HeartLogic Multisensor Algorithm (Approximate Calculator)

HeartLogic Multisensor Algorithm — Explanation, clinical context and references The HeartLogic algorithm is a proprietary, multisensor device diagnostic implemented in certain Boston Scientific implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy devices. It combines trends from multiple sensors — notably accelerometer-derived first and third heart sounds (S1, S3), intrathoracic (thoracic) impedance, respiratory measurements (rate and derived indices), night (nocturnal) heart rate, activity, and arrhythmia burden — into a single composite index. In published validation (the MultiSENSE study and subsequent analyses) HeartLogic demonstrated high sensitivity for detecting worsening heart failure events and a low unexplained alert rate when operated at the nominal threshold; the device vendor commonly references a nominal alert threshold of 16 (index ≥16 considered an “in-alert” state).

This page provides an open, transparent approximation (not the proprietary formula) that lets clinicians or researchers explore how relative changes from patient-specific baselines in the listed sensors could alter a composite index. The approximation uses normalized percent-changes and illustrative weights to produce an index scaled for comparison with the nominal threshold; it is intended for educational and research exploration only and must not be used as a substitute for device-generated HeartLogic outputs or direct clinical judgment. Why this limitation?

The exact HeartLogic weighting, normalization, and internal filtering are proprietary and implemented within device firmware and vendor systems; reproducing the exact algorithm is not possible from public sources. For device-level monitoring, use the manufacturer’s device reports (LATITUDE platform / Heart Failure Management Report) and consult the original publications and vendor clinical guides. Key references (selected): Boehmer JP, Hariharan R, Devecchi FG, et al.

A Multisensor Algorithm Predicts Heart Failure Events in Patients With Implanted Devices: Results from the MultiSENSE Study. JACC: Heart Failure. 2017;5(3):216–225.

DOI:10.1016/j.jchf.2016.12.011. Gardner RS, Singh JP, Stancak B, et al. HeartLogic multisensor algorithm identifies patients during periods of significantly increased risk of heart failure events: results from the MultiSENSE study.

Circulation: Heart Failure. 2018;11(7):e004669. Boston Scientific.

HeartLogic / MultiSENSE clinical information and HeartLogic Alert Management Guide. (manufacturer clinical compendia and alert guide). Santini L, et al. Prospective evaluation of the multisensor HeartLogic algorithm in clinical practice. (early clinical experience / validation reports).