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Interatrial conduction time and left atrial function in patients with left ventricular systolic dysfunction: effects

Alan D Waggoner1, Sujith Kalathiveetil, Karen E Spence

  • 1Cardiovascular Imaging and Clinical Research Core Laboratory, Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA. awaggone@dom.wustl.edu

Journal of the American Society of Echocardiography : Official Publication of the American Society of Echocardiography
|April 7, 2009
PubMed

Insights

Prolonged interatrial conduction time (IACT) is common in patients with left ventricular systolic dysfunction (LVSD). An IACT over 100 ms impacts left atrial remodeling after cardiac resynchronization therapy (CRT).

Area of Science:

  • Cardiology
  • Cardiac Electrophysiology
  • Echocardiography

Background:

  • Prolonged interatrial conduction time (IACT) is linked to abnormal left atrial (LA) function.
  • IACT has not been previously studied in patients with left ventricular systolic dysfunction (LVSD) and wide QRS intervals (>130 ms).

Purpose of the Study:

  • To investigate interatrial conduction time (IACT) in patients with LVSD and wide QRS intervals.
  • To assess the impact of prolonged IACT on left atrial (LA) remodeling and function following cardiac resynchronization therapy (CRT).

Main Methods:

  • Utilized two-dimensional Doppler echocardiography and Doppler tissue imaging (DTI) in 41 patients with LVSD and 41 controls.
  • Defined IACT as the time from P wave onset to the onset of the DTI-derived late diastolic (A') wave at the lateral mitral annulus.
  • Reassessed Doppler measurements in LVSD patients after CRT.

Main Results:

  • Patients with LVSD exhibited significantly longer IACT (105 +/- 25 ms) compared to controls (74 +/- 12 ms).
  • IACT correlated with LA volume but not directly with LA function in LVSD patients.
  • Pre-CRT IACT > 100 ms was associated with larger LA volumes and reduced LA function post-CRT, despite similar LV improvements in both groups.

Conclusions:

  • Doppler tissue imaging-derived IACT can be prolonged in severe LVSD with wide QRS intervals.
  • IACT exceeding 100 ms affects early LA remodeling and function after CRT.
  • Prolonged IACT does not influence the improvement in LV end-systolic volume or ejection fraction following CRT.
Abstract

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