Haemodynamic Benefit of Cardiac Resynchronisation Therapy Requires Left Bundle Branch Block: A Case Report

Area of Science:

• Cardiology
• Biomedical Engineering
• Cardiac Electrophysiology

Background:

• Dilated cardiomyopathy (DCM) often presents with conduction abnormalities like left bundle branch block (LBBB).
• LBBB can impair left ventricular (LV) systolic function and worsen heart failure symptoms.
• Cardiac resynchronisation therapy (CRT) is a treatment option for eligible heart failure patients.

Purpose of the Study:

• To describe the acute hemodynamic effects of LBBB on LV pressure dynamics.
• To evaluate the impact of CRT on LV function in the presence and absence of LBBB.
• To analyze the invasively measured maximum rate of left ventricular pressure rise (dP/dt(max)) as a functional parameter.

Main Methods:

• Invasive hemodynamic monitoring during CRT implantation.
• Measurement of LV pressure and its first derivative (dP/dt) to assess contractility.
• Comparison of dP/dt(max) before and after CRT, with and without LBBB.

Main Results:

• A significant acute negative effect of LBBB on dP/dt(max) was observed.
• CRT demonstrated a differential effect on LV hemodynamics depending on LBBB presence.
• CRT improved dP/dt(max), indicating enhanced LV contractility and function.

Conclusions:

• LBBB acutely impairs LV systolic performance, as evidenced by reduced dP/dt(max).
• CRT can effectively improve LV hemodynamic function in patients with DCM and LBBB.
• Invasive dP/dt(max) measurement is a valuable tool for assessing CRT response.