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Aims The number of procedures involving upgrade or revision of cardiac implantable electronic devices (CIEDs) is increasing and the risks of adding additional leads are significant. Central venous occlusion in patients with pre-existing devices is often asymptomatic and optimal management of such patients in need of device revision/upgrade is not clear. We sought to assess our use of laser lead extraction in overcoming venous obstruction. Methods and results Patients in need of device upgrade/revision underwent pre-procedure venography to assess venous patency. In patients with venous occlusion or stenosis severe enough to preclude passage of a hydrophilic guide wire, laser lead extraction with retention of the outer sheath in the vasculature was performed with the aim of maintaining a patent channel through which new leads could be implanted. Data were recorded on a dedicated database and patient outcomes were assessed. Between July 2004 and April 2012, laser lead extractions were performed in 71 patients scheduled for device upgrade/revision who had occluded or functionally obstructed venous anatomy. New leads were successfully implanted across the obstruction in 67 (94%) cases. There were two major complications (infection) and four minor complications with no peri-procedural mortality. Device follow-up was satisfactory in 65 (92%) cases with mean follow-up up to 26 ± 19 months. Conclusion Laser lead extraction is a safe and effective option when managing patients with central venous obstruction in need of CIED revision or upgrade.

Background— There is considerable heterogeneity in the myocardial substrate of patients undergoing cardiac resynchronization therapy (CRT), in particular in the etiology of heart failure and in the location of conduction block within the heart. This may account for variability in response to CRT. New approaches, including endocardial and multisite left ventricular (LV) stimulation, may improve CRT response. We sought to evaluate these approaches using noncontact mapping to understand the underlying mechanisms. Methods and Results— Ten patients (8 men and 2 women; mean [SD] age 63 [12] years; LV ejection fraction 246%; QRS duration 161 [24] ms) fulfilling conventional CRT criteria underwent an electrophysiological study, with assessment of acute hemodynamic response to conventional CRT as well as LV endocardial and multisite pacing. LV activation pattern was assessed using noncontact mapping. LV endocardial pacing gave a superior acute hemodynamic response compared with conventional CRT (26% versus 37% increase in LV dP/dt max , respectively; P P =0.08). The majority (71%) of patients with nonischemic heart failure etiology or functional block responded to conventional CRT, whereas those with myocardial scar or absence of functional block often required endocardial or multisite pacing to achieve CRT response. Conclusions— Endocardial or multisite pacing may be required in certain subsets of patients undergoing CRT. Patients with ischemic cardiomyopathy and those with narrower QRS, in particular, may stand to benefit.

Background: As the population receiving cardiac device therapy ages, the number of extraction procedures performed in octogenarians is increasing. This group has more comorbidities and may be at higher risk of such procedures. Objectives: Document the safety and success of percutaneous lead extraction in octogenarians. Methods: All extraction cases performed between January 2001 and April 2011 entered into a computer database were analyzed for patient characteristics and indications, extraction technique, procedural success, and complications. Success and complications were classified according to the Heart Rhythm Society consensus statement. Outcomes in octogenarians were compared to younger patients undergoing extraction during the same period. Results: Four hundred and six cases were performed: 72 procedures in octogenarians (mean age 84, range 80–95) and 334 in younger adults (mean age 62, range 20–79). Octogenarians had a greater number of comorbidities per case. Infection was the commonest indication for extraction in both groups. One hundred forty-one leads were extracted in octogenarians and 657 in younger patients. Laser assistance was required in 51.4% of octogenarians versus 49.7% of younger patients. Procedural success was achieved in 71/72 (98.6%) octogenarians versus 329/334 (98.5%) younger patients. No procedural mortality occurred in either group. Overall, complications were more frequent in octogenarians with major and minor complications occurring in 2.8 and 8.3% of octogenarians versus 0.6 and 3.0% of younger patients (P = 0.014). Conclusions: Procedural success was equally high in octogenarians and younger patients. Percutaneous lead extraction can be performed effectively and safely in octogenarians and is associated with a higher complication rate but no increased mortality. (PACE 2012;00:1–9)

Background: Cardiac resynchronization therapy (CRT) device and coronary sinus (CS) lead extraction is required due to the occurrence of system infection, malfunction, or upgrade. Published series of CS lead extraction are limited by small sample sizes. We present a 10-year experience of CRT device and CS lead extraction. Methods: All lead extractions between 2000 and 2010 were entered into a computer database. From these, a cohort of 71 cases involving a CRT device or CS lead was analyzed for procedural method, success, and complications. Results: Sixty coronary sinus leads were extracted in 71 cases (median age 71 years; 90% male) by manual traction/locking stylets (n = 54) or using a laser sheath (n = 6). Procedural success was achieved in 98% of CS leads. A total of 143 non-CS leads were extracted, with laser required in 46% of cases. The mean duration of lead implantation was 35.8 months (range 1–116 months) and 2.86 ± 1.07 leads were extracted per case. CRT extraction case load increased significantly over time. Minor complications occurred in four (5.6%) cases and major complications in one (1.4%) case. There were no intraprocedural deaths, but two deaths occurred within 30 days of extraction. Conclusions: Our 10-year experience confirms that percutaneous removal of CS leads can be achieved with high procedural success. Our recorded complication rates are no higher than those of non-CS lead extraction series, and should be taken in the context of the frail nature of CRT patients. Ongoing audit of procedure success and complications will be required to further guide best practice in CS lead extraction. (PACE 2011; 34:1209–1216)

Aims The aim of this study is to investigate the safety and effectiveness of Excimer laser-assisted lead extraction in Europe. The final European multi-centre study experience is presented. Method and results The Excimer is a cool cutting laser (50°C) with a wavelength of 308 nm. The energy is emitted from the tip of a flexible sheath and is absorbed by proteins and lipids, 64% of the energy is absorbed at a tissue depth of 0.06 mm. The sheath is positioned over the lead, and the fibrosis surrounding the lead is vaporized while advancing the sheath without damaging other leads. From August 1996 to March 2001, 383 leads (170 atrial, 213 ventricular) in 292 patients (mean age 61.6 years, range 13–96) were extracted at 14 European centres. Mean implantation time was 74 months (3–358). Most frequent indications were pocket infection (26%), non-functional leads (21%), patient morbidity (21%), septicaemia or endocarditis (14%), erosion (5%), and lead interference (8%). Median extraction time was 15 min (1–300). Complete extraction was achieved in 90.9% of the leads and partial extraction in 3.4%. Extraction failed in 5.7% of the leads. Major complications = perforations caused 10/22 (3.4/5.7%) of the failures. Most partially extracted patients were considered clinically successful, as only minor lead parts without clinical significance were left. Femoral non-laser technique was used to remove 8/12 of the non-complication failures. The total complication rate, including five minor complications (1.7%), was 5.1%. No in-hospital mortality occurred. Conclusion Pacing and implantable cardioverter–defibrillator leads can safely, effectively, and predictably be extracted. Open-heart extractions can be limited to special cases. The results indicate that the traditional policy of abandoning redundant leads, instead of removing them, may be obsolete in many patients.

The purpose of this study was to determine the changes in atrial electrophysiology associated with chronic persistent atrial fibrillation in man.Atrial monophasic action potential duration at 90% repolarization and the effective refractory period were measured in 13 patients with chronic persistent atrial fibrillation after low-energy endocardial cardioversion, and compared to eight controls without a history of atrial fibrillation. Measurements were made at the right atrial appendage and midlateral right atrial wall at basic, 600 ms and 400 ms drive cycle lengths. In control patients, the effective refractory periods were significantly longer at the atrial appendage than the lateral wall at 600 ms (right atrial appendage 265 ms, midlateral right atrial wall 228 ms, P0.05), and 400 ms cycle lengths (right atrial appendage 270 ms, midlateral right atrial wall 218 ms, P0.05), but this was not evident in patients with atrial fibrillation. The monophasic action potentials and effective refractory periods at both atrial sites were shorter in the atrial fibrillation patients compared to controls; however, only the effective refractory periods at atrial appendage at 600 ms (atrial fibrillation 210 ms, controls 265 ms, P0.001), and 400 ms cycle lengths (atrial fibrillation 200 ms, controls 270 ms, P0.001) reached statistical significance. Effective refractory period dispersion was significantly greater in controls than in patients with atrial fibrillation (cycle length 600 ms: controls 36, atrial fibrillation 13, P=0.01; cycle length 400 ms: controls 54, atrial fibrillation 18, P0.01).In patients without a history of atrial fibrillation, the refractory period at the right atrial appendage is significantly longer than at the midlateral right atrial wall. This 'normal' pattern of atrial refractory dispersion is lost in patients with chronic persistent atrial fibrillation, with marked shortening of the effective refractory period at the right atrial appendage. This may explain the high risk of recurrence of atrial fibrillation following successful electrical cardioversion.

Objectives. We sought 1) to compare three pacing modalities—DDDR with mode switching (DM), DDDR with conventional upper rate behavior (DR) and VVIR (VR)—in patients with a history of atrial tachyarrhythmias, and 2) to assess the efficacy of six mode-switching algorithms.Background. A history of atrial tachyarrhythmias has been a relative contraindication to dual-chamber pacing. Several mode-switching algorithms have recently been developed to prevent rapid tracking of atrial tachyarrhythmias.Methods. Forty-eight patients (mean age 64 years, 58% male) with a history of atrial tachyarrhythmias and heart block had a DM pacemaker implanted. Pacemakers were programmed to DM, DR and VR modes for 4 weeks each in a randomized crossover design. All subjects used a patient-activated electrocardiographic (ECG) recorder throughout the study and additionally underwent ambulatory ECG monitoring and a treadmill exercise test in each mode. They completed three symptom questionnaires at the end of each pacing period. At the end of the study, patients chose their preferred pacing period.Results. DM was significantly better than VR mode objectively (exercise time DM 8.1 min, VR 7.0 min, p < 0.01) and subjectively (perceived well-being DM 69, VR 51, p < 0.001; functional class DM 2.2, VR 2.5, p < 0.05; subjective symptom score DM 21.2, VR 26.8, p = 0.01). Patient-perceived well-being was significantly better with DM than with DR mode (DM 69, DR 60, p = 0.02). DM mode was the preferred pacing period (DM 51%, DR 14%, VR 14%). Early termination of pacing because of adverse symptoms was requested by 33% of patients during VR, 19% during DR but only 3% during DM mode. A higher proportion of patients with a fast mode-switching device preferred DM mode (fast 55%, slow 49%), whereas no patients with a fast mode-switching device chose VR as the preferred mode (fast 0%, slow 19%). In the subgroup of patients who had had atrioventricular node ablation, DM was also preferred to VR mode (DM 53%, VR 27%). Overall, there were only two cases of inappropriate mode switching and one case of inappropriate tracking of an atrial tachyarrhythmia.Conclusions. DM is the pacing mode of choice of patients with paroxysmal atrial tachyarrhythmias. With optimal programming, inappropriate mode switching and tracking of atrial tachyarrthmias was very uncommon.

A wrist-applied transtelephonic device (WrTTD) and a precordial (PrTTD) patient-activated transtelephonic electrocardiographic (ECG) recorder were compared objectively (quality of ECG traces) and subjectively (device preference) in a prospective randomized crossover study of 24 patients. All underwent cardioversion for chronic atrial fibrillation and were then randomized to each device for 1 month. The ECG traces were sent weekly with additional traces if symptomatic. Self-administered questionnaires were completed after 1 month with each device, and the first five telemetered ECG traces for each patient were blindly assessed by two experienced cardiologists. Although the QRS complexes were smaller with the WrTTD (P < .001), the quality of the traces was similar. In particular, there was no significant difference in number of nondiagnostic traces, ability to detect atrial activity, degree of baseline fluctuation, or amount of artifact. Overall, patients preferred the PrTTD (P = .02). Patients found the PrTTD easier to use (P = .007) and were able to apply it more rapidly (P = .02). The quality of ECG traces obtained from the upper limbs by using a wrist-applied transtelephonic device was concluded to be comparable with those obtained by direct precordial application. In order to increase patient acceptability of the former, further improvements to simplify its operation are necessary.

Background— Cardiac resynchronization therapy (CRT) using endocardial left ventricular (LV) pacing may be superior to conventional CRT. We studied the acute hemodynamic response to conventional CRT and LV pacing from different endocardial sites using a combined cardiac MRI and LV noncontact mapping (NCM) protocol to gain insights into the underlying mechanisms. Methods and Results— Fifteen patients (age, 63±10 years; 12 men) awaiting CRT were studied in a combined x-ray and MRI laboratory. Delayed-enhancement cardiac magnetic resonance was performed to define areas of myocardial fibrosis. Patients underwent an electrophysiological study incorporating endocardial and epicardial LV pacing. Acute hemodynamic response was measured using a pressure wire within the LV cavity to derive LV dP/dt max. NCM was used to define areas of slow conduction. There was a significant improvement in all LV pacing modes versus baseline ( P P P Conclusions— Endocardial LV pacing appears superior to conventional CRT, although the optimal site varies between subjects and is influenced by pacing within areas of slow conduction. Delayed-enhancement cardiac magnetic resonance was a poor predictor of zones of slow conduction in nonischemic patients.

Background:Extraction of cardiac implantable electric devices is an accepted procedure when systems become infected or malfunction. However, there is an associated morbidity and mortality. We report our 5-year experience and identify predictors of mortality, and long-term follow-up. Methods:We analyzed extraction data from January 2003 to November 2007. Extraction methods used were: locking stylets, telescoping sheaths ± laser, and femoral work stations. Results:One hundred and eighty-three cases were referred, aged 65 ± 16 years (range 28–83); 76% were males. Mean implant time was 75 months (range 4–312 months) and indications were: pocket infection (48%), nonfunctioning lead (22%), erosion through skin (18%), endocarditis/septicemia (11%), bilateral superior vena cava thrombosis (0.5%), and painful lead (0.5%). The number of leads extracted were 369, with complete removal in 90.7% and partial in 7.6%. There were no intraoperative deaths but five (2.7%) died within the same admission as their extraction from overwhelming sepsis. Twelve deaths (6.6%) occurred during an average follow-up of 965 days (range 40–1670). Multivariate logistic regression demonstrated that C-reactive protein preprocedure was predictive of acute in-hospital mortality. Conclusions:Intravascular lead extraction is a safe and efficient method of removing leads. However, there is a subgroup of patients with systemic sepsis with raised inflammatory markers who are at high risk of in-hospital mortality. Long-term follow-up demonstrates mortality which is a marker of the underlying etiology for device implantation, with heart failure patients particularly at risk. (PACE 2010; 33:209–216)

With the advent of increasing number of implants and more complex pacing systems, referrals for explantations are likely to increase. These procedures have their attendant peri-procedural risks. We report a delayed complication of a system explant, which could have been avoided, and suggest changes in clinical practice that may prevent similar cases.

Background: recent short-term observations have shown an improvement in cardiac function and heart failure symptoms from atrio-biventricular pacing. This study was designed to assess the safety and feasibility of an atrio-biventricular transvenous pacing system, and examine the long-term effects of cardiac resynchronization in patients with advanced heart failure and ventricular conduction abnormalities. Methods and results: between August, 1997 and November, 1998, 103 patients received a cardiac resynchronization system (CRS) consisting of a pulse generator interfaced with an atrio-biventricular lead system, including a lead designed for left ventricular (LV) pacing via cardiac veins. Baseline evaluation included 12-lead electrocardiogram, estimation of New York Heart Association (NYHA) functional class, assessment of quality of life (QOL), and distance covered during a 6-min walk (6-MW). Detailed echocardiographic data were also collected in a subset of 46 patients. Measurements were repeated in all surviving patients at 1, 3, 6 and 12 months after implantation of the CRS. A single, self-limiting procedure-related complication occurred. Over a follow-up of 12 months, 21 patients died. The 12-month actuarial survival was 78% (CI 70–87%). Nine surviving patients were withdrawn from the study during long-term follow-up for miscellaneous reasons. At each point of follow-up, a significant shortening of QRS duration was measured. In addition, significant improvements were observed in mean NYHA functional class, 6-MW and QOL score. In the 46 patients with complete echocardiographic data, LV ejection fraction increased from 21.7±6.4% at baseline to 26.1±9.0% at last follow-up (P-0.006), LV end diastolic dimension decreased from 72.7±9.2 to 71.6±9.1 mm (P-0.233), interventricular mechanical delay decreased from 27.5±32.1 to 20.3±25.5 ms (P-0.243), mitral regurgitation apical four-chamber area decreased from 7.66±5.5 to 6.69±5.9 cm2 (P-0.197), and left ventricular filling time increased from 363±127 to 408±111 ms (P-0.002). Conclusions: long-term cardiac resynchronization can be safely and reliably achieved by transvenous atrial synchronized right and left ventricular pacing. These changes were accompanied by clinically relevant improvements in functional status and QOL, as well as a measurable increase in LV performance. The outcome of randomised controlled trials is awaited.

The purpose of this study was to assess the efficacy of overdrive, single-site right atrial appendage pacing to reduce the burden of atrial fibrillation (AF) when compared with a standard lower rate limit of 60 bpm. This was verified by using the pacemaker's Holter. Eighteen subjects with a pre-implant history of paroxysmal AF and implanted DDDR mode-switching pacemakers were recruited. The pacemaker lower rate limit was programmed in random order to 60, 75 or 90 bpm for three 2-month periods and the amount of AF quantified. In addition, the exercise tolerance (ET), general well being (GWB), functional capacity (FC) and specific symptom prevalence (SSP) were assessed. The main finding of the study was that when ranked according to the amount of AF, there was no significant difference in the amount of AF according to the pacing rate. Six patients failed to tolerate pacing at 90 bpm. There were no differences in the ET, GWB, FC and SSP scores. It is concluded that those clinicians that manage patients with paroxysmal

Dual sensor ventricular demand rate responsive (VVIR mode) pacing was compared with single sensor rate responsive pacing to assess whether this new development should be more widely incorporated in modern pacemaker devices. A within patient randomized, double-blind crossover study involving ten patients, mean age 67.4 years (70% male), had Medtronic Legend Plus dual sensor VVIR pacemakers implanted for high grade AV block and chronic or persistent paroxysmal atrial fibrillation. Performance values were compared to 20 healthy control subjects of a similar age and gender. Patients were both subjectively and objectively assessed after 2 weeks of out-of-hospital activity in VVIR mode (minute ventilation sensing), VVIR mode (activity sensing), VVIR mode (dual sensor), and VVI mode (no rate response). All patients were assessed for subjective preference for, and objective improvement in, any pacing modality as assessed by standardized daily activity protocols and graded exercise treadmill testing. Subjective perception of exercise capacity and functional status was significantly lower in VVI mode (P < 0.05) compared to any of the VVIR modes, which did not differ. After completion of the study 70% of patients chose VVIR as their preferred mode, with 30% expressing no preference. Forty percent preferred activity sensor VVIR mode pacing, 30% preferred dual sensor VVIR mode pacing, and 70% found either dual sensor VVIR mode, minute ventilation sensor VVIR mode, or both modalities least acceptable. No patient found activity sensing VVIR mode least acceptable. Graded treadmill testing revealed significantly lower exercise tolerance during VVI mode pacing (P < 0.01) compared to the VVIR modalities, which did not differ. Overall, chronotropic response was best with dual sensor pacing during standardized daily activity protocols and during the standard car journey. The data from this study suggest that there is no marked clinical advantage obtained from the use of dual sensor devices over current activity sensing ventricular demand rate responsive pacemakers, but with the probable added disadvantages of increased size, complexity, cost, and decreased longevity.

Zimarino et al. have based their conclusions on a comparison of events between the TOAT [(1)][1]and GISSOC [(2)][2]studies. This comparison is not justified as neither study was powered to examine clinical end points. Furthermore, the inclusion criteria of the trials differed. For example, only 50%

Aims Cardiac resynchronization therapy is an accepted treatment for heart failure but it may be necessary to explant these systems along with their leads. The evidence base for coronary sinus (CS) lead extractions is limited. We aimed to evaluate the percutaneous removal of these leads and the utility of laser extraction when necessary. Methods and results Of 265 patients referred for lead extraction between January 2004 and June 2008, 32 (12.1%) involved CS leads (30 males, mean age 67 years). Mean implantation time was 26.5 ± 28.7 months (range 1–116 months). Indications for extraction were pocket infection (34.4%), lead malfunction (43.8%), skin erosion (15.6%), and endocarditis (6.2%). Twenty-eight (87.5%) CS leads were removed with manual traction, with laser utilized in four cases (12.5%). No major complications of CS laceration, pericardial effusion, emergency surgery, or death occurred. Conclusion Our experience supports the percutaneous extraction of CS leads as a safe and effective procedure including the utility of laser when necessary.

The anomalous origin of the left main coronary artery from the right sinus of Valsalva and coursing between the aorta and pulmonary trunk to reach the left side of the heart was once considered a minor anomaly. This is now recognised to be a cause of sudden cardiac death and myocardial ischaemia that can be fatal. If symptoms of myocardial ischaemia arise from this anomaly patients usually present before the age of 20 years but often there are no prodromal signs or symptoms and sudden cardiac death is the first presentation of this anatomical variant [ 1,2]. Janata et al. [3] in this issue highlight that the diagnosis is all too often made following failed resuscitation secondary to massive myocardial infarction While fatal cardiac arrest occurs in some young patients with this anomaly, other patients have a normal life span. The anomaly can be classified into four major groups according to the course taken by the left main stem in relation to the aorta and pulmonary trunk on route to the left side of the heart. The left main stem can course either (i) anterior to the pulmonary trunk, (ii) posterior to the aorta, (iii) within the ventricular septum beneath the right ventricular infundibulum or (iv) between the aorta and the pulmonary trunk as in the case described in this issue. In the first group there have been no reports of sudden cardiac death or myocardial

The new SMARTracking (SMT) algorithm was evaluated in seven patients with the Intermedics Relay DDDE pacemakers and a history of atrial tachyarrhythmias. The SMT algorithm uses the sensor calculated rate to define a physiological band whose upper limit is defined by the SMT rate. Pacemakers were programmed to DDDR with SMT (DDDRSM), DDDR with Conditional Ventricular Tracking Limit (DDDRC), DDDR with standard upper rate behavior, and VVIR, for a period of one month each. Patients underwent a CAEP exercise test and 24-hour ECG Holter monitoring in each mode. They also had ambulatory ECG monitoring during daily activities including rest, slow and fast walk, stairs ascent and descent. Three patients were in atrial fibrillation during the daily activities protocol. Their ventricular rates were paced and highly irregular, in both DDDRSM and DDDRC modes. The heart rate was lower in DDDRSM than DDDRC at rest and low levels of exercise but not during more strenuous activity. Two patients in DDDRSM and 3 in DDDRC requested early change of their mode due to unacceptable symptoms. Two patients exhibited Wenckebach behavior at atrial rates below the upper rate limit in both DDDRSM and DDDRC modes. In conclusion, CVTL or SMARTracking are not adequate protection against atrial tachyarrythmias in patients with DDDR pacemakers.