Changes in Left Ventricular Global and Regional Longitudinal Strain During Right Ventricular Pacing

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Electrophysiology

Background:

• Right ventricular pacing can alter left ventricular (LV) function.
• Right ventricular apical pacing (RVAP) may have detrimental effects on LV strain.
• Right ventricular septal pacing (RVSP) is explored as a potentially better alternative.

Purpose of the Study:

• To compare the short-term effects of RVAP versus RVSP on LV regional and global longitudinal strain (GLS).
• To assess the impact of pacing location on LV systolic function in patients with preserved ejection fraction.

Main Methods:

• Sixty-two patients with preserved LV ejection fraction received dual-chamber pacemakers.
• Patients were randomized into RVAP (n=32) or RVSP (n=30) groups.
• Echocardiography and 2D speckle tracking assessed LV function and strain at baseline and 6 months.

Main Results:

• Paced QRS duration was shorter in the RVSP group (P=0.02).
• At 6 months, GLS was significantly reduced in the RVAP group compared to RVSP (P=0.01).
• Regional longitudinal strain (RLS) and relative apical longitudinal strain (rALS) were significantly affected by RVAP.

Conclusions:

• RVAP leads to a greater reduction in GLS compared to RVSP.
• The decrease in apical strain is the primary correlate of GLS reduction following RV pacing.