Long-term follow-up of patients treated with ICD: Benefit in patients with preserved left ventricular function

Department of Cardiology, Heart Centre, Umeå University Hospital, Sweden.
Scandinavian Cardiovascular Journal (Impact Factor: 1.03). 05/2008; 42(2):125-9. DOI: 10.1080/14017430701762719
Source: PubMed


Most major defibrillator trials have short follow-up and may neither capture the benefit for those with preserved function nor the progressive nature of advanced heart disease. We intended to investigate the long-term outcome in an unselected population of patients treated with ICD.
We followed 124 consecutive patients that received an ICD during 1993-2002 at our institution for a median of 6.1 years. Information about heart disease, index arrhythmia, follow-up and death was extracted from medical records.
The crude mortality was 26% (32/124). One- and two-year mortality was 6% and 12%, estimated 5- and 10-year mortality 20% and 33%. The cause of death was heart failure in 75% of deaths. The ejection fraction was below 35% in 91% of the 32 patients who died. We estimated that 28% of the patients received lifesaving therapy. The relative number of saved lives and complications was not related to the ejection fraction.
Patients with preserved left ventricular function are excellent candidates for ICD, with life-saving ICD therapies in a substantial proportion, low mortality and good quality of life.

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    ABSTRACT: Implantable cardioverter-defibrillators (ICD) were introduced in clinical practice in 1980 and they are considered the standard treatment for individuals at risk for fatal ventricular arrhythmias. To ensure proper working conditions, the energy necessary to interrupt ventricular tachycardia or ventricular fibrillation should be determined during implantation by a test called defibrillation threshold. For this test, it is necessary to induce ventricular fibrillation, which should be identified and treated by the device. The objective of the present study was to determine the frequency of cognitive dysfunction 24 hours after the implantation of a cardioverter-defibrillator. Thirty consecutive patients with indication of cardioverter-defibrillator (ICD) placement and 30 patients with indication of implantable pacemaker (PM) were enrolled in this study. Patients were evaluated at the following moments: 24 hours before placement of the ICD or PM with a pre-anesthetic evaluation form, Mini Mental State Examination (MMSE), and Confusion Assessment Method (CAM); during implantation of the ICD or PM, the following parameters were determined: number of cardiac arrests and total time of cardiac arrest. Twenty-four hours after placement of the device, the following parameters were evaluated: MMSE and CAM. Differences in the frequency of altered MMSE and CAM scores between both groups before and after implantation were not detected by the Fisher Exact test. The mean time of cardiac arrest was 7.06 seconds, with a maximal of 15.1 and minimal of 4.7 seconds. Induction of cardiac arrest during defibrillation threshold testing did not cause cognitive dysfunction 24 hours after implantation of the cardioverter-defibrillator.
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