High-degree Atrioventricular Block Research Articles

Abstract 4112639: A Rare Case of Atypical Sarcoidosis Presenting as an Intra-Atrial Septal Mass

Introduction: Sarcoidosis is a granulomatous disease that can affect multiple organ systems, including the heart. Cardiac Sarcoidosis (CS) is one of the most severe manifestations. It is characterized by a dysregulated T-cell driven immune response which generates non-necrotic inflammatory granulomas with myocardial infiltration. CS has a range of clinical syndromes: impaired conduction, arrhythmias, heart failure, and sudden cardiac death. We discuss a rare presentation of CS as an intra-atrial septal mass. Case Description: A 27-year-old Caucasian female with history of depression on citalopram presented with a one-month history of palpitations, fatigue, and dyspnea with exertion. An EKG demonstrated sinus rhythm with first-degree AV block. A cardiac monitor revealed intermittent 2-1 AV block and high degree AV block occurring mostly during sleep. An echocardiogram revealed normal biventricular function and morphology. Due to the concern for infiltrative cardiomyopathy, she underwent a cMRI which revealed a focal mass centered along the intra-atrial septum extending from the fossa ovalis to the septal AV junction, measuring 4.5 cm in size. She underwent pacemaker implantation with mild improvement of symptoms. PET scan demonstrated hypermetabolic activity of the intra-atrial region. She underwent surgical resection of the cardiac mass. Pathology was significant for fibrotic tissue with non-caseating granuloma and multinucleated giant cells consistent with an extremely rare presentation of CS. She was started on immunosuppressive medications. Subsequent cMRI and PET demonstrated resolution of the mass and hypermetabolic activity. Discussion: CS is a severe condition that most commonly presents with symptoms of heart failure, conduction abnormalities, and cardiac morphological changes of hypertrophy or thinning. However, it is often missed as a diagnosis, even in patients with extracardiac sarcoidosis. It is rare for CS to present as an isolated cardiac mass, especially in a younger patient as in this case. Advances in imaging techniques such as echocardiography, MRI, and PET have improved the ability to diagnosis CS and provide timely specialized treatment. This case highlights the need to include CS as an important diagnosis on the differential for a patient presenting with conduction abnormalities, heart block, and dyspnea. It also accentuates the critical role of multimodality imaging in working up this disease.

Behavior of Leadless atrioventricular synchronous pacing during exercise.

The leadless Micra AV pacemaker is designed to provide atrio-ventricular (AV) synchronous tracking by detecting the atrial contraction. Detection of the mechanical atrial signals can become challenging at fast sinus rate. The purpose of the study was to evaluate the AV synchronous performance at exercise in outpatients implanted with a Micra AV pacemaker. Patients were enrolled at least 1-month after a Micra AV implant and underwent a cycle test protocol. Serial device interrogations (each minute) and continuous electrocardiogram were collected to measure AV synchrony and determine maximum achieved sinus and ventricular rate for each patient. Additionally, the A1, A2, A3 and A4 accelerometer signal amplitudes were measured at start and peak of exercise. Thirty-five patients (mean age: 75.6 ± 13.4 years, 80% male) were enrolled in the study; 22 (64%) were predominantly ventricular paced (>90%) during exercise. The average AV synchrony was 90.4% in the entire cohort and 84.7% in patients with high degree AV block. The mean amplitude of the accelerometer signals increased significantly from start to peak of exercise: A1 (4.1 to 6.3 m/s2), A2 (2.4 to 3.8 m/s2) and A4 (4.5 to 7.6 m/s2) (all, p<0.01). The time from the VP-A2 decreased 25 ms for each 100 ms of R-R interval decrease. Maintaining AV synchrony during maximal exercise in elderly patients is achievable by adequate detection of atrial contraction at high sinus rates by the leadless Micra AV pacemaker. All components of the accelerometer signal increased, likely due to increased contractility related to exercise.

Clinical evidence of pacemaker implantation during gestation: a case series

Abstract Background Although recommended avoid any intervention during gestation in cases of poor tolerance to high degree atrioventricular block, pacemaker implantation may be necessary in pregnant women. Purpose To present outcomes of pacemaker implantation during gestation. Methods This prospective, single center study included 10 cases of pacemaker implantation during gestation (median age of patient - 26 years old at 18 weeks of gestation). We evaluated the further course of gestation and obstetric outcomes after implantation in comparison with pregnant with tachyarrythmias (n=111). Results Among 121 pregnant women with varying arrhythmias high degree atrioventricular block was detected in 10 cases (8,3%). In 6 cases this bradyarrhythmia diagnosed for the first time in gestation (60%). All pregnant with high degree atrioventricular block had clinical signs: dizziness and weakness (100%), syncope (70%), episodes of low blood pressure (100%). Pacemaker implantation performed due to hemodynamic instability and poor tolerance of bradyarrhythmia in all cases. Using electroanatomical mapping (Ensite Precision system)and echocardiographic guidance helped to reduce fluoroscopy time. For one pregnant implanted leadless pacemaker (Micra) with achieved more than 80% atrio-ventricular synchronization. Outcomes: further course of gestation characterized by increased incidence of uterine contractile activity (30%) in cases of high degree atrioventricular block, that was significantly higher than in pregnant with tachyarrhythmias (2%) (p=0.007). There were no differences in the rate of other complication: uterine blood flow violation (20% vs 12%, p=0.520), placental abraption (10% vs 5%, p=0.237) and preeclampsia (10% vs 5%, p=0.237). Vaginal type of delivery was in the majority of cases in both groups (70% vs 86%, p=0.553). Neonatal outcomes characterized with normal range of fetal birth weight (median 3163 vs 3212 grams, p=0.981) and 5 minute Apgar score (median 8.6 vs 8.7, p=0.564). There was no incidence of maternal and fetal mortality. In 12 month follow-up all patient have optimal electrical parameters of devise and remained stable over time. Conclusions High degree atrioventricular block in pregnant characterized by increased rate of uterine contractile activity. Pacemaker implantation during gestation can be effectively performed and associated with benign outcomes.

Clinical validation of the 2021 European Society of Cardiology guidelines on pre-existing right bundle branch block patients undergoing transcatheter aortic valve replacement

Abstract Introduction The management of patients with right bundle branch block (RBBB) undergoing transcatheter aortic valve replacement (TAVR) remains challenging. In these patients, the 2021 ESC guidelines recommend early pacemaker (PM) implantation in case of PR prolongation, QRS axis change or transient high-degree atrioventricular block (HAVB). However, evidence for the proposed criteria is scarce. Purpose Our aim was to evaluate the ESC recommendation for risk stratification of RBBB patients undergoing TAVR. Methods We retrospectively analyzed patients with pre-existing RBBB undergoing TAVR at our institution between 2011-2023. A surface 12-lead electrocardiogram (ECG) was available before and after procedure in all patients. The following, proposed ESC criteria were validated: ΔPR interval ≥ 20ms, QRS axis change or transient HAVB &amp;lt; 24 hours after TAVR. Results Of a total 1412 patients undergoing TAVR, 109 had pre-existing RBBB and were eligible for final analysis (mean age 83±5 years, 39% female). Of 109 RBBB patients, 36 (33%) developed persistent HAVB and received a permanent PM. Among the other 73 patients (67%), 17 patients (23%) suffered delayed HAVB during 30-days FU. When applying the ESC Guidelines, PM placement would have been indicated in 52% (38/73) of patients with RBBB after TAVR: due to transient HAVB in 17 (23%), due to PR prolongation ≥ 20ms in 19 (26%) and due to QRS axis change in 20 patients (27%). The proposed ESC criteria identified 82% of patients (14/17) with delayed HAVB during 30-day FU, while missing 3 patients (18%, 2.8% of overall cohort, Figure). This resulted in a sensitivity of 82% and a negative predictive value of 91%. Among the 17 patients with delayed HAVB, 12 patients (71%) displayed transient atrioventricular (AV) block within 24 hours after TAVR. Conclusion In this large cohort of RBBB patients undergoing TAVR with contemporary valves and techniques, the proposed ESC criteria of PR prolongation, QRS axis change or transient HAVB correctly identified 4/5 patients developing HAVB during 30-day FU. Prospective studies are warranted to confirm these findings.

Genotype-phenotype correlations in patients with titin variants and cardiomyopathy from a Swiss cohort

Abstract Background Alterations in titin (TTN) are mostly described with dilated cardiomyopathy (DCM). Few studies identified TTN variants in arrhythmogenic cardiomyopathy (ACM), but the overlap of dilated and arrhythmogenic phenotypes in TTN variants is scarcely studied. Most pathogenic TTN variants are located on the A-band, but there is few knowledge about the phenotypic presentation of I-band and Z-disc (non-A-band) variants. Purpose The aim of this study is to characterize and investigate the outcome of patients with cardiomyopathy and pathogenic (P) or likely pathogenic (LP) TTN variants with a particular focus on the cardiomyopathy phenotype (DCM vs. ACM) at initial presentation and follow-up. Further, we studied the association of the TTN variant (A-band vs. non-A-band regions) and a unique phenotype. Methods This is a retrospective multicenter study from a Swiss cohort including 34 patients with P/LP TTN variants and cardiomyopathy. The variables of the secured anonymized database include patient characteristics, genetic, ECG, echocardiographic, and cardiac magnetic resonance (CMR) data. Ventricular arrhythmia (VA) events were divided into non-sustained ventricular tachycardia (nsVT), sustained ventricular tachycardia (sVT) and sudden cardiac arrest (SCA +/- ventricular fibrillation). Results Of 34 included patients, 68% were male. Median age at presentation was 43.5 years. 29 (85%) patients presented with DCM, 7 (21%) left dominant ACM (2020 Padua criteria) and none ARVC (2010 ARVC Task Force criteria). At median follow-up of 48.5 months, 17 (50%) patients had VA events (15 nsVT, 5 sVT and 3 SCA events). VA events significantly increased over time (p=0.008) and were not associated with gender or left ventricular ejection fraction (LVEF) &amp;lt;35%. Under optimal guideline-directed medical therapy (GDMT) mean LVEF and right ventricular function increased significantly (LVEF: 28.3±14.4% vs. 41.9±9.8% and right ventricular fractional area change (RV FAC): 24.7±7.5% vs. 35.8±4.8%, p&amp;lt;0.05). Late gadolinium enhancement (LGE) on CMR was commonest in the basal septum, but no patient had higher degree atrioventricular block (AVB) at baseline and follow-up. At last follow-up, 8 (24%) patients fulfilled ACM and 13 (38%) DCM criteria (Figure 1). Most TTN variants were located on the A-band (21, 62%), 10 (29%) on the non-A-band regions. Latter had higher rates of sVT (log-rank p=0.041) during follow-up (Figure 2). 20 (59%) had LP and 11 (32%) P variants. P variant carriers were younger at disease presentation compared to LP variant carriers. Conclusion Patients with TTN variants frequently present as DCM, whereas presentation as left dominant ACM is less common. TTN does not seem to be a classical ARVC causing gene. Despite favourable biventricular remodelling under GDMT, ventricular arrhythmic events increase during follow-up. I-band and Z-disk variants are associated with a higher risk of sVT, which may help in the risk stratification process.

Long-term follow-up of single-chamber atrial pacing - system upgrade and wenckebach block point behavior: potential implications for leadless AAI pacing?

Abstract Introduction Until recently leadless pacemakers (PM) did not support atrial pacing. A novel dual chamber leadless PM system now provides treatment option for a wide range of indications. Single-chamber atrial stimulation (AAI) for the treatment of symptomatic sick sinus syndrome (SSS) is scarcely used due to concerns about the potential development of atrioventricular block (AVB) and development of paroxysmal atrial fibrillation (AF). Long-term follow-up data of AAI-PM is however scarce. Little is known about the role of serial Wenckebach block point (WBP) measurements in AAI-PM patients for risk stratification. Purpose To assess the incidence of dual chamber upgrade of patients treated with AAI-PM for SSS during long-term follow-up and to investigate the role of serial WBP measurements for risk stratification. Methods Prospectively enrolled patients undergoing implantation of an AAI-PM between October 2002 and December 2023. WBP was measured at implantation and serially during follow up. Results We included a total of 178 patients, of which 58% were female and the median age at implantation was 78 [IQR 71 – 83] years. The median follow-up duration was 6.5 [IQR 2.0 – 9.7] years. 24 patients (13.5%) received a system upgrade to DDD including 3 patients (1.7%) with a mode change to ventricular pacing only (VVI). Adjusted for years of follow-up the upgrade rate was 2.1% per year. Median time to system upgrade was 5.2 [IQR 1.6 – 8.7] years. Reasons for system upgrade were high-degree AVB (38%), low WBP (17%), atrial arrhythmias (33%), unclear syncope (8%) and infection (4%). Median WBP at implantation was 130 [120 – 140] bpm, showing a significant decline over time in the upgrade-group with 105 [95 – 130] bpm compared to the rest of the cohort with 130 [120-130] bpm (p = 0.009). A decline in WBP &amp;gt;20 bpm was found in 17.9% patients and a decline of 10-20 bpm in 33.7% of patients. New-onset atrial arrythmias were found in 36 patients (20%), 29% in the upgrade group and 19% in the rest of the cohort (p = 0.3). Neither age at implantation, sex, WBP at implantation, nor atrial arrhythmia prior to implantation were predictive for the need of a future system upgrade. Conclusion In this cohort of patients undergoing AAI-PM implantation for SSS, a system upgrade was required in 2% per year. The WBP remained stable in 48% of patients. Therefore, AAI-PM due to SSS emerges as a judicious and secure therapeutic modality, warranting increased consideration in the light of new treatment options for leadless pacing.

Leadless pacemaker - lead parameters stability and battery longevity in the mid-term follow-up

Abstract Background A leadless pacemaker (L-PM) has been designed to avoid the need for a pacemaker pocket and transvenous lead. Long-term safety will largely depend on the need for replacements, mainly due to battery depletion (end-of-life). While the mean L-PM battery longevity predicted by the manufacturer is 12 years, real-world longevity data are still scarce. We aimed to describe L-PM parameters’ stability and battery longevity during the mid-term follow-up. Methods Single-center registry of consecutive patients undergoing L-PM implantation from May 2015 to November 2023. Procedural characteristics, lead parameters and battery longevity were collected immediately after implantation and during the most recent follow-up visit. Results Overall, 261 consecutive patients had a transcatheter L-PM implanted through a femoral vein (mean age 78±10 years; 66% male). Mean procedural duration was 44±28min and fluoroscopy time was 4,4±3,9min. The device was successfully implanted in all but one patient. The main indications for permanent pacing were high-degree atrioventricular block [N=130 (50%)], atrial fibrillation with pauses [N=78 (30%)], and sinus node disease [N=28 (11%)]. Immediately after implantation, three cases (1,2%) of pericardial effusion (one with tamponade) were reported. In one case (0,4%), a conventional pacemaker was implanted due to L-PM acute dysfunction. No other procedure-related complications, including dislodgment, were reported at discharge. After a mean follow-up of 2,8±1,7years, the pacing threshold and R-wave amplitude remained stable [0,67mV vs. 0,62mV (p=0,9); and 10,3mV vs. 16,1mV (p&amp;lt;0,001), respectively] and mean ventricular pacing was 54±38%. Expected battery longevity was &amp;gt;8 years (maximum value) in 84% of the patients. In the subgroup of patients with &amp;gt;5 years of follow-up (N=20; mean follow up of 6,3±1,8years), the expected battery longevity was &amp;gt;8 years in 85% (N=17) of the patients. In three cases, the L-PM was upgraded to cardiac resynchronization therapy or left bundle branch area pacing due to pacing-induced left ventricular dysfunction. There was one case of L-PM end-of-life 6 years after implant (pacing threshold 0,5mV; ventricular pacing 100%), in which a second L-PM was successfully implanted. Overall, 78 (31%) patients died, a mean of 2,2±1,9 years after L-PM implantation, none related to the device. Conclusion In this real-world cohort, L-PM maintained stable pacing parameters and, in the mid-term follow-up, only one battery depletion was observed while expected longevity remained above 8 years in the large majority of patients. Longer follow up will allow better understanding of both technical and clinical aspects relevant to manage end-of-life devices.Table 1Figure 1

Intracardiac leadless pacemaker: long term safety over traditional pacemakers. a systematic review and meta-analysis

Abstract Introduction Leadless pacemaker (LP) is a novel technology designed to reduce lead-related, including pocket infections, associated with traditional pacemakers. LP can be used in patients with high-degree AV block, sinus node dysfunction, and bradycardia with syncope. We conducted a systematic review and meta-analysis to examine the long-term safety of intra-cardiac leadless pacemakers compared with traditional pacemakers. Methods Our protocol was registered in advance on PROSPERO. Studies were eligible if they compared complications, revision, cardiac perforation, infections, and all-cause mortality between patients who received leadless pacemakers versus traditional pacemakers. The systematic search was conducted in five databases (MEDLINE, EMBASE, CENTRAL, Web of Science, Scopus) without restriction. The random-effect model was implemented to calculate pooled odds ratio (OR) with a 95% confidence interval (CI). Also, the Mantel-Haenszel method, Paule-Mandel estimator for tau^2, Q-Profile method for the confidence interval of tau^2 and tau, and Hartung-Knapp adjustment for random effects model methods were used for the prediction of data extracted directly from the curves. ROBINS-I tool was used for the risk of bias assessment, and the certainty of the evidence was evaluated with the GRADE approach. Results Of 6450 studies screened, we identified 21 observational studies of Nanostim and Micra leadless pacemakers. The pooled incidence of complications of leadless versus traditional pacemakers at 1, 6, 12-24 months show the odds are clinically and statistically different (OR=0.66, 95% CI: 0.42–1.02; OR=0.44, 95% CI: 0.22–0.86; OR=0.41, 95% CI: 0.32–0.53 respectively). The pooled incidence of infection rate at 6, 12-24 months is lower in patients with LP (OR=0.37, 95% CI: 0.31–0.44; OR=0.20, 95% CI: 0.00–97.31). The studies comparing all-cause mortality during 6, 12-24 months in leadless versus traditional pacemakers did not show statistically significant differences in these outcomes (OR=1.26, 95% CI: 0.88–1.81; OR=0.86, 95% CI: 0.25–2.92 respectively. Conclusion Our results show that complications and infections occur less frequently in patients with leadless pacemakers than in patients with conventional pacemakers with no difference in all-cause mortality. However, there is a need for high-quality randomized clinical trials and propensity score-matched studies focusing on this clinically relevant question.Complication Forest plotsInfection Forest plots

Beating the clock: the impact of heart failure duration on CRT efficacy

Abstract Background Cardiac Resynchronization Therapy (CRT) stands as an established intervention for selected patients with heart failure (HF) presenting with a wide QRS complex. The optimal timing for CRT implantation remains uncertain. Current evidence suggests superior outcomes post-CRT in patients who have not been previously hospitalised for HF and those receiving the implant during their initial hospitalisation for HF.1 Purpose The primary objective of this study is to investigate the long-term clinical outcomes following CRT implantation relative to the duration of HF previous to the implant. It was analysed in a cohort of consecutive patients from a HF Unit who met the criteria for CRT as recommended by the ESC guidelines (QRS duration ≥150ms, left bundle branch block morphology, and left ventricular ejection fraction (LVEF) ≤35% despite optimal medical therapy). Methods We evaluated all patients who received CRT from January 2011 through September 2022. Follow-up ended in September 2023. Patients with CRT indicated for ventricular pacing due to high-degree atrioventricular block were excluded. Patients were categorized into two groups based on the duration of HF progression prior to CRT implantation: more than 3 years and 3 years or less. The primary outcome was all-cause mortality (ACM). Secondary outcomes included a composite of ACM and HF hospitalisation and the proportion of patients who demonstrated a significant improvement in LVEF (defined as an increase of ≥10% from baseline and a subsequent measurement of LVEF ≥40%). Results The cohort consisted of 127 patients, mean age 65.8±10.7 years, 23.6% were women, mean LVEF was 28.4±8.6% and 36.2% had ischaemic aetiology (Table 1). 62 patients either died or were hospitalized for HF. Mean follow-up was 4.9±2.7 years. After adjusting for age, sex and baseline LVEF, patients with HF for more than three years before CRT implantation had a worse prognosis: HRs of 2.31 for ACM (p=0.016) and 2.13 for the combined endpoint of ACM+HFH (p=0.010) (Figure 1). The proportion of patients with improved LVEF after CRT was significantly higher in the group with shorter HF duration (68.25%) compared to the group with longer HF duration (25%), p &amp;lt;0.001. Conclusions Our findings reveal that patients with a shorter history of HF (less than three years) prior to CRT implantation exhibit significantly better clinical outcomes. These results highlight the role of early intervention with CRT in patients with HF, suggesting that shorter HF duration prior to CRT may lead to more favourable long-term outcomes.

Incidence and risk factors associated with atrioventricular block in the general population: the atherosclerosis risk in communities study and Cardiovascular Health Study

ObjectivesTo identify risk factors correlated with atrioventricular block (AVB) in the general population.MethodsParticipants in the Atherosclerosis Risk in Communities study (ARIC) and the Cardiovascular Health study (CHS) were enrolled. The presence of AVB was confirmed at an electrocardiogram (ECG) reading center using Minnesota ECG Classification. Cox proportional hazards models were performed to investigate potential risk factors of AVB, after adjustment for age, sex, race and traditional cardiovascular risk factors.ResultsDuring the 17 years of follow-up, a total of 731 high-degree AVB cases were identified. Age and sex-standardized rate of AVB was 2.79 and 2.35 per 1000 person-years in the white and the black population, respectively. With the increase of the geriatric population, the incidence of high-degree AVB will increase from 378,816 in 2020 to 535,076 in 2060, and most increment would occur among the elderly. Older age, male sex, the white race, overweight, comorbidities, declined forced vital capacity (FVC), elevated inflammation biomarkers, left bundle branch block and bifascicular block were independently associated with the incidence of high-degree AVB.ConclusionTo conclude, older age, male sex, white population, overweight, combined diabetes or chronic kidney disease, impaired FVC, elevated inflammation biomarkers, left bundle branch block and bifascicular block were independent predictors for high-degree AVB. The next 40 years would witness a dramatic increase in the incidence of high-degree AVB.

Leadless pacemaker implantation using halo-shape technique in a severe dextroscoliosis octogenarian

The halo-shape technique (HST) is an emerging approach for implanting a leadless pacemaker in scoliosis patients in recent years. Severe scoliosis and humpback made it challenging to push the tip of the delivery catheter towards the ventricular septum using the conventional gooseneck-shape technique. The feasibility and safety of the use of HST in an octogenarian with severe dextroscoliosis and humpback have not been well-assessed. Here, we report a case of high-degree atrioventricular block octogenarian with severe dextroscoliosis and humpback who successfully received a leadless pacemaker implantation using HST. Procedure-related complications were not observed, and the electrical parameters were stable at 6-month follow-up.

Hereditary and wild type transthyretin amyloid cardiomyopathy in Bulgaria in patients suspected for cardiac amyloidosis

Introduction: Transthyretin amyloid cardiomyopathy (ATTR-CM) is a severe progressive disease, more common than previously expected. The main objectives were to evaluate hereditary and wild type ATTR-CM frequency and clinical manifestations. Material and methods: One hundred seventy-eight patients at mean age 68 &amp;plusmn; 13 years (129 males), referred by cardiologists with suspected cardiac amyloidosis (left ventricular wall thickness &amp;ge; 12 mm and red flags) were evaluated. Pyrophosphate scintigraphy (99mTc-PYP) grade 2-3 myocardial uptake in the absence of monoclonal protein confirmed the diagnosis. Genetic test differentiated variant from wild type ATTR-CM. Endomyocardial biopsy with amyloid typing was performed in two patients. Results: Cardiac amyloidosis was diagnosed in 69 patients: light chain in 24 (13%) and ATTR-CM in 45 patients (25%). Wild type (ATTRwt) was found in 21 (12%) male patients at mean age 81 &amp;plusmn; 6 years and variant type (ATTRv) in 24 patients (13%) at mean age 58 &amp;plusmn; 7 years (15 males). In all ATTRv-CM patients some degree of peripheral polyneuropathy was found. The most common clinical red flags at diagnosis in both ATTRv and ATTRwt were heart failure in all patients, atrial fibrillation (16; 36%), pacemaker (5; 11%), and carpal tunnel syndrome (8; 18%). Severe aortic stenosis (4; 19%), spinal stenosis (2;10%), biceps tendon rupture (1; 5%) were characteristic for the wild type. At follow up, four patients needed a pacemaker for high degree AV block, six patients developed new onset atrial fibrillation, seventeen patients needed either initiation or an increase of the dose of loop diuretic, another 7 patients were hospitalized for heart failure exacerbation. Eight patients (18%) died, 7 (33%) with ATTRwt-CM and 1 (4%) with ATTRv-CM, all with advanced heart failure, 4 with concomitant severe aortic stenosis. Conclusions: This study provides the first nationwide estimates of the frequency and the clinical manifestations of ATTR-CM. Confirming the severity of the disease and poor prognosis, a low threshold for screening is needed for early diagnosis and timely treatment.

Contemporary Diagnostics of Cardiac Sarcoidosis: The Importance of Multimodality Imaging.

Sarcoidosis is an inflammatory condition that can affect multiple organ systems and is characterized by the formation of non-caseating granulomas in various organs, including the heart. Due to suboptimal diagnostic rates, the true prevalence and incidence of cardiac sarcoidosis (CS) remain to be determined. In patients with suspected CS, an initial examination should include 12-lead ECG or ambulatory ECG monitoring, and echocardiography with the estimation of LV, RV function, and strain rate. In patients with confirmed extracardiac sarcoidosis and with high clinical suspicion for CS, sophisticated imaging modalities, including cardiac MRI and PET, are indicated. Typical inflammation patterns and myocardial scarring should pose a high suspicion for CS. In patients without diagnosed extracardiac sarcoidosis and high clinical suspicion, although with low diagnostic probability, an endomyocardial biopsy should be considered to establish the diagnosis of definite isolated cardiac sarcoidosis. Timely diagnosis enables the initiation of therapy and close monitoring of adverse cardiac events that can be life-threatening, including sudden cardiac death, ventricular tachycardia, high-degree AV block, and heart failure. Implementing biomarkers in correlation to cardiac imaging can determine the disease's severity and progression but can also be helpful in following the treatment response. The formation of larger global registries can be helpful in the identification of independent predictors of adverse clinical events and the development of specific diagnostic algorithms to reduce the overall risk of this serious condition.

Role of new generation implantable loop recorders in managing undiagnosed pediatric cardiac symptoms

Pediatric cardiac symptoms such as palpitations, syncope, or seizure-like episodes pose diagnostic challenges for general pediatricians. These symptoms, though often benign, may reveal underlying arrhythmias or inherited cardiac conditions (ICCs), affecting the quality of life and limiting activity participation. The purpose of this study is to determine the effectiveness and safety of implantable loop recorders (ILRs) in diagnosing and managing arrhythmias in pediatric patients. A retrospective cohort study conducted over an 8-year period from January 2016 to December 2023 in a single pediatric cardiology center. A cohort of 155 pediatric patients (median age 11.4 years) who underwent ILR implantation were selected based on symptoms such as palpitations, chest pain, or syncope, and those with previously recorded arrhythmias or high-risk ICCs. The primary outcomes were the diagnostic yield of ILRs for arrhythmias and subsequent changes in patient management. Diagnostic yield was defined as the detection of relevant arrhythmias, such as pauses of 3 s or longer, high-degree AV block, sinus node dysfunction, supraventricular tachycardia, ventricular tachycardia, or inappropriate sinus tachycardia. The median follow-up period was 2.3 years (845 days). Diagnostic arrhythmias were recorded in 60% of patients with symptom-activated transmissions and 80% of device-activated transmissions. Sinus pauses (37.5%) and VT (30%) were the most common arrhythmias detected. In patients with syncope (n = 76), 30% had relevant arrhythmias. In the palpitations group (n = 20), 35% had relevant arrhythmias. Approximately 80% of patients with ILR-diagnosed arrhythmias underwent targeted management, including medication changes and additional procedures. No significant complications were observed; minor complications occurred in 2.5% of patients.Conclusions: New generation ILRs are effective and safe for diagnosing and managing pediatric arrhythmias, providing significant reassurance to patients and families. Further studies are needed to evaluate the impact of ILRs on quality of life and sports participation in high-risk young patients.What is Known:• Pediatric Cardiac Symptoms: Symptoms like palpitations, syncope, and seizure-like episodes in pediatric patients pose significant diagnostic challenges.• Diagnostic Tools: Traditional diagnostic tools such as ECG, Holter monitors, and external loop recorders often have low diagnostic yields due to the sporadic nature of symptoms.• Implantable Loop Recorders (ILRs): ILRs have been shown to improve the diagnostic yield for arrhythmias in adults and provide long-term rhythm monitoring.What is New:• Effectiveness in Pediatrics: This study demonstrates that new generation ILRs significantly enhance the diagnostic yield for arrhythmias in pediatric patients with undiagnosed cardiac symptoms.• Safety and Efficacy: The study confirms that ILRs are both safe and effective in the pediatric population, with minimal complications and high diagnostic accuracy.• Targeted Management: Findings show that ILR-diagnosed arrhythmias lead to targeted management changes in approximately 80% of cases, including medication adjustments and additional procedures.• Long-term Monitoring: ILRs provide continuous long-term monitoring, offering reassurance to patients and families, and potentially improving quality of life and participation in activities for high-risk young patients.

Intermittent High-Degree AV Block, Rash, and Facial Droop with Negative Lyme PCR

Intermittent High-Degree AV Block, Rash, and Facial Droop with Negative Lyme PCR

Smartwatch-Detected Arrhythmias in Patients After Transcatheter Aortic Valve Replacement (TAVR): Analysis of the SMART TAVR Trial.

There are limited data available on the development of arrhythmias in patients at risk of high-degree atrioventricular block (HAVB) or complete heart block (CHB) following transcatheter aortic valve replacement (TAVR). This study aimed to explore the incidence and evolution of arrhythmias by monitoring patients at risk of HAVB or CHB after TAVR using smartwatches. We analyzed 188 consecutive patients in the prospective SMART TAVR (smartwatch-facilitated early discharge in patients undergoing TAVR) trial. Patients were divided into 2 groups according to the risk of HAVB or CHB. Patients were required to trigger a single-lead electrocardiogram (ECG) recording and send it to the Heart Health App via their smartphone. Physicians in the central ECG core lab would then analyze the ECG. The incidence and timing of arrhythmias and pacemaker implantation within a 30-day follow-up were compared. All arrhythmic events were adjudicated in a central ECG core lab. The mean age of the patients was 73.1 (SD 7.3) years, of whom 105 (55.9%) were men. The mean discharge day after TAVR was 2.0 (SD 1.8) days. There were no statistically significant changes in the evolution of atrial fibrillation or atrial flutter, Mobitz I, Mobitz II, and third-degree atrial ventricular block over time in the first month after TAVR. The incidence of the left bundle branch block (LBBB) increased in the first week and decreased in the subsequent 3 weeks significantly (P<.001). Patients at higher risk of HAVB or CHB received more pacemaker implantation after discharge (n=8, 9.6% vs n=2, 1.9%; P=.04). The incidence of LBBB was higher in the group with higher HAVB or CHB risk (n=47, 56.6% vs n=34, 32.4%; P=.001). The independent predictors for pacemaker implantation were age, baseline atrial fibrillation, baseline right bundle branch block, Mobitz II, and third-degree atrioventricular block detected by the smartwatch. Except for LBBB, no change in arrhythmias was observed over time in the first month after TAVR. A higher incidence of pacemaker implantation after discharge was observed in patients at risk of HAVB or CHB. However, Mobitz II and third-degree atrioventricular block detected by the smartwatch during follow-ups were more valuable indicators to predict pacemaker implantation after discharge from the index TAVR. ClinicalTrials.gov NCT04454177; https://clinicaltrials.gov/study/NCT04454177.

Implantable cardiac monitor and leadless pacemaker in the management of syncope due to intermittent high-degree atrioventricular block: a case report

BackgroundLead dislodgements, tricuspid valve failure, and wound infections are prominent issues addressed by leadless pacemakers (LPM). These devises have emerged as viable alternatives to conventional transvenous pacemakers. LPMs offer minimized complications and effective pacing, particularly beneficial for elderly patients with a low body mass index (BMI) who are at heightened infection of risk. The Micra AV leadless pacemaker was released in the US in 2020, featuring a VDD pacing mode akin to conventional pacemakers. It senses atrial activity to pace ventricular beats while maintaining the natural atrioventricular activation sequence. Micra AV achieves atrioventricular synchronization through mechanical sensing principles. Ongoing research aims to assess its efficacy, implantation feasibility, and clinical safety.Case presentationAn 83-year-old man with a history of syncope was the focus of this case study. An implantable cardiac monitor (ICM) recorded occasional high-degree atrioventricular block in the patient. Subsequently, the Micra AV was implanted via the left femoral vein, and its settings were adjusted in accordance with data obtained from the ICM. No significant issues regarding pacing threshold or impedance were found during the follow-up examinations post-surgery. Importantly, the patient experienced a noticeable reduction in symptoms compared to before the implantation.DiscussionThis case underscores the significance of ICM monitoring in elucidating cardiac events leading to syncope and guiding appropriate treatment. It also highlights the successful outcomes and reliable implantation of the Micra AV for managing high-degree atrioventricular block. This study contributes to the growing body of evidence supporting the adoption of leadless pacemakers as a viable option for patients requiring cardiac pacing, particularly those vulnerable to complications associated with traditional pacemakers. It provides real-world evidence of Micra AV’s efficacy and safety, further validating its role in clinical practice.

Management of cardiac sarcoidosis.

Cardiac sarcoidosis (CS) is a form of inflammatory cardiomyopathy associated with significant clinical complications such as high-degree atrioventricular block, ventricular tachycardia, and heart failure as well as sudden cardiac death. It is therefore important to provide an expert consensus statement summarizing the role of different available diagnostic tools and emphasizing the importance of a multidisciplinary approach. By integrating clinical information and the results of diagnostic tests, an accurate, validated, and timely diagnosis can be made, while alternative diagnoses can be reasonably excluded. This clinical expert consensus statement reviews the evidence on the management of different CS manifestations and provides advice to practicing clinicians in the field on the role of immunosuppression and the treatment of cardiac complications based on limited published data and the experience of international CS experts. The monitoring and risk stratification of patients with CS is also covered, while controversies and future research needs are explored.

Peri-mortem arrhythmias in the non-cardiac intensive care unit.

Cardiovascular failure is recognized as a common final pathway at the end of life but there is a paucity of data describing terminal arrhythmias. We aimed to describe arrhythmias recorded peri-mortem in critically ill patients. We enrolled intensive care unit patients admitted to two tertiary Canadian medico-surgical centres. Participants wore a continuous electrocardiogram (ECG) monitor for 14 days, until discharge, removal or death. We recorded all significant occurrences of arrhythmias in the final hour of life. Among 39 patients wearing an ECG monitor at the time of death, 22 (56%) developed at least 1 terminal arrhythmia as adjudicated by an arrhythmia physician: 23% (n = 9) had ventricular fibrillation/polymorphic ventricular tachycardia, 18% (n = 7) had sinoatrial pauses, 15% (n = 6) had atrial fibrillation and 13% (n = 5) had high-degree atrioventricular block. Five participants (13%) developed multiple arrythmias. Arrhythmias are common in dying critically ill patients. There is a roughly even distribution between ventricular arrhythmias, atrial fibrillation, sinus node dysfunction and atrioventricular block. The results of this study may be most useful for critically ill patients who are organ donation candidates. The appearance of arrhythmias may serve as a marker of change in clinical status for organ donation teams to plan mobilization efforts. In participants who are sedated or intubated, arrhythmias could be a surrogate marker for respiratory or neurologic changes.

Electrophysiology-guided algorithm for patients with conduction abnormalities post TAVR: one-year follow-up

Abstract Introduction Transcatheter aortic valve replacement (TAVR) revolutionized the treatment of aortic stenosis [1]. Although TAVR is an effective treatment for AS patients, it is associated with high incidence of new-onset conduction disturbances and pacemaker implantations. The two most common conduction disturbances after TAVR are new onset left bundle branch block (LBBB) and high-degree atrioventricular block (HDAVB) [2]. While patients with HDAVB require a permanent pacemaker implantation (PPM), the management of LBBB is not completely established yet. According to the ESC 2021 guidelines, a PPM is indicated in patients with persistent HDAVB or new onset alternating BBB after TAVR. Yet, the recommendations regarding other conduction abnormalities are not well defined. In patients with persistent new onset LBBB, ambulatory continuous ECG monitoring or electrophysiology study (EPS) are recommended [3]. Purpose To evaluate the clinical outcomes of patients with conduction disorders after TAVR who were managed according to electrophysiology-guided algorithm (Figure 1), including mortality, late pacemaker’s implantations, and heart failure hospitalizations. Predictors of periprocedural LBBB and HDAVB were also assessed. Methods Retrospective population-based cohort study including all patients who developed new onset LBBB after TAVR at a tertiary University Medical Center from October 1, 2018, to December 31, 2022, and were managed according to specific electrophysiology-guided algorithm. Results The study cohort included 230 consecutive patients who underwent TAVR. Mean age was 80.3 and 56.5% were females (Figure 2). Twenty patients (8.7%) developed HDAVB and required a PPM, whereas 40 patients (17.4%) developed persistent LBBB. According to the algorithm, 8 patients (20%) with a QRS&amp;lt;130ms were discharged without PPM [group A], 20 patients (50%) with a QRS of 130-160ms underwent EPS, and 12 patients (30%) with a QRS&amp;gt;160ms [Group C] received a PPM. Among the EPS group: 9 patients (22.5%) with HV&amp;gt;65ms underwent PPM [group B2], while 11 patients with HV&amp;lt;65ms (27.5%) were discharged without PPM [group B1]. During a one-year follow-up only one patient required late PPM [group B1]. Mortality was higher among the subgroups with PPM [B2 and C] compared to the subgroups without a PPM [A and B1]: 4 vs. 1 patient accordingly. Conclusions The presented electrophysiology-guided algorithm for patients with persistent LBBB after TAVR appears safe and efficient, with a modest incidence of PPM (17.6% of the total cohort) during hospitalization and a minimal need for late PPM at one year follow-up. Importantly, there was no excess of mortality among patients who were discharged without a pacemaker implantation. Thus, we suggest that the presented algorithm may serve as a reliable strategy to distinguish between individuals with new onset persistent LBBB after TAVR who require PPM compared to those in whom a PPM can be safely avoided.