Tidal volume and minute ventilation parameters derived from pacemaker impedance measurements can predict experimental...

Area of Science:

• Cardiology
• Respiratory Physiology
• Biomedical Engineering

Background:

• Heart failure (HF) is often associated with specific respiratory patterns.
• Changes in tidal volume (TV) and minute ventilation (MV) during early HF decompensation are not well understood.

Purpose of the Study:

• To investigate changes in TV and MV during early heart failure (HF) decompensation.
• To assess the potential of using these respiratory parameters for HF detection and therapy assessment.

Main Methods:

• Yucatan minipigs underwent biventricular pacemaker and left ventricular pressure sensor implantation.
• Heart failure was induced via high-rate pacing, with respiratory parameters monitored using intrathoracic impedance (RVITI and LVITI).
• Echocardiograms and pressure measurements confirmed HF development and recovery.

Main Results:

• Tidal volume (TV) decreased significantly (68% for RVITI, 61% for LVITI) during HF.
• Minute ventilation (MV) also dropped significantly (34% for RVITI, 27% for LVITI).
• Respiratory rate and longest breath interval showed blunted circadian variation during HF, but median values did not change significantly.

Conclusions:

• TV and MV changes occur independently of respiratory rate in early HF.
• Monitoring TV and MV via implantable devices could offer a novel method for early HF detection.
• These parameters may also help assess treatment response in HF patients.