[Antitachyarrhythmic interventions of implantable cardioverter-defibrillator in primary and secondary sudden cardiac death prevention patients].
Antitachycardia pacing (ATP) and high voltage interventions (CV) are methods of interrupting dangerous ventricular arrhythmias. The aim of the study was to determine the frequency of ventricular tachyarrhythmias and form of ICD interventions in patients in the primary and secondary sudden cardiac death (SCD) prevention groups.


METHODS
The study involved 399 patients (334 male, 65 female), mean age was 65.2 +/- 12.1 years (21-89 years), who had an ICD implanted in years 2008-2010. The analysis comprised age, gender, indications for ICD implantation, intracardiac electrograms derived from ICD during the follow-up.


RESULTS
The patients were divided in 2 groups depending on the SCD prevention type: group A - primary prevention, group B - secondary prevention. In the A group, the peak death rate was in the 7th decade of life, while in the B group it was 10 years later. In the A group the main condition was coronary arteries disease (CAD) (76%) and dilating non-ischemic cardiomiopathy (18%), whilst in the B group, only CAD (100%). In the A group different forms of ventricular tachyarrhythmias were registered more often in the dead (57%), than living patients (38%). The difference was statistically significant (p < 0.025) and considered mainly ventricular fibrillation observed in 21% of dead patients and only in 4,2% living. Despite the fact, that in the B group the percentage of dangerous ventricular tachyarrhythmias (VT and especially VF) was higher, there were fewer deaths than in A group (7.8 vs 12.8%). In living patients in the B group, there were registered twice as many ICD interventions as in the A group. In the A group, in patients over 70 years old, in contrary to the younger, more frequently ventricular tachyarrhythmias and antiarrhythmic interventions (ATP, CV) were observed. In the B group, the relation was reversed. Inadequate and ineffective interventions occurred mainly in the A group.


CONCLUSIONS
There were twice as many ICD interventions in patients implanted in secondary SCD prevention than in patients implanted in primary prevention. In secondary prevention, in contrary to the primary, the frequency of ventricular tachyarrhythmias and ICD interventions in patients younger than 70 years old is higher than in older patients. The most frequent reason for inadequate ICD interventions are sinus tachycardia and atrial fibrillation.
Jagiellonian University, School of Medicine, Cracow, Poland, Institute of Cardiology, Department of Electrocardiology, The John Paul II Hospital in Krakow, Poland.
Justyna
J
Piekarz
Anna
A
Rydlewska
Jacek
J
Majewski
Jacek
J
Lelakowski
D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015897:Comorbidity; D003324:Coronary Artery Disease / Q000453:epidemiology; D016757:Death, Sudden, Cardiac / Q000453:epidemiology* / Q000517:prevention & control*; D017147:Defibrillators, Implantable / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011322:Primary Prevention / Q000706:statistics & numerical data; D055502:Secondary Prevention / Q000706:statistics & numerical data; D015996:Survival Rate; D017180:Tachycardia, Ventricular / Q000453:epidemiology* / Q000517:prevention & control*; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000453:epidemiology* / Q000517:prevention & control; D055815:Young Adult