Israel Medical Association Journal

Background: Defibrillation threshold (DFT) testing at the time of implantable cardioverter defibrillator (ICD) insertion is performed routinely. Recently this practice is being reconsidered due to doubts about its ability to improve ICD efficacy and evidence that survival may not be affected by the test.

Objectives: To compare the outcome of ICD recipients who underwent DFT testing and those in whom no testing was performed.

Methods: A total of 213 eligible patients were implanted with an ICD between 2004 and 2009. DFT testing was performed in 80. We compared total mortality, appropriate and inappropriate ICD shocks, and anti-tachycardia pacing (ATP) events between DFT and non-DFT patients during a follow-up of 2 years.

Results: On comparing the DFT and non-DFT groups, we found a 2 year mortality rate of 7.5% versus 8.3%, respectively (P = 0.8). Furthermore, 20.7% of patients in the DFT group and 12.4% in the non-DFT group had at least one episode of ICD shock (P = 0.15). With regard to ICD treatment (ICD shocks or ATP events), 57.7% in the DFT group and 64.2% in the non-DFT group received appropriate treatments (P = 0.78).

Conclusions: No significant differences in the incidence of 2 year mortality or percentage of ICD treatment emerged between the DFT and non-DFT groups.
 

Background: As the lowest natural site on earth (-415 meters), the Dead Sea is unique for its high pressure and oxygen tension in addition to the unparalleled combination of natural resources. Furthermore, its balneotherapeutic resorts have been reported to be beneficial for patients with various chronic diseases.

Objectives: To evaluate the safety, quality of life (QoL), exercise capacity, heart failure, and arrhythmia parameters in patients with systolic congestive heart failure (SCHF) and implantable cardioverter defibrillator (ICD) following descent and stay at the Dead Sea.

Methods: The study group comprised patients with SCHF, New York Heart Association functional class II-III after ICD implantation. The following parameters were tested at sea level one week prior to the descent, during a 4 day stay at the Dead Sea, and one week after return: blood pressure, O₂ saturation, ejection fraction (echocardiography), weight, B-type natriuretic peptide (BNP), arrhythmias, heart rate, heart rate variability (HRV), and QoL assessed by the Minnesota Living with Heart Failure questionnaire.

Results: We evaluated 19 patients, age 65.3 ± 9.6 years, of whom 16 (84%) were males and 18 (95%) had ICD-cardiac resynchronization therapy. The trip to and from and the stay at the Dead Sea were uneventful and well tolerated. The QoL score improved by 11 points, and the 6 minute walk increased by 63 meters (P < 0.001). BNP levels slightly increased with no statistical significance. The HRV decreased (P = 0.018). There were no significant changes in blood pressure, weight, O₂ saturation or ejection fraction.

Conclusions: Descent to, ascent from, and stay at the Dead Sea resort are safe and might be beneficial in some aspects for patients with sCHF and an ICD.
 

Background: The predictive value of electrophysiologic studies depends on the aggressiveness of the programmed ventricular stimulation protocol.

Objectives: To assess if non-inducibility with an "aggressive" protocol of PVS[1] identifies post-infarction patients with low ejection fraction (EF[2] ≤ 30%) who may safely be treated without implantable cardioverter defibrillator.

Methods: We studied 154 patients during a 9 year period. Our aggressive PVS protocol included: a) stimulus current five times the diastolic threshold (≤ 3 mA) and b) repetition of double and triple extrastimulation at the shortest coupling intervals that capture the ventricle.

Results: Sustained ventricular tachyarrhythmias were induced in 116 patients (75.4%) and 112 (97%) of them received an ICD[3] (EPS[4]+/ICD+ group). Of the 38 non-inducible patients, 34 (89.5%) did not receive an ICD (EPS-/ICD- group). In comparison to the EPS+/ICD+ group, EPS-/ICD- group patients were older (69 ± 10 vs. 65 ± 10 years, P < 0.05), had a lower EF (23 ± 5% vs. 25 ± 5%,  P < 0.05) and a higher prevalence of left bundle branch block (45.5% vs. 20.2%, P < 0.005). Follow-up was longer for EPS+/ICD+ patients (40 ± 26 months) than for EPS-/ICD- patients (27 ± 22 months) (P = 0.011). Twelve EPS+/ICD+ patients (10.7%) and 5 EPS-/ICD- patients (14.7%) died during follow-up (P = 0.525). Kaplan-Meier survival curves did not show a significant difference between the two groups (P = 0.18).
Conclusions: The mortality rate in patients without inducible VTAs[5] using an aggressive PVS protocol and who did not undergo subsequent ICD implantation is not different from that of patients with inducible arrhythmias who received an ICD. Using this protocol, as many as one-fourth of primary prevention ICD implants could be spared without compromising patient prognosis