Israel Medical Association Journal

Inappropriate implantable cardiac defibrillator (ICD) shock due to electromagnetic interference (EMI) induced by electrocautery is a well-known theoretical association but is rarely reported [1]. We report a case of EMI induced by electrocautery causing inappropriate ICD shock, underlining that, with the use of monopolar cautery, not only the location of the surgery but also electrodispersive pad (EDP) placement may be important to avoid EMI.

Inappropriate shocks are a serious and still unresolved problem associated with implantable cardioverter defibrillators (ICDs) that have been associated with increased mortality and impairment of quality of life [1] despite advances in device safety. We report a case of electromagnetic interference (EMI) while showering that resulted in an inappropriate ICD discharge.

Background: Gender-related differences (GRD) exist in the outcome of patients with cardiac resynchronization therapy (CRT).

Objectives: To assess GRD in patients who underwent CRT.

Methods: A retrospective cohort of 178 patients who were implanted with a CRT in a tertiary center 2005–2009 was analyzed. Primary outcome was 1 year mortality. Secondary endpoints were readmission and complication rates.

Results: No statistically significant difference was found in 1 year mortality rates (14.6% males vs. 11.8% females, P = 0.7) or in readmission rate (50.7% vs. 41.2%, P = 0.3). The complication rate was only numerically higher in women (14.7% vs. 5.6%, P = 0.09). Men more often had CRT-defibrillator (CRT-D) implants (63.2% vs. 35.3%, P = 0.003) and had a higher rate of ischemic cardiomyopathy (79.2% vs. 38.2%, P < 0.001). There was a trend to higher incidence of ventricular fibrillation/ventricular tachycardia in men before CRT implantation (29.9% vs. 14.7%, P = 0.07%). A higher proportion of men upgraded from implantable cardioverter defibrillator (ICD) to CRT-D, 20.8% vs. 8.8%, P = 0.047. On multivariate model, chronic renal failure was an independent predictor of 1 year mortality (hazard ratio [HR] 3.6; 95% confidence interval [95%CI] 1.4–9.5), CRT-D had a protective effect compared to CRT-pacemaker (HR 0.3, 95%CI 0.12–0.81).

Conclusions: No GRD was found in 1 year mortality or readmission rates in patients treated with CRT. There was a trend toward a higher complication rate in females. Men were implanted more often with CRT-D and more frequently underwent upgrading of ICD to CRT-D.

Background: Syncope prognosis varies widely: 1 year mortality may range from 0% in the case of vasovagal events up to 30% in the presence of heart disease. 

Objectives: To assess the outcomes and prognosis of patients with implantable cardiac defibrillator (ICD) and indication of primary prevention and compare patients presenting with or without prior syncope.

Methods: We reviewed the charts of 75 patients who underwent ICD implantation with the indication of primary prevention and history of syncope and compared them to a control group of 80 patients without prior syncope. We assessed the number of ventricular tachycardia (VT), ventricular fibrillation (VF), shock, anti-tachycardia pacing (ATP), and death in each group during the follow-up.

Results: Mean follow-up was 893 days (810–976, 95% confidence interval) (no difference between groups). Patients with prior syncope had a higher ejection fraction (EF) (35.5 ± 12.6 vs. 31.4 ± 8.76, P = 0.02), more episodes of VT (21.3% vs. 3.8%, P = 0.001) and VF (8% vs. 0%, P = 0.01) and also received more electric shocks (18.7% vs. 3.8%, P = 0.004) and ATP (17.3% vs. 6.2%, P = 0.031). There were no differences in inappropriate shocks (6.7% vs. 5%, P = 0.74), in cardiovascular mortality (cumulative 5 year estimate 29.9% vs. 32.2% P = 0.97) and any death (cumulative 5 year estimate 38.1% vs. 48.9% P = 0.18) during the follow-up.

Conclusions: Syncopal patients before ICD implantation seem to have more episodes of VT/VF and shock or ATP. No mortality differences were observed

 

Background: Syncope is a common clinical condition spanning from benign to life-threatening diseases. There is sparse information on the outcomes of syncopal patients who received an implantable cardiac defibrillator (ICD) for primary prevention of sudden cardiac death (SCD). 

Objectives: To assess the outcomes and prognosis of patients who underwent implantable cardiac defibrillator (ICD) implantation for primary prevention of SCD and compare them to patients who presented with or without prior syncope.

Methods: We compared the medical records of 75 patients who underwent ICD implantation for primary prevention of SCD and history of syncope to those of a similar group of 80 patients without prior syncope. We assessed the episodes of ventricular tachycardia (VT), ventricular fibrillation (VF), shock, anti-tachycardia pacing (ATP) and mortality in each group during follow-up.

Results: Mean follow-up was 893 days (810–976, 95%CI) (no difference between groups). There was no significant difference in gender or age. Patients with prior syncope had a higher ejection fraction rate (35.5 ± 12.6 vs. 31.4 ± 8.76, P = 0.02), experienced more episodes of VT (21.3% vs. 3.8%, P = 0.001) and VF (8% vs. 0%, P = 0.01), and received more electric shocks (18.7% vs. 3.8%, P = 0.004) and ATP (17.3% vs. 6.2%, P = 0.031). There were no differences in inappropriate shocks (6.7% vs. 5%, P = 0.74), cardiovascular mortality (cumulative 5 year estimate 29.9% vs. 32.2%, P = 0.97) and any death (cumulative 5 year estimate 38.1% vs. 48.9%, P = 0.18).

Conclusions: Patients presenting with syncope before ICD implantation seemed to have more episodes of VT/VF and shock or ATP. No differences in mortality were observed

 

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