DEVICE DIAGNOSTICS TriageHF™ technology

THORACIC IMPEDANCE TREND

The thoracic impedance trend plots the daily averages of the patient’s raw intrathoracic impedance against the reference trend.

Decreases in intrathoracic impedance occur on average 15 days before symptom onset and 18 days before hospitalisation.¹

OPTIVOL FLUID INDEX TREND

The OptiVol fluid index quantifies the spread between the daily averages and the reference trend. It is a graphical representation of the accumulation of consecutive day-to-day differences between the Daily and Reference impedance.

(OptiVol monitoring is not intended to replace assessments, which are part of standard clinical practice.)

AT/AF BURDEN

The atrial tachycardia/atrial fibrillation (AT/AF) burden trend plots the total time spent in AT/AF on a daily basis.

Underappreciated AT episodes may be an important trigger for acute pulmonary congestion/volume overload.²

VENTRICULAR RATE DURING AT/AF

This trend displays the daily average and maximum ventricular rates occurring during AT/AF.

Poor rate control with atrial tachyarrhythmias is associated with earlier time to first hospitalisation.^{3, 4}

PATIENT ACTIVITY

The device accelerometer accumulates the number of activity counts sensed each minute. A minute is considered active if the counts exceed a threshold equal to walking approximately 70 steps per minute.

Activity level measured by an implantable cardiac device decreased significantly in the days leading up to a heart failure hospitalisation.⁵

HEART RATE VARIABILITY (HRV)

The median atrial heart rate is determined every 5 minutes, and a variability value is plotted each day.

Low HRV (< 50 ms) is associated with increased risk for heart failure hospitalisations and mortality. Conversely, patients with HRV > 100 ms are at significantly lower risk.⁵

PERCENT PACING PER DAY

The percent pacing per day trend provides a view of pacing over time; it displays the daily percentage of atrial and ventricular pacing.

Information regarding percentage of ventricular pacing is important for maximising CRT, especially in patients with AF where poor rate control can compromise CRT and therapies.^{7, 8}

ONE OR MORE SHOCKS PER DAY

This trend displays an annotation for the day on which a defibrillation therapy, cardioversion therapy, or atrial shock therapy was delivered.

TREATED VT/VF EPISODES PER DAY

This trend provides a history of ventricular tachyarrhythmias. The device records the total number of spontaneous VT and VF episodes each day.