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Aims To allow timely initiation of anticoagulation therapy for the prevention of stroke, the European guidelines on atrial fibrillation (AF) recommend remote monitoring (RM) of device-detected atrial high-rate episodes (AHREs) and progression of arrhythmia duration along pre-specified strata (6 min… Methods and results In 1841 DX ICD patients with daily automatic RM transmissions, electrograms of first device-detected AHREs per patient in each duration stratum were adjudicated, and the corresponding positive predictive values (PPVs) for the detections to be true atrial arrhythmia were calculated. Moreover, the incidence and progression of new-onset AF was assessed in 1451 patients with no AF history. A total of 610 AHREs ≥6 min were adjudicated. The PPV was 95.1% (271 of 285) for episodes 6min… Conclusion A 99.7% detection accuracy for AHRE ≥1 h in patients with DX ICD systems in combination with daily RM allows a reliable guideline-recommended screening for subclinical AF and monitoring of AF-duration progression.

Purpose The Biotronik LinoxSmart DX implanted cardioverter defibrillator (ICD) lead is a novel VDD lead with the advantage of integrated atrial sensing dipole combined with a special augmentation and filtering mechanisms. We sought to determine the efficacy of the Biotronik LinoxSmart DX ICD lead. Methods Non-randomized consecutive patients implanted with Biotronik LinoxSmart DX lead at Sheba Medical Center were included in this study. Electrical parameters and arrhythmic events were recorded during follow up of one year. Results Seventy-three patients (69 males (94.5%), mean age 61 ± 12 years) were included. All patients were successfully implanted with a Biotronic VR-T DX device and LinoxSmart DX ICD lead (DX-17 in 37% and DX-15 in 63% patients). Mean P wave amplitude at time of implantation was 3.66 ± 2.9 mV and improved significantly throughout the follow-up (5.29 ± 4.39 mV, p = 0.009). Appropriate atrial sensing (defined as P wave amplitude of ≥0.8 mV) rate of 100% at implantation significantly decreased to 89% (p = 0.015) at 12 months. Three out of 67 (4.5%) patients without a known history of atrial fibrillation had documented new onset paroxysmal atrial fibrillation. Appropriate shocks occurred in 4 (5.5%) patients. One patient with atrial sensing less than 0.4 mV had inappropriate shock. Conclusions Among patients implanted with the Biotronik LinoxSmart DX ICD lead in our single center, appropriate atrial sensing rate decreased over 12 months. Larger studies are needed to evaluate the reliability of long term appropriate atrial sensing.

Background An early failure of Biotronik Linox implantable cardioverter defibrillator (ICD) leads has been reported from several centers. Aim To compare the performance of Linox ICD leads with different other ICD leads as a report of the Sheba Medical Center experience. Methods All patients who had implantation of Linox ICD leads between 2007 and 2016 were included in this study. ICD lead failure was defined as low- or high-voltage impedance; failure to capture, sense, or defibrillate; or the presence of nonphysiological signals not due to external interference. The survival probability of Linox leads was determined and compared to Medtronic Sprint Quattro ICD leads. Results A total of 340 patients (age 64.4 ± 1.8 years) were included in this analysis. They were followed up to 105 months (mean 45.7 ± 7, median 44 (Interquartile range (IQR) 26-63) months). Twelve patients (3.5%) met the criteria for lead failure within 61.2 ± 22.9 months (median 66.5 [IQR 48-85 months]) post implantation. Noise with inappropriate ventricular arrhythmias detection, with or without therapy, was seen in 10 patients (83%). High pacing thresholds and high impedances were detected in two patients (17%). The survival probability of Linox leads at 60 months (97.3%) was similar to the survival probability of Sprint Quattro leads (98.2%) (P = .58). Nevertheless, the survival probability at 105 months was much lower (81% vs 97%, Linox ICD lead and Sprint Quattro lead, respectively, P = .0039). Conclusion Linox ICD leads have higher late failure rates compared to Sprint Quattro leads. These findings need to be confirmed in larger scale studies.

Infections after placement of cardiac implantable electronic devices (CIEDs) are associated with substantial morbidity and mortality. There is limited evidence on prophylactic strategies, other than the use of preoperative antibiotics, to prevent such infections.We conducted a randomized, controlled clinical trial to assess the safety and efficacy of an absorbable, antibiotic-eluting envelope in reducing the incidence of infection associated with CIED implantations. Patients who were undergoing a CIED pocket revision, generator replacement, or system upgrade or an initial implantation of a cardiac resynchronization therapy defibrillator were randomly assigned, in a 1:1 ratio, to receive the envelope or not. Standard-of-care strategies to prevent infection were used in all patients. The primary end point was infection resulting in system extraction or revision, long-term antibiotic therapy with infection recurrence, or death, within 12 months after the CIED implantation procedure. The secondary end point for safety was procedure-related or system-related complications within 12 months.A total of 6983 patients underwent randomization: 3495 to the envelope group and 3488 to the control group. The primary end point occurred in 25 patients in the envelope group and 42 patients in the control group (12-month Kaplan-Meier estimated event rate, 0.7% and 1.2%, respectively; hazard ratio, 0.60; 95% confidence interval [CI], 0.36 to 0.98; P = 0.04). The safety end point occurred in 201 patients in the envelope group and 236 patients in the control group (12-month Kaplan-Meier estimated event rate, 6.0% and 6.9%, respectively; hazard ratio, 0.87; 95% CI, 0.72 to 1.06; P0.001 for noninferiority). The mean (±SD) duration of follow-up was 20.7±8.5 months. Major CIED-related infections through the entire follow-up period occurred in 32 patients in the envelope group and 51 patients in the control group (hazard ratio, 0.63; 95% CI, 0.40 to 0.98).Adjunctive use of an antibacterial envelope resulted in a significantly lower incidence of major CIED infections than standard-of-care infection-prevention strategies alone, without a higher incidence of complications. (Funded by Medtronic; WRAP-IT ClinicalTrials.gov number, NCT02277990.).

CRT Response in Patients with Renal Dysfunction Introduction Renal dysfunction is associated with increased morbi-mortality in heart failure patients. Data regarding functional and clinical efficacy of cardiac resynchronization therapy (CRT) in this population are limited. Methods and Results We aimed to evaluate the rate of functional response to CRT in patients with renal dysfunction and its association with long-term mortality. Our study included a total of 179 consecutive patients implanted between 2007 and 2010. The rate of functional response to CRT (defined by a composite score using New York Heart Association functional class, 6-minute walk test, and quality of life) was compared between patients with and without renal dysfunction (defined as eGFR < or ≥60 mL/min/1.73 m2). Survival analysis estimates were constructed according to the Kaplan–Meier method, with results comparison using the log-rank test. During a median follow-up of 4.2 years, 73 patients (40%) died. Patients with low eGFR were older (72 ± 8 years vs. 64 ± 12 years; P < 0.001), and had higher prevalence of ischemic heart disease (75% vs. 53%; P = 0.003). Functional response rates did not differ significantly between patients with and without renal dysfunction (58% and 69%, respectively; P = 0.14). Despite overall higher mortality in patients with low eGFR (53.8% vs. 22.7%; P < 0.001), the presence of functional response at 1 year among patients with renal dysfunction was still independently associated with an improved long-term survival (HR = 0.49 [95%CI: 0.28–0.83]; P = 0.009). Conclusion Functional response to CRT at 1 year does not differ significantly between patients with or without kidney disease, and is an independent predictor of improved long-term survival in patients with renal dysfunction.

Introduction:Rate smoothing algorithms, while known to help prevent ventricular tachyarrhythmias in some patients, have been shown to result in underdetection of ventricular tachycardia (VT) due to interaction between bradycardia pacing and tachycardia detection parameters. A new algorithm named Bradycardia Tachycardia Response (BTR) has been developed in order to prevent rate smoothing-induced underdetection. The efficacy of BTR is not known. The aim of this study was to assess the effectiveness of BTR in preventing VT underdetection due to rate smoothing. Methods and Results:Two ICD models (TELIGEN and VITALITY AVT, Boston Scientific, St. Paul, MN, USA) bearing identical rate smoothing algorithms were connected to a VT simulator. Devices were programmed similarly except for the BTR feature that exists in TELIGEN only. The detection performance of both devices was tested using varying combinations of AV delay, rate smoothing down, and upper rate limit and compared between the two models. VT underdetection (delay or nondetection) occurred during pacing in 62% of the VT episodes with VITALITY AVT. In TELIGEN, all simulated VT episodes were detected appropriately as soon as their rates exceeded the programmed VT detection rate. Detection tended to be affected by higher upper rate, longer AV delays, and more aggressive rate smoothing. Conclusion:The BTR algorithm effectively counteracts VT detection delay caused by the interaction of rate smoothing with VT detection parameters, thus enabling safe use of the rate smoothing feature. (PACE 2012; 1–6)

Aims KCNE1 encodes an auxiliary subunit of cardiac potassium channels. Loss-of-function variations in this gene have been associated with the LQT5 form of the long QT syndrome (LQTS), secondary to reduction of I Ks current. We present a case in which a D85N rare polymorphism in KCNE1 is associated with an LQT2 phenotype. Methods and results An 11-year old competitive athlete presented with mild bradycardia and a QTc interval of 470 ms. An LQT2 phenotype, consisting of low-voltage bifid T waves, was evident in the right precordial electrocardiogram leads. During the tachycardia phase following adenosine, QTc increased to 620 ms. Genetic analysis revealed a rare heterozygous polymorphism in KCNE1 predicting the substitution of asparagine for aspartic acid at position 85 of minK (D85N). Patch clamp experiments showed that KCNE1- D85N, when co-expressed with KCNH2 in TSA201 cells, significantly reduced I Kr. Homozygous co-expression of the mutant with KCNH2 reduced I Kr tail current by 85%, whereas heterozygous co-expression reduced the current by 52%, demonstrating for the first time a dominant-negative effect of D85N to reduce I Kr. Co-expression of the mutant with KCNQ1, either homozygously or heterozygously, produced no change in I Ks. Conclusions Our results suggest that a rare polymorphism KCNE1- D85N underlies the development of an LQT2 phenotype in this young athlete by interacting with KCNH2 to cause a dominant-negative effect to reduce I Kr. Our data provide further evidence in support of the promiscuity of potassium channel β subunits in modulating the function of multiple potassium channels leading to a diversity of clinical phenotypes.

Background:Vasovagal syncope is one of the most common medical conditions in young adults. Previous trials have shown effectiveness of tilt training in treating this condition. We conducted a prospective, randomized study in order to evaluate the role of tilt-training in young adults with vasovagal syncope. Methods:Forty-six soldiers (mean age 19.4 ± 0.8 years, 25 males), with a clinical diagnosis of vasovagal syncope supported by positive tilt test, were randomized to either three months of daily tilt training (treatment group), or no training (control group). Patients in both groups were instructed to increase fluid and salt intake, and to refrain from syncope-inducing situations, such as prolonged standing. Results:Compliance, defined as performing 50% or more of the tilt training daily sessions, was 91% during the first month, and declined to 58% during three months. Treatment group patients had a median (interquartile range) of 5.0 (0.5–16.0) syncope episodes during one-year follow up, compared to a median of 2.0 (0–6.0) episodes in the control group (P = 0.737). Also, there was no difference in time to first syncope after randomization between groups: a median of 1.0 (0.5–2.0) month in the treatment group, compared to 0.8 (0.5–2.0) month in the control group (P = 0.336). Conclusions:Adding daily three-month tilt training to modifications in lifestyle does not improve treatment results in young adults with vasovagal syncope. Good compliance is difficult to achieve in a tilt training program.

Aims: To compare the clinical response of patients with right ventricular apical pacing (RVAP) upgraded to cardiac resynchronization therapy (CRT) to that of previously nonpaced heart failure (HF) patients who had de novo CRT implantation. Background: The role of CRT in patients with wide QRS and HF due to RVAP is less well established than in other CRT candidates. Methods: Ninety-eight consecutive patients with CRT were studied (mean age 70, mean ejection fraction 0.23). Group A: patients having RVAP prior to CRT implantation (n = 25), group B: patients without prior RVAP (n = 73). Clinical and echocardiographic parameters were recorded prior to, and 3 months after, CRT implantation. Results: Group A patients had a wider QRS at baseline compared to group B (203 ± 32 ms vs 163 ± 30 ms respectively, P < 0.001), and a shorter 6-minute walking distance (222 ± 118 m vs 362 ± 119 m, respectively, P < 0.005). Otherwise, clinical and echocardiographic parameters were not different. At follow up, group A patients had an average 0.7 ± 0.5 decrease in their NYHA functional class, compared to 0.3 ± 0.7 in group B patients (P < 0.05). Six-minute walking distance increased by 93 ± 113 m in group A, versus 36 ± 120 m in group B (P = 0.22). There was no difference in echocardiographic response to CRT between the groups. Conclusions: HF patients with prior RVAP demonstrate clinical improvement after upgrading to CRT that is comparable, and in some aspects, even better than that observed in HF patients with native conduction delay who undergo de novo CRT implantation.

Aims This study assesses short- and long-term performance of the S80TB ventricular lead manufactured by Sorin Biomedica, Italy. Methods and results Three hundred and thirty leads were implanted and had complete follow-up with us for a minimum of 60 months or up to failure, removal, and/or patient death (mean 40 months, range: 1 day to 81 months). Thirty-two patients (9.6%) had spontaneous lead-related complications: 7 (2.1%) occurred during the first week; 25 (7.6%) had chronic complications, of which 20 (6.1%) necessitated re-operations; 3 (0.9%) were lead material failures. Of the 110 re-operations (90 pacemaker replacements and 20 operations due to complications), 7 additional cases (6.4%) were complicated by unique connector damage that occurred during disconnection of the lead from the connector block. The Kaplan–Meier estimated 5-year lead survival free of lead material failure and free of any significant lead complication were 97.9 and 87%, respectively. Conclusion The S80TB lead demonstrates an acceptable rate of acute and chronic spontaneous complications and very few lead material failures over 5 years of follow-up. However, there seems to be a relatively high incidence of connector damage during disconnection from the connector block. Extra caution is required during those procedures in patients with this lead.

Objective: In this prospective, randomized, control study we compared performance of J-shaped (JL) and straight atrial leads (SL) with active (screw-in) fixation mechanism, over a 5-year follow-up period. Subjects and Methods: A total of 208 consecutive patients were randomized for implantation with a Medtronic 4568 JL model (n = 103) versus a Medtronic 4068 SL model (n = 105), and all lead-related measurements and complications were recorded. Results: Lead-related complications occurred in JL and SL with similar frequency (6% and 9%, respectively, P = 0.45). Lead dislodgment occurred in 8 (7.8%) cases in SL versus none in JL (P = 0.004). Lead malfunction and excessive pacing thresholds without macrodislodgment occurred more frequently in JL (11; 10.7%) than in SL (4; 3.8%), P = 0.055. Lead material failure (insulation break) occurred only once in SL at the 5-year checkup. Most complications occurred during the first year after implantation. Other events occurred in both leads with similar frequency and included: death in 39 and 35, loss of follow-up in 8 and 6, and development of atrial fibrillation in 9 and 15 patients, respectively. Of those who completed follow-up, lead impedance and pacing threshold increased significantly in both groups. P wave decreased in SL but not in JL. Conclusion: More dislocations occurred in SL, but were counterbalanced by more lead malfunctions and excessive pacing thresholds in the JL group. Both leads demonstrated minor deterioration in electrical measurements during follow-up, with only 1 case of lead material failure in SL. Overall, both groups demonstrated favorable lead performance throughout follow-up.

This report describes the experience of a large pacemaker center during three successive replacement operations due to safety alerts involving three models from the same manufacturer. Between March 1993 and May 1999, 210 patients were implanted with three DDD pacemaker models (Sorin Biomedica, Saluggia, Italy) that were subsequently subject to safety alerts. Pacemaker records were reviewed for complications related to device malfunction, and those secondary to the replacement procedure. Pacemaker malfunction was observed in 16.4% of units despite much lower estimates from the company (range 1-4%). With the exception of one, all units were replaced. Malfunctions were discovered in 7 of 20 pacemakers following an urgent call for follow-up issued as a result of the alert. Twenty units implanted as substitutes for those replaced following the first alert turned out to be subject to the third alert. Significant clinical consequences of malfunction occurred in 5.3% of patients including a near fatal event in one case, while complications related to the replacement procedure occurred in 8.3% of patients, including one fatality. On the issuance of a safety alert, failure rates in a particular center may be higher than published by the manufacturer, and should prompt action by the center to weigh local incidence of device failure against complications of replacement procedures. When device failure mechanism is not entirely clear, particularly in cases of successive model failures, replacement devices from a different manufacturer should be considered.

The aim of the study was to evaluate our experience with Physiocor 400T, a dual chamber unipolar pacemaker manufactured by Sorin Biomedica. Between March 1993 and December 1994, 63 units of that model were implanted at our center. Patients were followed for 46 +/- 16 months. By the end of follow-up, 15 patients had died, 1 patient was lost to follow-up, and two units had been replaced for unrelated reasons. During follow-up the following phenomena had been observed: (1) Spontaneous backup reversion (VOO, 80 ppm) in 6 (9.5%) of 63 patients. In three patients this phenomenon was accompanied by concomitant ineffective pacing artifacts at 130 beats/min with very low pulse widths. (2) Unexpected battery depletion (EOL) occurred in 3 (5%) of 63 patients; two of the three occurred within weeks of routine evaluation that confirmed normal battery status. (3) Early elective replacement time (ERT) unpreceded by a gradual drop in magnet rate in 2 (3.2%) of 63 patients. (4) Total loss of telemetry without change in pacing mode in 1 (1.6%) of 63 patients. The estimated event-free 5-year survival of this model was 46%. In conclusion, 12 (19%) of 63 patients had adverse events with Physiocor 400T pacemakers. The potential risk of asynchronous pacing for prolonged periods and the risk of unexpected EOL warrants consideration of elective replacement of all remaining units.

Rate smoothing algorithms, while known to help prevent ventricular tachyarrhythmias in some patients, have been shown to result in underdetection of ventricular tachycardia (VT) due to interaction between bradycardia pacing and tachycardia detection parameters. A new algorithm named Bradycardia Tachycardia Response (BTR) has been developed in order to prevent rate smoothing-induced underdetection. The efficacy of BTR is not known. The aim of this study was to assess the effectiveness of BTR in preventing VT underdetection due to rate smoothing.Two ICD models (TELIGEN and VITALITY AVT, Boston Scientific, St. Paul, MN, USA) bearing identical rate smoothing algorithms were connected to a VT simulator. Devices were programmed similarly except for the BTR feature that exists in TELIGEN only. The detection performance of both devices was tested using varying combinations of AV delay, rate smoothing down, and upper rate limit and compared between the two models. VT underdetection (delay or nondetection) occurred during pacing in 62% of the VT episodes with VITALITY AVT. In TELIGEN, all simulated VT episodes were detected appropriately as soon as their rates exceeded the programmed VT detection rate. Detection tended to be affected by higher upper rate, longer AV delays, and more aggressive rate smoothing.The BTR algorithm effectively counteracts VT detection delay caused by the interaction of rate smoothing with VT detection parameters, thus enabling safe use of the rate smoothing feature.

Aims Anodal stimulation (ANS) is a recognized phenomenon among patients with cardiac resynchronization therapy (CRT); this is noted during left ventricular (LV) pacing by the LV tip to right ventricular (RV) ring configuration. Its incidence varies according to the implanted hardware. We aim at evaluating the incidence of ANS and its acute haemodynamic effects among CRT patients. Methods and results We screened all our patients who previously had an implanted CRT-P/D devices for ANS. After excluding all non-eligible devices, the initial screening was done by evaluating the programmer electrocardiogram (ECG) during device interrogation while pacing LV only from LV tip to RV ring. Those with ANS underwent screening by 12-lead ECG during biventricular pacing with VV interval programmed to 0. Patients with electrocardiographic evidence of ANS underwent detailed echocardiography. We screened 224 patients, 187 patients were excluded due to various causes. Thirty-seven subjects were analysed for this study. Anodal stimulation was found in 29 patients (78.4%) by primary screening. Twelve patients (41.4%) showed electrocardiographic evidence of ANS by 12-lead ECG. The ANS threshold was significantly higher than true bipolar LV threshold (4.5 ± 1.7 vs. 1.1 ± 0.3 V, respectively, P = < 0.0001). Ten patients, with ECG evidence of ANS, underwent detailed echocardiography during biventricular pacing with and without ANS. Overall, there were no significant differences in the haemodynamic, echocardiographic, or resynchronization effects with and without ANS, two patients showed significant reduction in LV function with ANS. Conclusion Anodal stimulation is a common phenomenon among CRT patients. In many cases ANS is seen with LV pacing only, while these changes may not be seen by ECG during biventricular pacing. Echocardiography did not show any significant acute haemodynamic benefit during ANS, and some patients may even deteriorate.

Vasovagal syncope is one of the most common medical conditions in young adults. Previous trials have shown effectiveness of tilt training in treating this condition. We conducted a prospective, randomized study in order to evaluate the role of tilt-training in young adults with vasovagal syncope.Forty-six soldiers (mean age 19.4 +/- 0.8 years, 25 males), with a clinical diagnosis of vasovagal syncope supported by positive tilt test, were randomized to either three months of daily tilt training (treatment group), or no training (control group). Patients in both groups were instructed to increase fluid and salt intake, and to refrain from syncope-inducing situations, such as prolonged standing.Compliance, defined as performing 50% or more of the tilt training daily sessions, was 91% during the first month, and declined to 58% during three months. Treatment group patients had a median (interquartile range) of 5.0 (0.5-16.0) syncope episodes during one-year follow up, compared to a median of 2.0 (0-6.0) episodes in the control group (P = 0.737). Also, there was no difference in time to first syncope after randomization between groups: a median of 1.0 (0.5-2.0) month in the treatment group, compared to 0.8 (0.5-2.0) month in the control group (P = 0.336).Adding daily three-month tilt training to modifications in lifestyle does not improve treatment results in young adults with vasovagal syncope. Good compliance is difficult to achieve in a tilt training program.

Aims To compare different coronary sinus (CS) leads and delivery systems (DSs) for left ventricular pacing. Methods and results Delivery systems-related (including CS dissection and dislocations during sheath/stylet removal) and lead-related (including failure to accomplish implantations and long-term malfunctions resulting in abandonment or repositioning/replacing of the lead) complications between systems and leads were compared. We used Medtronic (MDT) attain® DS ( n = 123) with over-the-wire (OTW) (4193, 4194) and stylet-driven (2187) leads, and Guidant (GDT)® DS ( n = 126) with Easytrak OTW leads (4513, 4518, and 4525). Coronory sinus dissection occurred in 6/123 (5%) cases using the MDT DS vs. 7/126 (6%) with GDT DS ( P = NS). Dislocations during sheath/stylet removal occurred in 8/123 cases (6%) with MDT DS, and in 8/126 (6%) with GDT DS ( P = NS). Failure to achieve successful implantation occurred in 6/32 (19%) of the 2187 leads, in 11/87(13%) of the 4193/4194 leads, in 7/94(7%) of the 4513/4518 leads, and in 4/29 (14%) of the 4525 leads ( P = NS). Long-term lead-related complications occurred in 5/32 (15%) of the 2187 leads, 19/80 (23%) of the 4193/4194 leads, 19/93 (20%) of the 4513/4518 leads, and 2/28 (7%) of the 4525 leads ( P = NS). Conclusion No significant differences in complication rates between systems and leads were observed.

Background: High left ventricular pacing (LVP) thresholds and phrenic nerve stimulation (PNS) are common problems with cardiac resynchronization (CRT). Newer systems capable of multiple LVP configurations may help overcome these problems without the need for reoperation. Methods: CRT systems capable of multiple LVP configurations (Guidant models H155 and H145) were implanted in 43 patients (study group). An additional 49 patients (control group) received CRT systems (Guidant, Medtronic, Biotronik, St. Jude Medical, various models) lacking this feature. Results: Overall, acute high (≥2.5 V/0.5 ms) LVP thresholds were encountered in 13 (30%) of the study group, and 25 (50%) of control group patients (P = 0.03). PNS was encountered in 5 (12%) of the study group and 12 (24%) of control group patients (P = 0.13). All cases of high LVP thresholds and PNS in the study group were managed by switching to a different LVP configuration, while high thresholds remained in control group patients, and PNS was managed by replacing the lead. The CS lead was successfully placed in a lateral branch in 95% of study group, compared to only 77% of control group patients (P = 0.004). Conclusions: Multiple LVP configurations were clinically useful in a significant number of patients undergoing CRT system implantation by helping to overcome high LVP thresholds and PNS, and by providing more flexibility in placing the LV lead.

The appearance of pericarditis following insertion of a permanent pacemaker is not widely acknowledged in the literature.To describe our experience with pericarditis following 395 permanent pacemaker implantations over 2 years.We retrospectively reviewed the medical records of 395 consecutive patients in whom new pacing systems or pacemaker leads had been implanted over a 2 year period. We searched the records for pericarditis that developed within 1 month after pacemaker implantation according to the ICD-9 code. The incidence, clinical picture, response to treatment, and relationship to lead design and location were studied.Eight cases (2%) of pericarditis following implantation were detected. Clinical manifestations in all patients were similar to those of post-pericardiotomy syndrome and included chest pain (n = 7), friction rub (n = 1), fever (n = 2), fatigue (n = 2), pleural effusion (n = 2), new atrial fibrillation (n = 2), elevated erythrocyte sedimentation rate (n = 4), and echcardiographic evidence of pericardial effusion (n = 8). All affected patients had undergone active fixation (screw-in) lead implantation in the atrial position. The incidence of pericarditis with screw-in atrial leads was 3% compared to 0% in other cases (P0.05).Pericarditis is not uncommon following pacemaker implantation with active fixation atrial leads. Special attention should be paid to identifying pericardial complications following pacemaker implantation, especially when anticoagulant therapy is resumed or initiated. The use of passive fixation leads is likely to reduce the incidence of pericarditis but this issue should be further investigated.

The AutoCapture (AC) function of new pacemakers (PM) from St Jude Medical (SJM) was originally recommended for use with low polarization (LP) ventricular leads only.However, recent reports have encouraged the use of the AC function with various leads, including those lacking a special LP design. The objective of this study was to analyze the reliability and safety of the AC algorithm application with different types of pacing leads.The study group comprised 30 consecutive patients with AC PMs connected to three different types of non-LP leads. Ten patients with SJM LP leads served as the control group. The study protocol included a complete AC function test using four different pulse widths (PW). The pacing threshold was independently assessed by a manual/semiautomatic check. Erratic behavior of polarization measurements with increasing PWs was demonstrated in 43% (n = 13) of the study group. Invalid polarization measurements resulted in erroneous algorithm recommendation to apply AC function in 17% (n = 5) of the study patients. Subsequent AC function activation lead to incorrect threshold determination due to missed noncapture in three patients. AC function should be applied with caution with non-LP leads. “Off label” use of these leads may cause erroneous polarization signal measurements which, in some cases, may result in incorrect pacing threshold determination, rendering a potential risk to dependent patients. (PACE 2004; 27:453–459)

This report describes the experience of a large pacemaker center during three successive replacement operations due to safety alerts involving three models from the same manufacturer. Between March 1993 and May 1999, 210 patients were implanted with three DDD pacemaker models (Sorin Biomedica, Saluggia, Italy) that were subsequently subject to safety alerts. Pacemaker records were reviewed for complications related to device malfunction, and those secondary to the replacement procedure. Pacemaker malfunction was observed in 16.4% of units despite much lower estimates from the company (range 1-4%). With the exception of one, all units were replaced. Malfunctions were discovered in 7 of 20 pacemakers following an urgent call for follow-up issued as a result of the alert. Twenty units implanted as substitutes for those replaced following the first alert turned out to be subject to the third alert. Significant clinical consequences of malfunction occurred in 5.3% of patients including a near fatal event in one case, while complications related to the replacement procedure occurred in 8.3% of patients, including one fatality. On the issuance of a safety alert, failure rates in a particular center may be higher than published by the manufacturer, and should prompt action by the center to weigh local incidence of device failure against complications of replacement procedures. When device failure mechanism is not entirely clear, particularly in cases of successive model failures, replacement devices from a different manufacturer should be considered.

LIPCHENCA, I., et al.: Multiple Pulse Generator Malfunctions with a Dual Chamber Pacemaker. The aim of this study was to evaluate the dual chamber uni/bipolar pacemaker Minidual 50, manufactured by Sorin Biomedica. Between 1995 and 1998, 66 Minidual 50 models were implanted at the Heart Institute. During the follow-up period of 33 ± 12.8 months (range 0–50 months), total function loss in seven (10.6%) units and false threshold measurement of sensing and pacing in three (4.5 %) patients were observed. Average time from implantation to malfunction was 37 months (range 28–42). Malfunction was unrelated to battery status and could not be predicted by any measures obtained during the pacemaker follow-up period. Kaplan Meyer survival curve predicted a 70% 4-year malfunction-free survival of that pacemaker model. Given this high rate of total malfunction and the unpredictable nature of its occurrence, the authors recommend the replacement of all remaining Minidual 50 units at risk, at least in dependent patients.

To study the importance of a J shape in atrial pacing leads.We compared in a randomized controlled study acute and chronic results with 2 steroid-eluting, polyurethane, screw-in atrial lead models that differ only in shape. A total of 208 patients were randomized to have implantation of either a straight atrial lead (n = 105) or a J-shaped atrial lead (n = 103). Patients were followed up for 1 year.On implantation, there were no significant differences between leads in rates of failure to implant, implant measurements, number of attempts to achieve an acceptable position, and fluoroscopy times. Before discharge and at 3-month and 1-year follow-up, electrical measurements showed no statistical differences between leads. During the first year after implantation, there were 2.9% early dislodgments (1 week after implantation) and 2.9% late dislodgments in the straight lead group (5.9% rate of all dislodgments) vs no dislodgments in the J-shaped lead group (P = .01). There was a trend toward higher rates of exit block and lead malfunction in the J-shaped lead group. Rates of pericardial complications, subclavian/axillary thrombosis, and chronic atrial fibrillation were the same in both groups.Both leads appear to have an equally favorable performance profile for 1 year of follow-up. The J-shaped lead seems to be more stable and have fewer dislodgments, although it may have a somewhat higher malfunction rate.

Purpose: in a previous randomized controlled study we showed the advantage of J-shaped over straight screw-in leads in the atrium. In the present study we compared J-shaped tined passive fixation (PF) to screw-in active fixation (AF) leads. Methods: two hundred consecutive patients (pts) were randomized to have either a Medtronic 5568 J-shaped screw-in atrial lead (AF group, n=97) or a Medtronic 5592 J-shaped tined lead (PF group, n=103) implanted in the atrium. We documented implant data and electrical measurements at implant, pre-discharge, 3 months and one year; echocardiography and chest X-ray were performed at one day post implantation. All implant and follow-up complications were documented. Results: two hundred pts were included (103 males), aged 75.44-10.4, EF = 53 4- 11, of whom 39 (19.5%) had previously undergone cardiac surgery. In 5 cases (4 with a PF and one with an AF lead, P = 0.39), there was crossover to the alternate lead at implant due to inability to achieve a satisfactory position. Fluoroscopy times were shorter with PF: 2.14-3.6 vs. 3.3 4- 4.5 min (P=0.04). Bipolar electrical measurements are listed in the table. Lead Implant Pre-discharge 3 months One year 5568 (AF) Pwave mVoks 4.2±2.1 3.1±1.5 3.0±1.5 3.0±1.4 Impedance Ohm 434±133 533±126 531±142 529±139 Threshold Voks 0.9±0.3* 0.8±0.4* 1.2±0.7" 1.3±0.9" 5592 (PF) P wave mVoks 4.8±2.2 3.3±1.4 3.3±1.4 3.2±1.4 Impedance Ohm 448±100 476±88 498±84 500±77 Threshold Voks 0.7±0.5* 0.6±0.3* 0.7±0.6* 0.8±0.6* *P