Clinical Trial: Study of Paced QRS Duration as a Marker of Sudden Cardiac Death

Study Status: Terminated
Recruit Status: Terminated
Study Type: Observational

Official Title: Assessment of Prolonged Paced QRS Duration as a Marker of Sudden Cardiac Death in Subjects With Implantable Cardioverter-defibrillators

Brief Summary: The purpose of the study is to determine whether prolonged paced QRS duration is a marker of sudden cardiac death in subjects with implantable cardioverter-defibrillators (ICD).

Detailed Summary:

• Methods and Procedures Subjects for this study will be enrolled from the ICD clinic at Pocono Medical Center. The ICD clinic at Pocono Medical Center is located in the cardiology office 2.4 miles from the main hospital building where patients undergo interrogation of their ICD under the direction of the principal investigator.

During a routine ICD interrogation, the patient is attached to a 3 lead surface ECG. The ICD is then checked to assess sensing and pacing parameters and impedance for leads in all cardiac chambers. Battery voltage is assessed, and any stored events which include data from any appropriate or inappropriate therapies, are examined. Appropriate therapies consist of either an ICD shock or anti-tachycardia pacing for ventricular tachyarrhythmias. Inappropriate therapies consist of either an ICD shock or anti-tachycardia pacing for an event other than ventricular tachyarrhythmias, and may be triggered by supraventricular tachyarrhythmias or electronic noise.

Once the subjects are enrolled in the study, a 12-lead ECG will be performed (instead of a 3 lead ECG) before ICD interrogation (baseline ECG). A 12 lead ECG will then be repeated while performing right ventricular pacing through the programmer at 100 beats per minute at the time of pacing threshold testing (paced ECG). QRS durations from the baseline and paced ECG will be measured electronically in leads V3-V6. The measured QRS complexes should not be preceded by an atrial or ventricular premature complex.

All subjects will then continue to be followed every three months in the ICD clinic for routine ICD interrogation as clinically indicated for the duration of the study. Data for any appropriate and inappropriate ICD therapies will be retrieved and documented in the case report form. Subjects w
Sponsor: Pocono Medical Center

Current Primary Outcome: Sudden Cardiac Death [ Time Frame: Subjects will be followed for the duration of the study, an expected average of 2.5 years ]

Subjects will be considered to have suffered SCD if they meet one of the following criteria.

  • An appropriate ICD therapy (shock or anti-tachycardia pacing)
  • Death occurring within one hour of onset of cardiac symptoms
  • Death during sleep
  • Unwitnessed death in a formerly stable patient
  • Death during attempted resuscitation


Original Primary Outcome: Same as current

Current Secondary Outcome:

Original Secondary Outcome:

Information By: Pocono Medical Center

Dates:
Date Received: September 12, 2013
Date Started: October 2013
Date Completion:
Last Updated: December 11, 2016
Last Verified: December 2016