Format

Send to

Choose Destination
Heart Rhythm. 2014 Aug;11(8):1361-6. doi: 10.1016/j.hrthm.2014.04.025. Epub 2014 Apr 19.

Use of an electrocardiographic screening tool to determine candidacy for a subcutaneous implantable cardioverter-defibrillator.

Author information

1
Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois.
2
Division of Cardiology, Department of Medicine, Northwestern University, Chicago, Illinois. Electronic address: bknight@nmff.org.

Abstract

BACKGROUND:

An electrocardiographic (ECG) screening test has been developed to identify patients being considered for a totally subcutaneous implantable cardioverter-defibrillator (S-ICD) at risk for T-wave oversensing.

OBJECTIVE:

The purpose of this study was to determine the proportion of potential S-ICD recipients who fail the ECG screening test and to identify predictors of failure.

METHODS:

Patients who already have an ICD but are not receiving antibradycardia pacing are representative of patients who might be considered for an S-ICD. One hundred such outpatients were enrolled in the study. Surface rhythm strips were recorded along the sensing vectors of the S-ICD system and the screening template applied. Clinical and standard ECG characteristics of patients who failed the test were compared to those who passed.

RESULTS:

Patients had the following characteristics: 72% male, age 57 ± 16 years, body mass index 29 ± 6 kg/m(2), left ventricular ejection fraction 43% ± 17%, QRS duration 109 ± 23 ms, QTc interval 447 ± 39 ms, 44% had coronary disease, and 55% had heart failure. Among the 100 patients, 8% failed the screening test. There were no differences in patient clinical characteristics and most standard ECG measurements. However, patients with T-wave inversions in standard ECG leads I, II, and aVF had a 45% chance of failing.

CONCLUSION:

Eight percent of potential S-ICD patients were not eligible for the S-ICD after failing the screening test designed to identify patients susceptible to T-wave oversensing. Patients with T-wave inversions in leads I, II, and aVF on a standard ECG were 23 times more likely to fail. More work is needed in S-ICD sensing algorithms to increase patient eligibility for the S-ICD.

KEYWORDS:

Defibrillator screening; Implantable cardioverter-defibrillator; Inappropriate shocks; Subcutaneous implantable cardioverter-defibrillator; T-wave oversensing

PMID:
24755323
DOI:
10.1016/j.hrthm.2014.04.025
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center