Effect of cardiac resynchronization therapy on regional left ventricular function: a speckle tracking strain analysis

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Electrophysiology

Background:

• Cardiac resynchronization therapy (CRT) improves outcomes in heart failure patients.
• Mechanisms of CRT benefits are partially understood.
• The impact of biventricular pacing (BVP) on regional myocardial contractility remains unclear.

Purpose of the Study:

• To investigate the acute effects of BVP on regional left ventricular (LV) myocardial contractility.
• To assess changes in myocardial strain patterns during different pacing configurations.

Main Methods:

• Prospective study of 20 patients meeting CRT criteria.
• Speckle tracking strain analysis from echocardiographic acquisitions.
• Measurement of longitudinal and transverse strains in basal LV segments under spontaneous rhythm and BVP.

Main Results:

• BVP improved LV end-diastolic and end-systolic volumes; LV ejection fraction was unchanged.
• Significant changes in regional strain were observed with BVP.
• BVP increased longitudinal septal strain and decreased longitudinal and transverse lateral strain compared to spontaneous rhythm.

Conclusions:

• Biventricular pacing acutely alters regional LV myocardial contractility.
• BVP enhances septal contraction while reducing lateral wall deformation.
• These findings suggest BVP may improve the overall left ventricular contractile pattern.