Tilt-induced changes in haemodynamic parameters in patients with cardiac resynchronisation therapy - a pilot study

Area of Science:

• Cardiology
• Medical Devices

Background:

• Cardiac resynchronisation therapy (CRT) is standard for advanced chronic heart failure (CHF).
• Optimizing CRT device parameters is crucial for patient response.
• Current optimization typically occurs in a supine position, potentially missing critical upright hemodynamic data.

Purpose of the Study:

• To compare hemodynamic parameters in supine versus erect positions during CRT optimization.
• To identify potential discrepancies in hemodynamic measurements based on patient posture.

Main Methods:

• 10 male patients (mean age 69.6 years) with CHF underwent CRT follow-up.
• Hemodynamic parameters were measured using impedance cardiography (ICG) in supine and 80-degree tilted positions.
• Key parameters included heart rate, blood pressure, stroke volume, cardiac output (CO), and total peripheral resistance (TPR).

Main Results:

• Significant differences in hemodynamic parameters were observed between supine and erect positions in most measurements.
• Changes in cardiac output (CO) were significant in 8 out of 10 patients.
• Abnormal responses in total peripheral resistance (TPR) occurred in 50% of patients.
• A negative correlation was found between tilt-induced CO changes and left ventricular ejection fraction (r=-0.7, p<0.025).

Conclusions:

• Patient posture significantly impacts hemodynamic parameters during CRT optimization.
• Observed hemodynamic changes in the upright position can be substantial and sometimes abnormal.
• Further research is needed to determine the clinical significance of these postural hemodynamic variations in CRT patients.