Excessive Blood Pressure Rise and Cardiovascular Remodeling in Marathon Runners.

Exercise-induced hypertension (EIH) is thought to be associated with increased cardiovascular (CV) risks. However, no previous studies have investigated the effects of EIH on CV systems in marathon runners without CV risk factors using both 24-hr ambulatory blood pressure (BP) monitoring and exercise stress echocardiography (ESE). This study firstly described differences in CV adaptations according to EIH assessed by both exams. Marathon runners between 35 and 64 years of age without CV risk factors were eligible. All the participants underwent both 24-hr ambulatory BP monitoring and ESE. EIH was defined as a maximal exercise systolic BP≥210 mmHg. The EIH group (n=19) had shorter training history and higher exercise intensity compared to the non-EIH group (n=23). The average systolic BP was higher in the EIH group than in the non-EIH group. Left cardiac chamber size and left ventricular mass (LVM) were also higher in the EIH group compared to the non-EIH group. Maximal BP during ESE was positively correlated with both parameters. Exaggerated BP response during exercise needs to be monitored for pre-emptive measurements before it results in progressive cardiovascular maladaptation.

The efficacy of single-lead implantable cardioverter-defibrillator with atrial sensing dipole to detect atrial fibrillation and to reduce inappropriate therapy according to atrial sensing ON or OFF: Rationale and design of the SMART-CONTROL study, a prospective multicenter randomized trial.

BACKGROUND: Few studies have compared the efficacy of single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (VDD-ICD) and conventional single-chamber ICD from the aspect of atrial fibrillation (AF) detection or inappropriate ICD therapy reduction. In the SMART-CONTROL trial (NCT03932604), we primarily aim to investigate whether the atrial sensing capability of VDD-ICD is useful in AF detection and inappropriate therapy reduction by randomly activating or deactivating the atrial sensing function. METHODS AND DESIGN: This study was designed as a prospective, multicenter, open-label, randomized trial to enroll 640 patients with no history of clinical AF or rhythm control for AF within 1 year who were undergoing the implantation of VDD-ICD system. Patients are assigned randomly to atrial sensing "ON" or "OFF" group, with crossover allowed during follow-up. The coprimary outcomes are the incidence of AF detection and inappropriate ICD therapy over a 2-year follow-up period. The secondary outcomes include non-AF atrial tachyarrhythmia, ventricular tachyarrhythmia with or without ICD therapy, thromboembolic events, bleeding, heart failure hospitalization, mortality, a composite of adverse cardiovascular events, and long-term atrial sensing stability or variability. CONCLUSION: We expect that this trial can evaluate the efficacy of a single-lead ICD system on various clinical outcomes including AF detection and inappropriate therapy reduction, and ultimately provide guidance to selection of ICD system.

Characteristics of symptomatic recurrent tachyarrhythmia after thoracoscopic ablation for persistent atrial fibrillation.

BACKGROUND: Recurrent atrial tachyarrhythmia (ATa) is a challenge in all ablation procedures for atrial fibrillation (AF). However, data on ATa after totally thoracoscopic ablation (TTA) is lacking. This study aimed to investigate the mechanisms and outcomes of recurrent ATa after TTA. METHODS: Eligible patients for the present study were those who underwent electrophysiologic study and catheter-based radiofrequency ablation (RFA) at least 3 months after TTA for symptomatic recurrent ATa that was refractory to antiarrhythmic drugs and/or cardioversion. Follow-up outcomes included recurrent ATa after first or repeated RFA. RESULTS: A consecutive 154 TTA patients were evaluated. A total of 24 patients showed symptomatic recurrent ATa after TTA, and 22 underwent RFA. Half of the patients (11/22, 50%) had AF as a form of recurrent ATa. Nonpulmonary vein (PV)-related mechanisms of ATa were noted in half of patients. PV gaps showed a characteristic distribution: most gaps in right PVs were located at the posterior ridge (71.4%) with the posterior ridge of left PVs saved in all patients. Post-RFA recurrence rate was 27.3% during a median follow-up of 9.1 months, with all recurrences except for one occurring within 3 months after first RFA. CONCLUSIONS: During a median of 17.8 months after TTA, 24 patients (24/154, 15.6%) developed symptomatic recurrent ATa, and 22 patients underwent RFA. Post-RFA recurrence rate was 27.3%, which mostly occurred within 3 months after RFA. Catheter-based ablation of recurrent arrhythmias may be effective, but challenging.

Right ventricle apex pacing identifies the presence of ventricular premature depolarizations-induced cardiomyopathy.

BACKGROUND: A high burden of ventricular premature depolarizations (VPDs) has been associated with potentially reversible left ventricular (LV) dysfunction, termed as VPD-induced cardiomyopathy (CMP). However, many patients maintain normal LV function despite a high VPD burden. The purpose of this study was to identify CMP by right ventricle apex (RVa) pacing method in patients with high VPD burden. METHODS: A total of 62 patients (28 male; mean age = 50 ± 15 years) with idiopathic VPDs undergoing ablation were enrolled. RVa pacing was recorded in all patients during the procedure. The paced QRS duration (QRSd) during RV pacing was measured from the pacing spike to the latest QRS deflection on any surface electrocardiogram lead. Patients were divided into two groups: reversible VPD-induced CMP (Group R; n  = 15, 14 males, mean age = 54 ± 14 years) and normal LV function (Group N; n = 47, 23 males, mean age = 54 ± 15 years). RESULTS: The LV ejection fraction (%) was significantly lower in Group R as compared with Group N (Group R, Group N = 36 ± 6, 58 ± 4; P < 0.001); however, LV end-diastolic dimension mm was not significantly different between the two study groups (Group R, Group N = 54 ± 5, 50 ± 6; P = 0.06). Similarly, sinus QRS width (P = 0.10), VPD-burden (P = 0.36), and body surface area (P = 0.75) were not significantly different between Group R and Group N. The QRSd was significantly longer in Group R compared with Group N (177 ± 8 vs 150 ± 14; P < 0.001). Using a QRSd cut-off value of 170.1 ms, VPD-induced CMP was identified with a sensitivity of 73% and a specificity of 97%. CONCLUSION: RVa pacing with transmyocardial conduction time assessment was a useful method for identifying idiopathic VPD-induced CMP. Using a QRSd cut-off value of 170.1 ms, VPD-induced CMP was identified with a sensitivity of 73% and a specificity of 97%.

Efficacy of Cardiac Resynchronization Therapy Using Automated Dynamic Optimization and Left Ventricular-only Pacing.

BACKGROUND: Although device-based optimization has been developed to overcome the limitations of conventional optimization methods in cardiac resynchronization therapy (CRT), few real-world data supports the results of clinical trials that showed the efficacy of automatic optimization algorithms. We investigated whether CRT using the adaptive CRT algorithm is comparable to non-adaptive biventricular (BiV) pacing optimized with electrocardiogram or echocardiography-based methods. METHODS: Consecutive 155 CRT patients were categorized into 3 groups according to the optimization methods: non-adaptive BiV (n = 129), adaptive BiV (n = 11), and adaptive left ventricular (LV) pacing (n = 15) groups. Additionally, a subgroup of patients (n = 59) with normal PR interval and left bundle branch block (LBBB) was selected from the non-adaptive BiV group. The primary outcomes included cardiac death, heart transplantation, LV assist device implantation, and heart failure admission. Secondary outcomes were electromechanical reverse remodeling and responder rates at 6 months after CRT. RESULTS: During a median 27.5-month follow-up, there was no significant difference in primary outcomes among the 3 groups. However, there was a trend toward better outcomes in the adaptive LV group compared to the other groups. In a more rigorous comparisons among the patients with normal PR interval and LBBB, similar patterns were still observed. CONCLUSION: In our first Asian-Pacific real-world data, automated dynamic CRT optimization showed comparable efficacy to conventional methods regarding clinical outcomes and electromechanical remodeling.

Is the stroke volume during post-ectopic beat associated with ventricular premature complex-related symptoms?

Aims: This study aimed to investigate if increased stroke volume (SV) after a ventricular premature complex (VPC) was related to VPC-related symptoms. Methods and results: We selected patients having an isolated VPC during echocardiography from a prospective registry that included patients with a structurally normal heart and 24-h VPC >1%. Patients were divided into two groups according to the presence or absence of VPC-related symptoms (skipped beat or palpitation) when VPC occurred. Left ventricular (LV) volumes and time-velocity integral (TVI) at the LV outflow tract were measured during the preceding sinus beat, VPC, and post-ectopic sinus beat. Percent LV SV of the VPC and post-ectopic sinus beat were calculated by dividing each SV by the SV of the preceding sinus beat. A total of 47 patients were eligible. Most patients had VPC with left bundle branch block morphology and inferior axis. Patients in the symptom (+) group had a significantly lower SV, %LV SV, and TVI during post-ectopic sinus beat than those in the symptom (-) group. The sum of SVs during VPC and post-ectopic beat was significantly lower in symptomatic patients than non-symptomatic patients (103.4 mL vs. 125.1 mL, P = 0.02), while the sum of %LV SVs during VPC and post-ectopic beat tended to be lower in patients with symptoms than those without symptoms (P = 0.08). The sum of %LV SVs during VPC and post-VPC was positively correlated with coupling interval (CI) and CI ratio. Conclusion: Ventricular premature complex-related symptoms may not be associated with the amount of post-VPC SV.

Fate of Acute Heart Failure Patients With Mid-Range Ejection Fraction.

BACKGROUND: The outcomes of heart failure (HF) with mid-range ejection fraction (HFmrEF) have been rarely studied, and follow-up data on left ventricular ejection fraction (LVEF) are scarse.Methods and Results:Patients were selected from a prospective multicenter registry of patients hospitalized for acute HF and then classified in the improved group if they exhibited %LVEF change ≥5 with follow-up LVEF ≥50%. Follow-up LVEF reported at least 90 days after discharge was used for classification. Of the 3,085 patients with acute HF, 454 were classified in the HFmrEF, and 276 had follow-up data. Of these 276 patients, 34.1% were classified in the improved group. Multivariate analysis revealed that hypertension, higher heart rate, lower serum sodium level, and maintenance therapy with ß-blocker were associated with improved LVEF. The survival rate was significantly higher in the improved group than in the other groups. Young age and maintenance therapy with renin-angiotensin system blockers or aldosterone antagonists were significantly associated with better survival in HFmrEF. CONCLUSIONS: One-third of HFmrEF patients showed improved LVEF; moreover, the survival rate in the improved group was higher than the other groups. Renin-angiotensin system blockers and aldosterone antagonists could improve the survival of HFmrEF patients.

The Incidence of Riata Defibrillator Lead Failure: a Single-Center Experience.

Riata defibrillator leads were recalled due to a high failure rate. This study measured the incidence of externalized conductor (EC) and electrical dysfunction (ED) and sought to determine the predictors of ED with Riata defibrillator leads. We enrolled patients who received Riata® or Riata® ST silicone defibrillator leads at our center between January 2003 and December 2010. The presence of EC was evaluated with chest radiography. The incidence rates were measured at < 3 years, 3-5 years, and > 5 years after lead implantation. We also investigated the rates of ED and other clinical events during the follow-up period. A total of 44 patients were analyzed. The total cumulative incidence of EC was 27.3%. During the median dwell time (80 months), the incidence of ED was 22.7%. Patients with ED were younger (46.5 vs. 56.5 years, P = 0.018) and had a higher prevalence of cardiomyopathy than those without ED (60.0% vs. 20.6%, P = 0.043). ECs were most frequently detected in patients who underwent X-ray analysis 3-5 years after lead implantation (44.4%). In contrast, ED had a bimodal incidence pattern, with peaks at 5 years (7.0%) and 9 years (5.3%). There was no difference in ED-free survival rate between patients with and without EC (P = 0.628). Given the delayed occurrence of EC and ED after implantation of Riata defibrillator leads, long-term close monitoring is critically important.

Uric Acid Level Has a U-shaped Association with Clinical Outcomes in Patients with Vasospastic Angina.

No data are available on the association of serum uric acid and vasospastic angina (VSA) which has endothelial dysfunction as a possible pathophysiologic mechanism. Low uric acid level might cause adverse outcomes in VSA in connection with endothelial dysfunction. We enrolled 818 VSA patients whose uric acid level was measured at admission. Patients were categorized according to tertiles of uric acid level: group I, ≤ 4.8 mg/dL; group II, 4.9-5.9 mg/dL; and group III, ≥ 6.0 mg/dL. Primary outcome was major adverse cardiac events (MACEs), defined as a composite of cardiac death, acute myocardial infarction (MI), ischemic stroke, coronary revascularization, and rehospitalization for angina. Median follow-up duration was 49.2 months. Median uric acid values were 4.1 mg/dL for group I, 5.4 mg/dL for group II, and 6.7 mg/dL for group III. In the overall population, group II had a significantly lower incidence of MACE compared to group I (47 [17.1%] vs. 66 [24.6%]; hazard ratio [HR], 1.52; 95% confidence interval [CI], 1.02-2.26; P = 0.040) and a tendency of lower incidence of MACEs compared to Group III (47 [17.1%] vs. 62 [22.5%]; HR, 1.44; 95% CI, 0.98-2.13; P = 0.067). Among group I patients, those who received nitrates had a higher incidence of MACEs than those without nitrate therapy (P < 0.001). Low uric acid level was associated with adverse clinical outcomes, while high uric acid level had a trend toward an increase in it. Use of nitrate in patients with low uric acid level might have adverse effects on clinical outcomes of VSA.

Comparison of clinical characteristics in patients with Takayasu arteritis with and without concomitant tuberculosis.

Because of frequent tuberculosis in patients with Takayasu arteritis (TA), a possible relationship between TA and tuberculosis has been proposed. However, there are no studies to date that have examined clinical manifestations in patients diagnosed with TA with or without tuberculosis. Two hundred sixty-seven patients were diagnosed with TA according to the 1990 American College of Rheumatology criteria between September 1994 and April 2014. Patients with TA were classified into groups with or without tuberculosis. Among the 267 patients with TA studied, 47 patients (17.7 %) who had a history of previous treatment of tuberculosis (34 patients), concurrent diagnosis of tuberculosis with TA (10 patients), or diagnosis of tuberculosis during the follow-up period for TA (3 patients) were included in the group with tuberculosis. The group with tuberculosis comprised of 33 patients (70.2 %) with pulmonary tuberculosis, 12 patients (25.5 %) with tuberculous lymphadenitis, and 2 patients (4.3 %) with tuberculosis of the skin and colon, respectively. Comorbid disease and patients' signs and symptoms were not significantly different between TA patients with and without tuberculosis. Additionally, the site of disease involvement in angiographic findings and distribution of angiographic type were similar between the two groups. In conclusion, tuberculosis including tuberculous lymphadenitis was frequently observed in patients with TA. Clinical features and angiographic findings in TA were not different according to the presence or absence of concomitant tuberculosis.

Analysis of Protrusio Acetabuli Using a CT-based Diagnostic Method in Korean Patients with Marfan Syndrome: Prevalence and Association with Other Manifestations.

A new CT-based diagnostic method of protrusio acetabuli (PA) was introduced. However, prevalence of PA by this method and correlation between PA and other manifestations of Marfan syndrome (MFS) is unknown in Korean MFS patients. This study aimed to investigate the prevalence of PA diagnosed by a CT-based method in Korean patients with MFS, the association of PA with other manifestations of MFS, and the contribution of PA to MFS diagnosis. We retrospectively reviewed the records of 146 MFS patients with the presence of a causative FBN1 mutation and 146 age- and sex-matched controls from a single tertiary care center. All MFS patients underwent a complete assessment of criteria based on the revised Ghent nosology. PA was assessed quantitatively using a CT-based circle-wall distance (CWD) method. PA was diagnosed in 77.4% of patients in the MFS group and in 11.0% of the control group. CWD was significantly different between the two groups (1.50 mm vs. -0.64 mm, P<0.001). The presence of PA did not correlate with the presence of ectopia lentis, aortic root diameter, or history of aortic dissection. The presence of PA did not have a significant impact on the final diagnosis of MFS. Even though the presence of PA does not related to the cardinal clinical features of MFS or influence MFS diagnosis, its presence may be helpful for the suspicion of MFS when aortic dissection or aneurysm is found on CT angiography of the aorta because of the high frequency of PA in MFS patients.

Impact of an expanded reimbursement policy on utilization of implantable loop recorders in patients with cryptogenic stroke in Korea.

BACKGROUND/AIMS: The reimbursement policy for cryptogenic stroke (CS) was expanded in November 2018 from recurrent strokes to the first stroke episode. No reports have demonstrated whether this policy change has affected trends in implantable loop recorder (ILR) utilization. METHODS: We identified patients who received an ILR implant using the Korea Health Insurance Review and Assessment Service database between July 2016 and October 2021. Patients meeting all the following criteria were considered to have CS indication: 1) prior stroke history, 2) no previous history of atrial fibrillation or flutter (AF/AFL), and 3) no maintenance of oral anticoagulant for ≥4 weeks within a year before ILR implant. AF/AFL diagnosed within 3 years after ILR implant or before ILR removal was considered ILR-driven. RESULTS: Among 3,056 patients, 1,001 (32.8%) had CS indications. The total ILR implant number gradually increased for both CS and non-CS indications and the number of CS indication significantly increased after implementing the expanded reimbursement policy. The detection rate for AF/AFL was 26.3% in CS patients over 3 years, which was significantly higher in patients implanted with an ILR within 2 months after stroke than those implanted later. CONCLUSION: The expanded coverage policy for CS had a significant impact on the number of ILR implantation for CS indication. The diagnostic yield of ILR for AF/AFL detection seems better when ILR is implanted within 2 months than later. Further investigation is needed to demonstrate other clinical benefits and the optimal ILR implantation timing.

Immunoglobulin g4 non-related sclerosing disease with intracardiac mass mimicking mitral stenosis: case report.

The cardiovascular system may be one of the target organs of both immunoglobulin G4 related and non-related systemic multifocal fibrosclerosis. We present a case of IgG4 non-related systemic multifocal fibrosclerosis mimicking mitral stenosis on echocardiography. For a more detailed differential diagnosis, we used multimodal imaging techniques. After surgical biopsy around the abdominal aortic area in the retroperitoneum, histological examination revealed IgG4 non-related systemic multifocal fibrosclerosis. We describe the multimodal imaging used to diagnose IgG4 non-related systemic multifocal fibrosclerosis and a positive response to steroid treatment. There have been no previous case reports of IgG4 non-related systemic multifocal fibrosclerosis with intracardiac involvement. Here, we report a case of IgG4 non-related systemic multifocal fibrosclerosis mimicking mitral stenosis.

Changes in cardiac conduction time following cardiac resynchronization therapy: rationale and design of the RECOVER study.

BACKGROUND: It has been known that ventricular conduction delays play a key role in the cardiac resynchronization therapy (CRT) response of patients with advanced heart failure (HF). However, no study to our knowledge has yet evaluated the serial changes in conduction times measured between different electrodes of CRT devices. METHODS AND RESULTS: The Reduction or Extension of Conduction Time with Ventricular Electromechanical Remodeling (RECOVER) study (NCT04397224) was designed to investigate serial changes in interelectrode conduction times and to elucidate their prognostic value. We plan to enroll 100 patients implanted with CRT systems with endocardial quadripolar left ventricular leads. Patients will be scheduled for follow-up every 3 months over a period of 2 years, where they will undergo measurement of interelectrode conduction times to evaluate their serial changes. The primary outcome of the RECOVER study is the correlation between the degree of conduction time changes and the CRT response as defined by echocardiography. The time course and prognostic value of the serial changes in conduction times will be investigated as well. CONCLUSION: The RECOVER study is investigating whether serial changes in interelectrode conduction times can be useful parameters in predicting the CRT response or detecting worsening HF at an early stage.

Left Ventricular Dysfunction in Outpatients with Frequent Ventricular Premature Complexes.

Frequent ventricular premature complexes (VPCs) and VPC QRS duration are risk factors for left ventricular (LV) dysfunction. To determine which clinical characteristics and electrocardiographic features are associated with LV dysfunction (ejection fraction, <50%) and frequent VPCs, we retrospectively reviewed data from a single-center registry of all patients diagnosed with frequent VPCs at a Korean outpatient clinic. We identified 412 consecutive outpatients (mean age, 54.7 ± 16.8 yr; 227 women [55.1%]) who were diagnosed with frequent VPCs and had no structural heart disease from January 2010 through December 2017. Available transthoracic echocardiograms and 24-hour Holter monitoring data were evaluated to correlate the occurrence of VPCs and symptoms. Typical VPC-related symptoms (palpitations or dropped beats) were observed in 251 patients (61.1%). Electrocardiograms revealed VPCs with a left bundle branch block-like morphology in 327 patients (79.5%) and VPCs with an inferior axis in 353 (85.8%). Twenty-six patients (6.3%) were diagnosed with VPC-related LV dysfunction. The mean VPC burden did not differ significantly by LV functional status (11.06% ± 10.13% [normal] vs 14.41% ± 13.30% [impaired]; P=0.211). Patients with impaired LV function were more often men (P=0.027), had no typical VPC-related symptoms (P=0.006), and had significantly longer VPC QRS durations (mean, 157 ms vs 139 ms; P <0.01). Our findings suggest that male sex, absence of typical VPC-related symptoms, and a VPC QRS duration >157 ms are associated with LV dysfunction in patients with frequent VPCs, findings that may be useful in predicting such dysfunction.

Low QRS Voltage in Limb Leads Indicates Accompanying Precordial Voltage Attenuation Resulting in Underestimation of Left Ventricular Hypertrophy.

Low QRS voltage (LQRSV) in electrocardiography (ECG) often occurs in limb leads without apparent cause. However, its clinical significance is obscure in healthy populations. We reviewed patients aged over 60 who were scheduled for non-cardiac surgery in two hospitals. Patients underwent pre-operative ECG, echocardiography, pulmonary function test, and chest X-ray. Patients with LQRSV isolated to limb leads and patients without LQRSV were selected from separate hospitals. Among the 9832 patients screened in one hospital, 292 (3.0%) showed LQRSV in limb leads. One-hundred and ninety-four without LQRSV were selected as the control from the 216 patients screened at the other hospital. For primary analysis, patients with structural heart disease or classic etiologies of LQRSV were excluded. Patients with LQRSV had a higher proportion of male and a greater body mass index. Precordial QRS voltages were smaller, whereas left ventricular mass index and the prevalence of echocardiographic left ventricular hypertrophy (LVH) was higher in patients with LQRSV than in those without. Consequentially, diagnostic performance of precordial voltage criteria for LVH was particularly poor in patients with LQRSV in limb leads. LQRSV in limb leads frequently occurs without apparent etiologies. ECG voltage criteria may underestimate LVH in a relatively healthy population with LQRSV in limb leads.

Safety of mechanical lung vibrator and high-frequency chest wall oscillation in patients with cardiac implantable electronic device.

BACKGROUND: Chest physiotherapy (CPT) is a non-pharmacological therapy to facilitate airway secretion removal. There have been concerns about potential electromagnetic interference (EMI) and lead integrity problems during the use of vibrating CPT devices in patients with cardiac implantable electronic devices (CIEDs). HYPOTHESIS: Two CPT devices can be used safely in patients with CIED. METHODS: Volunteer patients with CIED underwent device interrogation to check lead integrity and device function before and after application of CPT devices. Mechanical lung vibrator and high-frequency chest wall oscillation (HFCWO) vests were used while monitoring surface electrocardiograms and intra-cardiac electrograms. RESULTS: We prospectively enrolled 46 patients with CIEDs (25 pacemakers, 15 implantable cardioverter-defibrillators, and six cardiac resynchronization therapy-defibrillators). There was no noise detection or EMI during CPT in any patient. None of the patients showed clinically significant changes in lead integrity parameters. HFCWO inappropriately accelerated the pacing rate up to the maximal programmed value in five patients with pacemakers and two with cardiac resynchronization therapy-defibrillators. CONCLUSION: CPT may be safely applied to patients with CIED without compromising lead integrity or device function, except for unwanted increase in pacing rate caused by misdetection of chest wall vibration as patients' activity while using HFCWO. Deactivation of the accelerometer-based activity sensor may be needed when HFCWO is planned for CPT.

Long-term evaluation of sensing variability of a floating atrial dipole in a single­lead defibrillator: The mechanistic basis of long-term stability of amplified atrial electrogram.

BACKGROUND: A single­lead implantable cardioverter-defibrillator (ICD) with a floating atrial dipole has been developed to enhance the diagnostic capability of atrial arrhythmias and to facilitate adjudication of arrhythmic events without the additional effort required for atrial lead insertion. However, there have been concerns about the long-term reliability of atrial sensing. METHODS: We enrolled patients with the single-chamber ICD with atrial-sensing electrodes from 4 tertiary university hospitals in Korea. Minimal, maximal, and mean P wave amplitudes were collected at 3-6 months, 6-12 months, and 12-24 months after implantation. The difference between the minimal and maximal sensing amplitudes was calculated as an indicator of the variability of atrial sensing, while the atrial sensing stability was assessed using the mean amplitude. RESULTS: A total of 86 patients were included for analysis. The variability of atrial sensing amplitudes significantly decreased at 12-24 months compared to 3-6 months (p = 0.01), while mean atrial amplitudes were stable throughout the mean follow-up duration of 17.4 months. Nine patients (10.5%) experienced inappropriate ICD therapy mostly due to misclassification of supraventricular tachycardia. CONCLUSIONS: Under the hypothesis that sensing stability can be guaranteed as the variability decreases with time, we suggest that the concern about long-term sensing stability of a floating dipole can be abated with an ICD that has been implanted for over 2 years.

Is transjugular insertion of a temporary pacemaker a safe and effective approach?

Temporary pacemakers (TPMs) are usually inserted in an emergency situation. However, there are few reports available regarding which route of access is best or what the most preferred approach is currently in tertiary hospitals. This study aimed to compare procedure times, complication rates, and indications for temporary pacing between the transjugular and transfemoral approaches to TPM placement. We analyzed consecutive patients who underwent TPM placement. Indications; procedure times; and rates of complications including localized infection, any bleeding, and pacing wire repositioning rates were analyzed. A total of 732 patients (361 treated via the transjugular approach and 371 treated via the transfemoral approach) were included. Complete atrioventricular block was the most common cause of TPM placement in both groups, but sick sinus syndrome was especially common in the transjugular approach group. Separately, procedure time was significantly shorter in the transjugular approach group (9.0 ± 8.0 minutes vs. 11.9 ± 9.7 minutes; P < 0.001). Overall complication rates were not significantly different between the two groups, and longer duration of temporary pacing was a risk factor for repositioning. The risk of reposition was significantly increased when the temporary pacing was continued more than 5 days and 3 days in the transjugular approach group and the transfemoral approach group, respectively. The transjugular approach should be considered if the TPM is required for more than 3 days.