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Feasibility of Heart Sounds Measurements from an Accelerometer within an ICD Pulse Generator
Author(s) -
SIEJKO KRZYSZTOF Z.,
THAKUR PRAMODSINGH H.,
MAILE KEITH,
PATANGAY ABHILASH,
OLIVARI MARIATERESA
Publication year - 2013
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/pace.12059
Subject(s) - medicine , accelerometer , implantable cardioverter defibrillator , cardiology , heart failure , ambulatory , heart sounds , biomedical engineering , computer science , operating system
Objective The feasibility of detecting heart sounds (HS) from an accelerometer sensor enclosed within an implantable cardioverter defibrillator (ICD) pulse generator (PG) was explored in a noninvasive pilot study on heart failure (HF) patients with audible third HS (S3) . Methods Accelerometer circuitry enhanced for HS was incorporated into non‐functional ICDs. A study was conducted on 30 HF patients and 10 normal subjects without history of cardiac disease. The devices were taped to the skin surface over both left and right pectoral regions to simulate subcutaneous implants. A lightweight reference accelerometer was taped over the cardiac apex. Waveforms were recorded simultaneously with a surface electrocardiogram for 2 minutes. Algorithms were developed to perform off‐line automatic detection of HS and HS time intervals (HSTIs) . Results S1, S2, and S3 vibrations were detected in all accelerometer locations for all 40 subjects, including 16 subjects without an audible S3. A substantial proportion of S3 energy was infrasonic (<20 Hz). Extending the signal bandwidth accordingly increased HS amplitudes and the ability of S3 to separate HF patients from the normal subgroup. HSTIs also separated the subgroups and were less susceptible to patient‐dependent acoustic propagation properties than amplitude measures . Conclusion HS, including S3 amplitude and HSTIs, may be measured using PG‐embedded circuitry at implant sites without special purpose leads. Further study is warranted to determine if relative changes in heart sounds measurements can be effective in applications such as remote ambulatory monitoring of HF progression and the detection of the onset of HF decompensation .