Long-Term Impact of Left Bundle Branch Block on Cardiopulmonary Exercise Test Variables and Left Ventricular Systolic...

Area of Science:

• Cardiology
• Exercise Physiology

Background:

• Left bundle branch block (LBBB) impairs left ventricular electrical activation, potentially causing LBBB-induced cardiomyopathy.
• This study investigates cardiopulmonary exercise test (CPET) variables and longitudinal left ventricular ejection fraction (LVEF) changes in patients with and without LBBB.

Purpose of the Study:

• To compare CPET variables between patients with and without LBBB.
• To assess the 4-year change in LVEF in these patient groups.
• To identify early indicators of ventricular dysfunction in LBBB patients.

Main Methods:

• An observational, comparative study included 27 patients (11 LBBB, 16 non-LBBB) with preserved LVEF (>50%) and no ischemia.
• Cardiopulmonary exercise testing (CPET) was performed.
• Transthoracic echocardiography re-evaluated LVEF after 4 years.

Main Results:

• LBBB patients showed significant differences in CPET variables, including peak
• LBBB patients exhibited a greater decline in LVEF over 4 years compared to controls.
• Despite initial preserved LVEF, LBBB led to altered contractile patterns, suggesting early ventricular dysfunction.

Conclusions:

• Patients with LBBB and initially preserved LVEF demonstrate reduced exercise tolerance and a longitudinal decrease in LVEF.
• Vigilant monitoring and early intervention are recommended for LBBB patients to manage potential ventricular dysfunction.