Percentage Of Right Ventricular Pacing Research Articles

THROW YOUR LEAD OVER THE OBSTACLE: A CHALLENGING CRT UPGRADING

Abstract High percentage of right ventricular pacing could lead to pacing induced cardiomyopathy in a non–negligible proportion of patients. Cardiac resynchronization therapy upgrading could represent an option to improve ventricular function, reducing heart failure hospitalizations. A 82 yo male was admitted to hospital with symptomatic heart failure. He had history of complete AV block treated with dual chamber pacemaker implantation five years earlier following coronary artery bypass graft surgery, bioprosthetic aortic valve replacement and septal myectomy. He had also history of cardiac arrest occurred in the context of acute coronary syndrome treated with PCI so that ICD implant was not considered at that time, and two more HF hospitalizations in previous years. Progressive LVEF decline was documented since PM impantation until last echo showed severe left ventricular dysfunction (EF 20% from baseline EF 60%). The ECG showed sinus rhythm and wide paced QRS (206 ms) with 100% pacing percentage. A CRT device upgrading was planned. Baseline venography initially showed pervious axillary–subclavian left axis, but unfortunately the guidewire encountered a complete occlusion before entering the superior vena cava. Nevertheless, dye contrast injection documented the presence of a proximal collateral branch (fig A) having a vertical course in the thorax and reaching the lateral wall of the left ventricle with an extrapericardic course then entering the right heart through inferior vena cava. Using a IM 5Fr sheath (usually used by interventional cardiologists to cannulate internal mammary artery) we could reach this branch, inserting a guidewire and finally advancing a quadripolar lead (Fig B–C) which reached the lateral left ventricular wall. LV capture was confirmed when pacing from the three proximal poles, while the distal one caused phrenic nerve capture. The quadripolar lead was connected to the LV port of a three chamber PM along with previous implanted leads thus obtaining biventricular pacing. QRS paced was 50 ms shorter than baseline. No peri–procedural complications occurred. Lead–related venous occlusion might represent an obstacle to CRT upgrade requiring high technical expertise. The presence of a complete venous occlusion might cause procedural failure, particularly in hospitals without surgical facility. In this case, the presence of a collateral branch reaching the lateral wall of the left ventricle allowed to successfully complete the CRT upgrade.

Initial heart rate score predicts new-onset atrial tachyarrhythmias in pacemaker patients.

Heart rate score (HRSc), the per cent of atrial paced and sensed event in the largest 10 b.p.m. rate histogram bin of a pacemaker, predicts survival in patients with cardiac devices. No correlation between HRSc and development of atrial fibrillation (AF) has been reported. In this study, we evaluated the relationship between pacemaker post-implantation HRSc and the incidence of newly developed atrial tachyarrhythmias (ATAs). Patients with dual-chamber pacemakers, implanted 2013-17, with the LATITUDE remote monitoring data with ≥600 000 beats of histogram data collected at baseline were included (N = 34 543). Heart rate score was determined from the initial 3-month post-implantation histogram data. Patients were excluded if they had ATAs, defined as atrial high-rate episodes >5 min or >1% of right atrial beats >170 b.p.m. during the initial 3 months post-implantation. New ATAs, after the baseline period, were defined by each of the following: >1, >10, or >25% of atrial beats >170 b.p.m. or atrial tachycardia response (ATR) events >24 h. Patients were followed a median of 2.8 (1.0-4.0) years. The incidence of ATAs increased in proportion to HRSc (log-rank P-value <0.001), and the initial HRSc ≥70% was associated with increased ATAs by all definitions. Patients with initial HRSc ≥70% were older, had a higher percentage of right atrium pacing (%RA pacing), had a lower percentage of right ventricular pacing (%RV pacing), and were more likely programmed with rate-response vs. subjects with HRSc <70%. Initial HRSc (hazard ratio: 1.07, 95% confidence interval: 1.05-1.09; P < 0.0001) independently predicted ATAs after adjusting for age, gender, %RV pacing, and rate-response programming. The %RA pacing and initial HRSc were correlated. Heart rate score independently predicts any subsequent duration of ATAs in pacemaker patients.

Variation in optimal hemodynamic atrio-ventricular delay of biventricular pacing with different endocardial left ventricular lead locations using precision hemodynamics.

It is not known whether the optimal atrioventricular (AVopt ) delay varies between left ventricular (LV) pacing site during endocardial biventricular pacing (BiVP) and may therefore needs consideration. We assessed the hemodynamic AVopt in patients with chronic heart failure undergoing endocardial LV lead implantation. AVopt was assessed during atrio-BiVPwith a "roving LV lead."Up to four locations were studied: mid-lateral wall, mid-septum (or a close alternative), site of greatest hemodynamic improvement, and LV lead implant site. The AVopt was compared to a fixed AV delay of 180 ms. Seventeen patients were included (12 male, aged 66.5 ± 12.8 years, ejection fraction 26 ± 7%, 16 left bundle branch block or high percentage of right ventricular pacing [RVP], QRS duration 167 ± 27 ms). In most locations (62/63), AVopt increased systolic blood pressure during BiVP compared with RVP (relative improvement 6 mmHg,interquartile range [IQR] 4-9 mmHg). Compared to a fixed AV delay, the hemodynamic improvement at AVopt was higher (1 mmHg, IQR 0.2-2.6 mmHg, p < .001). Within most patients (16/17), we observed a difference in AVopt between pacing sites (median paced AVopt 209 ms, IQR 117-250). Within this range, the hemodynamic impact of these differences was small (median loss 0.6 mmHg, IQR 0.1-2.6 mmHg). Within a patient, different endocardial LV lead locations have slightly different hemodynamic AVopt which are superior to a fixed AV delay. The hemodynamic consequence of applying an optimum from a different lead location is small.

Impact of Right Ventricular Pacing in Patients With TAVR Undergoing Permanent Pacemaker Implantation

BackgroundLong-term right ventricular pacing (VP) has been related to negative left ventricular remodeling and heart failure (HF), but there is a lack of evidence regarding the prognostic impact on transcatheter aortic valve replacement (TAVR) patients. ObjectivesThe aim of the PACE-TAVI registry is to evaluate the association of high percentage of VP with adverse outcomes in patients with pacemaker implantation after TAVR. MethodsPACE-TAVI is an international multicenter registry of all consecutive TAVR patients who underwent permanent pacemaker implantation for conduction disturbances in the first 30 days after the procedure. Patients were divided into 2 subgroups according to the percentage of VP (<40% vs ≥40%) at pacemaker interrogation. The primary endpoint was the composite of cardiovascular mortality or hospitalization for HF. ResultsA total of 377 patients were enrolled, 158 with VP <40% and 219 with VP ≥40%. After multivariable adjustment, VP ≥40% was associated with a higher incidence of the primary endpoint (HR: 2.76; 95% CI: 1.39-5.51; P = 0.004), first HF hospitalization (HR: 3.37; 95% CI: 1.50-7.54; P = 0.003), and cardiovascular death (HR: 3.77; 95% CI: 1.02-13.88; P = 0.04), while the incidence of all-cause death was not significantly different (HR: 2.17; 95% CI: 0.80-5.90; P = 0.13). Patients with VP ≥ 40% showed a higher New York Heart Association functional class both at 1 year (P = 0.009) and at last available follow-up (P = 0.04) and a nonsignificant reduction of left ventricular ejection fraction (P = 0.18) on 1-year echocardiography, while patients with VP <40% showed significant improvement (P = 0.009). ConclusionsIn TAVR patients undergoing permanent pacemaker implantation, a high percentage of right VP at follow-up is associated with an increased risk for cardiovascular death and HF hospitalization. These findings suggest the opportunity to minimize right VP through dedicated algorithms in post-TAVR patients without complete atrioventricular block and to evaluate a more physiological VP modality in patients with persistent complete atrioventricular block.

Risk factors of pacing dependence and cardiac dysfunction in patients with permanent pacemaker implantation.

AimsRight ventricular pacing (RVP) dependence could impair left ventricular ejection fraction (LVEF). This study aimed to illuminate the relationship between RVP proportion and LVEF, as well as disclosing independent predictors of RVP dependence.Methods and resultsPatients indicated for permanent pacemaker implantation were included (2016–2020). The ventricular pacing lead was placed in right ventricular apex or septum. Pacing mode programming followed universal standard. Electrocardiographic, echocardiographic, and serological parameters were collected. RVP dependence was defined according to its influence on LVEF. This study was of case–control design. Included patients were matched by potentially confounding factors through propensity score matching. A total of 1183 patients were included, and the mean duration of follow‐up was 24 months. Percentage of RVP < 80% hardly influenced LVEF; however, LVEF tended to decrease with higher RVP proportion. High degree/complete atrioventricular block (AVB) [odds ratio (OR) = 5.71, 95% confidence interval (CI): 3.66–8.85], atrial fibrillation (AF) (OR = 2.04, 95% CI: 1.47–2.82), percutaneous coronary intervention (PCI) (OR = 2.89, 95% CI: 1.24–6.76), maximum heart rate (HRmax) < 110 b.p.m. (OR = 2.74, 95% CI: 1.58–4.76), QRS duration > 120 ms (OR = 2.46, 95% CI: 1.42–4.27), QTc interval > 470 ms (OR = 2.01, 95% CI: 1.33–3.05), and pulmonary artery systolic pressure (PASP) > 40 mmHg (OR = 1.93, 95% CI: 1.46–2.56) were proved to predict RVP dependence.ConclusionsHigh RVP percentage (>80%) indicating RVP dependence significantly correlates with poor prognosis of cardiac function. High degree/complete AVB, AF, ischaemic aetiology, PCI history, HRmax < 110 b.p.m., QRS duration > 120 ms, QTc interval > 470 ms, and PASP > 40 mmHg were verified as independent risk factors of RVP dependence.

Dual-chamber cardiac pacing effect on left and right atria morphometric parameters and function

Abstract Background Dual-chamber pacemaker implantation is a standard interventional treatment strategy for atrioventricular block (AVB) and sick sinus syndrome (SSS). It has been proven that a high percentage of right ventricular pacing might have detrimental effects on cardiac function. However, there is a lack of data on atrial pacing effect on left (LA) and right (RA) atria function. Purpose To assess the impact atrial pacing on left and right atria morphologic and functional parameters in patients after dual-chamber pacemaker implantation. Methods We conducted a prospective study that included patients who received a dual-chamber pacemaker for an indication of AVB or SSS. After signing of the informed consent pacemaker was programmed for base rate of 40 bpm and no rate response in case of clear AVB indication or for base rate of 60 bpm and rate response if indication was SSS. An transthoracic echocardiography was done the next day after pacemaker implantation and after one month at follow up (FU). During the FU the atrial pacing (AP) and ventricular pacing (VP) percentage were captured. To exclude the impact of right ventricular pacing, patients with high VP percentage (&amp;gt;40%) were excluded from analysis. Patients were divided into two groups – group A with high AP (&amp;gt;50%), and group B – low AP (&amp;lt;50%). LA expansion fraction reflecting reservoir function, emptying – reflecting conduit, and active emptying reflecting “atrial kick” were analysed. To compare means the Mann Whitney U test, and for categorical variables – X2 test were used. Results A total of n=100 patients underwent dual-chamber implantation and signed informed consent. Due to significant structural heart disease or reduced ejection fraction (&amp;lt;50%) 11 patients were excluded. Out of those, n=30 were excluded due to a high VP percentage. Group consisted of n=28 and group B of – n=31 patients. Average AP in group A was 66.2% and 5.0% in group B. The mean age (group A 73.6 SD 8.8 years vs group B 79.2 SD 7.3 years, p=0.197), gender distribution (group A males 45.5% vs group B 50.0%, p=0.773), and mean BMI (group A 26.5 SD 4.7 kg/m2 vs group B 29.2 SD 3.3 kg/m2, p=0.191) did not differ significantly between the two groups. The baseline LA and RA morphometric and functional parameters presented in figure 1 and did not differ significantly between the two groups. The change in LA and RA functional parameters presented in figure 2. Even though it did not reach statistical significance, a tendency for lower LA expansion fraction, active emptying fraction and LA ejection fraction were observed in group A. RA morphometric parameters did not change significantly between the two groups at FU. Conclusion A higher percentage of atrial pacing in dual-chamber pacemaker population could lead to impaired LA function over time. Though, longer observational period is needed. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2

Long-term follow-up of heart transplant patients treated with permanent pacemaker: a monocentric study

Abstract Funding Acknowledgements Type of funding sources: None. Background and purpose Permanent pacemaker implantation (PPMi) is needed in about 5% of patients following heart transplant (HTx) primarily due to sinus node dysfunction (SND), which commonly occurs in an early phase, or to atrio-ventricular block (ABV), which is common later on. Currently, data on rate of ventricular pacing (VP) is lacking and little is known on long-term outcomes after PPMi. Methods This was a retrospective, monocentric study. Among 1123 patients treated with HTx, all with biatrial technique, from november 1985 to march 2019 at our institution, 61 (5.4%) patients needed PPMi. PM parameters, clinical and echocardiographic data were collected at 1 month and at 1-3-5-10 years follow-up. The primary aim was to analyse the percentage of right ventricular pacing in the overall population and in subgroups stratified by the timing of PPMi and by pacing indication. Secondary endpoints were to analyze long-term outcomes according to the percentage of ventricular pacing and to the type of implanted PM (single vs. dual chamber). Results Among patients treated with PPMi (68.9% single-chamber), 62.2% were implanted for SND and 36% for AVB. Early PPMi (&amp;lt; 3 months after HTx), occurred in 34.4% of patients, mainly due to SND, while late PPMi (&amp;gt; 3 months after HTx) occurred in 65,6% with an equal distribution between SND and AVB. Median follow-up time from HTx was 140 months and 82 months from PPMi. Overall mean rate of VP was 21%. Rate of VP was higher in patients implanted early rather than late after HTx, both at 1 month (91% vs 2%, P = 0,002) and at 1 year after the procedure (43 vs 1, P = 0,037). Patients with AVB had a greater rate of VP compared to those implanted for SND, irrespective of timing of implantation and these findings were still present at 3 and 5 years follow-up (62 vs 1%, P = 0,011 at 3 years and 80 vs 6%, P = 0,002 at 5 years). VP declined progressively after PPM implantation. No differences were observed in terms of 10-years mortality between early vs late PPMi, dual vs single-chamber and mean VP &amp;gt; 21% vs ≤ 21%. Conclusions Patients treated with PPMi after HTx show on average low percentage of VP over long-term follow-up. AV block indication and early implantation are associated with a higher percentage of VP. The rate of VP, the timing of PPMi and the use of single vs dual chamber PM do not affect overall prognosis or left ventricular systolic function. Our data may justify implantation of a single-chamber PPM, which bears less complications and procedural time, in the majority of HTx patients needing PPMi.

Catheter ablation for atrial fibrillation in patients with end-stage heart failure and eligibility for heart transplantation.

AimsTimely referrals for transplantation and left ventricular assist device (LVAD) play a key role in favourable outcomes in patients with advanced heart failure (HF). The purpose of the Catheter Ablation for atrial fibrillation in patientS with end‐sTage heart faiLure and Eligibility for Heart Transplantation (CASTLE‐HTx) trial is to test the hypothesis that atrial fibrillation (AF) ablation has beneficial effects on mortality and morbidity during ‘waiting time’ for heart transplantation (HTx) or to prolong the time span until LVAD implantation.Methods and ResultsCASTLE‐HTx is a randomized evaluation of ablative treatment of AF in patients with severe left ventricular dysfunction who are candidates and eligible for HTx. The primary endpoint is the composite of all‐cause mortality, worsening of HF requiring a high urgent transplantation, or LVAD implantation. The secondary study endpoints are all‐cause mortality, cardiovascular mortality, cerebrovascular accidents, worsening of HF requiring unplanned hospitalization, AF burden reduction, unplanned hospitalization due to cardiovascular reason, all‐cause hospitalization, quality of life, number of delivered implantable cardioverter defibrillator therapies, time to first implantable cardioverter defibrillator therapy, number of device‐detected ventricular tachycardia/ventricular fibrillation episodes, left ventricular function, exercise tolerance, and percentage of right ventricular pacing. Ventricular myocardial tissue will be obtained from patients who will undergo LVAD implantation or HTx to assess the effect of catheter ablation on human HF myocardium. CASTLE‐HTx will randomize 194 patients over a minimum time period of 2 years.ConclusionsCASTLE‐HTx will determine if AF ablation has beneficial effects on mortality in patients with end‐stage HF who are eligible for HTx.

Leadless pacemaker for patients following cardiac valve intervention

Permanent pacing is common after valve intervention. The presence of a conventional pacemaker in this population is recognized as a risk factor for infectious events. Therefore, a leadless pacing system could be the preferred strategy when permanent pacing is required after valve intervention. To report periprocedural outcomes and follow-up of patients undergoing implantation of a leadless pacing system after valve intervention. Patients with previous valve intervention at the time of attempted implantation of a leadless pacemaker (Micra™, Medtronic, Minneapolis, MN, USA) were included, and were compared with a control group (patients also implanted with Micra™ without valve intervention). Among a total of 170 Micra™ implantation procedures, 54 patients (31.8%) had a history of valve intervention: 28 after aortic valve replacement; 10 after mitral valve replacement; one after single tricuspid valvuloplasty; and 15 after multiple valve surgery. Median age of the patients was 82.5 (77.0-86.0) years and 53.7% were male. Patients with previous valve intervention had a higher incidence of arterial hypertension (P=0.014) and ischaemic heart disease (P=0.040). The primary indications for permanent pacing after valve intervention were high-degree atrioventricular block (59.3%) and atrial fibrillation with bradycardia (27.8%). Micra™ was successfully implanted in all patients (n=170) without any procedure-related major complications. During a median follow-up of 12 months, electrical performance was excellent and similar in both groups. Also, a similar reduction in left ventricular ejection fraction was observed at 12 months in both groups, which was correlated with the percentage of right ventricular pacing. A leadless pacemaker is safe and efficient after valve intervention, and therefore represents an effective pacing option in patients after valve intervention.

Paroxysmal supraventricular tachycardia in patient with dilated cardiomyopathy and concomitant cardiac conduction defects: a case report and discussion

Patients with dilated cardiomyopathy (DCM) often have intraventricular conduction disorders, which contribute to aggravation of heart failure, are progressive in most cases and can specify the prognosis of the disease. Paroxysmal supraventricular arrhythmias in such patients proceed with severe clinical manifestations, often accompanied by hemodynamic instability and syncope. A case report of patient (59 years old) with DCM, reduced left ventricular ejection fraction (35-37%), left bundle branch block, and paroxysmal orthodromic reciprocating tachycardia is presented. When an electrode was inserted on the right ventricular (RV) apex during the radiofrequency ablation, a third-degree atrioventricular (AV) block was recorded. This was maintained during the operation and was recurrent when trying to remove the electrode from the RV apex, and therefore there was a need for temporary and then permanent cardiac pacing therapy. Given DCM, reduced left ventricular ejection fraction, left bundle branch block, and the expected high percentage of RV pacing, a decision was made to implant a cardiac resynchronization therapy defibrillator. The literature review considers risk factors for formation of third-degree AV block during cardiac catheterization, methods of its prevention, as well as discusses the prognostic significance of catheter-induced conduction disorders, and indications for temporary and permanent cardiac pacing therapy.

Long-term percentage of ventricular pacing in patients requiring pacemaker implantation after transcatheter aortic valve replacement: A multicenter 10-year experience

Recent studies suggest that atrioventricular (AV) conduction may recover after pacemaker (PM) implantation following transcatheter aortic valve replacement (TAVR), but little is known about long-term follow-up of such patients. The purpose of this study was to evaluate the long-term percentage of right ventricular pacing in patients who underwent TAVR and required PM implantation stratified based on the indication for permanent pacing. Retrospective analysis of all consecutive patients who underwent TAVR from February 2008 to August 2019 at 3 centers was performed. Patients already implanted with a PM/implantable cardioverter-defibrillator (ICD) before TAVR, implanted with a cardiac resynchronization therapy device, or implanted >30 days after TAVR were excluded. Eligible patients were divided into 2 groups based on the presence (persistent atrioventricular block [AVB] group) or absence (nonpersistent AVB group) of persistent third-degree AVB after TAVR. A total of 1594 patients underwent TAVR. Two hundred four patients were implanted with a PM or ICD after TAVR and 32 met exclusion criteria, so 172 patients were eligible (median time TAVR-PM implant 4 days) for a total of 352 follow-up visits analyzed. A significant difference in the percentage of ventricular pacing was observed at follow-up performed 7-90 days after implantation (98% persistent AVB group vs 8% nonpersistent AVB group; P <.001). This difference remained significant at follow-up performed 91-270 days (95% vs 3.5%; P <.001), 271-540 days (95.5% vs 3%; P = .006), and 541-900 days (97.4% vs 2.2%; P <.001) after implantation. Patients requiring PM implantation due to persistent third-degree AVB after TAVR were less likely to show AV conduction recovery, whereas patients implanted for other indications showed a low percentage of pacing during follow-up.

Estimation of OptiVol Alert for Identifying Heart Failure in Conventional Bradyarrhythmia Pacing Patients with Preserved Left Ventricular Function: A Multicenter Prospective Cohort Study (OptiVol Study)

BACKGROUND: The usefulness of OptiVol, an algorithm to detect heart failure (HF) using continuous intrathoracic impedance monitoring, is established in high-power device patients with reduced left ventricular ejection fraction (LVEF). However, the utility of OptiVol in conventional bradyarrhythmia pacing patients with preserved LVEF is not established. OBJECTIVES: This study aimed to describe the utility of the OptiVol alert feature in monitoring HF in conventional pacemaker or implantable-cardioverter defibrillator (ICD) patients with preserved LVEF. METHODS: Forty-three patients implanted with a conventional pacemaker or ICD with the OptiVol function were enrolled. Of these, 39 completed the observation period. OptiVol fluid index and cumulative percentage of right ventricular pacing (%RVp) were obtained every three months for 12 months after device implantation. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) to predict HF hospitalization of the OptiVol alert defined by an OptiVol fluid index &gt;100Ω-day or &gt;60Ω-day were compared. The combination of OptiVol positivity and right ventricular pacing site and/or %RVp &gt;40% for the prediction of HF hospitalization were also assessed. RESULTS: Three patients (7.6%) had HF hospitalization within one year after device implantation. The sensitivity, specificity, PPV and NPV of OptiVol alert definition with OptiVol fluid index &gt;100Ω-day were 100%, 64%, 19%, and 100%, while those of OptiVol alert definition with OptiVol fluid index &gt;60Ω-day were 100%, 42%, 13% and 100%, respectively. These parameters were improved by the combination of OptiVol fluid index &gt;100Ω-day and RV apex pacing and/or %RVp &gt;40%, attaining values of 100%, 97%, 75%, and 100%, respectively; by the combination of OptiVol alert and RV apex pacing; or their combination. CONCLUSION: The OptiVol alert using cut-off value of 100Ω-day would be useful for the prediction of HF hospitalization in conventional bradyarrhythmia pacing patients with preserved LVEF. The utility of OptiVol alert would be emphasized in patients with RV apex pacing and/or %RVp &gt;40%. KEYWORDS: Heart failure; bradycardia; cardiac pacing; OptiVol; intrathoracic impedance

Impact of QRS Duration and Ventricular Pacing on Clinical and Arrhythmic Outcomes in Continuous Flow Left Ventricular Assist Device Recipients: A Multicenter Study

Wide QRS duration and ventricular pacing are common in recipients of continuous-flow left ventricular assist devices (CF-LVADs) but their impact on outcomes remains unclear. We assessed the clinical and arrhythmic outcomes of CF-LVAD patients with wide QRS or right ventricular (RV) pacing at baseline, compared with those with narrow QRS and those with continued cardiac resynchronization therapy (CRT). A total of 520 patients (57 ± 13 years) with an implantable cardioverter-defibrillator (ICD) (n = 240) or CRT-defibrillator (n = 280) who underwent CF-LVAD implantation at 5 centers in 2007-2015 were studied. Patients were divided into 3 groups: ICD-N (QRS ≤120 ms; n = 134), ICD-W (QRS >120 ms; n = 106), and CRT (n = 280). Mortality, hospitalization, and ventricular arrhythmia (VA) incidence were compared among the groups. Baseline QRS duration was different among the groups (100 ± 13 [ICD-N] vs 155 ± 26 [ICD-W] vs 159 ± 29 ms [CRT]; P < .0001). In the ICD-W group, 37 (35%) had >80% RV pacing at baseline. Median biventricular pacing in the CRT group was 96%. Over 523 days of CF-LVAD support, Kaplan-Meier analysis showed no difference in survival among groups (log rank P = .9). According to multivariate Cox regression, wide QRS duration and RV pacing were not associated with survival. QRS narrowed during CF-LVAD support in the ICD-W and CRT groups but was not associated with improved survival (P = .9). No differences were noted among the groups in hospitalizations (P = .9), VA (P = .2), or ICD shocks (P = .06). In this large CF-LVAD cohort, a wide QRS duration, high percentage of RV pacing at baseline, and changes in QRS duration after LVAD implantation were not associated with survival. Continued CRT after CF-LVAD implantation also was not associated with improved survival or HF hospitalizations.

Badanie EKG metodą Holtera u chorego z urządzeniem wszczepialnym — przykłady algorytmów ograniczających stymulację prawej komory

High percentage of right ventricular pacing is associated with an increased risk of adverse clinical events such as worsening of heart failure symptoms or atrial fibrillation. Right ventricular pacing should be minimized especially in patients with heart failure and reduced left ventricular ejection fraction after implantation of one- or two-chamber cardioverter-defibrillator. Adequate atrioventricular delay programming or appropriate pacing mode programming that promotes patients own rhythm for example AAI/DDD or DDD/ADI helps in avoiding right ventricular pacing. There are special algorithms, different between pacemaker-producing companies, basing on the above methods that spare right ventricular pacing. Some of those algorithms can mimic pacemaker dysfunction and can be a challenge during Holter electrocardiogram (ECG) interpretations. In this article Holter ECG examples of different algorithms to reduce right ventricle pacing are presented and discussed.

Occurrence of implantable cardioverter-defibrillator therapy in clinical practice

The landmark trials MADIT II, SCD-HeFT, and COMPANION in 2002–2005 years have reported their positive results to sudden cardiac death reduction. Since that time the indications for the use of implantable cardioverter-defibrillators (ICDs) have substantially broadened. The occurrence of appropriate ICD therapy differs in the individual trials. We were retrospectively analyzing the occurrence of ventricular tachycardia/ventricular fibrillation (VT/VF) from ICD remote monitoring database (Biotronik Home Monitoring TM, www.biotronik-homemonitoring.com). No significant difference was found between subgroups divided by the implantation indication, the programmed ventricular stimulation, the aggressivity of programmed ventricular stimulation protocol, left ventricular ejection fraction, ICD types, percentage of right ventricular pacing, diabetes mellitus, renal dysfunction and gender. VT/VF occurred statistically significantly more often in patients with non-sustained VT on the preimplant Holter monitoring report in patients with primary preventive indication for postinfarction coronary artery disease but not in primary preventive indication for non-ischemic dilated cardiomyopathy. We observed higher VT/VF occurrence in patients with preimplant syncope or presyncope even higher than in patients after cardiopulmonary resuscitation. There was a visible trend for higher VT/VF occurrence in patients with positive programmed ventricular stimulation especially with less aggressive protocol and in patients with left ventricular ejection fraction of 30% and less. Authors found the preimplant nonsustained ventricular tachycardia (NSVT) on Holter monitoring as the only independent predictor of VT/VF occurrence.

Reducing Ventricular Pacing Frequency in Patients With Atrioventricular Block: Is It Time to Change the Current Pacing Paradigm?

With aging of the general population, an increased incidence of conduction disease will result in an increased need for permanent pacemaker therapy. According to the 2015 European Heart Rhythm Association (EHRA) White Book, in the 56 member countries of the European Society of Cardiology (ESC), the pacemaker implantation rate has increased from a mean implantation rate of 614 per million inhabitants in 2010 to 641 in 2014, thus growing at a rate of about 0.4% to 0.6% per year.1 Much has been learned from clinical studies to identify optimal device mode selection and device programming for an individual patient to maximize the benefits of cardiac implantable electronic device therapy, as well as to minimize any potential adverse outcomes caused by ventricular pacing (VP). Several clinical studies have reported that chronic right ventricular (RV) pacing has detrimental effects on cardiovascular outcomes, including adverse cardiac remodeling, atrial fibrillation (AF), congestive heart failure (HF), and mortality. The potential mechanism(s) by which RV pacing increases the risk for HF and AF are not completely elucidated, but are likely caused by both electric and mechanical dyssynchrony, disruption of sympathetic/parasympathetic balance that alters myocardial activation pattern and contraction sequence, thereby modifying myocardial strain resulting in less efficient contraction. These changes lead to chamber enlargement, functional mitral regurgitation, reduction of parasympathetic/sympathetic balance in response to reduced ventricular output, and contribute to the development of HF and AF. Notably, not all patients paced in the RV experience adverse outcomes; these detrimental effects seem to be dependent on a high cumulative percentage of RV pacing, generally indicated by >40%. Furthermore, the increased risk of HF has been more frequently observed in those with pre-existing left ventricular (LV) systolic dysfunction. A recent review by Gillis2 has covered the optimal pacing mode for RV and biventricular devices. It is …

Long‐Term Impact of Right Ventricular Pacing on Left Ventricular Systolic Function in Pacemaker Recipients With Preserved Ejection Fraction: Results From a Large Single‐Center Registry

BackgroundThere is limited evidence of long‐term impact of right ventricular pacing on left ventricular (LV) systolic function in pacemaker recipients with preserved LV ejection fraction (LVEF). The objective of the study was to evaluate the outcome and echocardiographic course of baseline preserved LVEF in a large cohort of pacemaker recipients with respect to pacing indication and degree of right ventricular pacing.Methods and ResultsWe enrolled 991 patients (73±10 years, 54% male) with baseline normal (>55%) LVEF (n=791) or mildly reduced (41–55%) LVEF (n=200) who had paired echocardiographic data on LV systolic function recorded at implantation and last follow‐up. According to pacing indication, patients were divided into atrioventricular block group A (n=500) and sinus node disease group B (n=491). Main outcome measures were all‐cause mortality and deterioration of LV function ≥2 LVEF categories at last follow‐up. Patients were followed for an average of 44 months. Death from any cause occurred in 166 (17%), and deterioration of LV function ≥2 LVEF categories in 56 (6%) patients. There was no significant difference in outcome between group A and group B either in patients with normal LVEF or in those with mildly reduced LVEF. Mean percentage of right ventricular pacing was not predictive of outcome.ConclusionsIn a large cohort of pacemaker recipients with predominantly normal LVEF, clinically relevant LV dysfunction develops rather infrequently. No significant difference in all‐cause mortality and development of severe LV dysfunction is observed between patients with atrioventricular block and sinus node disease. Accordingly, de novo biventricular pacing cannot be recommended for patients with preserved LVEF.

Pacing From the Right Ventricular Septum and Development of New Atrial Fibrillation in Paced Patients With Atrioventricular Block and Preserved Left Ventricular Function.

Whether pacing from the right ventricular (RV) septum improves prognosis is unclear. Furthermore, the clinical characteristics of patients who develop atrial fibrillation (AF) and cardiovascular events during long-term RV septal pacing have not been described.Methods and Results:We retrospectively evaluated the incidence of AF and cardiovascular events, including cardiac death, heart failure requiring hospitalization, or stroke, for a median of 4.0 years in 123 recipients of dual-chamber pacemakers implanted for atrioventricular block with preserved left ventricular function, who were free from AF before device implantation. AF developed in 30 patients (24%), and multivariable analysis suggested that the cumulative percentage of RV pacing was the only independent predictor of newly developed AF (hazard ratio: 1.19 for each 10% increment; 95% confidence interval: 1.04-1.41; P=0.01). Furthermore, older age, newly developed AF and a paced QRS duration ≥155 ms at pacemaker implantation were significant predictors of cardiovascular events. RV septum pacing may induce AF in up to one-quarter of patients paced for atrioventricular block, according to the frequency of pacing. More importantly, in such patients, AF induced by RV pacing and a paced QRS duration ≥155 ms at pacemaker implantation are significantly associated with poor prognosis. Therefore, we recommend pacing from sites producing a paced QRS duration <155 ms and avoiding unnecessary RV pacing. (Circ J 2016; 80: 2302-2309).

Upgrading and replacement in CRT devices: experience counts.

Cardiac resynchronisation therapy has proven to be highly effective in patients with heart failure and an asynchronous contraction pattern of the left ventricle, due to late activation of the posterolateral wall with left bundle branch block configuration on the ECG of more than 150 ms [1]. In pacemaker patients with a high percentage of right ventricular pacing, pacing-induced left ventricular (LV) dysfunction can appear. This newly developing heart failure is most probably the result of pacing-induced LV asynchrony. These patients with pacing-induced heart failure and ICD patients with heart failure who develop a wide QRS complex during follow-up account for the majority of patients who are eligible for an upgrade to a CRT device. In an European survey, up to 25 % of CRT implants were upgrading procedures [2]. The REPLACE registry demonstrated a high percentage of complications in upgrade and revision procedures in 434 CRT patients from 71 centres. It was not stated how many centres actually contributed to this total number of CRT upgrades [3]. Their conclusion ‘pacemaker and implantable cardioverter-defibrillator generator replacements are associated with a notable complication risk, particularly those with lead additions’ made cardiologists somewhat cautious and even reluctant to perform a therapeutic upgrade to CRT. These REPLACE data support careful decision making before device replacement when managing device advisories and when considering upgrades to more complex systems, concluded the authors [3]. And indeed, an upgrade procedure can be complicated and is in need of an experienced skilled operator or at least her or his direct supervision during the procedure. As experience is a major factor in reducing complications during and after device implantation [4], it is reasonable that experience is an even stronger denominator in complicated procedures as primary CRT implants and CRT upgrades. In this issue, the retrospective data of upgrading procedures to CRT devices were compared with the complications in primary CRT implants during the same period [5]. These retrospective data originate from one tertiary centre with a high patient load. Only three experienced operators performed the majority of procedures or supervised them. A: Total number of individual implants of 165 (62 %), including 82 upgrade procedures. Thirty assists of which 16 assists in an upgrade procedure. B: Total number of individual implants of 30 (11 %), including 13 upgrade procedures. Six assists of which 4 assists in an upgrade procedure. C: Total number of individual implants of 18 (7 %), including 9 upgrade procedures. Three assists of which 0 assists in an upgrade procedure. Though these data are retrospective, the complication rate is considerably lower when compared with the literature [3]. The most determining factor in the difference of complication rate is most likely skill, which comes from experience and cooperation during these complicated procedures. It was not investigated whether the determining factor was cooperation or experience or its combination.

Patients with long-term permanent pacemakers have a high prevalence of left ventricular dysfunction.

Patients with right ventricular pacemakers are at increased risk of left ventricular systolic dysfunction (LVSD). We aimed to establish the prevalence, degree and associations of LVSD in patients with long-term right ventricular pacemakers listed for pulse generator replacement (PGR). All patients listed for PGR at Leeds General Infirmary were invited to attend for an assessment during which we recorded medical history, symptomatic status, medical therapy, date and indication of first implantation, the percentage of right ventricular pacing (% RVP) and an echocardiogram. We collected data on 491 patients. A left ventricular ejection fraction less than 50% was observed in 40% of our cohort, however, this was much higher (59%) in those with more than 80% RVP than in those with less than 80% RVP (22%) (P < 0.0001). Multivariable analysis revealed % RVP, (but not complete heart block at baseline), serum creatinine and previous myocardial infarction to be independently related to the presence of LVSD. A model combining % RVP and previous myocardial infarction has a c-statistic of 0.74 for predicting LVSD. After a mean follow-up time of 668 days, 56 patients (12%) were dead or had been hospitalized for heart failure. In multivariable analysis, previous myocardial infarction and high % RVP were independently associated with a worse survival. Patients with right ventricular pacemakers have a high prevalence of LVSD, and this is greater in those exposed to more RVP. Those with LVSD and high amounts of RVP are at higher risk of hospitalization or death. Simple variables can identify those patients who might benefit from a more comprehensive review.