJ interval (PEP surrogate) - the time interval between the ECG R-wave and the BCG J-wave (Fig 1b) - during the recovery and compared the recovery slope of HR (bpm/min) and PEP (ms/min).
Results: The 6MWD was lower for D vs C: 244 ± 118 m vs 364 ± 94 m (p < 0.01) and the recovery slope for HR (-0.9 ± 2.3 bpm/min vs -8.1 ± 9.8 bpm/min, p < 0.02) and PEP (2.4 ± 3.1 ms/min vs 6.8 ± 6.3 ms/min, p < 0.02) were significantly slower for D vs C (sample results from a pt in each group shown in Fig 1c). High quality BCG and ECG measurements were obtained for all pts during the recovery period.
Conclusions: Non-invasive measurements of hemodynamic responses to activity obtained using a small, inexpensive, low-power chest patch can differentiate between D and C HF pts. The ability to longitudinally track improving and worsening condition may provide new means of remotely predicting HF exacerbations.
Author Disclosures: O.T. Inan: None. A. Dorier: None. S. Dowling: None. A.Q. Javaid: None. M. Etemadi: None. S. Roy: None. T. De Marco: None. L. Klein: None.
- © 2016 by American Heart Association, Inc.