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Introduction In patients with sinus node disease (SND), the dual-chamber pacemaker (PM) is programmed in DDDR mode with an algorithm to avoid unnecessary right ventricular (RV) pacing. This pacing mode may prolong PR interval with consequently atrioventricular (AV) asynchrony which is associated with a higher risk of atrial fibrillation (AF). We evaluate whether preserving AV synchrony by setting a fixed AV delay during physiological RV pacing, that is, His bundle pacing (HBP), could reduce the risk of AF occurrence in comparison with a standard pacing mode with an algorithm to avoid unnecessary RV pacing (DDD-VPA). Methods and results We collected retrospective data from 313 consecutive patients who had undergone PM for SND. The first occurrence of persistent AF (>7 consecutive days) as a function of the pacing mode was evaluated. HBP and DDD-VPA were implemented in 82 and 231 patients, respectively. Persistent AF occurred in 128 (40.9%) patients over a median follow-up of 70 months (67-105). The DDD-VPA pacing mode was significantly correlated with the occurrence of persistent AF only when the basal PR was long (>180 ms). The risk of persistent AF was significantly lower in patients on HBP than in those on DDD-VPA, adjusted HR = .57 (95% CI, .36- .89, p=.014). Other independent predictors of persistent AF occurrence were: A history of AF (HR = 3.91; 95% CI, 2.48-6.19, p = .001), age, and long PR interval (HR = 2.98; 95% CI, 2.00-4.43, p=.001). Conclusion In SND patients and long basal PR interval, the HBP may reduce the risk of persistent AF in comparison with the DDD-VPA.

Background Conduction system pacing (CSP)is becoming increasingly popular thanks to the ability to both maintain physiological electrical activation in patients with narrow QRS and restore ventricular synchrony in patients with bundle branch block (BBB). The Selectra3D introducer is a new tool able to support the correct positioning and screwing of the catheter on the bundle of His (HBP) or on the left branch (LBBP). It does exist in 3 different shapes: S, M, L (Fig. 1) based on the radius of main curvature. The internal diameter of 7.3 Fr allows it to support both the 3830 lumen-less catheter historically used for CSP, as well as standard 6Fr stylet-driven leads. Objective To evaluate the effectiveness of the Selectra3D introducer for CSP (including both HBP and LBBP), considering the procedural success rate and the lead stability (stability of electrical parameters or need for implant revision) in the medium-term follow-up. Methods and results The Selectra3D introducer was used in 56 patients' candidates for CSP (mean age 80±6 years). Pacing indications included A-V block in 21 patients, AF with slow ventricular response in 9 patients; SND in 8 patients and HF and severe ventricular dysfunction in 18 patients (of which 4 were PICM). The mean baseline EF was 40±15%. A PM was implanted in 40 patients and an ICD in 16. A standard stylet-driven lead was used in 48 cases, a fixed exposed screw lead was used in 8 patients. HBP was obtained in 21 cases and LBBP in 30 cases, while in 5 cases (8.9%) neither HBP nor LBBP could be obtained. Implants were performed via a left-sided approach in 55 cases and a right-sided approach in 1 case. The baseline QRS duration was 144±38 ms and the paced QRS duration was 118±21 ms. The electrical parameters were optimal with sensing 8.7±8 mV; impedance 625±276 ohm; threshold 1±0.5 V. During follow-up, 2 lead dislodgement (3.9%) (1 HBP and 1 LBBP) were recorded, both within 7 days after implantation. All the others showed stability of the electrical parameters at a mean follow-up of 8.4±4.2 months. Conclusions The new Selectra3D introducer supports effectively and safely the lead implant on conduction system catheters (HBP and LBBP), allowing the implant of both exposed fixed screw leads and standard stylet-driven leads, leading to procedural success>90%. The electrical parameters were optimal at implantation and remained stable during follow-up. Funding Acknowledgement Type of funding sources: None. Figure 1

Background Conduction system pacing (CSP) includes both His Bundle Pacing (HBP) and left bundle branch pacing (LBBP). It engages the conduction system ensuring synchronous activation of ventricles, potentially acting as cardiac resynchronization. Purpose The aim of the study is to report technical and clinical outcomes of CSP (HBP or LBBP) utilized in patients referred for cardiac resynchronization therapy. Methods CSP was applied in 51 patients (mean age 75±9 years; 47 males) referred for cardiac resynchronization therapy. 41 cases were de-novo implant and 10 were up-grading after PICM. Ischemic aetiology was present in 23 (45%) patients, hypertension in 31 (61%); diabetes in 19 (37%), severe kidney disease in 4 (8%). Devices were checked 48 hours and 1 month after implant and then remotely. Clinical, echocardiographic, electrocardiographic data were also collected. Results Conduction system pacing was successfully obtained in 45 (88.3%) patients. In 28 (62%) cases the lead was implanted in the His Bundle and in 17 (38%) in the left bundle. In 6 (11.7%) patients it was not possible to fix the lead in the His Bundle neither in the Left bundle, in these cases a standard quadripolar lead in the coronary sinus was implanted. In 28 (62%) patients was utilized the 3830 4 Fr lumen-less lead and in the remaining 17 (38%) cases a standard stylet-driven lead. Basal mean EF was 33±9% and improved to 42±9% (P Conclusions Conduction system pacing can act effectively as cardiac resynchronization in patients with severe cardiac disfunction and bundle branch block with high success rate, significantly narrowed QRS and improved EF at short-medium term follow-up. Funding Acknowledgement Type of funding sources: None. Case report: CRT-D including LB lead

Background His bundle pacing (HBP) can be affected by high thresholds and low sensing. Thus, in selected patients including a back-up lead is advisable. Objective Single-centre retrospective analysis of a large HBP experience, focusing on the back-up lead utilization over the years. Methods 677 pts (76±8 years; 433 males) were implanted with HBP from 2004 to 2019 July. The pts received S-HBP (67%) or NS-HBP by the 3830 lead. The pacing indications were AV block 54%, sinus node disease 17%, slow atrial fibrillation 23%, heart failure 6%. Ischemic cardiopathy was found in 26%; hypertension in 83%, diabetes in28% pts. Baseline QRS duration was 123±32 ms and EF 56±12%. Results 266 (39%) pts received the back-up lead. In sinus rhythm we implanted 3-chamber PM (His lead:LV port; VV delay 80 ms: His pulses and apical pacing during the refractory period). 30 pts (11%) received a particular type of 3-chamber PM which provides back-up pacing only if His capture fails, thus saving energy. In atrial fibrillation 2-chamber PM was implanted (His lead: atrial port, DVI). We recorded a significant decrease of back-up lead use over the years, strictly related to operators/centre experience (>70% during the first years, nearly 10% during the last year). The C315 fixed curve sheath, strongly contributed to the rapid reduction of back-up lead use thanks to better lead fixation and stability. Conclusion The back-up lead utilization is progressively decreasing. It is strictly related to the operator/centre experience. The presence of the back-up lead could strengthen the Hisian pacing reliability, potentially impacting pacing indication even in advanced conduction disturbances and saving device longevity. Funding Acknowledgement Type of funding source: None

His bundle pacing (HBP) preserves physiological ventricular synchrony, with clinical benefits particularly evident when a high percentage of ventricular pacing is required. First experiences with standard leads and manually shaped stylets produced the impression that HBP is highly complex and time-consuming. However, with dedicated leads and sheaths, reliable HBP can be achieved in routine clinical practice. Implantation success in more than 90% of patients can be reached with current technology and has been shown to be reliable and effective, both at implantation and during long-term follow-up. At the same time, fluoroscopy and total procedural time can be reduced. New customized technologies will continue to improve the implant success rate and system performance. Large randomized trials will prove the long-term clinical benefits of HBP definitively and may render HBP the first choice in patients requiring ventricular pacing.

PurposeIn order to increase the responder rate to CRT, stimulation of the left ventricular (LV) from multiple sites has been suggested as a promising alternative to standard biventricular pacing (BIV). The aim of the study was to compare, in a group of candidates for CRT, the effects of different pacing configurationsBIV, triple ventricular (TRIV) by means of two LV leads, multipoint (MPP), and multipoint plus a second LV lead (MPP + TRIV) pacingon both hemodynamics and QRS duration.MethodsFifteen patients (13 male) with permanent AF (mean age 767years; left ventricular ejection fraction 337%; 7 with ischemic cardiomyopathy; mean QRS duration 178 +/- 25ms) were selected as candidates for CRT. Two LV leads were positioned in two different branches of the coronary sinus. Acute hemodynamic response was evaluated by means of a RADI pressure wire as the variation in LVdp/dtmax.Resultsp id="Par3"Per patient, 2.7 +/- 0.7 veins and 5.2 +/- 1.9 pacing sites were evaluated. From baseline values of 998 +/- 186mmHg/s, BIV, TRIV, MPP, and MPP-TRIV pacing increased LVdp/dtmax to 1200 +/- 281mmHg/s, 1226 +/- 284mmHg/s, 1274 +/- 303mmHg, and 1289 +/- 298mmHg, respectively (p

Introduction His bundle pacing (HBP) allows physiological ventricular activation and prevents the electrical and mechanical desynchronization generally induced by myocardial stimulation, which can increase the risk of atrial fibrillation and heart failure. On the other hand, reliable HBP capture often requires higher energy than conventional myocardial pacing. This reduces the expected life of the stimulator and might limit the diffusion of HBP in the clinical practice. Purpose Decreasing HBP current drain by careful management of stimulation safety margin and pulse duration. Methods In 28 patients undergoing DDD pacing with HBP, a third lead was implanted in RV apex to provide back-up pacing on demand. HBP and apical leads were connected, respectively, to the V1 and V2 channels of a 3-chamber stimulator. When HBP was effective, apical sensing occurred within the VV delay and prevented V2 stimulation. In contrast, in case of HBP failure, V2 sensing was missing and apical back-up pacing was promptly delivered at the end of the VV delay. The availability of a back-up pulse on demand allowed reducing the HBP safety margin with no risk. Furthermore, the individual HBP strength-duration curve was derived in the aim of optimizing the Hisian pulse parameters, which are the major determinants of the device current drain. Results Correct back-up inhibition by successful HBP and stimulation in the event of capture loss was achieved in all the patients. The latency from Hisian pacing to apical sensing averaged 96±14 ms. According to the pacemaker counters, no back-up pulse was delivered in daily life in 59% of patients. In the remaining, the prevalence of back-up stimulation never exceeded 15% of paced ventricular cycles. The high HBP threshold was essentially due to an increased rheobase (1.2±0.6 V), while the chronaxie ranged from 0.30 to 0.53 ms in 71% of patients (median 0.44 ms), exceeding 0.6 ms only in 29% of the cases. An average current saving of 5.4±3.0 μA was obtained at the expense of a mild reduction in HBP safety margin (from 1.6±0.2 to 1.4±0.1 times). HBP and apical back-up Conclusions Back-up stimulation on demand is a reliable option to decrease HBP current drain and prolong the stimulator service life with full safety. In most of the cases, significant saving can be achieved by pulse shortening, as the chronaxie time is in the same range as with myocardial stimulation and longer pulses are not required. A pulse duration exceeding 0.6 ms is indicated in less than 1/3 of the implants.

INTRODUCTION Several single-center short-term studies have demonstrated the feasibility, safety, and positive clinical outcomes of permanent His bundle pacing (HBP). We performed a retrospective study to evaluate long-term technical and safety performances of HBP in a large population of pacemaker patients from two different centers. METHODS AND RESULTS The analysis includes 844 patients (345 female, mean age = 75 ± 9 years) who underwent successful permanent HBP for pacemaker indications from 2004 to 2016. The main endpoints were long term electrical performances including pacing threshold, sensing, impedance, and freedom from pacing related complications. The pacing indication was AV Block in 348 (41.2%) patients, sinus node disease in 147 (17.4%), any bradycardia indication in patients with atrial fibrillation in 335 (39.7%) patients and need for cardiac resynchronization therapy in 14 (1.7%) patients. Mean pacing capture thresholds and sensed R waves were 1.6 V and 5.8 mV, respectively at implant and 2.0 V and 6.1 mV at chronic follow-up. During the median follow up of 3 years (interquartile range = 1-6 years), HBP was free of any complication in 91.6% of patients. In the first 368 patients, HBP was achieved using a deflectable curve delivery system, while in 476 using the fixed curve sheath. A significant difference was found in the thresholds (2.4 ± 1.0 V and 1.7 ± 1.1 V, P

Estimating left ventricular electrical delay (Q-LV) from a 12-lead ECG may be important in evaluating cardiac resynchronization therapy (CRT).The purpose of this study was to assess the impact of Q-LV interval on ECG configuration.One hundred ninety-two consecutive patients undergoing CRT implantation were divided electrocardiographically into 3 groups: left bundle branch block (LBBB), right bundle branch block (RBBB), and nonspecific intraventricular conduction delay (IVCD). The IVCD group was further subdivided into 81 patients with left (L)-IVCD and 15 patients with right (R)-IVCD (resembling RBBB, but without S wave in leads I and aVL). The Q-LV interval in the different groups and the relationship between ECG parameters and the maximum Q-LV interval were analyzed.Patients with LBBB presented a long Q-LV interval (147.7 ± 14.6 ms, all exceeding cutoff value of 110 ms), whereas RBBB patients presented a very short Q-LV interval (75.2 ± 16.3 ms, all110 ms). Patients with an IVCD displayed a wide range of Q-LV intervals. In L-IVCD, mid-QRS notching/slurring showed the strongest correlation with a longer Q-LV interval, followed, in decreasing order, by QRS duration150 ms and intrinsicoid deflection60 ms. Isolated mid-QRS notching/slurring predicted Q-LV interval110 ms in 68% of patients. The R-IVCD group presented an unexpectedly longer Q-LV interval (127.0 ± 12.5 ms; 13/15 patients had Q-LV110 ms).Patients with LBBB have a very prolonged Q-LV interval. Mid-QRS notching in lateral leads strongly predicts a longer Q-LV interval in L-IVCD patients. Patients with R-IVCD constitute a subgroup of patients with a long Q-LV interval.

ObjectiveHeart failure (HF) has been associated with increased risk of fragility fractures. Indeed, most literature data on fractures were based on an historical and clinical approach focused on the identification of peripheral fractures, whereas the risk of vertebral fractures in this clinical setting is still unclear.DesignCross-sectional study.AimTo evaluate the prevalence and determinants of radiological thoracic vertebral fractures in patients with HF.MethodsThe study includes 1031 elderly hospitalized patients (491 females and 540 males; median age, 75 years; range, 65–90; 430 patients with HF) who were evaluated for the presence of thoracic vertebral fractures by quantitative morphometric analysis, using chest X-ray routinely performed in the diagnostic work-up of HF.ResultsVertebral fractures were found in 166 patients (16.1%), the prevalence being significantly higher in patients with HF as compared with those without HF, both in females (30.9 vs 15.8%; PP=0.001). The association between HF and vertebral fractures remained statistically significant (odds ratio, 2.14; 95% CI, 1.25–3.66; P=0.01) even after adjustment for age, sex, loop diuretic therapy, anticoagulant therapy, proton pump therapy, coexistent chronic obstructive pulmonary disease, diabetes mellitus, renal insufficiency, and chronic liver diseases. In patients with HF, vertebral fractures were positively correlated with female sex, duration of HF, ischemic heart disease, cigarette smoking, and treatment with anti-osteoporotic drugs, and inversely correlated with left ventricular ejection fraction.ConclusionsHospitalized patients suffering from HF are at higher risk of vertebral fractures than patients without HF in the same clinical context.

Background— One of the reasons for patient nonresponse to cardiac resynchronization therapy is a suboptimal left ventricular (LV) pacing site. LV electric delay (Q-LV interval) has been indicated as a prognostic parameter of cardiac resynchronization therapy response. This study evaluates the LV delay for the optimization of the LV pacing site. Methods and Results— Thirty-two consecutive patients (23 men; mean age, 71±11 years; LV ejection fraction, 30±6%; 18 with ischemic cardiomyopathy; QRS, 181±25 ms; all mean±SD) underwent cardiac resynchronization therapy device implantation. All available tributary veins of the coronary sinus were tested, and the Q-LV interval was measured at each pacing site. The hemodynamic effects of pacing at different sites were evaluated by invasive measurement of LV d P /d t max at baseline and during pacing. Overall, 2.9±0.8 different veins and 6.4±2.3 pacing sites were tested. In 31 of 32 (96.8%) patients, the highest LV d P /d t max coincided with the maximum Q-LV interval. Q-LV interval correlated with the increase in LV d P /d t max in all patients at each site (AR1 ρ=0.98; P 95 ms corresponded to a >10% in LV d P /d t max . An inverse correlation between paced QRS duration and improvement in LV d P /d t max was seen in 24 patients (75%). Conclusions— Pacing the LV at the latest activated site is highly predictive of the maximum increase in contractility, expressed as LV d P /d t max . A positive correlation between Q-LV interval and hemodynamic improvement was found in all patients at every pacing site, a value of 95 ms corresponding to an increase in LV d P /d t max of ≥10%.

Background Approximately one-third of the patients with heart failure (HF) treated with cardiac resynchronization therapy (CRT) fail to respond. Positioning the left ventricular (LV) pacing lead in the area of the latest electrical delay may improve the response to CRT. Multipoint pacing (MPP) of the LV has been shown to improve the acute hemodynamic response. Objective The purpose of this study was to test the hypothesis that patients treated with MPP in whom LV pacing location is optimized have better long-term clinical outcomes than do patients treated with conventional CRT. Methods We evaluated the echocardiographic and clinical response of 110 patients with HF treated for nearly 1 year with either conventional CRT (standard [STD] group, n=54, 49%), CRT with hemodynamic and electrical optimization of the LV pacing site (optimized [OPT] group, n=36, 33%), or OPT combined with MPP (OPT + MPP group, n=20, 18%). Responders were classified in terms of reduction in end-systolic volume index ≥15%, reduction in New York Heart Association (NYHA) class ≥1, and Packer score variation (NYHA response with no HF-related hospitalization events or death). Results In STD, OPT, and OPT + MPP groups, 56%, 72%, and 90% of patients, respectively, were end-systolic volume index responders ( P = .004) and 67%, 78%, and 95% were NYHA class responders ( P = .012); 59%, 67%, and 90% of patients exhibited a 1-year Packer score of 0 ( P = .018). These trends remained significant after adjustment for confounding factors by multivariate logistic analysis. Conclusion Combining MPP with optimal positioning of the LV lead on the basis of electrical delay and hemodynamics enhances reverse remodeling and improves clinical outcomes beyond the effect due to conventional CRT.

BACKGROUND: Atrial fibrillation is the most common cardiac arrhythmia, and no current therapy is ideal for control of this condition. Experimental studies suggest that angiotensin II-receptor blockers (ARBs) can influence atrial remodeling, and some clinical studies suggest that they may prevent atrial fibrillation. METHODS: We conducted a large, randomized, prospective, placebo-controlled, multicenter trial to test whether the ARB valsartan could reduce the recurrence of atrial fibrillation. We enrolled patients who were in sinus rhythm but had had either two or more documented episodes of atrial fibrillation in the previous 6 months or successful cardioversion for atrial fibrillation in the previous 2 weeks. To be eligible, patients also had to have underlying cardiovascular disease, diabetes, or left atrial enlargement. Patients were randomly assigned to receive valsartan or placebo. The two primary end points were the time to a first recurrence of atrial fibrillation and the proportion of patients who had more than one recurrence of atrial fibrillation over the course of 1 year. RESULTS: A total of 1442 patients were enrolled in the study. Atrial fibrillation recurred in 371 of the 722 patients (51.4%) in the valsartan group, as compared with 375 of 720 (52.1%) in the placebo group (adjusted hazard ratio, 0.97; 96% confidence interval [CI], 0.83 to 1.14; P = 0.73). More than one episode of atrial fibrillation occurred in 194 of 722 patients (26.9%) in the valsartan group and in 201 of 720 (27.9%) in the placebo group (adjusted odds ratio, 0.89; 99% CI, 0.64 to 1.23; P = 0.34). The results were similar in all predefined subgroups of patients, including those who were not receiving angiotensin-converting-enzyme inhibitors. CONCLUSIONS: Treatment with valsartan was not associated with a reduction in the incidence of recurrent atrial fibrillation. (ClinicalTrials.gov number, NCT00376272.) Copyright © 2009 Massachusetts Medical Society.

Background: The right ventricular septum (RVS) and Hisian area (HA) are considered more “physiological” pacing sites than right ventricular apex (RVA). Studies comparing RVS to RVA sites have produced controversial results. There are no data about variability of electromechanical activation obtained by an approach using fluoroscopy and electrophysiological markers. This study compared the variability of left ventricular (LV) electromechanical activation in patients undergoing short-term RVA and RVS with that measured during HA pacing based on fluoroscopy and electrophysiological markers. Methods: Tissue Doppler echocardiography was performed in 142 patients before and after RVA (54), RVS (44), and HA (44) pacing. Electromechanical activation was assessed by: (1) electromechanical latency (EML)-interval between QRS onset and mechanical activation of basal LV; (2) intra-LV dyssynchrony (intra-LV)-interval between earliest to the latest LV basal motion. The intra- and interpatients variability among pacing groups were assessed. Results: Pacing from RVA showed longer EML and higher degree of intra-LV than RVS and HA pacing. RVA and RVS showed a higher variability than HA pacing with regard to intrapatient changes of EML (RVA vs RVS, P = 0.4; RVS vs HA, P = 0.01, RVA vs HA, P = 0.0002) and intra-LV (RVA vs RVS, P = 0.2; RVS vs HA, P = 0.04; RVA vs HA, P = 0.005). Similar results were found in interpatients variability from paced-values. Conclusions: RVA and RVS pacing produce a variable effect on LV electromechanical activation that is significantly more pronounced than HA pacing. A pacing site such as HA selected by fluoroscopic and electrophysiological markers maintains baseline and homogeneous LV activation pattern. (PACE 2010; 566–574)

Objectives:Evaluation of left ventricular (LV) dyssynchrony in patients undergoing short-term right ventricular apical (RVA) pacing and correlation with baseline echocardiographic and clinical characteristics. Background:RVA pacing causes abnormal ventricular depolarization that may lead to mechanical LV dyssynchrony. The relationships between pacing-induced LV dyssynchrony and baseline echocardiographic and clinical variables have not been fully clarified. Methods:Tissue Doppler echocardiography was performed in 153 patients before and after RVA pacing. LV dyssynchrony was measured by the time between the shortest and longest electromechanical delays in the five basal LV segments (intra-LV). The prevalence and degree of LV dyssynchrony after RVA pacing was evaluated in three groups: baseline LV ejection fraction (LVEF)

Aims The His bundle is regarded as the most physiological site for ventricular pacing, in that it avoids the adverse effects of right ventricular apical pacing (RVAP). However, very few studies have compared the effects of direct His bundle pacing (DHBP) and RVAP. The aim of our study was the intra-patient comparison of myocardial perfusion corresponding to these two different pacing techniques, as perfusion expresses local workload and is related to long-term outcome. Methods and results Twelve consecutive patients with standard pacemaker indication (9 male, 74+ 9 years) entered the study. Pacing leads were implanted in the right ventricular apex and directly in the His bundle, and were connected to different ports of the pacemaker. All patients first underwent 3 months of DHBP, followed by 3 months of RVAP. At the end of each 3-month period, myocardial perfusion was measured at rest using scintigraphy with Tc99m-SestaMIBI. The average values of perfusion were evaluated on a 20-segment basis. All patients also underwent clinical evaluation, echocardiography, and tissue Doppler imaging (TDI), to measure dyssynchrony, and a blood sample was taken for brain natriuretic peptide (BNP) assay. The perfusion score during DHBP pacing was significantly better than during RVAP (0.44+ 0.5 vs. 0.71+ 0.53, respectively; P ¼ 0.011). None of the patients showed lower perfusion during DHBP than during RVAP. We found no significant difference in NYHA class, ventricular volumes, ejection fraction, or plasmatic BNP between DHBP and RVAP. However, mitral regurgitation (0.26+ 0.21 vs. 0.37+ 0.25; P , 0.001) and dyssynchrony (13.75+ 4.28 vs. 22.02+ 8.44; P ¼ 0.008) were significantly less during DHBP than during RVAP. Conclusion Direct His bundle pacing is superior to RVAP in preserving the physiologic distribution of myocardial blood flow and reducing mitral regurgitation and left ventricular dyssynchrony.

Aims Right ventricular pacing adversely affects left atrial (LA) structure and function that may trigger atrial fibrillation (AF). This study compares the occurrence of persistent/permanent AF during long-term Hisian area (HA), right ventricular septal (RVS), and right ventricular apex (RVA) pacing in patients with complete/advanced atrioventricular block (AVB). Methods and results We collected retrospective data from 477 consecutive patients who underwent pacemaker implantation for complete/advanced AVB. Ventricular pacing leads were located in the HA, RVS, and RVA in 148, 140, and 189 patients, respectively. The occurrence of persistent/permanent AF was observed in 114 (23.9%) patients (follow-up 58.5 ± 26.5 months). Hisian area groups presented a lower rate of AF occurrence (16.9%) compared with RVS and RVA groups (25.7 and 28.0%, respectively), P = 0.049. Cox's proportional hazard model was used to estimate HR. The risk of persistent/permanent AF was significantly lower in the patients paced from HA compared with those paced from RVA, HR = 0.28 (95% CI 0.16–0.48, P = 0.0001). The RVS and RVA pacing groups showed a similar AF risk: HR 1.04 (95% CI 0.66–1.64, P = 0.856). Other independent predictors of persistent/permanent AF occurrence included previous (before device implantation) paroxysmal AF (HR = 4.08; 95% CI 3.15–7.31, P = 0.0001), LA diameter, and age, whereas baseline bundle-branch block was associated with a lower risk of AF occurrence (HR = 0.56; 95% CI 0.35–0.81, P = 0.003). Conclusions HA pacing compared with RVA or RVS pacing seems to be associated with a lower risk of persistent/permanent AF occurrence. The risk of persistent/permanent AF was similar in the RVA vs. RVS groups.

BACKGROUND Response to cardiac resynchronization therapy (CRT) remains challenging. Pacing from multiple sites of the left ventricle (LV) has shown promising results. OBJECTIVE The purpose of this study was to systematically compare the acute hemodynamic effects of multipoint pacing (MPP) by means of a quadripolar lead with conventional biventricular (BiV) pacing. METHODS Twenty-nine patients (23 men; mean age 72 12 years; LV ejection fraction 29% +/- 7%; 15 with ischemic cardiomyopathy, 17 with left bundle branch block; mean ORS 183 +/- 23 ms) underwent CRT implantation. Per patient, 3.2 +/- 1.2 different veins and 6.3 +/- 2.4 pacing sites were tested. LV electrical delay (Q-LV) was measured at each Location, along with the increase in LV dP/dt(max) (maximum rate of rise of LV pressure) obtained by BiV and MPP. The effect of MPP, by means of simultaneous pacing from distal and proximal dipoles, was investigated at all available sites. RESULTS Overall, 3.2 +/- 1.2 different MPP measurements were collected per patient. When all sites were considered, LV dP/d(max) increased from 951 +/- 193 mm Hg/s at baseline to 1144 +/- 255 and 1178 +/- 259 mm Hg/s on BiV and MPP, respectively. When the best site was considered, LV dP/dt(max) increased from a baseline value of 942 +/- 202 mm Hg/s to 1200 +/- 267 mm Hg/s (BiV) and 1231 +/- 267 mm Hg/s (MPP). The mean QRS duration at any site during MPP and conventional CRT was 171 +/- 18 and 175 +/- 16 ms (P = .003), respectively. CONCLUSION Compared with BiV pacing at any LV site, MPP yielded a small but consistent increase in hemodynamic response. A correlation between the increase in hemodynamics and Q-LV on MPP was observed for all measurements, including those taken at the best and worst sites. The MPP-induced improvement in contractility was associated with significantly greater narrowing of the QRS complex than conventional BiV pacing.

Multipoint pacing (MPP) in CRT produces a more uniform ventricular depolarization and could reduce the arrhythmic burden in patients implanted with an ICD. Aim of the study was to compare the ventricular arrhythmic burden in a long term follow up in two homogeneous group of CRT patient, the first

Hisian pacing might entail a higher threshold than conventional pacing methods. Back-up stimulation on demand allows managing the risk of capture loss with the lowest energy cost. His-bundle and apical back-up leads were connected, respectively, to the V1 and V2 channels of a suitable three-chamber

Implantable cardioverter defibrillator (ICD) testing in patients with left ventricular noncompaction (LVNC) at the time of implantation and potential difficulties with ventricular fibrillation (VF) induction/termination in LVNC patients are often not stated in the literature. This report describes the failure of transvenous implantation of an ICD in a 40-year-old patient with LVNC and polycystic kidneys. A high defibrillation threshold (DFT) prevented termination of ICD-induced VF. This case suggests that DFT testing should be considered in any LVNC patient during ICD implantation. The association of LVNC and polycystic kidneys is also discussed. PACE 2012; 35:e40–e42)

Aims The deleterious effects of apical right ventricular pacing has fostered the utilization of alternative pacing sites. Although right ventricular septal (RVS) sites are commonly used, the results have been controversial because of poor standardization of lead position by fluoroscopy. This study investigated the utility of a new RVS pacing technique based on the combination of fluoroscopy (F), and electrophysiological mapping (F + EP). Left ventricular (LV) electromechanical activation was determined in patients undergoing RVS pacing and the results of the F + EP approach were compared with those derived from standard F alone. Methods and results Between December 2008 and November 2010 we enrolled 156 consecutive patients undergoing permanent RVS pacing. The standard F approach was used in 93 patients and the F + EP technique was applied to 63 patients. Electromechanical activation was assessed by: (i) electromechanical latency (EML) interval measured from the QRS onset to the mechanical activation of the basal LV and (ii) intra-LV dyssynchrony measured as the interval from the earliest to the latest LV basal motion. Intra-LV dyssynchrony was found in 46.2% patients in the F group compared with 15.9% in the group F + EP ( P < 0.001). The F group demonstrated a significantly higher degree of intra-LV dyssynchrony than F + EP group (43.9 ± 24.3 vs. 26.5 ± 15.4 ms; P < 0.001). The F group exhibited a significantly higher EML duration compared with the F + EP group (215.8 ± 25.3 vs. 195.1 ± 17.4 ms; P < 0.001). Conclusion During RVS pacing, the F + EP approach provides a more physiological LV activation than the standard F technique. The prognostic significance of these short-term findings needs to be correlated with long-term data.

The appearance of an increased pulmonary artery (PA) pressure is an important moment in the clinical history of mitral stenosis. A direct measurement of PA pressure levels is possible only with rightsided cardiac catheterization. This technique, being invasive is not risk-free and, consequently, many noninvasive methods for the evaluation of PA pressure have been proposed.1 These procedures usually lack sensitivity and are limited in their ability to detect and quantify mild to moderate modifications of PA pressure. The introduction of Doppler echocardiography allowed the development of new procedures.2–6 Unfortunately this method is not applicable in the absence of Doppler-detectable tricuspid regurgitation.7 Furthermore, the computed systolic PA pressure value is approximate because a clinical estimation of the right atrial pressure is necessary. Moreover, a good acoustic window and satisfactory flow tracings are indispensable. To avoid the aforementioned drawbacks we attempted a different approach to the noninvasive estimation of PA pressure, devising a method based on the modifications induced by an increased PA pressure on the power spectrum of the pulmonary component of the second heart sound. We used fast-Fourier analysis to examine the acoustic characteristics of this heart sound and to define its frequency distribution in patients with normal and increased PA pressure to search for a relation between the PA pressure level and the spectral characteristics of the pulmonary component of the second heart sound.

Objective To evaluate the effects of cardiac resynchronization therapy (CRT) on ventricular-arterial coupling (VAC) in patients with refractory congestive heart failure (HF), left bundle brunch block, and sinus rhythm. Background The ratio between arterial elastance (Ea) and left ventricular end-systolic elastance (Ees), the so-called VAC, defines the efficiency of the myocardium in pumping blood. Methods Seventy-eight patients were studied with echocardiography before CRT, and 1 year later. End-systolic elastance was calculated according to the method of Chen. Arterial elastance (ratio of the systolic pressure to the stroke volume), end-systolic volume (ESV), and quality of life (QoL) (Minnesota Living with Heart Failure Questionnaire) were assessed at the baseline and after 1 year. Patients with a reduction >15% of ESV or a decrease >33% in QoL score were considered responders to CRT. Results QRS duration and interventricular delay were significantly reduced with CRT compared with baseline (156 ± 2 vs. 195 ± 3 ms, P < 0.001; and 25 ± 2 vs. 55 ± 3 ms, P < 0.001, respectively). Arterial elastance/Ees decreased significantly on CRT (2.47 ± 1.48 vs. 1.41 ± 0.87, P < 0.0001). The lowering of Ea/Ees was congruent to a decrease in intraventricular delay (83.1 ± 55.7 vs. 28.4 ± 49.5 ms, P < 0.0001) and an increase in ejection fraction (26 ± 6.3 vs. 36.9 ± 8.0%, P < 0.0001). Responders to CRT were 74 and 71% of the overall patient population, considering as endpoint QoL or ESV, respectively. The analysis of VAC showed a baseline cut-off value of 2, above which 88% and 69% of patients responded to CRT, considering as endpoint QoL or ESV, respectively. Conclusions The non-invasive assessment of VAC may be proposed as an immediate, easy, and optimal tool for quantifying the effect of CRT in patients with HF.

To evaluate the prevalence of severe right atrial conduction delay in patients with sinus node dysfunction (SND) and atrial fibrillation (AF) and the effects of pacing in the right atrial appendage (RAA) and in the inter-atrial septum (IAS).Forty-two patients (15 male, 72 +/- 7 years) underwent electrophysiologic study to measure the difference between the conduction time from RAA to coronary sinus ostium during stimulation at 600 ms and after extrastimulus (DeltaCTos). Patients were classified as group A if DeltaCTos60 ms and group B if60 ms. Each Group was randomized to RAA/IAS pacing and algorithms ON/OFF.Fifteen patients (36%, group A) had DeltaCTos = 76 +/- 11 ms and 27 patients (64%, group B) had DeltaCTos = 36 +/- 20 ms. Twenty-two patients were paced at the RAA and 20 at the IAS. During the study, no AF recurrences were reported in 11 of 42 (26%) patients, independently of RAA or IAS pacing. Patients from group A and RAA pacing had 0.79 +/- 0.81 episodes of AF/day during DDD, which increased to 1.52 +/- 1.41 episodes of AF/day during DDDR + Alg (P = 0.046). Those with IAS pacing had 0.5 +/- 0.24 episodes of AF/day during DDD, which decreased to 0.06 +/- 0.08 episodes of AF/day during DDDR + Alg (P = 0.06). In group B, no differences were reported between pacing sites and pacing modes.Severe right atrial conduction delay is present in one-third of patients with SND and AF: continuous pacing at the IAS is superior to RAA for AF recurrences. In patients without severe conduction delay, no differences between pacing site or mode were observed.

Increasing clinical evidence shows that conventional right ventricular pacing is detrimental to left ventricular function. Recent studies in canines [1] showed that right ventricular apical (RVA) pacing causes abnormal contraction patterns due to abnormal activation of the left ventricle during RVA pacing compared to normal sinus rhythm. Moreover, these studies gave evidence that sustained RVA pacing is associated with histological and structural changes that cause left ventricular function to deteriorate. In humans, shortand long-term studies [2, 3] have confirmed the adverse effects of RVA pacing. A theoretical pacing system that could preserve the normal Purkinje activation should be considered the ideal pacing approach, because the ventricular dyssynchrony would be prevented and the normal activation pattern maintained. However, the traditional pacing tools do not allow an easy approach to the His bundle, and therefore few clinical reports of this pacing mode exist in the literature. Deshmukh et al. [4, 5] reported the results of direct His-bundle pacing (DHBP) in patients with chronic heart failure and atrial fibrillation who were candidates for ablate-and-pace strategy because of a rapid and pharmacologically uncontrolled ventricular rate. According to Deshmukh et al., the criteria for verification of the DHBP were the following: (1) recording of His bundle potential with the permanent pacing lead; (2) pace-ventricular interval equal to His-ventricular interval ± 15 ms; (3) paced QRS morphology and duration equal to the intrinsic QRS in all 12 ECG leads. Twelve out of 18 patients in the first study and 39 out of 54 patients in the second study were successfully paced. In a long-term follow-up (42 months) the

Introduction: Much clinical evidence has shown that right ventricular (RV) apical pacing is detrimental to left ventricular function. Preservation of the use of the His-Purkinje (H-P) system may be ideal in heart block that is restricted to the AV node, but may be of no benefit when H-P disease exists. Aim: To investigate the feasibility of direct His-bundle pacing (DHBP) using a new system consisting of a steerable catheter and a new 4.1 F screw-in lead. Method: Between May and December 2004, 26 patients (19 male, mean age: 77 ± 5 years) with a standard pacemaker (PM) indication and preserved His-bundle conduction were enrolled and DHBP was attempted. Results: DHBP was achieved in 24 patients (92%); two patients were paced in the His area, but the paced QRS morphology and duration were different from the native QRS. The mean time for lead positioning was 19 ± 17 minutes, the mean fluoroscopy time was 11 ± 8 minutes, and the total procedure time (skin-to-skin including positioning of a quadripolar diagnostic catheter for His recording) was 75 ± 18 minutes. In DHBP pacing, the acute pacing threshold was 2.3 ± 1.0 V at a pulse duration of 0.5 msec, and the sensed potentials were 2.9 ± 2.0 mV. At a 3-month follow-up examination, the same QRS duration and morphology recorded on implantation were observed in all patients. The pacing threshold was 2.8 ± 1.4 V, and sensed potentials were 2.5 ± 1.8 mV; the sensing configuration was changed from bipolar to unipolar in 6 patients to resolve undersensing issues. No major complications were observed. Conclusions: This feasibility study shows that DHBP can be accomplished with a new system consisting of a steerable catheter and an active fixation lead in 92% of the patients in whom it was attempted.

A 14-year-old girl was rescued from a sudden cardiac arrest at school. Aortography disclosed mild aortic root dilation with aortic valve incompetence and subocclusion of coronary ostia and left common carotid artery. An emergency aortocoronary bypass operation was undertaken, but the patient did not recover from cardiopulmonary bypass. Postmortem disclosed massive myocardial infarction. The microscopic feature of arterial involvement was consistent with giant cell Takayasu's arteritis. The abrupt clinical presentation in this teenager with coronary ostial subocclusion is very unusual.