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.

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.

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.

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.

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.

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.

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.

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.

Electrocardiographic features of the presence of occult myocardial disease in patients with VPD-induced cardiomyopathy.

BACKGROUND: Frequent ventricular premature depolarizations (VPDs) can cause reversible cardiomyopathy (CMP). However, many patients maintain a normal left ventricular (LV) function with a high VPD burden. The electrocardiographic characteristics of VPD-induced CMP have not been elucidated. METHODS: One hundred and eighty (91 men, age; 51 ± 15 years) patients with frequent idiopathic VPDs (>10% VPDs/day or >10 000 VPDs/day) were studied. All patients underwent successful ablation and were then divided into two groups according to the echocardiographic findings before and after the ablation procedure. RESULTS: Group A (n = 139) had a normal LV function with VPD frequencies, and Group B (n = 41) had reversible LV dysfunction after ablation. The VPD QRS duration (QRSd) was wider in patients with CMP (Group A vs Group B; 137.2 ± 12.0 milliseconds vs 159.7 ± 5.3 milliseconds, P < .001). VPDs with a terminal QRS delay marked by a notch followed by a discrete lower amplitude signal after the peak R wave in any precordial lead were identified. The incidence of terminal signals was higher in the CMP group (Group A vs Group B; 2.1% vs 53.6%, P < .001). CONCLUSIONS: The wider VPD QRSd and terminal QRS delay in patients with VPD-induced CMP suggest subclinical cell-to-cell conduction abnormalities as a potential factor predisposing VPD-induced CMP.

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.

Electrocardiographic characteristics for successful radiofrequency ablation of right coronary cusp premature ventricular contractions.

Electrocardiographic (ECG) criteria identifying right- and left-sided outflow tract origins have been established. The purpose of this study was to define the criteria for premature ventricular contractions (PVCs) originating from the right coronary cusp (RCC) adequately.We analyzed ECG and electrophysiologic study data from patients who underwent successful ablation of PVCs originating from the RCC and right ventricular outflow tract (RVOT). Eighteen RCC and 28 septal RVOT PVCs were studied. Among these 18 successful RCC PVCs, a predominantly positive QRS in lead I in 18/18 (100%), longer V1-2 R-wave duration (81.4 ±â€Š31.1 vs 44.8 ±â€Š7.0 ms, P = .02), V1-2 R wave duration index (RWDI) (51.3 ±â€Š22.0 vs 31.2 ±â€Š7.5%, P = .06) were observed compared to those with posteroseptal RVOT. Local ventricular activation time preceding QRS onset was significantly earlier (-38 ±â€Š12 ms) at the successful RCC ablation site compared to the failed ablation site of the septal RVOT (-22 ±â€Š8 ms), even without good pace mapping at the RVOT (P < .001). The receiver operating characteristic curve showed that a pre-QRS time of ≥-31 ms predicted successful RCC ablation with 67% sensitivity and 94% specificity. A predominantly positive QRS in lead I, longer R-wave duration and RWDI in lead V1 or V2 with a local ventricular activation preceding QRS onset by an average of -31 ms suggests an effective RCC ablation site.

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.

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.

Clinical features, predictors, and long-term prognosis of pacing-induced cardiomyopathy.

AIMS: We investigated the clinical features, predictors, and long-term prognosis of pacing-induced cardiomyopathy (PiCM). METHODS AND RESULTS: From a retrospective analysis of 1418 consecutive pacemaker patients, 618 were found to have a preserved baseline left ventricular ejection fraction (LVEF), follow-up echocardiographic data, and no history of heart failure (HF). PiCM was defined as a reduction in LVEF (< 50%) along with either (i) a ≥ 10% decrease in LVEF, or (ii) new-onset regional wall motion abnormality unrelated to coronary artery disease. PiCM occurred in 87 of 618 patients (14.1%), with a decrease in mean LVEF from 60.5% to 40.1%. The median time to PiCM was 4.7 years. Baseline left bundle branch block, wider paced QRS duration (≥ 155 ms), and higher ventricular pacing percentage (≥ 86%) were identified as independent predictors of PiCM in multivariate logistic regression analysis. The risk of PiCM increased gradually with the number of identified predictors, becoming more significant in the presence of two or more predictors (P < 0.001). During the entire follow-up (median 7.2 years), the risk of all-cause death or HF admission was significantly higher in patients with PiCM compared to those without PiCM (38.3% vs. 54.0%, adjusted hazard ratio 2.93; 95% confidence interval 1.82-4.72; P < 0.001). CONCLUSION: Pacing-induced cardiomyopathy patients showed a worse long-term prognosis than those without PiCM. Therefore, patients with multiple risk factors of PiCM should be monitored carefully even if their left ventricular systolic function is preserved initially. A timely upgrade to a biventricular or His-bundle pacing device needs to be considered in patients with PiCM.

Rationale, design, and endpoints of the 'DEvice-Detected CArdiac Tachyarrhythmic Events and Sleep-disordered Breathing (DEDiCATES)' study: Prospective multicenter observational study of device-detected tachyarrhythmia and sleep-disordered breathing.

BACKGROUND: Few studies have investigated the prognostic value of cardiac implantable electronic device (CIED)-detection of sleep-disordered breathing (SDB) for risk stratification of cardiovascular events. In the Device-Detected CArdiac Tachyarrhythmic events and Sleep-disordered breathing (DEDiCATES) study, we aim to determine whether device-detected SDB events are associated with increased risk of cardiac arrhythmias or other cardiovascular outcomes. METHODS AND DESIGN: Six-hundred patients (300 patients with low-voltage pacing devices and 300 with high-voltage defibrillator devices) who have dual chamber CIEDs with AP Scan™ function (Boston Scientific Inc., Marlborough, MA, USA) are planned to be enrolled in this study. AP Scan reports the average number of sleep disturbance events per hour per night in the form of a Respiratory Disturbance Index (RDI). The daily RDI values are to be used for quantitative measurement of the severity and burden of SDB. CIED-detected atrial high rate episodes (AHREs) and clinical atrial tachyarrhythmia will be assessed as the primary outcomes over a follow-up period of 2 years. Correlations between CIED-detected SDB and AHRE burdens will be analyzed. The secondary outcomes are CIED-detected or clinical ventricular arrhythmic events, stroke, heart failure hospitalization, mortality, and quality of life. CONCLUSION: This study will determine the prognostic value of automated diagnostic function of CIED for SDB, which will help to improve the cardiovascular prognoses of CIED patients by enabling convenient and accurate assessments of SDB events.

Outcomes of cardiac resynchronization therapy in patients with atrial fibrillation accompanied by slow ventricular response.

It remains unclear as to whether cardiac resynchronization therapy (CRT) would be as effective in patients with atrial fibrillation (AF) accompanied by slow ventricular response (AF-SVR, < 60 beats/min) as in those with sinus rhythm (SR). Echocardiographic reverse remodeling was compared between AF-SVR patients (n = 17) and those with SR (n = 88) at six months and 12 months after CRT treatment. We also evaluated the changes in QRS duration; New York Heart Association (NYHA) functional class; and long-term composite clinical outcomes including cardiac death, heart transplantation, and heart failure (HF)-related hospitalization. Left ventricular pacing sites and biventricular pacing percentages were not significantly different between the AF-SVR and SR groups. However, heart rate increase after CRT was significantly greater in the AF-SVR group than in the SR group (P < 0.001). At six and 12 months postoperation, both groups showed a comparable improvement in NYHA class; QRS narrowing; and echocardiographic variables including left ventricular end-systolic volume, left ventricular ejection fraction, and left atrial volume index. Over the median follow-up duration of 1.6 (interquartile range: 0.8-2.2) years, no significant between-group differences were observed regarding the rates of long-term composite clinical events (35% versus 24%; hazard ratio: 1.71; 95% confidence interval: 0.23-12.48; P = 0.60). CRT implantation provided comparable beneficial effects for patients with AF-SVR as compared with those with SR, by correcting electrical dyssynchrony and increasing biventricular pacing rate, in terms of QRS narrowing, symptom improvement, ventricular reverse remodeling, and long-term clinical outcomes.

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%.

Additional cavotricuspid isthmus ablation may reduce recurrent atrial tachyarrhythmia after total thoracoscopic ablation for persistent atrial fibrillation.

OBJECTIVES: Unlike catheter ablation, little is known about the benefits of cavotricuspid isthmus (CTI) ablation in total thoracoscopic ablation (TTA) of atrial fibrillation (AF). This study aimed to investigate the incidence of recurrent atrial tachyarrhythmia (ATa) according to additional CTI ablation after TTA in patients with persistent AF. METHODS: Among 208 consecutive patients who underwent TTA for persistent AF at the Samsung Medical Center from February 2012 to January 2016, a total of 63 patients with CTI ablation and 91 patients without CTI ablation were included in the final analysis. CTI ablation was performed in patients who had long-standing AF or atrial flutter episodes during the admission period. RESULTS: There was no difference in baseline characteristics between the CTI ablation and non-CTI ablation groups, except for a higher number of male patients in the CTI ablation group. The CTI ablation group showed a significantly higher survival rate free from recurrent ATa than that of the non-CTI ablation group at 5 years (52.5% vs 41.4%, P = 0.046). In the multivariable analysis, CTI ablation (hazard ratio 0.46, 95% confidence interval 0.217-0.971; P = 0.042) and left atrial volume index (hazard ratio 1.05, 95% confidence interval 1.029-1.070; P < 0.001) were significantly correlated with recurrent ATa. CONCLUSIONS: Patients with CTI ablation showed a better survival rate free from recurrent ATa compared with the non-CTI ablation group. The additional CTI ablation may reduce recurrent ATa after TTA in patients with documented atrial flutter or long-standing AF.

Differential prognosis of vasospastic angina according to presentation with sudden cardiac arrest or not: Analysis of the Korean Health Insurance Review and Assessment Service.

BACKGROUND: The long-term prognosis of vasospastic angina (VSA) patients presenting with aborted sudden cardiac death (ASCD) is still unknown. We sought to compare the long-term clinical outcomes between VSA patients presenting with and without ASCD by retrospective analysis of a nationwide population-based database. METHODS: A total of 6972 patients in the Health Insurance Review and Assessment database who were hospitalized in the intensive care unit with VSA between July 1, 2007 and May 31, 2015 were enrolled. Primary outcome was the composite of cardiac arrest and acute myocardial infarction after discharge. RESULTS: Five hundred ninety-eight (8.6%) VSA patients presented with ASCD. On inverse probability of treatment weighting, ASCD patients had a significantly increased risk of the composite of cardiac arrest and acute myocardial infarction (adjusted hazard ratio, 2.52; 95% confidence interval, 1.72-3.67; p < 0.001) during the median follow-up duration of 4 years. The association of ASCD presentation with a worse outcome in terms of primary outcome was consistent across various subgroups, including comorbidity type and use of vasodilators (all p-values for interaction: non-significant). ASCD patients treated with an implantable cardioverter defibrillator (ICD) had a lower incidence of the composite of cardiac arrest and acute myocardial infarction during follow-up than those without an ICD (p = 0.009). CONCLUSIONS: VSA patients that present with ASCD are at increased risk of cardiac arrest or myocardial infarction during long-term follow-up despite adequate vasodilator therapy. An ICD is a potential therapeutic option for secondary prevention.