Left ventricular torsion in paced patients

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Mechanics

Background:

• Healthy left ventricles exhibit distinct apical counter-clockwise and basal clockwise rotations during systole.
• This rotation generates systolic torsion, a crucial aspect of ventricular function.
• The impact of permanent conventional pacing on left ventricular torsion is not well understood.

Purpose of the Study:

• To evaluate left ventricular rotation and torsion in patients undergoing conventional right ventricular apex pacing.
• To compare these parameters with healthy individuals using speckle tracking echocardiography.

Main Methods:

• Speckle tracking echocardiography was used to assess left ventricular apical and basal rotation and torsion.
• Thirteen conventionally paced patients and 17 healthy participants were included.
• Left ventricular dyssynchrony was evaluated by assessing the temporal uniformity of strain.

Main Results:

• Paced patients showed a significant reduction in early-systolic clockwise torsion compared to controls.
• Late-systolic counter-clockwise torsion was also significantly reduced in the paced group.
• Circumferential strain uniformity was significantly lower in patients with conventional pacing.

Conclusions:

• Conventional right ventricular apex pacing adversely affects left ventricular torsional mechanics.
• Pacing also leads to alterations in the synchrony of left ventricular contraction.
• These findings underscore the mechanical consequences of standard pacing on cardiac function.