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Background: Today quantitative information about the type of complications and their incidence during long-term pacemaker (PM) follow-up is scarce.Objective: To assess the incidence and determinants of short- and long-term complications after first pacemaker implantation for bradycardia.Methods: A prospective multicenter cohort study (the FOLLOWPACE study) was conducted among 1517 patients receiving a PM between January 2003 and November 2007. The independent association of patient and implantation-procedure characteristics with the incidence of PM complications was analyzed using multivariable Cox regression analysis.Results: A total of 1517 patients in 23 Dutch PM centers were followed for a mean of 5.8 years (SD 1.1), resulting in 8797 patient-years. Within 2 months, 188 (12.4%) patients developed PM complications. Male gender, age at implantation, body mass index, a history of cerebrovascular accident, congestive heart failure, use of anticoagulant drugs, and passive atrial lead fixation were independent predictors for complications within 2 months, yielding a C-index of 0.62 (95% confidence interval 0.57-0.66). Annual hospital implanting volume did not additionally contribute to the prediction of short-term complications. Thereafter, 140 (9.2%) patients experienced complications, mostly lead-related complications (n = 84). Independent predictors for long-term complications were age, body mass index, hypertension, and a dual-chamber device, yielding a C-index of 0.62 (95% confidence interval 0.57-0.67). The occurrence of a short-term PM complication was not predictive of future PM complications.Conclusions: Complication incidence in modern pacing therapy is still substantial. Most complications occur early after PM implantation. Although various patient- and procedure-related characteristics are independent predictors for early and late complications, their ability to identify the patient at high risk is rather poor. This relatively high incidence of PM complications and their poor prediction underscores the usefulness of current guidelines for regular follow-up of patients with PM. [ABSTRACT FROM AUTHOR]

Aims: One-third of dilated cardiomyopathy patients receiving a biventricular pacing-device do not respond to this form of therapy. Therefore, the utility of mechanical dyssynchrony by real-time 3D echocardiography (RT3DE) for predicting systolic response to biventricular pacing, of which maximal rate of pressure rise (dP/dt(max)) served as the gold-standard, was evaluated. Methods and Results: Seventeen consecutive heart failure patients (aged 64 +/- 10 years, 8 male, 6 ischaemic cardiomyopathy, mean QRS duration 136 +/- 32 ms) underwent RT3DE and biventricular pacing. Post-processing software provided data of global left ventricular (LV) function and the systolic dyssynchrony index of 17 LV segments (SDI(17), %) for mechanical dyssynchrony. During biventricular pacing, percentual change in dP/dt(max) compared to the non-pacing mode, DeltadP/dt(max) was measured invasively with conductance catheters. LV ejection fraction was 31 +/- 10%, SDI(17) was 10.2 +/- 4.2% and percentual DeltadP/dt(max) during biventricular pacing was 14.5 +/- 12.4. A significant correlation (r = 0.729, P = 0.001) was found between SDI(17) and percentual DeltadP/dt(max), and between QRS duration and percentual DeltadP/dt(max) (r = 0.721, P = 0.001). Conclusion: The present study suggests that mechanical dyssynchrony measured by RT3DE shows a good correlation with invasively determined acute haemodynamic response to biventricular pacing in patients with symptomatic dilated cardiomyopathy. Future studies are needed to further define the clinical utility of RT3DE in identifying patients who are most likely to respond to cardiac resynchronization therapy. [ABSTRACT FROM AUTHOR]

Dislocation of the transvenous left ventricular lead has been reported in a substantial number of patients selected for cardiac resynchronization therapy. We describe a novel technique using a retained guidewire in patients with repetitive intraoperative dislocation to stabilize the lead in its final position. Pacing and sensing parameters between patients in whom the retained guidewire technique was used (n = 6) were not significantly different as compared to the group of patients (n = 67) without this technique during a 6-month follow-up. No dislocations were observed in the group of patients with the retained guidewire technique and fluoroscopic evaluation did not reveal (minor) dislocation. This technique might be considered for patients with repetitive intraoperative left ventricular lead dislocation. [ABSTRACT FROM AUTHOR]

Transvenous temporary pacing is associated with a substantial dislocation rate reported to range from 10 to 37%. The aim of the study was to assess the safety and utility of a recently introduced 3.5 Fr temporary pacing lead using active fixation in a consecutive series of 36 patients with prolonged (> or = 48 hours) transvenous temporary pacing (validation group). A group of 36 patients with prolonged transvenous pacing managed with a passive-fixation lead just prior to the introduction of the active-fixation lead served as a control group (reference group). Pacing related adverse events included dislocation, inappropriate pacing (i.e., two-fold or greater increase of initial pacing threshold), local infection, and thrombosis. There were no significant differences in patient characteristics or duration of pacing (5.84 +/- 2.4 days in the reference group vs 5.94 +/- 2.6 days in the validation group). Acute pacing threshold was significantly higher in the validation group as compared to the reference group (1.38 +/- 0.67 V vs. 0.7 +/- 0.21 V, P < 0.01). The dislocation rate was significantly lower in the validation group as compared to the reference group (5.5 vs 33.3%, P < 0.001). There were 11 (31%) pacing related adverse events in the validation group versus 21 (58%) in the reference group (P < 0.01). The vast majority of patients in the validation group (75%) had ambulatory temporary pacing. Thus, transvenous temporary pacing using active fixation is safe and is associated with a low dislocation rate and a reduction in pacing related adverse events. [ABSTRACT FROM AUTHOR]

INTRODUCTION Cardiac resynchronization therapy (CRT) can be applied in patients with impaired left ventricular (LV) function and advanced heart failure if a reversible cause of a depressed LV function is excluded. We studied 23 patients with an ischemic cardiomyopathy and heart failure class III-IV NYHA and QRS duration > 120 msec who were rejected for surgical and percutaneous interventions. In 14 patients revascularisation was not amenable for technical reasons, 7 had extensive co-morbidity and 2 refused a (repeated) surgical intervention. All had documented myocardial ischemia on nuclear or echocardiographic stress studies. In all successful implantation was performed and follow-up was 13±1.9 months. RESULTS Nine patients had two-vessel disease and 14 patients had three-vessel disease on coronary angiography. Seven patients had previous myocardial infarction. Mean LV ejection fraction was 23±4 %. During follow-up 4 patients died: 3 patients had sudden death while 1 patient died 2 days after (recurrent) myocardial infarction. In the remaining group functional class improved from 3.2±1.4 to 2.0±1.0, p< 0.01. Quality-of-life assessed by the Minnesota Living with Heart Failure questionnaire improved from 39±15 to 28±13, p< 0.01. The 6-minutes walking test increased from 264±104 to 385±121(m), p<0.01). Despite an improvement in exercise capacity anginal attacks/week remained the same (2.3±0.7 to 2.2±0.6, p=ns). CONCLUSION In patients with advanced heart failure, stable angina and documented myocardial ischemia CRT can be performed safely with good long term follow-up. [ABSTRACT FROM PUBLISHER]

Aims: This study evaluates the relative importance of two components of QRS prolongation, myocardial conduction velocity and travel distance of the electrical wave front (i.e. path length), for the prediction of acute response to cardiac resynchronization therapy (CRT) in left bundle branch block (LBBB) patients., Methods and Results: Thirty-two CRT candidates (ejection fraction <35%, LBBB) underwent cardiac magnetic resonance (CMR) imaging to provide detailed information on left ventricular (LV) dimensions. Left ventricular end-diastolic volume (LVEDV) was used as a primary measure for path length, subsequently QRSd was normalized to LV dimension (i.e. QRSd divided by LVEDV) to adjust for conduction path length. Invasive pressure-volume loop analysis at baseline and during CRT was used to assess acute pump function improvement, expressed as LV stroke work (SW) change. During CRT, SW improved by +38 ± 46% (P < 0.001). The baseline LVEDV was positively related to QRSd (R = 0.36, P = 0.044). Despite this association, a paradoxical inverse relation was found between LVEDV and SW improvement during CRT (R = -0.40; P = 0.025). Baseline unadjusted QRSd was found to be unrelated to SW changes during CRT (R = 0.16; P = 0.383), whereas normalized QRSd (QRSd/LVEDV) yielded a strong correlation with CRT response (R = 0.49; P = 0.005). Other measures of LV dimension, including LV length, LV diameter, and LV end-systolic volume, showed similar relations with normalized QRSd and SW improvement., Conclusion: Since normalized QRSd reflects myocardial conduction properties, these findings suggest that myocardial conduction velocity rather than increased path length mainly determines response to CRT. Normalizing QRSd to LV dimension might provide a relatively simple method to improve patient selection for CRT., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.)

Objectives: This study sought to determine prospectively the rate of conductor externalization (CE), and whether this was associated with electrical failure., Background: The Riata family of defibrillator leads was placed under U.S. Food and Drug Administration advisory as of November 28, 2011 because of high rates of CE., Methods: A nationwide cohort established in 2012 of 1,029 patients with recalled Riata leads with 147 CE were followed until death, lead discontinuation, or 3 annual screenings with fluoroscopy and device interrogation., Results: Follow-up of 882 patients with normal baseline fluoroscopy revealed incident overt CE in 95 leads (11%) after median risk time of 2.9 years, yielding an incidence rate of 4.9 (95% confidence interval [CI]: 3.9 to 5.9) per 100 patient-years. The incidence rate was significantly higher in 8-F Riata leads than in 7-F Riata ST leads (7.0 vs. 3.2 per 100 patient-years; p < 0.001). Electrical follow-up demonstrated electrical abnormality in 77 leads, resulting in an incidence rate of 4.0 (95% CI: 3.2 to 5.0) per 100 patient-years. The incidence rate of electrical abnormalities was not different between leads without CE and those with CE (3.9 vs. 5.2 per 100 patient-years; p = 0.39)., Conclusions: The development of CE is progressive in nature with an incidence rate of new CE of 4.9 per 100 patient-years, with a higher rate for 8-F Riata leads than for 7-F Riata ST leads. Despite the high rate of structural failure, no association between development of CE and electrical failure was observed., (Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Aims: Several implantation strategies have been proposed to improve response to cardiac resynchronization therapy (CRT), including bifocal left ventricular (LV) stimulation and optimal single-LV lead placement. This study aimed to compare these two strategies during invasive pressure-volume (PV) loop measurements., Methods and Results: Thirty-three patients eligible for CRT were included [21 (64%) men, 20 (61%) ischaemic aetiology, QRS 155 ± 23 ms], and underwent cardiac magnetic resonance (CMR) imaging and invasive PV loop measurements. Left ventricular pump function was characterized by stroke work (SW) and dP/dtmax (5.1 ± 3.4 L mmHg and 856 ± 190 mmHg/s, respectively). Haemodynamic response was assessed during stimulation at single-LV sites and during bifocal LV [anterolateral and posterolateral (PL)] stimulation. Response during bifocal LV stimulation was not significantly higher compared with standard PL pacing (SW; β = 9.4 ± 5.4, P = 0.080; dP/dtmax, β = 0.2 ± 1.9, P = 0.922). However, mean pump function improvement was significantly higher during stimulation at the optimal LV site compared with bifocal LV stimulation (SW; β = 12.7 ± 5.1, P = 0.012; dP/dtmax, β = 3.3 ± 1.2, P = 0.020). Myocardial tissue properties were assessed by CMR tissue tagging. Mechanical activation at the optimal LV site was significantly more delayed compared with the worst LV site (431 ± 93 ms vs. 326 ± 127 ms; P = 0.004)., Conclusion: Stimulation at the optimal LV site showed a significantly higher pump function improvement compared with bifocal LV stimulation. Mechanical activation at the optimal LV site was significantly more delayed compared with the non-optimal LV site. In general, these results suggest that implantation of a second LV lead yields no additional benefit over implantation of one optimally placed LV lead. However, a bifocal approach might be beneficial in the individual patient., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.)

Background: Patients with left ventricular (LV) dyssynchrony have a marked misbalance in LV myocardial work distribution, with wasted work in the septum and increased work in the lateral wall. We hypothesized that a low septum-to-lateral wall (SL) myocardial work ratio at baseline predicts acute LV pump function improvement during cardiac resynchronization therapy (CRT)., Methods and Results: Twenty patients (age 65 ± 10 y, 15 men) underwent cardiac magnetic resonance (CMR) tagging for regional LV circumferential strain assessment and invasive pressure-volume loop assessment at baseline and during biventricular pacing. Segmental work at baseline was calculated from regional strain rate and LV pressure. Subsequently, the SL work ratio was calculated and related to acute pump function (stroke work [SW]) improvement during CRT. During biventricular pacing, SW increased by 33% (P <.001). SL work ratio at baseline was found to be significantly related to SW improvement by means of CRT (R = -0.54; P = .015). Moreover, it proved to be the only marker that was significantly related to acute response to CRT, whereas QRS duration and other measures of dyssynchrony or dyscoordination were not., Conclusions: The contribution of the septum to LV work varies widely in CRT candidates with left bundle branch block. The lower the septal contribution to myocardial work at baseline, the higher the acute pump function improvement that can be achieved during CRT., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: The contribution of right ventricular (RV) stimulation to cardiac resynchronisation therapy (CRT) remains controversial. RV stimulation might be associated with adverse haemodynamic effects, dependent on intrinsic right bundle branch conduction, presence of scar, RV function and other factors which may partly explain non-response to CRT. This study investigates to what degree RV stimulation modulates response to biventricular (BiV) stimulation in CRT candidates and which baseline factors, assessed by cardiac magnetic resonance imaging, determine this modulation., Methods and Results: Forty-one patients (24 (59 %) males, 67 ± 10 years, QRS 153 ± 22 ms, 21 (51 %) ischaemic cardiomyopathy, left ventricular (LV) ejection fraction 25 ± 7 %), who successfully underwent temporary stimulation with pacing leads in the RV apex (RVapex) and left ventricular posterolateral (PL) wall were included. Stroke work, assessed by a conductance catheter, was used to assess acute haemodynamic response during baseline conditions and RVapex, PL (LV) and PL+RVapex (BiV) stimulation. Compared with baseline, stroke work improved similarly during LV and BiV stimulation (∆+ 51 ± 42 % and ∆+ 48 ± 47 %, both p < 0.001), but individual response showed substantial differences between LV and BiV stimulation. Multivariate analysis revealed that RV ejection fraction (β = 1.01, p = 0.02) was an independent predictor for stroke work response during LV stimulation, but not for BiV stimulation. Other parameters, including atrioventricular delay and scar presence and localisation, did not predict stroke work response in CRT., Conclusion: The haemodynamic effect of addition of RVapex stimulation to LV stimulation differs widely among patients receiving CRT. Poor RV function is associated with poor response to LV but not BiV stimulation.

Background: Response to cardiac resynchronization therapy (CRT) is hampered by the extent and location of left ventricular (LV) scar tissue. It is commonly advised to avoid scar tissue while placing the LV lead. However, whether individual patients benefit from this strategy remains unclear., Methods: Thirty-two CRT candidates with ischemic cardiomyopathy were enrolled from 2 successive clinical trials (TBS and E-pot study). Magnetic resonance imaging with late contrast enhancement was performed to assess location, degree and transmurality of LV scar tissue. Patients underwent invasive pressure-volume loop measurements to assess acute LV pump function changes during pacing at posterolateral (PL) and anterolateral LV sites., Results: In the study population (26 [81%] men, ejection fraction [EF] 22% ± 8%, QRS 149 ± 20 milliseconds), baseline mean stroke work (SW) and dP/dtmax were 4.4 ± 2.2 L∙mmHg and 849 ± 212 mmHg/s, respectively. The extent of scar tissue was inversely related to the acute increase in SW during pacing (R = -0.53, P = .002). Stimulating PL scar tissue resulted in deterioration of pump function (∆SW -17% ± 17%, P = .018), whereas pacing PL viable tissue led to an increase in pump function (∆SW +62% ± 51%, P < .001). Switching from pacing at the location of scar tissue, irrespective of the scar location, to viable tissue showed a significant increase in SW (-8% ± 20% vs +20 ± 40, P = .004)., Conclusions: The extent of LV scar tissue is inversely related to acute pump function improvement during CRT. Pacing at the location of (transmural) scar tissue at any site of the LV will generally deteriorate LV pump function. Placing the LV lead over viable myocardium significantly improves pump function as compared with pacing at the location of scar tissue in patients with ischemic cardiomyopathy., (Copyright © 2014 Mosby, Inc. All rights reserved.)

Introduction: The purpose of this in vitro study was to evaluate the potential electromagnetic interference of electronic apex locators (EALs) on implantable cardioverter defibrillators (ICDs)., Methods: Four different EALs were tested for their ability to interfere with the correct function of 3 different ICDs. Each ICD was placed in a plastic container with 1.5 L physiological saline, and the EAL unit was placed at a distance of 2.5 cm from the ICD. The file electrode and lip clip were placed directly against the ICD. The EAL was turned on for 30 seconds while continuously showing the "APEX" mark. As a negative control, the ICD was tested without EAL for 30 seconds. An electrosurgical unit served as a positive control. During each test, the ICD output was monitored continuously by real-time telemetry, and after completion of the experiment, intracardiac electrocardiograms were printed. The tests were repeated 3 times for each device. The electrocardiograms were examined for interference on ICD ventricular activity., Results: All EALs tested and the negative control failed to produce electromagnetic interference in each of the ICDs tested. The electrosurgical unit induced interference in the ICDs, which were detected as episodes of ventricular tachycardia and led to the initiation of electrical shocks in all ICDs., Conclusions: The 4 EALs tested did not interfere with the correct functioning of ICDs in vitro., (Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Aims: Invasive assessment of acute haemodynamic response to biventricular pacing has been proposed as a tool to determine individual response and to optimize the effects of CRT. However, the long-term results of this approach have been poorly studied. The present study relates acute haemodynamic effects of CRT to long-term outcome., Methods and Results: Forty-one patients were analysed in the present study. During temporary biventricular pacing before implantation, acute changes in LV pump function were assessed by pressure-volume loop measurements and related to long-term response after CRT. In the study population [30 (71%) men, NYHA class 2.9 ± 0.4, EF 28 ± 7%, QRS 150 ± 25 ms], baseline mean stroke work (SW) and dP/dt(max) were 4.6 ± 2.6 L × mmHg and 874 ± 259 mmHg/s, respectively. During biventricular pacing, mean SW and dP/dt(max) increased significantly by 43 ± 39% (+ 2.2 ± 2.4 L × mmHg, P < 0.001) and 13 ± 18% (+ 96 ± 136 mmHg/s, P < 0.001), respectively. In long-term responders (n = 29, 71%) compared with non-responders (n = 12, 29%), the acute increase in SW was significantly higher (+57 ± 33% vs. + 10 ± 30%, P < 0.001), whereas the acute increase in dP/dt(max) was not significantly different between responders and non-responders (+ 15 ± 18% vs. 6 ± 15%, P = 0.139). Receiver operating characteristic (ROC) curve analysis indicated that SW was superior to dP/dt(max), QRS duration and LV dyssynchrony in prediction of response to CRT. A cut-off value for SW of 20% yielded a sensitivity of 90% and specificity of 75% to predict reverse remodelling at 6 months., Conclusion: Invasive assessment of acute haemodynamics is a reliable tool to determine individual response to CRT. An acute increase in SW predicts long-term response to CRT with a higher accuracy than an acute increase in dP/dt(max), baseline QRS duration, and degree of LV mechanical dyssynchrony.

Background: Over the last decades, a gradual decrease in ventricular fibrillation (VF) as initial recorded rhythm during resuscitation for out-of-hospital cardiac arrest (OHCA) has been noted. We sought to establish the contribution of implantable cardioverter-defibrillator (ICD) therapy to this decline., Methods and Results: Using a prospective database of all OHCA resuscitation in the province North Holland in the Netherlands (Amsterdam Resuscitation Studies [ARREST]), we collected data on all patients in whom resuscitation for OHCA was attempted in 2005-2008. VF OHCA incidence (per 100 000 inhabitants per year) was compared with VF OHCA incidence data during 1995-1997, collected in a similar way. We also collected ICD interrogations of all ICD patients from North Holland and identified all appropriate ICD shocks in 2005-2008; we calculated the number of prevented VF OHCA episodes, considering that only part of the appropriate shocks would result in avoided resuscitation. VF OHCA incidence decreased from 21.1/100 000 in 1995-1997 to 17.4/100 000 in 2005-2008 (P<0.001). Non-VF OHCA increased from 12.2/100 000 to 19.4/100 000 (P<0.001). VF as presenting rhythm declined from 63% to 47%. In 2005-2008, 1972 ICD patients received 977 shocks. Of these shocks, 339 were caused by a life-threatening arrhythmia. We estimate that these 339 shocks have prevented 81 (minimum, 39; maximum, 152) cases of VF OHCA, corresponding with 33% (minimum, 16%; maximum, 63%) of the observed decline in VF OHCA incidence., Conclusions: The incidence of VF OHCA decreased over the last 10 years in North Holland. ICD therapy explained a decrease of 1.2/100 000 inhabitants per year, corresponding with 33% of the observed decline in VF OHCA.

Introduction: During therapeutic hypothermia (TH), electrocardiographic (ECG) abnormalities such as Osborn waves and/or ST-segment elevation have been described. However, the incidence and prognostic value of these ECG changes are uncertain given the small-scale studies that have been carried out to date. The aim of this study is to further evaluate the electrocardiographic changes during TH., Methods: During a period of 3 years, 81 patients (age 63 ± 14 years) were included retrospectively. All patients underwent TH after being resuscitated. ECG registrations before, during and after TH were collected and analyzed. Patients were divided into two groups based on the presence or absence of transmural ischemia ST elevation on the first representative ECG upon arrival at the hospital (ST-segment elevation myocardial infarction (STEMI) and non-STEMI)., Results: A total of 243 ECGs were analyzed. During TH 24 patients (30%) had Osborn waves, which disappeared in 22 patients (92%) after regaining normal body temperature. The presence of Osborn waves was not associated with age, gender, average pH, electrolytes, or lactate levels and was not associated with excess in-hospital mortality. In 10 patients (12%, six non-STEMI patients) new STEMI was observed during TH, which disappeared after TH discontinuation. The STEMI group (44 patients) had significantly more Osborn waves during TH than the non-STEMI group (38.6% vs. 15.2%, odds ratio = 3.508; 95% confidence interval = 1.281 to 9.610)., Conclusions: Hypothermia-induced Osborn waves are relatively common and are not associated with an unfavorable short-term outcome. TH is associated with ECG changes that may mimic STEMI.

Remote monitoring of cardiac implanted electronic devices (CIED: pacemaker, cardiac resynchronisation therapy device and implantable cardioverter defibrillator) has been developed for technical control and follow-up using transtelephonic data transmission. In addition, automatic or patient-triggered alerts are sent to the cardiologist or allied professional who can respond if necessary with various interventions. The advantage of remote monitoring appears obvious in impending CIED failures and suspected symptoms but is less likely in routine follow-up of CIED. For this follow-up the indications, quality of care, cost-effectiveneness and patient satisfaction have to be determined before remote CIED monitoring can be applied in daily practice. Nevertheless remote CIED monitoring is expanding rapidly in the Netherlands without professional agreements about methodology, responsibilities of all the parties involved and that of the device patient, and reimbursement. The purpose of this consensus document on remote CIED monitoring and follow-up is to lay the base for a nationwide, uniform implementation in the Netherlands. This report describes the technical communication, current indications, benefits and limitations of remote CIED monitoring and follow-up, the role of the patient and device manufacturer, and costs and reimbursement. The view of cardiology experts and of other disciplines in conjunction with literature was incorporated in a preliminary series of recommendations. In addition, an overview of the questions related to remote CIED monitoring that need to be answered is given. This consensus document can be used for future guidelines for the Dutch profession.

Cardiac resynchronization therapy (CRT) decreases the morbidity and mortality in patients with end-stage heart failure. However, patient selection remains challenging, because a considerable 30% to 50% do not respond. Controversy exists on the cutoff values for the QRS duration and the optimal lead location. The present study relates these parameters on an individual basis to acute pump function improvement using invasively obtained pressure-volume loops. Fifty-seven patients with symptomatic end-stage heart failure were included in our temporary biventricular stimulation study and were grouped according to the QRS duration (QRS <20 ms, QRS ≥120 ms but <150 ms, and QRS ≥150 ms). All patients underwent pressure-volume loop assessment of the response to biventricular pacing, comparing the baseline measurements to both right ventricular apex pacing combined with a left ventricular lead in the posterolateral and anterolateral region of the LV. Group analysis during conventional (posterolateral and right ventricular apex) CRT did not show improvement in stroke work and dP/dt(max) (-2%, p = NS; and -7%; p <0.001) in the narrow QRS group but a significant increase in the intermediate (+27%, p = 0.020, and +5%, p = 0.044) and wide (+48%, p = 0.002, and +18%, p <0.001) QRS groups. CRT using the anterolateral and right ventricular apex configuration evoked a consistently lower response compared to posterolateral and right ventricular apex, resulting in a significant hemodynamic deterioration in the narrow QRS group. However, analysis on an individual basis identified 25% of patients with narrow QRS duration showing possible hemodynamic benefit from CRT compared to 83% of patients with intermediate and wide QRS combined. In contrast, 15% of patients had deterioration by conventional (posterolateral right ventricular apex) CRT in the intermediate and wide QRS groups compared to 31% in the narrow QRS group; 19% of patients could be improved by lead placement in the anterolateral rather than the posterolateral region. In conclusion, the acute hemodynamic response to CRT is generally in line with the long-term results from large randomized trials; however, the individual variation is large. The temporary biventricular stimulation protocol might aid in individual patient selection and in research aiming at a reduction of nonresponders and improvement in lead positioning., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: Information is scarce on the effects of right ventricular apical (RVA) pacing on regional and global myocardial blood flow (MBF). The purpose of this study was to assess the relationship between pacing rate and both regional and global MBF., Methods: Four patients with exclusive atrial pacing and six patients with exclusive RVA pacing underwent three consecutive H(2) (15)O positron emission tomography scans at 60, 90, and 130 pulses per minute (ppm). For each pacing rate, regional and global MBF was determined. In all patients, the left ventricular (LV) function was normal., Results: By varying the atrial pacing rate from 60 to 130 ppm, the mean global MBF increased from 0.94 to 1.40 mL/g/min, whereas the mean septal to lateral MBF ratio decreased from 1.09 to 0.83. In ventricular-paced patients at corresponding rates, the mean global MBF also increased from 1.07 to 1.52 mL/g/min but here the mean septal to lateral MBF ratio increased from 0.83 to 1.0., Conclusions: During both acute atrial and RVA pacing, regional and global MBF increases with higher pacing rates. However, the septal to lateral MBF ratio decreases with atrial pacing and increases with RVA pacing in patients with normal LV function. In RVA pacing, these different rate-dependent effects on regional MBF can be considered as a favorable factor that helps to understand why in some long-term paced patients, LV function is preserved., (©2011, The Authors. Journal compilation ©2011 Wiley Periodicals, Inc.)

Objectives. The aim of this study was to analyse the rate of major adverse clinical events in patients with coronary artery disease and a fractional flow reserve (FFR) of ≥0.75 and deferred for coronary intervention in daily practice. Methods. From 1 January to 31 December 2006, FFR measurement was initiated in 122 patients (5%) out of 2444 patients referred for coronary angiography. In two patients FFR measurement failed and in one patient the FFR value could no longer be traced in the documents. Thus, 119 patients (84 men, 64 years, range 41-85) were included in the evaluation (145 lesions). Major adverse clinical events (death, myocardial infarction, percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG)) and the presence of angina were evaluated at follow-up. Furthermore a cost-effectiveness analysis was performed.Results. In 93 patients (76%) the FFR value was ≥0.75. Seventy of these 93 patients (76%) were treated with medication alone or underwent PCI for a different lesion (medical treatment group). Average duration of follow-up of all 119 patients was 22 months (range 4 days to 30 months). In the medical treatment group seven patients (10%) experienced a major adverse clinical event related to the FFR-evaluated lesion during follow-up. In this study population, the use of FFR measurement is cost-reducing provided that at least 65% of the patients in the medical treatment group has had a PCI with stent implantation when the use of FFR measurement is impossible. In this case, the decision to use PCI with stent implantation is purely based on the angiogram. Conclusions. In patients with a coronary stenosis based on visual assessment and an FFR of ≥0.75 deferral of PCI or CABG is safe in daily clinical practice and saves money. (Neth Heart J 2010;18:402-7.).

The introduction of the implantable cardioverter defibrillator (ICD) has had a major impact on survival and treatment of patients with ischaemic cardiomyopathy. However, only a third of patients receive appropriate ICD discharges during the first 3 years of follow-up, hence creating opportunities for improvement in patient care as well as for health care costs containment. Therefore, refinement of ICD implantation criteria is needed. Evaluation of pathophysiological substrates related to electrical instability with imaging modalities such as nuclear imaging, cardiac magnetic resonance imaging, and echocardiography might yield important prognostic information. This review discusses the currently available literature regarding the value of these imaging modalities for prediction of ventricular arrhythmias in patients with ischaemic cardiomyopathy.

Background: Normal left ventricular (LV) torsion is caused by opposite basal and apical rotation. Opposite rotation can be lost in heart failure, but might be restored by pacing; therefore, the predictive value of the loss of opposite base-apex rotation in heart failure patients for the response to cardiac resynchronization therapy (CRT) was studied., Methods and Results: In 34 CRT candidates and 12 controls, basal and apical LV rotations were calculated using magnetic resonance image tagging. Loss of opposite rotation was quantified by the correlation between both rotation curves: a negative correlation indicates normal, opposite rotation and a positive correlation indicates that base and apex rotate in the same direction. In patients, LV pressure was measured invasively during biventricular stimulation. Acute response to CRT was defined by >10% increase in dP/dt(max) relative to baseline. LV volume was determined at baseline and 8 months follow-up using echocardiography. The base-apex rotation correlation (BARC) was significantly higher in acute responders (n=22) than in nonresponders (n=12) and controls (0.64+/-0.51, -0.23+/-0.67, and -0.68+/-0.22, respectively; P=.001). The sensitivity and specificity for prediction of acute response were 82% and 83%, respectively, at a cutoff value of 0.5. At follow-up, volumes could be analyzed in 18 patients. In the group with BARC >0.5, end-diastolic volume decreased by 7% (NS), end-systolic volume by 16%, and ejection fraction increased by 28% (both P=.02), whereas in the group with BARC <0.5, no significant changes were observed., Conclusions: The loss of opposite base-apex rotation in patients eligible for CRT is an excellent predictor of acute response and is associated with LV reverse remodeling.

Background: The effects of different breath-holding positions during electrocardiographic (ECG) recording on the QRS complex are unknown., Methods: In 73 subjects, ECG recordings were made in 3 different breath-holding positions: normal expiration (rest), maximum inspiration, and maximum expiration. QRS wave excursions and changes in the frontal electrical heart axis were analyzed., Results: The mean effect of respiration in most leads was small (> or =1 mm only in the S wave in V(4) and in the R wave in V(5)), but the degree of interindividual variability was often substantial, with standard deviations of > or =1.5 mm in multiple leads., Conclusion: The effect of different extreme breath-holding positions on the QRS complex is on average small but may be substantial in individuals. Lack of standardization of breathing instructions during recording of the ECG may result in differences in application of amplitude criteria and poorer reproducibility.

Objective: We studied the comparability of left ventricular (LV) mechanical dyssynchrony assessment by tissue Doppler imaging (TDI) and real-time three-dimensional echocardiography (RT3DE) in patients with a wide range of LV ejection fractions and different causes of cardiomyopathy. In addition, we evaluated the ability of both techniques to predict response to cardiac resynchronization therapy (CRT)., Methods: A total of 90 patients and 30 healthy volunteers underwent both TDI and RT3DE. A subgroup of 27 patients underwent CRT and were evaluated before and 6 months after implantation. Mechanical dyssynchrony was measured with TDI using the standard deviation of time to peak systolic tissue velocity of 12 LV myocardial segments. With RT3DE, the standard deviation of time from QRS onset to minimal volume of 16 LV subvolumes was assessed. Indicators of response to CRT were a clinical improvement of >or= 1 New York Heart Association functional class, and reverse remodeling defined as a reduction of >or= 15% in LV end-systolic volume at 6 months., Results: A moderate correlation (r = 0.581, P < .001) was observed between TDI and RT3DE. No significant difference in the presence of mechanical dyssynchrony by TDI and RT3DE was observed (53% vs 48%, respectively). Agreement between techniques was comparable between patients with ischemic and nonischemic cardiomyopathy. However, up to 30% nonagreement between the 2 techniques was found, depending on the severity of LV dysfunction. Of the 27 patients undergoing CRT, clinical response was observed in 70% of patients, whereas reverse remodeling occurred in 63% of patients. All baseline characteristics were similar between responders and nonresponders, except for mechanical dyssynchrony assessed by RT3DE, which was significantly higher in responders compared with nonresponders (10.1% +/- 2.6% vs 5.1% +/- 1.2% for clinical response, P < .001; 10.0% +/- 2.8% vs 6.3% +/- 2.3% for reverse remodeling, P = .001). By applying previously defined cutoff values, receiver operating characteristic curve analysis demonstrated a sensitivity of 58% with a specificity of 50% for TDI and a sensitivity of 95% with a specificity of 87% for RT3DE to predict clinical response to CRT. For prediction of reverse remodeling after CRT, sensitivity and specificity were 59% and 50% for TDI, and 88% and 60% for RT3DE, respectively. The optimal cutoff value for systolic dyssynchrony index by RT3DE of 6.7% yielded a sensitivity of 90% with a specificity of 87% to predict clinical response, and a sensitivity of 88% with a specificity of 70% to predict reverse remodeling., Conclusion: Marked differences between techniques are found for the presence of mechanical dyssynchrony when current cutoff values are applied, making interchangeability of these techniques uncertain. Assessment of mechanical dyssynchrony by RT3DE might be an appropriate alternative to TDI for accurate prediction of response to CRT.

Background: Intraoperative measurements of left ventricular (LV) pacing and sensing values were assessed using a novel 0.014-inch guidewire (Visionwire, Biotronik GmbH, Berlin, Germany) enabling pacing and sensing at the distal tip before final LV lead implantation., Methods: Twenty-two consecutive patients selected for cardiac resynchronization therapy were studied., Results: Significant correlation was found between the LV pacing threshold as assessed by the Visionwire and values after final LV lead implantation (r = 0.92, P < 0.001). Correlation for LV sensing was also significant (r = 0.72, P < 0.001). No significant correlation was present with respect to phrenic nerve stimulation. However, no phrenic nerve stimulation at 10 V/0.5 ms using the Visionwire identified 88% of patients without phrenic nerve stimulation at 10 V/0.5 ms with subsequent LV lead measurements., Conclusion: This technique may facilitate transvenous LV lead implantation by preventing implantation in a unsuitable target vessel with respect to pacing and sensing values or phrenic nerve stimulation, thereby reducing procedure and fluoroscopy time.

Coronary artery spasm has been known to induce ischaemia and ventricular arrhythmias. We present a case of recurrent ventricular fibrillation caused by spasm-associated transmural myocardial ischaemia. During an intra-coronary acetylcholine provocation test, severe coronary spasm could be induced. The patient was treated with a hybrid approach of medication and an implantable defibrillator.

Fifty years after its introduction, cardiac pacing has evolved from an experimental medical treatment to an expanding field in today's cardiology. Only recently there is accumulating evidence that prolonged stimulation of the right ventricular apex is associated with clinically significant adverse effects. In this commentary, the potential adverse effects are summarised and potential modifications in contemporary pacing are discussed. (Neth Heart J 2008;16(Suppl1):S12-S14.).

Objectives: This study was designed to investigate the influence of high dose intracoronary adenosine on persistent ST-segment elevation after primary percutaneous coronary intervention (PCI)., Background: After successful PCI for acute myocardial infarction 40-50% of patients show persistent ST-segment elevation indicating suboptimal myocardial reperfusion. Adenosine has been studied to ameliorate reperfusion and is frequently used in a variety of doses, but there are no prospective studies to support its use for treatment of suboptimal reperfusion., Methods: We conducted a blinded, randomized, and placebo-controlled study with high dose intracoronary adenosine in 51 patients with <70% ST-segment resolution (STRes) after successful primary PCI. All patients were treated with stents and abciximab., Results: Immediately after adenosine, significantly more patients showed optimal (>70%) STRes compared with placebo (33% versus 9%, P < 0.05). Mean STRes was higher after adenosine (35.4% versus 23.0%, P < 0.05). In addition, TIMI frame count was significant lower (15.7 versus 30.2, P < 0.005), Myocardial Blush Grade was higher (2.7 versus 2.0, P < 0.05) and resistance index was lower in the adenosine group (0.70 versus 1.31 mm Hg per ml/min, P < 0.005)., Conclusions: Intracoronary adenosine accelerates recovery of microvascular perfusion in case of persistent ST segment elevation after primary PCI.

Purpose: To investigate whether mechanical dyssynchrony (regional timing differences) or heterogeneity (regional strain differences) in myocardial function should be used to predict the response to cardiac resynchronization therapy (CRT)., Materials and Methods: Baseline mechanical function was studied with MRI in 29 patients with chronic heart failure. Using myocardial tagging, two mechanical dyssynchrony parameters were defined: the standard deviation (SD) in onset time (T onset) and in time to first peak (T peak,first) of circumferential shortening. Electrical dyssynchrony was described by QRS width. Further, two heterogeneity parameters were defined: the coefficient of variation (CV) in end-systolic strain and the difference between peak septal and lateral strain (DiffSLpeakCS). The relative increase in maximum rate of left ventricle pressure rise (dP/dt max) quantified the acute response to CRT., Results: The heterogeneity parameters correlated better with acute response (CV: r = 0.58, DiffSLpeakCS: r = 0.63, P < 0.005) than the mechanical dyssynchrony parameters (SD(T onset): r = 0.36, SD(T peak,first) r = 0.47, P = 0.01, but similar to electrical dyssynchrony (r = 0.62, P < 0.001). When a heterogeneity parameter was combined with electrical dyssynchrony, the correlation increased (r > 0.70, P incr < 0.05)., Conclusion: Regional heterogeneity in myocardial shortening correlates better with response to CRT than mechanical dyssynchrony, but should be combined with electrical dyssynchrony to improve prediction of response beyond the prediction from electrical dyssynchrony only., ((c) 2007 Wiley-Liss, Inc.)

Aims: The BRIGHT study evaluated bifocal right ventricular (RV) (apex and outflow tract) pacing in a single, blind, randomized crossover study in patients eligible for cardiac resynchronization therapy (CRT). Forty-two patients were enrolled with the following characteristics: chronic drug refractory heart failure New York Heart Association (NYHA) class III-IV; ejection fraction (EF)<35%; QRS width >or= 120 ms; and a left bundle branch block. The aim of the study was to assess an improvement in left ventricular (LV) EF, 6 min walk test, Minnesota quality-of-life score, and NYHA classification. Methods and result Patients were randomized to receive either bifocal pacing or the control mode, each for a period of 3 months. Parameters were measured prior to randomization and after 3 months of control or bifocal pacing. Eight patients failed to make the 7 month follow-up, three patients died (one prior to randomization at the first month), five patients dropped out, and three patients refused further participation. One patient had a persistent lead problem, which was subsequently replaced with an LV lead, and one patient suffered with persistent atrial fibrillation. Compared with baseline, bifocal pacing improved EF from 26 +/- 12% to 36 +/- 11% (P < 0.0008), NYHA classification decreased from 2.8 +/- 0.4 to 2.3 +/- 0.7 (P < 0.007). Furthermore, the 6 min walk test improved from 372 +/- 129 m to 453 +/- 122 m (P < 0.05), and the Minnesota Living with Heart Failure scores decreased from 33 +/- 20 to 24 +/- 21 (P < 0.006). In the control group, no significant changes in any parameters were observed. Eight patients did not tolerate reprogramming from DDD BRIGHT to control pacing, with symptoms disappearing in all patients after reprogramming to bifocal pacing., Conclusion: Bifocal RV pacing in patients with a classic indication for CRT shows improvement in all parameters.

Purpose: Although resynchronisation therapy (CRT) is a promising addition to heart failure therapy, a substantial number of patients do not respond to CRT. As FDG PET has routinely been used for prediction of improvement after revascularisation in ischaemic cardiomyopathy, it was hypothesised that there is also a relationship between the extent of viable tissue and improvement as a result of CRT., Methods: Thirty-nine patients with ischaemic cardiomyopathy (ejection fraction 27 +/- 9%) and a wide QRS complex underwent temporary pacing to determine the optimal pacing combination, i.e. that with the highest increase in cardiac index (CI) compared with baseline (measured by Doppler echocardiography). All patients also underwent FDG PET imaging. In 19 patients, CI measurements were repeated 10-12 weeks after permanent biventricular pacemaker implantation., Results: Echocardiography (13-segment model) showed a mean of 9.8 +/- 1.6 dyssynergic segments, with preserved FDG uptake in 4.1 +/- 2.4 segments. CI improvement at the optimal pacing site was 20 +/- 9%. There was a linear relationship between the extent of viable tissue and CI improvement during pacing (p < 0.001). Using a cut-off value of more than three viable segments (ROC analysis), FDG PET had a sensitivity of 72% and a specificity of 71% for detection of the presence of haemodynamic improvement (i.e. a CI improvement >15%). The relation between CI improvement and viable tissue was similar at follow-up., Conclusion: A correlation was found between the extent of viable tissue and the haemodynamic response to CRT in patients with ischaemic cardiomyopathy, suggesting that FDG PET imaging may be useful to discriminate between responders and non-responders to CRT.

The response to cardiac resynchronization therapy (CRT), which is applied to patients with heart failure (HF) and left bundle-branch block (LBBB), can be predicted from the mechanical dyssynchrony measured on circumferential strain. Circumferential strain can be assessed by either 2D or 3D strain analysis. In this study was evaluated the difference between 2D and 3D circumferential strain using MR tagging with high temporal resolution (14 ms). Six healthy volunteers and five patients with LBBB were evaluated. We compared the 2D and 3D circumferential strains by computing the mechanical dyssynchrony and the cross correlation (r) between 2D and 3D strain curves, and by quantifying the differences in peak circumferential shortening, time to onset, and time to peak of shortening. The obtained maximum r(2) values were 0.97 +/- 0.03 and 0.87 +/- 0.16 for the healthy and LBBB populations, respectively, and thus showed a good similarity between 2D and 3D strain curves. No significant difference was observed between 2D and 3D in time to onset, time to peak, or peak circumferential shortening. Thus, to measure dyssynchrony, 2D strain analysis will suffice. Since 2D analysis is easier to implement than 3D analysis, this finding brings the application of MRI tagging and strain analysis closer to the clinical routine.

Background: Cardiac resynchronization therapy (CRT) improves left ventricular (LV) systolic function and clinical status, and prolongs survival of patients suffering from heart failure. An optimal LV site selection is key with respect to improvements in systolic function, though whether a site-specific effect on diastolic function exists is unclear. This study compared the effects of CRT on changes in systolic and diastolic function from 2 LV stimulation sites., Methods: We studied 21 patients in New York Heart Association functional classes >/= III, and a LV ejection fraction < 0.30 and QRS duration > 130 ms. CRT leads were placed in the right ventricle, right atrium, and coronary sinus tributaries. LV stimulation was applied from the postero-lateral and antero-lateral wall. A LV conductance catheter was used to measure LV systolic and diastolic function. Systolic responders had > 10% changes in dP/dt(max), and diastolic responders < 10% changes in tau during CRT versus baseline. Response was highly dependent on LV lead position for both diastolic and systolic function. Diastolic responders decreased from 29% to 10% of patients, and systolic responders from 76% to 48%, in the best versus the worst lead position, respectively. Improvements in diastolic function were less pronounced than in systolic function (relative change -14% vs +28%, P < 0.05). Overall, 45% were both systolic and diastolic responders, 17% were both systolic and diastolic nonresponders, and 38% had opposite responses., Conclusions: Changes in systolic and diastolic function were both highly dependent on the LV stimulation site. Diastolic function was less influenced by CRT and a high proportion of patients had discordant results.

Background: Biventricular pacing is a new therapy for the treatment of heart failure. However, a substantial number of patients do not respond to this therapy., Hypothesis: Individually determined maximal pacing sites will improve the haemodynamic response and increase the number of responders., Methods: In 48 patients with heart failure, the acute haemodynamic effects of nine different pacing configurations were studied, using two right and left ventricular pacing sites and their combinations. Cardiac index was measured using Doppler echocardiography. For further analysis, the combination with the highest cardiac index improvement was compared with baseline. Moreover, the number of responders was calculated using a cut-off value of 10% increase in cardiac index., Results: The mean (SD) increase in cardiac index ranged between 3.8% (6.0%) and 11.1% (8.6%). The pacing site with maximal cardiac index was highly variable between patients, and here the cardiac index increased to 14.8% (7.6%; (p<0.001). The number of responders varied between 15% and 64%, increasing to 75% at the site with maximal increase in cardiac index. In a subset of patients, the haemodynamic improvement after pacemaker implantation correlated well with the acute haemodynamics., Conclusion: Individualisation of pacing configuration for biventricular pacing leads to further haemodynamic improvement in patients with heart failure and reduces the number of patients not responding to this therapy.

The Clinical and Angiographic analysis with a Cobalt Alloy Coronary Stent (Driver) (CLASS) study was a prospective, nonrandomized, multicenter study designed to assess the safety and efficacy of a cobalt-chromium alloy-based stent in patients with stable or unstable angina pectoris. A total of 203 lesions were treated in 202 enrolled patients. The percentage of major adverse cardiac event-free patients was 87.6% (177 of 202) at 6 months (primary safety end point; major adverse cardiac events were defined as death, myocardial infarction, emergency bypass surgery, or target lesion revascularization [percutaneous transluminal coronary angioplasty or coronary artery bypass grafting]). The angiographic success rate (primary efficacy end point) was 100%, and the procedural success rate was 98%. The binary in-stent restenosis rate at 6 months was 12.6%. Our results have demonstrated that the Driver cobalt-chromium alloy stent can be used with a low 6-month incidence of major adverse cardiac events, a low 6-month binary restenosis rate, and high angiographic and procedural success rates.

In recent years cardiac resynchronization therapy has emerged as a promising new treatment strategy in a subgroup of patients with congestive heart failure and an asynchronous contraction pattern. By simultaneously pacing both right ventricular apex and lateral side of the left ventricle, ventricular synchrony can be partially restored and beneficial effects on cardiac performance can be observed. This review discusses the principles of ventricular dyssynchrony, and the acute and chronic effects of cardiac resynchronization therapy on systolic function, cardiac metabolism, and clinical parameters. Furthermore, the issue of identifying patients who do not respond to this therapy is addressed.

Studies in patients without coronary artery disease have shown the restoration of glucose metabolism by cardiac resynchronization therapy (CRT) without changes in myocardial perfusion. We report on the long-term outcome of CRT in 24 patients with severe heart failure (HF) and advanced coronary artery disease not amenable for revascularization. All patients had documented myocardial ischemia on stress (99)Tc-sestamibi single-photon emission computed tomography, and all underwent successful implantations of CRT systems. The mean left ventricular ejection fraction was 21%+/- 4%, 19 patients (79%) had anginal complaints and 20 (83%) had diffuse three-vessel disease. During a follow-up of 13 +/- 0.7 months, two patients died suddenly and one died of progressive HF. Among survivors, functional capacity decreased from New York Heart Association class 3.2 +/- 1.4 to 2.1 +/- 1.0 (P < 0.01), and the Minnesota questionnaire quality-of-life scores decreased from 43 +/- 15 to 28 +/- 13 (P < 0.01). Despite an increase from 264 +/- 104 to 385 +/- 121 m in distance walked in 6 minutes (P < 0.01), the number of anginal attacks/week remained unchanged (4.7 +/- 0.7 to 4.5 +/- 0.6). Patients with advanced HF, stable angina, and documented myocardial ischemia may undergo safe and successful implantations of CRT systems.