Electrophysiology / HeartLogic™ Heart Failure Diagnostic / Multi-Sensor Technology

Multi-Sensor Technology

HeartLogic is the only FDA-approved heart failure diagnostic that uses multiple sensors to track physiological trends and combine them into one composite index. When the index crosses over a configurable threshold, HeartLogic provides a proactive alert to the clinician via the Heart Failure Management Report from the LATITUDE™ NXT Remote Patient Management System. These actionable insights may help you adjust treatment and potentially avoid an impending heart failure event. An extraordinary first, only from Boston Scientific.

HeartLogic Sensors

Sensors	What It Measures	Why It Matters
Heart Sounds	The device uses the embedded accelerometer to detect cardiac vibrations associated with heart sounds in intensity in milligravities (mG).	S3 is known as an early sign of HF and elevated filling pressure. S1 is associated with ventricular contraction. Worsening heart failure may be associated with an increase in S3, a decrease in S1, or both.
Thoracic Impedance	Measures impedance between electrodes on the RV lead and the pulse generator, which is indicative of fluid accumulation and pulmonary edema.	Lower thoracic impedance may be associated with pulmonary congestion,^1,2 pocket infection,² pleural/pericardial effusion³ and respiratory infection.²
Respiration	Monitors respiratory patterns associated with shortness of breath. In particular, it monitors respiratory rate and rapid shallow breathing via RSBI (rapid shallow breathing index), which is a ratio of respiratory rate (RR) to tidal volume.	Worsening heart failure may be associated with a worsened rapid shallow breathing pattern, an elevated RR, an increase in RR, or an increase in day-to-day RR variability.
Night Heart Rate	Monitors night heart rate, captured between midnight and 6 a.m., which for most patients is indicative of the resting heart rate.	An increase in night heart rate may be associated with worsening heart failure^4-7 or autonomic dysfunction.⁷
Activity Level	Shows the number of hours per day a patient is active and reflects the patient’s overall status and fatigue.	Worsening heart failure may be associated with a decrease in activity.^4-6

Additional Diagnostic Trends

Although the following diagnostic trends are not part of the HeartLogic algorithm, they can help clinicians understand the context of the HeartLogic alert.

Sensors	What It Measures	Why It Matters
Sleep Incline	Measures the angle between the patient’s torso and the horizontal plane during a sleep period specified by the patient.	Elevated sleep incline angle was indicative of orthopnea or paroxysmal nocturnal dyspnea.
AT/AF Burden	Displays the total amount of time spent in an atrial tachy response (ATR) mode switch, in hours per day.	AF can exacerbate heart failure^8-10 and worsening heart failure may result in the new onset or exacerbation of AF.^9,11
V Therapy	Provides an abbreviated summary of antitachycardia pacing (ATP) and shock therapy type delivered each day: ATP (dot) or shock (electrical shock sign).	Delivery of device therapy may signify an increase in abnormal cardiac rhythms or insufficient rate control.
% LV Placed	Monitors the percentage of cardiac beats paced with a left ventricular (LV) lead per day.*	A high percentage of biventricular pacing in patients with a CRT device is associated with improved prognosis.¹²
Weight	Displays daily patient weight data collected by an external weight scale via the LATITUDE™ NXT Remote Patient Management System.	Sudden or steady gain in daily weight may be associated with fluid retention and worsening heart failure.^{13, 14}