Detection of atrial fibrillation in persons aged 65 years and above using a mobile electrocardiogram device.

BACKGROUND: Untreated atrial fibrillation (AF) often results in increased morbidity and mortality. Opportunistic AF screening in persons aged ≥ 65 years is recommended to identify patients with AF in order to prevent AF-related complications. OBJECTIVE: The aim of this study was to assess the feasibility of screening persons for AF with the Kardia mobile electrocardiogram device (MED) and to determine the percentage of newly detected AF cases by selective population screening in the Netherlands. METHODS: Persons aged ≥ 65 years, without a medical history of AF, in nursing homes, at public events or visiting the general practitioner (GP) were approached to participate. A Kardia MED smartphone ECG (sECG) was recorded and the CHA2DS2-VASc score was calculated. An automated AF algorithm classified the sECGs as 'sinus rhythm', 'AF' or 'unclassified'. In the case of AF, participants were referred to their GP. All sECGs were assessed by blinded experts. RESULTS: A total of 2168 participants were screened for AF. According to the expert's interpretation, 2.5% had newly detected AF, of whom 76.4% never experienced palpitations and 89.1% had a CHA2DS2-VASc score ≥ 2. The algorithm result was unclassified in 12.2% of cases, of which 95.5% were interpretable by experts. With expert opinion as the gold standard and excluding unclassified sECGs, the Kardia MED's negative and positive predictive value for detecting AF was 99.8% and 60.0%, respectively. CONCLUSION: Screening for AF using the Kardia MED is feasible and results in 2.5% newly detected AF cases. Expert interpretation of algorithm outcomes AF and unclassified is recommended.

Lead extractions: dissecting adhesions up to the lead-tip of the right ventricle: safety and success-rates.

AIMS: Goal of Transvenous Lead Extraction (TLE) is complete removal of all targeted leads, without complications. Despite counter traction manoeuvres, efficacy rates are often hampered by broken right ventricle lead (RV-lead) tips. Mechanically powered lead extraction (Evolution sheath) is effective, however safety of dissection up to the lead tip is unclear. Therefore, we examined the feasibility and safety of RV-lead extraction requiring dissection up to the myocardium. METHODS AND RESULTS: From 2009 to 2018, all TLE in the Isala Heart Centre (Zwolle, The Netherlands) requiring the hand-powered mechanical Evolution system to extract RV-leads (n = 185) were examined from a prospective registry. We assessed 4 groups: TLE with the first generation Evolution (n = 43) with (A1,n = 18) and without (A2,n = 25) adhesions up to the myocardium and TLE with the Novel R/L type (n = 142) of sheath with (B1, n = 59) and without (B2, n = 83) adhesions up to the myocardium. Complete success rate in Group B was significantly higher than group A (96.5 vs 76.7%, p = 0.0354). When comparing the patients with adhesions up to the myocardium, total complete success is higher in the R/L group (61.1% vs 90.5%, p = 0.0067). There were no deaths. Overall major complication rates were low (2/185; 1.1%) and there was no statistically significant difference in major and minor complications between the two groups. CONCLUSION: Extraction strategy with the bidirectional Evolution R/L sheath for right ventricular leads with adhesions up to the myocardium is safe and feasible.

Value of 3D mapping-guided endomyocardial biopsy in cardiac sarcoidosis: Case series and narrative review on the value of electro-anatomic mapping-guided endomyocardial biopsies.

AIM: Integration of endomyocardial biopsy (EMB) in the diagnostic workup of cardiac sarcoidosis (CS) is under-recognized in current clinical practice, since capturing focal granulomas is challenging. Our aim was to describe our experience with electro-anatomic mapping (EAM)-guided EMB and provide a comprehensive review of the literature. METHODS AND RESULTS: Five patients (age 49.4 ± 11.4) with suspected CS underwent EAM-guided EMB in Isala Heart Center (Zwolle, the Netherlands) between 2017 and 2019. In all patients, a 3D bipolar voltage map (<0.5-1.5 mV) and unipolar voltage map (LV < 8.3 mV, RV < 5.5 mV) was created using a high-density mapping catheter. The bioptome was connected to the mapping system to guide targeted EMB. Biopsy samples (2-9 samples) were taken from both LV and RV sites, guided by EAM and areas with abnormal electrograms, without complications. CS diagnosis was based on EMB in 2/5 patients. A granuloma was captured in one patient at the LV basal septum with normal bipolar and abnormal unipolar voltage. All patients with delayed enhancement on cardiac magnetic resonance, revealed fibrosis in the biopsy sample. In one patient with suspected isolated cardiac sarcoidosis, diagnosis could not be confirmed by histopathology analysis, while unipolar voltage mapping was abnormal and diastolic potentials were present. Literature search revealed 7 reports (18 patients) describing EAM-guided EMB in CS patients, with 100% of the EMB taken form the RV. CONCLUSION: Unipolar voltage mapping may be superior to target active inflamed tissue and should be evaluated in future research regarding EAM-guided EMB in CS.

Significantly less inappropriate shocks in ischemic patients compared to non-ischemic patients: The S-ICD experience of a high volume single-center.

BACKGROUND: The subcutaneous cardioverter-defibrillator (S-ICD) continues to be preferentially used in relatively young patients, with less advanced heart disease. OBJECTIVE: We, therefore, studied the short and long-term efficacy and safety of the S-ICD in subgroups of patients, which are underreported at present. METHODS: A total of 218 patients between November 2010 and February 2019 undergoing S-ICD with a follow up of at least 6 months implantation were included in a prospective registry. Mean follow up was 38 months. RESULTS: The most common indication for S-ICD implantation was ischemic cardiomyopathy (n = 106, 49%). Complication rate needing invasive intervention was 9% (n = 21). Appropriate shock rate in patients with an S-ICD was 3.5%/year. A total of 30 inappropriate shocks (IAS) occurred in 19 patients (8.7%; 2.7%/year). The proportion of appropriate and inappropriate shock rates in patients with different cardiomyopathies shows remarkable variances. There were significant more IAS (3.6%/year vs. 1.7%/year, p = .048) in patients with non-ischemic cardiomyopathy versus patients with ischemic cardiomyopathy. Multivariate analysis identified, besides type of cardiomyopathy, atrial fibrillation (AF) as predictor for IAS. CONCLUSION: In this real-world prospective registry we analyzed S-ICD performance in the more traditional ICD patient. Patients with ischemic cardiomyopathy had significantly less inappropriate therapy compared to patients with non-ischemic cardiomyopathy and appear to be appropriate patients for this type of device.

The association between body temperature and electrocardiographic parameters in normothermic healthy volunteers.

BACKGROUND: Previous studies reported that hypo- and hyperthermia are associated with several atrial and ventricular electrocardiographical parameters, including corrected QT (QTc) interval. Enhanced characterization of variations in QTc interval and normothermic body temperature aids in better understanding the underlying mechanism behind drug induced QTc interval effects. The analysis' objective was to investigate associations between body temperature and electrocardiographical parameters in normothermic healthy volunteers. METHODS: Data from 3023 volunteers collected at our center were retrospectively analyzed. Subjects were considered healthy after review of collected data by a physician, including a normal tympanic body temperature (35.5-37.5°C) and in sinus rhythm. A linear multivariate model with body temperature as a continuous was performed. Another multivariate analysis was performed with only the QT subintervals as independent variables and body temperature as dependent variable. RESULTS: Mean age was 33.8 ± 17.5 years and mean body temperature was 36.6 ± 0.4°C. Body temperature was independently associated with age (standardized coefficient [SC] = -0.255, P < .001), female gender (SC = +0.209, P < .001), heart rate (SC = +0.231, P < .001), P-wave axis (SC = -0.051, P < .001), J-point elevation in lead V4 (SC = -0.121, P < .001), and QTcF duration (SC = -0.061, P = .002). In contrast, other atrial and atrioventricular (AV) nodal parameters were not independently associated with body temperature. QT subinterval analysis revealed that only QRS duration (SC = -0.121, P < .001) was independently associated with body temperature. CONCLUSION: Body temperature in normothermic healthy volunteers was associated with heart rate, P-wave axis, J-point amplitude in lead V4, and ventricular conductivity, the latter primarily through prolongation of the QRS duration.

Renal nerve stimulation: complete versus incomplete renal sympathetic denervation.

PURPOSE: Blood pressure (BP) reduction after renal sympathetic denervation (RDN) is highly variable. Renal nerve stimulation (RNS) can localize sympathetic nerves. The RNS trial aimed to investigate the medium-term BP-lowering effects of the use of RNS during RDN, and explore if RNS can check the completeness of the denervation. MATERIAL AND METHODS: Forty-four treatment-resistant hypertensive patients were included in the prospective, single-center RNS trial. The primary study endpoint was change in 24-h BP at 6- to 12-month follow-up after RDN. The secondary study endpoints were the acute procedural RNS-induced BP response before and after RDN; number of antihypertensive drugs at follow-up; and the correlation between the RNS-induced BP increase before versus after RDN (delta [Δ] RNS-induced BP). RESULTS: Before RDN, the RNS-induced systolic BP rise was 43(±21) mmHg, and decreased to 9(±12) mmHg after RDN (p < 0.001). Mean 24-h systolic/diastolic BP decreased from 147(±12)/82(±11) mmHg at baseline to 135(±11)/76(±10) mmHg (p < 0.001/<0.001) at follow-up (10 [6-12] months), with 1 antihypertensive drug less compared to baseline. The Δ RNS-induced BP and the 24-h BP decrease at follow-up were correlated for systolic (R = 0.44, p = 0.004) and diastolic (R = 0.48, p = 0.003) BP. Patients with ≤0 mmHg residual RNS-induced BP response after RDN had a significant lower mean 24-h systolic BP at follow-up compared to the patients with >0 mmHg residual RNS-induced BP response (126 ± 4 mmHg versus 135 ± 10 mmHg, p = 0.04). 83% of the patients with ≤0 mmHg residual RNS-induced BP response had normal 24-h BP at follow-up, compared to 33% in the patients with >0 mmHg residual RNS-induced BP response (p = 0.023). CONCLUSION: The use of RNS during RDN leads to clinically significant and sustained lowering of 24-h BP with fewer antihypertensive drugs at follow-up. RNS-induced BP changes were correlated with 24-h BP changes at follow-up. Moreover, patients with complete denervation had significant lower BP compared to the patients with incomplete denervation.

Hybrid Ventricular Tachycardia Ablation after Failed Percutaneous Endocardial and Epicardial Ablation.

INTRODUCTION: Recurrent ventricular tachycardia (VT) after percutaneous ablation is associated with a high morbidity and mortality. We assessed the feasibility of open chest extracorporeal circulation (ECC)-supported 3D multielectrode mapping and targeted VT substrate ablation in patients with previously failed percutaneous endocardial and epicardial VT ablations. METHODS: In patients with previously failed percutaneous endocardial and epicardial VT ablations and a high risk of hemodynamic collapse during the procedure, open chest ECC-supported mapping and ablation were performed in a hybrid EP lab setting. Electro-anatomic maps (3D) were acquired during sinus rhythm and VT using a multielectrode mapping catheter (HD grid; Abbott or Pentaray, Biosense Webster). Irrigated radiofrequency ablations of all inducible VT were performed with a contact force ablation catheter. RESULTS: Hybrid VT ablation was performed in 5 patients with structural heart disease (i.e., 3 with previous old myocardial infarction and 2 with nonischemic cardiomy-opathy) and recurrent VT. Acute procedural success was achieved in all patients. Four patients were successfully weaned off the ECC. In 1 patient with a severely reduced LVEF (16%), damage to the venous graft occurred after sternotomy and that patient died after 1 month. Four patients (80%) remained VT free after a median follow-up of 6 (IQR 4-10) months. CONCLUSION: In high-risk patients with previously failed percutaneous endocardial and epicardial VT ablations, open chest ECC-supported multielectrode epicardial mapping revealed a VT substrate in all of the patients, and targeted epicardial ablation abolished VT substrate in these patients.

Elimination of Benign Ventricular Premature Beats or Ventricular Tachycardia with Catheter Ablation versus Two Different Optimal Antiarrhythmic Drug Treatment Regimens (Sotalol or Verapamil/Flecainide).

BACKGROUND: Symptomatic idiopathic ventricular arrhythmias (VA), including premature beats (VPB) and nonsustained ventricular tachycardia (VT) are commonly encountered arrhythmias. Although these VA are usually benign, their treatment can be a challenge to primary and secondary health care providers. Mainstay treatment is comprised of antiarrhythmic drugs (AAD) and, in case of drug intolerance or failure, patients are referred for catheter ablation to tertiary health care centers. These patients require extensive medical attention and drug regimens usually have disappointing results. A direct comparison between the efficacy of the most potent AAD and primary catheter ablation in these patients is lacking. The ECTOPIA trial will evaluate the efficacy of 2 pharmacological strategies and 1 interventional approach to: suppress the VA burden, improve the quality of life (QoL), and safety. HYPOTHESIS: We hypothesize that flecainide/verapamil combination and catheter ablation are both superior to sotalol in suppressing VA in patients with symptomatic idiopathic VA. STUDY DESIGN: The Elimination of Ventricular Premature Beats with Catheter Ablation versus Optimal Antiarrhythmic Drug Treatment (ECTOPIA) trial is a randomized, multicenter, prospective clinical trial to compare the efficacy of catheter ablation versus optimal AAD treatment with sotalol or flecainide/verapamil. One hundred eighty patients with frequent symptomatic VA in the absence of structural heart disease or underlying cardiac ischemia who are eligible for catheter ablation with an identifiable monomorphic VA origin with a burden ≥5% on 24-h ambulatory rhythm monitoring will be included. Patients will be randomized in a 1:1:1 fashion. The primary endpoint is defined as >80% reduction of the VA burden on 24-h ambulatory Holter monitoring. After reaching the primary endpoint, patients randomized to one of the 2 AAD arms will undergo a cross-over to the other AAD treatment arm to explore differences in drug efficacy and QoL in individual patients. Due to the use of different AAD (with and without ß-blocking characteristics) we will be able to explore the influence of alterations in sympathetic tone on VA burden reduction in different subgroups. Finally, this study will assess the safety of treatment with 2 different AAD and ablation of VA.

Blood pressure-related electrocardiographic findings in healthy young individuals.

Purpose: Elevated blood pressure induces electrocardiographic changes and is associated with an increase in cardiovascular disease later in life compared to normal blood pressure levels. The purpose of this study was to evaluate the association between normal to high normal blood pressure values (90-139/50-89 mmHg) and electrocardiographic parameters related to cardiac changes in hypertension in healthy young adults.Methods: Data from 1449 volunteers aged 18-30 years collected at our centre were analyzed. Only subjects considered healthy by a physician after review of collected data with systolic blood pressure values between 90 and 139 mmHg and diastolic blood pressure values between 50 and 89 mmHg were included. Subjects were divided into groups with 10 mmHg systolic blood pressure increment between groups for analysis of electrocardiographic differences. Backward multivariate regression analysis with systolic and diastolic blood pressure as a continuous variable was performed.Results: The mean age was 22.7 ± 3.0 years, 73.7% were male. P-wave area, ventricular activation time, QRS-duration, Sokolow-Lyon voltages, Cornell Product, J-point-T-peak duration corrected for heart rate and maximum T-wave duration were significantly different between systolic blood pressure groups. In the multivariate model with gender, body mass index and cholesterol, ventricular rate (standardized coefficient (SC): +0.182, p < .001), ventricular activation time in lead V6 (SC= +0.065, p = .048), Sokolow-Lyon voltage (SC= +0.135, p < .001), and Cornell product (SC= +0.137, p < .001) were independently associated with systolic blood pressure, while ventricular rate (SC= +0.179, p < .001), P-wave area in lead V1 (SC= +0.079, p = .020), and Cornell product (SC= +0.091, p = .006) were independently associated with diastolic blood pressure.Conclusion: Blood pressure-related electrocardiographic changes were observed incrementally in a healthy young population with blood pressure in the normal range. These changes were an increased ventricular rate, increased atrial surface area, ventricular activation time and increased ventricular hypertrophy indices on a standard 12 lead electrocardiogram.

Long-term outcome of catheter ablation in post-infarction recurrent ventricular tachycardia.

OBJECTIVES: Severe LV dysfunction and advanced age are associated with VT recurrence after catheter ablation in patients with post-infarction drug-refractory VT. We present retrospective analysis of long-term outcome after single and repeat VT ablation procedures in patients with ischemic heart disease. DESIGN: Patients with recurrent VT post infarction who underwent catheter ablation between 2006 and 2017 in Isala Heart Centre were retrospectively analyzed. Univariate and multivariate analysis were used to identify predictors of arrhythmia recurrence post ablation. Patients were allocated to subgroups based on LVEF: severe (<30%), moderate (30-40%) and mild LV dysfunction (41-51%) and analyzed with log rank test. RESULTS: A total of 144 patients were included. Two years VT free survival after a single procedure was 56.6% with median follow-up 46 [17-78] months. Recurrence of VT postablation wash high among patients with an old anteroseptal MI and LVEF < 30% with multiple morphologies of inducible VTs, indicating an extensive and complex substrate. Patients who underwent repeat ablations (27.1%) had significant more often LV aneurysms (20.5% vs. 7.6%, p = .03) and electrical storms (38.5% vs. 21.9%, p = .04). VT free survival was higher in patients with LVEF 41-51% compared to LVEF < 30% (71.4% vs. 47.8%, p = .01). In multivariate analysis, LVEF < 30% (vs 41-51%) was an independent predictor of arrhythmia recurrence (HR = 2.16, CI 1.15-4.06, p = .02). CONCLUSIONS: In patients with ischemic VT, success rate of ablation was highest among patients with preserved LV function and recurrent VT and ES was highest among patients with severe LV dysfunction after single and multiple ablation procedures.

Mechanical power sheath mediated recanalization and lead implantation in patients with venous occlusion: Technique and results.

INTRODUCTION: Chronic venous occlusion hampers lead revisions and upgrades in patients with a cardiac implantable electronic devices (CIEDs). This can make cardiothoracic surgery, venoplasty, or contra-lateral implantation of leads with tunneling necessary. A technique using venous recanalization may be a preferred alternative. We assessed the efficacy and safety of this new technique. METHODS AND RESULTS: From 2009 to 2016, all consecutive patients planned for lead revision or upgrade with known chronic venous occlusion were studied. All patients underwent extraction of an existing malfunctional or functional CIED lead with the Cook Evolution mechanical power sheath. By using the lumen of the sheath, endovascular access to the heart was obtained for new leads. Forty-two patients (107 leads, 2.6 ± 1.1) were included. The indication for this procedure was replacement of malfunctional leads (n = 35, 83%) or device upgrade (n = 7, 17%). In total, 77 leads were extracted (30 leads stayed in situ) with a mean age at time of extraction of 8.4 years. Because of damage to bystander leads during extraction, two additional leads (one RA lead, one LV lead) were extracted. Clinical success was achieved in 41 patients (97%) and complete success in 39 patients (93%). There were two minor complications (two pocket hematomas, managed conservatively) and one major complication (tamponade, needing thoracotomy). Mean procedure time was 3.0 hours (median, 2.0; range, 1:28-5:35 hours) with a mean fluoroscopy time of 14.9 ± 12.5 minutes. CONCLUSIONS: The technique of Evolution-mediated recanalization in case of lead revisions or upgrades is feasible with an acceptable safety profile and high efficacy.

Renal nerve stimulation identifies aorticorenal innervation and prevents inadvertent ablation of vagal nerves during renal denervation.

PURPOSE: Recently we reported the use of renal nerve stimulation (RNS) during renal denervation (RDN) procedures. RNS induced changes in blood pressure (BP) and heart rate are not fully delineated yet. We hypothesized that electrical stimulation of the sympathetic nerve tissue in the renal artery would lead to an increase in BP and vagal stimulation would cause a decrease in BP. We report the different patterns of BP and heart rate responses elicited by RNS prior to RDN. METHODS: 35 patients with drug-resistant hypertension were included. RNS was performed under general anesthesia at four sites in the right and left renal arteries, both before and immediately after RDN. RNS-induced BP and heart rate changes were monitored. RESULTS: A total of 289 RNS sites in 35 patients were analyzed. An increase in systolic BP of >10 mmHg was regarded as a positive BP response to RNS. This pattern of response was observed in 180 sites (62%). 86 RNS sites (30%) showed an indifferent response with BP changes ≤10 mmHg. At 13 sites (4.5%) RNS elicited a decrease in BP up to -8 mmHg. However, 10 RNS sites (3.5%) showed a pronounced vagal response with hypotension and sinus cycle lengths ranging between 4224-10272 milliseconds. These sites were distributed among two patients. CONCLUSION: RNS identified sympathetic and parasympathetic nerve tissue in the renal arteries. RNS can be potentially used to map nerve bundles and guide selective ablation of sympathetic nerve fibers and prevent inadvertent ablation of parasympathetic nerve tissue during RDN.

Success and complication rates of lead extraction with the first- vs. the second-generation Evolution mechanical sheath.

AIMS: The Evolution sheath (Cook Medical, USA) is a power sheath frequently used for chronic lead extraction. In 2013, a novel type (bidirectional) of Evolution sheath (the RL type) was introduced. We evaluated differences in success and complication rates of the two types. METHODS AND RESULTS: From 2009 to 2015, all lead extractions requiring the use of an Evolution sheath were prospectively examined. According to the current guidelines, complete procedural success was defined as the removal of all targeted lead materials. Clinical success was the retention of a small portion of the lead, and failure was the inability to achieve either complete procedural or clinical success or the development of any permanently disabling complication. The Evolution sheath was used to extract 149 leads in 103 patients. The first 56 leads were extracted with the original unidirectional sheath, and 93 leads were extracted with the novel bidirectional R/L type. The median age of the lead at the time of extraction was 6.8 vs. 9.1 years (P = 0.007). Complete procedural success was higher for the Evolution R/L (80.0 vs. 98%, P = 0.0004). Clinical success rate was 98 vs. 99%. There were no major complications and 6 (12.0%) vs. 2 (3.8%) minor complications (P = 0.153). We did not observe changes in success rates or complications over time, meaning that the difference cannot be explained by learning curve. CONCLUSION: Use of the novel Evolution R/L sheath vs. the original Evolution sheath was associated with significant higher complete success rates, without major complications and with a trend towards the reduction of minor complications.

Lead extractions: the Zwolle experience with the Evolution mechanical sheath.

AIMS: The Evolution sheath (Cook, USA) is a power sheath with a cutting screw tip operated by mechanical rotation. It has been reported to be an effective tool for chronic lead extraction. We evaluated the safety and efficacy of this system. METHODS AND RESULTS: From 2009 to 2014, all lead extractions requiring the use of an Evolution sheath were prospectively examined. In 77 patients, 111 leads were extracted. The first 57 leads were extracted with the original unidirectional sheath, and since 2013, 54 leads were extracted with the bidirectional R/L type. According to the current guidelines, complete procedural success was defined as the removal of all targeted lead material. Clinical success was the retention of a small portion of the lead, and failure was the inability to achieve either complete procedural or clinical success or the development of any permanently disabling complication. The Evolution sheath was used to extract 111 leads in 77 patients. The median age of the lead at time of extraction was 8.0 years (median 6.9, interquartile range 6.4, minimum: 0.6 and maximum: 34.4), with a clinical success rate of 98% and a complete procedural success of 88%. Complete procedural success was higher for the R/L type Evolution sheath (96 vs. 80%, P = 0.006). There were 21 (19%) implantable cardioverter defibrillator leads, 22 (20%) right ventricular pacing leads, 60 (54%) right atrial leads, and 8 (7%) left ventricular leads. There were no major complications and six (8%) minor complications. There was no need for the usage of a femoral tool or snares. CONCLUSION: Use of Evolution for lead extractions seems to be safe and effective, with a high clinical success rate.

Ablation of focal atrial tachycardia from the non-coronary aortic cusp: case series and review of the literature.

AIMS: Focal atrial tachycardia successfully ablated from the non-coronary cusp (NCC) is rare. Our aim was to describe the characteristics of mapping and ablation therapy of NCC focal atrial tachycardias and to provide a comprehensive review of the literature. METHODS AND RESULTS: Seven patients (age 40 ± 9 years) with symptomatic, drug-refractory atrial tachycardia were referred for electrophysiological study. Extensive right and left atrial mapping revealed atrial tachycardia near His in all patients but either failed to identify a successful ablation site or radiofrequency applications only resulted in temporary termination of the tachycardia. Mapping and ablation of the NCC were performed retrogradely via the right femoral artery. Mapping of the NCC demonstrated earliest atrial activation during atrial tachycardia 38 ± 14 ms (ranging 17-56 ms) before the onset of the P-wave. Earliest atrial activation in the NCC was earlier than earliest activation in the right atrium and left atrium in all patients. The P-wave morphology was predominantly negative in the inferior leads and biphasic in leads V1 and V2. The tachycardia was successfully terminated by radiofrequency application in 10 ± 6 s (2-16 s), without complications. All patients were free of symptoms during a follow-up of 19 ± 9 months. Literature search revealed 18 reports (91 patients) describing NCC focal atrial tachycardia, with 99% long-term ablation success with a 1% complication rate. CONCLUSION: Symptomatic focal atrial tachycardia near His may originate from the NCC and can be treated safely and effectively with radiofrequency ablation.

Response to cardiac resynchronization therapy as assessed by time-based speckle tracking imaging.

BACKGROUND: Response to cardiac resynchronization therapy (CRT) is still difficult to predict with previously investigated dyssynchrony indices. The predictive value of speckle tracking strain analysis has not been fully delineated yet. The objective of this study was to assess the predictive value of longitudinal strain (LS) and radial strain (RS) speckle tracking measurements on echocardiographic and clinical response to CRT. METHODS: A total of 138 consecutive patients with functional class II-IV heart failure who underwent CRT were studied. Echocardiography was performed at baseline and during follow-up. Six different time-based left ventricular (LV)-dyssynchrony indices were measured with LS and RS. Echocardiographic response to CRT was defined as a reduction in LV end-systolic volume ≥15% and clinical response as survival without heart failure hospitalization. Multivariable analyses were performed to adjust for potential confounding factors. RESULTS: Echocardiographic and clinical follow-up was 22 ± 8 and 42 ± 8 months, respectively. Ninety-six patients (70%) were classified as echocardiographic responders and 114 patients (83%) survived without heart failure hospitalization. QRS duration and nonischemic etiology predicted echocardiographic response to CRT. None of the speckle tracking indices was different between echocardiographic responders and nonresponders to CRT. Regarding clinical response, only maximal delay between six segments in four-chamber view measured with LS was different between responders and nonresponders, with 154-ms delay as the optimal cut-off value. Neither stratified analyses in patients with sinus rhythm nor multivariable analyses did change these findings. CONCLUSION: Of all time-based measured speckle tracking indices, only maximal delay between six segments in four-chamber view as assessed with LS was associated with clinical response to CRT.

Mechanical and electrical dysfunction of Riata implantable cardioverter-defibrillator leads.

AIM: Riata implantable cardioverter-defibrillator leads are prone to failure by conductor externalization and/or electrical dysfunction. The objectives of this study were to determine the predictors of the Riata lead failure, to assess the association of conductor externalization and electrical lead failure, and to analyse the rates of lead failure over time. METHODS AND RESULTS: Of 273 implanted Riata leads in our centre, 197 were investigated according to the Riata recall protocol, including electrical measurements by device interrogation and annually fluoroscopy. During a mean follow-up period of 5.6 ± 1.4 years, Riata lead failure was 18.8% (37 of 197) for externalization and 17.3% (34 of 197) for electrical lead failure. Electrical lead failure was correlated with time after implant. Externalization and electrical dysfunction co-existed in only 6 of 197 (3%) patients and were not related (Phi's coefficient -0.013, P = 0.85). During the second annual screening, 145 (73.6%) patients underwent fluoroscopy and 9 patients had novel externalizations resulting in an incidence of 6.72%/patient/year which was higher than expected based on cross-sectional analysis. Besides, there was a significant increase in the extent of externalization (17.65 ± 11.14 mm vs. 21.77 ± 11.95 mm, P = 0.001). In multivariate Cox regression analysis, non-ischaemic cardiomyopathy and impaired LVEF were independent predictors of externalization, and 7 Fr lead was a predictor of electrical lead failure. CONCLUSION: Riata leads show progressive and high externalization rates without correlation between externalization and electrical lead failure. Non-ischaemic cardiomyopathy and impaired LVEF are independent predictors of structural lead failure in cross-sectional analysis, whereas 7 Fr lead is a predictor of electrical lead failure.

Variant Location Is a Novel Risk Factor for Individuals With Arrhythmogenic Cardiomyopathy Due to a Desmoplakin (DSP) Truncating Variant.

BACKGROUND: Truncating variants in desmoplakin (DSPtv) are an important cause of arrhythmogenic cardiomyopathy; however the genetic architecture and genotype-specific risk factors are incompletely understood. We evaluated phenotype, risk factors for ventricular arrhythmias, and underlying genetics of DSPtv cardiomyopathy. METHODS: Individuals with DSPtv and any cardiac phenotype, and their gene-positive family members were included from multiple international centers. Clinical data and family history information were collected. Event-free survival from ventricular arrhythmia was assessed. Variant location was compared between cases and controls, and literature review of reported DSPtv performed. RESULTS: There were 98 probands and 72 family members (mean age at diagnosis 43±8 years, 59% women) with a DSPtv, of which 146 were considered clinically affected. Ventricular arrhythmia (sudden cardiac arrest, sustained ventricular tachycardia, appropriate implantable cardioverter defibrillator therapy) occurred in 56 (33%) individuals. DSPtv location and proband status were independent risk factors for ventricular arrhythmia. Further, gene region was important with variants in cases (cohort n=98; Clinvar n=167) more likely to occur in the regions resulting in nonsense mediated decay of both major DSP isoforms, compared with n=124 genome aggregation database control variants (148 [83.6%] versus 29 [16.4%]; P<0.0001). CONCLUSIONS: In the largest series of individuals with DSPtv, we demonstrate that variant location is a novel risk factor for ventricular arrhythmia, can inform variant interpretation, and provide critical insights to allow for precision-based clinical management.

Experience with malfunctioning leadless pacemakers: Troubleshooting and management during medium-term follow-up.

BACKGROUND: The Nanostim leadless pacemaker (LP) was launched in 2012. However, the use of Nanostim LP was suspended because of safety concerns. OBJECTIVE: The aim of this study was to report our experience with the management of malfunctioning Nanostim LPs, including premature battery depletion. METHODS: Fifty-one consecutive patients (mean age 83 ± 10 years; 65% male) who underwent Nanostim LP implantation between 2014 and 2016 at Isala Clinics were identified. Two patients were excluded from the analysis because of incomplete follow-up. The mean follow-up duration was 1114 ± 560 days. RESULTS: Nanostim LP malfunction occurred in 20 of 49 patients (40.8%). Premature LP battery failure was observed in 18 of 20 affected patients (90%). Furthermore, malpacing/malsensing was observed in 1 patient and mechanical dislocation of the Nanostim LP occurred in 1 patient. Of note, 17 of 18 Nanostim LPs with premature battery depletion (94%) showed normal device parameters 3 months before the diagnosis of (impending) premature battery failure. In 12 patients, Nanostim LPs with a mean device age at the time of extraction of 1040 ± 467 days was successfully extracted without complications. Implantation of another LP or a transvenous device was successfully performed in all 20 patients with Nanostim LP malfunction. All known cases of early-life battery failure were identified during the 3-monthly follow-up consultations. CONCLUSION: The incidence of Nanostim LP early-life battery failure was higher than previously reported. Nanostim LP extraction in an older population seems to be safe and effective. Three-monthly follow-up seems to be effective at preventing in-between Nanostim LP-related hospitalization.

Long-Term Outcome of the Randomized DAPA Trial.

BACKGROUND: The randomized DAPA trial (Defibrillator After Primary Angioplasty) aimed to evaluate the survival benefit of prophylactic implantable cardioverter defibrillator (ICD) implantation in early selected high-risk patients after primary percutaneous coronary intervention for ST-segment-elevation myocardial infarction. METHODS: A randomized, multicenter, controlled trial compared ICD versus conventional medical therapy in high-risk patients with primary percutaneous coronary intervention, based on one of the following factors: left ventricular ejection fraction <30% within 4 days after ST-segment-elevation myocardial infarction, primary ventricular fibrillation, Killip class ≥2 or TIMI (Thrombolysis in Myocardial Infarction) flow <3 after percutaneous coronary intervention. ICD was implanted 30 to 60 days after MI. Primary end point was all-cause mortality at 3 years follow-up. The trial prematurely ended after inclusion of 266 patients (38% of the calculated sample size). Additional survival assessment was performed in February 2019 for the primary end point. RESULTS: A total of 266 patients, 78.2% males, with a mean age of 60.8±11.3 years, were enrolled. One hundred thirty-one patients were randomized to the ICD arm and 135 patients to the control arm. All-cause mortality was significant lower in the ICD group (5% versus 13%, hazard ratio, 0.37 [95% CI, 0.15-0.95]) after 3 years follow-up. Appropriate ICD therapy occurred in 9 patients at 3 years follow-up (5 within the first 8 months after implantation). After a median long-term follow-up of 9 years (interquartile range, 3-11), total mortality (18% versus 38%; hazard ratio, 0.58 [95% CI, 0.37-0.91]), and cardiac mortality (hazard ratio, 0.52 [95% CI, 0.28-0.99]) was significant lower in the ICD group. Noncardiac death was not significantly different between groups. Left ventricular ejection fraction increased ≥10% in 46.5% of the patients during follow-up, and the extent of improvement was similar in both study groups. CONCLUSIONS: In this prematurely terminated and thus underpowered randomized trial, early prophylactic ICD implantation demonstrated lower total and cardiac mortality in patients with high-risk ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention. Registration: URL: https://www.trialregister.nl; Unique identifier: Trial NL74 (NTR105).