Are modern automatic pacemakers really automatic?
Medtronic Adapta and its automatic functions

Česká verzia

Authors: V. Vančura; J. Bytešník; K. Lefflerová; R. Krausová; R. Čihák; P. Peichl; J. Kautzner
Authors place of work: Kardiologická klinika, IKEM, Praha
Published in the journal: Kardiol Rev Int Med 2006, 8(4): 185-191
Category: Editorial

Summary

Introduction:
The concept of automatic pacemaker that would be able to monitor the development of parameters indicative of integrity and functionality of the whole stimulation system and that would itself be able to react to changes of stimulation thresholds and amplitudes of intracardial signals, is very old. The aim of this study was to find out to what extend has the modern pacemaker approached this concept.

Methods:
The monitored patients were the patients to whom the pacemaker Adapta ADDR01 (Medtronic) was implanted between 1. 6. 2005 and 31. 5. 2006. The data was gained retrospectively from the first ambulatory check-up records. The evaluated data concerned the number of patients who present all the required data indicative of integrity and functionality of the system displayed already in the first screen of the programming device immediately after the first data input download. Data about the battery condition, the development and the current electrode impedance value, the development and the current value of the atrial and ventricular stimulation threshold and the value of intracardial signal amplitude in atriums and ventricles were considered to be the required information. It was also observed how often the measured data required overprogramming of the stimulation energy values or sensing from the regime of automatic modification to the fixed value.

Results:
27 patients (17 men) were incorporated in the study. The average age was 67.8 ± 12.1 years. 20 patients in total were implanted the pacemaker within primoimplantation, 7 patients experienced a replacement of pacemaker. In 19 cases, the primary indication of the pacemaker implantation was the sick sinus syndrome. In one case it was the carotid sinus hypersensitivity and in 7 cases it was the AV conduction disorder. During the first ambulatory check-up of all patients after implantation, the data about the battery condition, the current electrode impedance value of both electrodes and its development were displayed graphically on the first screen. In 26 patients, the data concerning the ventricular threshold value were presented. In one case, these values were missing since the threshold value was too high regarding the boundaries on which the algorithm is based. In 26 patients, the data concerning the atrial threshold values were presented. In one case this value was missing because there was an atrial fibrillation from the time of replacement up to the ambulatory check-up. The atrial sensing value was given in 12 cases, other patients had high proportion of stimulation cycles in atria. The amplitude of signal in the ventricular channel was given in 20 cases. The other patients had a high proportion of stimulation cycles. The sensing values and stimulation energy values were left in the automatic correction regime, only in the patient with unmeasured ventricular threshold the doctor considered the transformation to the fixed stimulation energy value to be appropriate.

Conclusion:
The automatic monitoring of basic parameters indicating the correct function of the stimulation system is advanced in the current models of pacemakers. Modern pacemaker can measure battery life expectancy, electrode impedance values, atrial and ventricular stimulation threshold, as well as sensing values. These values are then displayed on the screen of the programming device immediately after the data input download. If the measured sensing values or stimulation threshold values are not displayed on the first screen, it is usually the result of high stimulation threshold, presence of atrial fibrillation or low number of scanned cycles during a higher proportion of stimulation in the respective cavity. The automatic sensing values and stimulation energy values correction regime seems to be appropriate to the majority of patients.

Keywords:
pacing – automatic pacemaker – pacemaker Adapta – sensing – stimulation threshold

Zdroje

1.Neuzner J, Schwarz T, Sperzel J. Pacemaker automaticity. Am J Cardiol 2000; 86(Suppl 1): 104-110.

2.Wallmann D, Degeratu FT, Fuhrer J. Ventricular capture management – reliability in the clinical practice. Europace 2001; 2(Suppl B): 129.

3.Sperzel J, Hugl B, Michaelsen J et al. The European Kappa registry: Automatic ventricular capture management. Europace 2002; 3(Suppl A): 53.

4.Cohen MI, Buck K, Tanel RE et al. Capture management efficacy in children and young adults with endocardial and unipolar epicardial systems. Europace 2004; 6: 248-255.

5.Sperzel J, Milasinovic G, Smith TW et al. Automatic measurement of atrial pacing thresholds in dual-chamber pacemakers: Clinical experience with atrial capture management. Heart Rhythm 2005; 2: 1203-1210.

6.Guyomar Y, Graux P, Heuls S et al. Evaluation, during exercise, of atrial auto adjusting sensitivity algorithm. Eurpace 2001; 2(Suppl A): 59.

7.Untereker DF, Shepard RB, Schmidt CL et al. Power systems for implantable pacemakers, cardioverters, and defibrillators. In: Ellenbogen KA, Kay GN, Wilkoff BL. Clinical cardiac pacing and defibrillation. 2nd ed. Philadelphia: WB Saunders Company 2000:167-193.

8.Levine PA, Love CJ. Pacemaker diagnostics and evaluation of pacing system malfunction. In: Ellenbogen KA, Kay GN, Wilkoff BL. Clinical cardiac pacing and defibrillation. 2nd ed. Philadelphia: WB Saunders Company 2000: 827-875.

9.Gelvan D, Crystal E, Dokumaci B et al. Effect of modern pacing algorithms on generator longevity: A predictive analysis. PACE 2003; 26: 1796-1802.

10.Castro A, Liebold A, Vincente J et al. Evaluation of autosensing as an automatic means of maintaining a 2:1 sensing safety margin in an implanted pacemaker. PACE 1996; 19: 1708-1713.

11.Boute W, Albers BA, Giele V. Avoiding atrial undersensing by assessment of P wave amplitude histogram data. PACE 1994; 17: 1878-1882.

12.Kolb C, Halbfass P, Zrenner B, Schmitt C. Paradoxical atrial undersensing due to inappropriate atrial noise reversion of atrial fibrillation in dual-chamber pacemakers. J Cardiovasc Electrophysiol 2005; 16: 696-700.

13.Leung SK, Lau CP, Lam CTF et al. Programmed atrial sensitivity: A critical determinant in atrial fibrillation detection and optimal automatic mode switching. PACE 1998; 21: 2214-2219.

14.Sweeney MO, Hellkamp AS, Ellenbogen KA et al. Adverse Effect of Ventricular Pacing on Heart Failure and Atrial Fibrillation Among Patients With Normal Baseline QRS Duration in a Clinical Trial of Pacemaker Therapy for Sinus Node Dysfunction. Circulation 2003; 107: 2932-2937

15.Wilkoff BL, Cook JR, Epstein AE et al. Dual-chamber pacing or ventricular backup pacing in patients with an implantable defibrillator: the Dual Chamber and VVI Implantable Defibrillator (DAVID) Trial. JAMA 2002; 288: 3115-3123.

16.Sharma AD, Rizo-Patron C, Hallstrom AP et al. Percent right ventricular pacing predicts outcomes in the DAVID trial. Heart Rhythm 2005; 2: 830-834.