Evolution of high-grade atrioventricular conduction disorders after transcatheter aortic valve implantation in patients who underwent implantation of a pacemaker with specific mode-that minimizes ventricular pacing-activated.

INTRODUCTION: The evolution of atrioventricular conduction disorders after transcatheter aortic valve implantation (TAVI) remains poorly understood. We sought to identify factors associated with late (occurring ≥7 days after the procedure) high-grade atrioventricular blocks after TAVI, based on specific pacemaker memory data. METHODS AND RESULTS: STIM-TAVI (NCT03338582) was a prospective, multicentre, observational study that enrolled all patients (from November 2015 to January 2017) implanted with a specific dual chamber pacemaker after TAVI, with the SafeR algorithm activated, allowing continuous monitoring of atrioventricular conduction. The primary endpoint was the occurrence of centrally adjudicated late high-grade atrioventricular blocks during the year after TAVI. Among 197 patients, 138 (70.1%) had ≥1 late high-grade atrioventricular block. Whereas oversizing (p = .005), high-grade atrioventricular block during TAVI (p < .001), and early (within 6 days) high-grade atrioventricular block (p < .001) were associated with occurrence of late high-grade atrioventricular block, self-expanding prothesis (p = .88), prior right bundle branch block (p = .45), low implantation (p = .06), and new or wider left bundle branch block and lengthening of PR interval (p = .24) were not. In multivariable analysis, only post-TAVI early high-grade atrioventricular block remained associated with late high-grade atrioventricular blocks (Days 0-1: odds ratio [OR], 3.25; 95% confidence interval [CI], 1.57-6.74; p = .001; Days 2-6: OR, 4.13; 95% CI, 2.06-8.31; p < .001), whereas other conventionally used predictors were not. CONCLUSION: One-third of pacemaker-implanted patients do not experience late high-grade atrioventricular block. Our findings suggest that post-TAVI early high-grade atrioventricular block is the main factor associated with occurrence of late high-grade atrioventricular blocks.

Impact of permanent pacemaker on mortality after transcatheter aortic valve implantation: the PRAGMATIC (Pooled Rotterdam-Milan-Toulouse in Collaboration) Pacemaker substudy.

AIMS: We sought to evaluate the impact of permanent pacemaker (PPM) implantation on two-year mortality and one-year left ventricular ejection fraction recovery (∆LVEFR=one-year LVEF-baseline LVEF) after transcatheter aortic valve implantation (TAVI). METHODS AND RESULTS: We pooled patient-level data from four European institutions with significant TAVI volume. Outcomes were compared between patients without PPM (no-PPM), patients with PPM prior to TAVI (old-PPM) and patients with PPM implanted after TAVI (new-PPM). Out of 1,062 patients included in the pooled data set, 783 (73.7%) were in the no-PPM group, 164 (15.4%) in the new-PPM group and 115 (10.8%) in the old-PPM group. All-cause and cardiovascular mortality at two years were similar for patients with no-PPM and new-PPM (adjusted HR 1.11, 95% CI: 0.74-1.67; p=0.62; and adjusted HR 1.16, 95% CI: 0.68-1.98; p=0.59). Conversely, old-PPM was associated with increased risk of both all-cause and cardiovascular mortality vs. no-PPM. By multivariable analysis new-PPM did not affect LVEFR, while old-PPM did. We observed a multiplicative interaction, between new-PPM and post-procedural aortic regurgitation ≥1+ on two-year mortality and one-year LVEFR, with increased risk of death and impaired LVEFR in patients with new-PPM and post-procedural aortic regurgitation (PPAR) ≥1+ (both pinteraction<0.0001). CONCLUSIONS: In patients undergoing TAVI, the presence of a PPM at baseline yielded a negative effect on long-term prognosis while new-PPM did not. The combination of new-PPM with PPAR adversely impacts on survival and LV function recovery.

Extensive Thrombosis Following Lead Extraction: Further Justification for Routine Post-operative Anticoagulation.

Lead extraction is becoming increasingly common as indications for pacing and ICD insertion expand. Periop management varies between extraction centers, and no clinical guidelines have addressed the need for perioperative anticoagulation. We report a case of massive thrombosis which occurred shortly after laser lead extraction and is undoubtedly related to the trauma of the extraction and ensuing hypercoagulabiilty. Routine post-operative anticoagulation has been advocated as a means to prevent access vein (subclavian) stenosis, but many centres do not employ a routine post-extraction anticoagulation strategy. Pulmonary embolism following lead extraction is a known complication of this procedure and late mortality following lead extraction is a significant and underappreciated problem. We propose that further research attention should be directed at addressing the issue of routine post-extraction anticoagulation.

Early repolarization is associated with symptoms in patients with type 1 and type 2 long QT syndrome.

BACKGROUND: Early repolarization (ER) is associated with an increased risk for death from cardiac causes. Recent evidence supports ER's role as a modifier and/or predictor of risk in many cardiac conditions. OBJECTIVE: The purpose of this study was to determine the prevalence of ER among genotype-positive patients with long QT syndrome (LQTS) and evaluate its utility in predicting the risk of symptoms. METHODS: ER was defined as QRS slurring and/or notching associated with ≥1-mV QRS-ST junction (J-point) elevation in at least 2 contiguous leads, excluding the anterior precordial leads. The ECG with the most prominent ER was used for analysis. Major ER was defined as ≥ 2-mm J-point elevation. Symptoms of LQTS included cardiac syncope, documented polymorphic ventricular tachycardia (VT), and resuscitated cardiac arrest. RESULTS: One hundred thirteen patients (mean age 41 ± 19 years; 63 female) were reviewed, among whom 414 (mean 3.7 ± 1.5) ECGs were analyzed. Of these, 30 patients (27%) with a history of symptoms. Fifty patients (44%) had ER, and 19 patients (17%) had major ER. Patients with major ER were not different from patients without major ER with respect to age, sex, long QT type, longest QTc recorded, number of patients with QTc >500 ms, or use of beta-blockade. Univariate and independent predictors of symptom status included the presence of major ER, longest QTc recorded >500 ms, and female sex. CONCLUSION: ER ≥2 mm was the strongest independent predictor of symptom status related to LQTS, along with female sex and QTc >500 ms.

Outcome after implantation of a cardioverter-defibrillator in patients with Brugada syndrome: a multicenter study-part 2.

BACKGROUND: Implantable cardioverter-defibrillator indications in Brugada syndrome remain controversial, especially in asymptomatic patients. Previous outcome data are limited by relatively small numbers of patients or short follow-up durations. We report the outcome of patients with Brugada syndrome implanted with an implantable cardioverter-defibrillator in a large multicenter registry. METHODS AND RESULTS: A total of 378 patients (310 male; age, 46±13 years) with a type 1 Brugada ECG pattern implanted with an implantable cardioverter-defibrillator (31 for aborted sudden cardiac arrest, 181 for syncope, and 166 asymptomatic) were included. Fifteen patients (4%) were lost to follow-up. During a mean follow-up of 77±42 months, 7 patients (2%) died (1 as a result of an inappropriate shock), and 46 patients (12%) had appropriate device therapy (5±5 shocks per patient). Appropriate device therapy rates at 10 years were 48% for patients whose implantable cardioverter-defibrillator indication was aborted sudden cardiac arrest, 19% for those whose indication was syncope, and 12% for the patients who were asymptomatic at implantation. At 10 years, rates of inappropriate shock and lead failure were 37% and 29%, respectively. Inappropriate shock occurred in 91 patients (24%; 4±4 shocks per patient) because of lead failure (n=38), supraventricular tachycardia (n=20), T-wave oversensing (n=14), or sinus tachycardia (n=12). Importantly, introduction of remote monitoring, programming a high single ventricular fibrillation zone (>210-220 bpm), and a long detection time were associated with a reduced risk of inappropriate shock. CONCLUSIONS: Appropriate therapies are more prevalent in symptomatic Brugada syndrome patients but are not insignificant in asymptomatic patients (1%/y). Optimal implantable cardioverter-defibrillator programming and follow-up dramatically reduce inappropriate shock. However, lead failure remains a major problem in this population.

A new electrocardiogram algorithm for diagnosing loss of ventricular capture during cardiac resynchronisation therapy.

AIMS: The prerequisite for cardiac resynchronization therapy (CRT) is ventricular capture, which may be verified by analysis of the surface electrocardiogram (ECG). Few algorithms exist to diagnose loss of ventricular capture. METHODS AND RESULTS: Electrocardiograms from 126 CRT patients were analysed during biventricular (BV), right ventricular (RV), and left ventricular (LV) pacing. An algorithm evaluating QRS narrowing in the limb leads and increasing negativity in lead I to diagnose changes in ventricular capture was devised, prospectively validated, and compared with two existing algorithms. Performance of the algorithm according to ventricular lead position was also assessed. RESULTS: Our algorithm had an accuracy of 88% to correctly identify the changes in ventricular capture (either loss or gain of RV or LV capture). The algorithm had a sensitivity of 94% and a specificity of 96% with an accuracy of 96% for identifying loss of LV capture (the most clinically relevant change), and compared favourably with the existing algorithms. Performance of the algorithms was not significantly affected by RV or LV lead position. CONCLUSION: A simple two-step algorithm evaluating QRS width in the limb leads and changes in negativity in lead I can accurately diagnose the lead responsible for intermittent loss of ventricular capture in CRT. This simple tool may be of particular use outside the setting of specialized device clinics.

Inappropriate mode switch consecutive to P-wave double counting.

We report a case of multiple inappropriate mode switches in a patient with a dual-chamber pacemaker, resulting from P-wave double counting due to a double potential on the atrial electrogram. The differential diagnosis of this rarely reported phenomenon is discussed.

Long-term outcomes after pocket or scar revision and reimplantation of pacemakers with preerosion.

INTRODUCTION: Cardiac pacemakers with preerosion are often reimplanted. Preerosion may be caused by an evolving local infectious process affecting the entire pacing system or by mechanical migration of the device causing ischemic necrosis of the skin tissues. We examined the long-term outcome of 33 patients who underwent pocket or scar revision and submuscular reimplantation of cardiac pacemakers in our institution. METHODS: Before undergoing pocket or scar revision and reimplantation, all patients (1) had negative serial blood cultures, (2) had no vegetation on transesophageal echocardiography, (3) had a normal blood C-reactive protein concentrations, (4) were afebrile, (5) had no cutaneous breakthrough, and (6) presented with preerosion of the pulse generator or granulomatous-like scar abnormality. RESULTS: THE mean follow-up was 37 ± 12 months. Among 16 patients presenting with preerosion associated with signs of local cutaneous inflammation, 62.5% developed an infection of the pacing system requiring later explantation. Of eight patients presenting initially with migration of the pulse generator and mechanical protrusion, none required subsequent explantation of the system. Among nine patients presenting initially with granulomatous-like scar abnormalities, 55.6% underwent explantation of the pacing system during follow-up for management of documented local infection. CONCLUSIONS: The reimplantation of pulse generators with preerosion in the presence of local inflammatory manifestations or granulomatous-like changes of the scar is complicated by documented cardiac pacemaker infection in >50% of cases. In these patients, the explantation of the pacing system is recommended before the development of prognostically much more serious spread of infection to the leads and cardiac tissues.