Left ventricular diastolic filling prior to cardiac resynchronization therapy: implications for atrioventricular...

Area of Science:

• Cardiology
• Cardiac Electrophysiology
• Heart Failure Management

Background:

• Programmed atrioventricular delay (AVD) is crucial for left ventricular (LV) systolic performance during cardiac resynchronization therapy (CRT).
• The influence of LV diastolic filling patterns on optimal AVD in CRT is not well understood.

Purpose of the Study:

• To investigate if the optimal AVD for CRT is affected by the pre-CRT LV diastolic filling pattern.
• To compare different Doppler-derived parameters for optimizing AVD during CRT.

Main Methods:

• Thirty patients underwent CRT with programmed AVD ranging from 60-160 ms.
• Doppler measurements assessed LV function and diastolic filling (VTI, E/A waves, DFT).
• Patients were categorized by pre-CRT mitral inflow patterns: impaired relaxation (IR) or pseudonormalized/restrictive filling (PNF/RF).

Main Results:

• Patients with PNF/RF showed greater improvement in aortic VTI compared to IR.
• Mitral E-wave velocity decreased in PNF/RF, while E-wave VTI increased in both groups.
• Optimal AVD for aortic VTI was longer than that for diastolic filling time (DFT) optimization.

Conclusions:

• Pre-CRT LV filling characteristics influence the response to programmed AVD during CRT.
• Optimizing AVD for DFT yields shorter intervals than optimizing for aortic VTI-derived LV stroke volume.