Subcutaneous air entrapment after subcutaneous implantable cardioverter defibrillator implantation evaluated by computed tomography.

BACKGROUND: Inappropriate shock (IAS) caused by subcutaneous air entrapment (AE) in an early period after subcutaneous implantable cardioverter defibrillator (S-ICD) implantation has been reported, however, no detailed data on air volume are available. We evaluated the subcutaneous air volume after implantation and its absorption rate one week after implantation. METHODS: Patients who underwent S-ICD implantation in our hospital received chest CT scans immediately after implantation and followed up 1 week later. The total subcutaneous air volume, air around the generator, the distal electrode, and the proximal electrode within 3 cm were calculated using a three-dimensional workstation. Fat areas at the level of the lower edge of the generator were also analyzed. RESULT: Fifteen patients received CT immediately after implantation. The mean age was 45.6 ± 17.9 (66.7% of men), and the mean body mass index was 24.3 ± 3.3. The three-incision technique was applied in seven patients and two-incision technique was in the latter eight patients. The mean total subcutaneous air volume was 18.54 ± 7.50 mL. Air volume around the generator, the distal electrode, and the proximal electrode were 11.05 ± 5.12, 0.72 ± 0.72, and 0.88 ± 0.87 mL, respectively. Twelve patients received a follow-up CT 1 week later. The mean total subcutaneous air was 0.25 ± 0.45 mL, showing a 98.7% absorption rate. CONCLUSION: Although subcutaneous air was observed in all patients after S-ICD implantation, most of the air was absorbed within 1 week, suggesting a low occurrence of AE-related IAS after a week postoperation.

Safety and Performance of the Micra VR Leadless Pacemaker in a Japanese Cohort　- Comparison With Global Studies.

BACKGROUND: The Micra leadless pacemaker has demonstrated favorable outcomes in global trials, but its real-world performance and safety in a Japan-specific population is unknown.Methods and Results: Micra Acute Performance (MAP) Japan enrolled 300 patients undergoing Micra VR leadless pacemaker implantation in 15 centers. The primary endpoint was the acute (30-day) major complication rate. The 30-day and 6-month major complication rates were compared to global Micra studies. All patients underwent successful implantation with an average follow-up of 7.23±2.83 months. Compared with previous Micra studies, Japanese patients were older, smaller, more frequently female, and had a higher pericardial effusion risk score. 11 acute major complications were reported in 10 patients for an acute complication rate of 3.33% (95% confidence interval: 1.61-6.04%), which was in line with global Micra trials. Pericardial effusion occurred in 4 patients (1.33%; 3 major, 1 minor). No procedure or device-related deaths occurred. Frailty significantly improved from baseline to follow-up as assessed by Japan Cardiovascular Health Study criteria. CONCLUSIONS: In a Japanese cohort, implantation of the Micra leadless pacemaker had a high success rate and low major complication rate. Despite the Japan cohort being older, smaller, and at higher risk, the safety and performance was in line with global Micra trials.

Characteristics and Prognosis of Patients with Vasospastic Angina Diagnosed by a Provocation Test with Secondary Prevention Implantable Cardioverter Defibrillator.

This study aimed to evaluate the characteristics and prognosis of patients with vasospastic angina (VSA) diagnosed by a provocation test with a secondary prevention implantable cardioverter defibrillator (ICD), compared with patients with organic coronary stenosis. We retrospectively evaluated 309 consecutive patients who received an ICD implantation between January 2010 and March 2018 in our institutions. Of these patients, 206 were implanted with an ICD for secondary prevention. In these 206 patients, 40 with VSA and 72 with organic coronary stenosis were evaluated. Patients with VSA were characterized by younger age (56.1 ± 13.1 versus 69.2 ± 9.5 years, respectively), and a lower prevalence of diabetes (15.0% versus 40.3%, respectively) and heart failure (2.5% versus 26.4%, respectively) than patients with organic coronary stenosis (P < 0.001). Using the Kaplan-Meier analysis, with the VSA group as the reference, the incidence of appropriate ICD shock was similar between the two groups (hazard ratio, 0.85; 95% confidence interval, 0.341-2.109; P = 0.722). The incidence of ventricular fibrillation was significantly higher in the VSA group (hazard ratio, 0.22; 95% confidence interval, 0.057-0.814; P = 0.024), whereas the incidence of major adverse cardiac events, including cardiac death, nonfatal myocardial infarction, hospitalization for unstable angina pectoris, and heart failure, was significantly higher in the organic coronary stenosis group (hazard ratio, 13.1; 95% confidence interval, 1.756-98.17; P = 0.012). In conclusion, patients with VSA with an ICD implanted for secondary prevention have a higher risk of ventricular fibrillation and lower risk of major adverse cardiac events than patients with organic coronary stenosis.

Significance of Ventricular Arrhythmia Based on Stored Electrogram Analysis in a Pacemaker Population.

The incidence of ventricular arrhythmia in patients with an implanted pacemaker is not yet known. The aim of this study was to analyze non-sustained ventricular tachycardia (NSVT) episodes based on stored electrograms (EGM) and determine the occurrence rate and risk factors for NSVT in a pacemaker population.This study included 302 consecutive patients with a dual-chamber pacemaker. A total of 1024 EGMs stored in pacemakers as ventricular high-rate episodes were analyzed. The definition of NSVT was ≥ 5 consecutive ventricular beats at ≥ 150 bpm lasting < 30 seconds.In baseline, most patients (94.8%) had ≥ 60% left ventricular ejection fraction. Of 1024 EGMs, 420 (41.0%) showed appropriate NSVT episodes, as well as premature atrial contractions, atrial tachyarrhythmia, or atrial fibrillation with a rapid ventricular response, whereas other EGMs did not show an actual ventricular arrhythmia. On EGM analysis, during a mean follow-up period of 46.1 months, NSVT occurred one or more times in 82 patients (33.1%). On multivariate analysis, ≥ 50% right ventricular pacing was an independent risk factor for NSVT (odds ratios, 4.519; P < 0.001), but NSVT was not associated with increased all-cause mortality.Moreover, in the pacemaker population, ≥ 50% right ventricular pacing is an independent risk factor for NSVT; however, NSVT was not associated with increased all-cause mortality because of the preserved left ventricular function.

An Inappropriate Shock Case Early after Implantation of a Subcutaneous Cardiac Defibrillator by Subcutaneous Entrapped Air.

A 17-year-old woman was resuscitated from cardiac arrest due to ventricular fibrillation and was diagnosed with concealed long QT syndrome. She underwent subcutaneous implantable cardiac defibrillator (S-ICD) implantation at our hospital. The device electrogram immediately after implantation was normal. Four days after implantation, she received an inappropriate shock. The device interrogation revealed a continuous baseline shift and frequent oversensing for low amplitude signals, followed by a shock. A chest radiograph in the orthogonal view showed entrapped subcutaneous air surrounding the distal electrode. Entrapped subcutaneous air can cause inappropriate shocks in the early period after S-ICD implantation.

Characteristics and Prognosis of Pacemaker-Identified New-Onset Atrial Fibrillation in Japanese People.

BACKGROUND: The characteristics and prognosis of implanted pacemaker-identified new-onset atrial fibrillation (AF) in Japanese people has not been well evaluated.Methods and Results:A total of 395 consecutive patients with newly implanted pacemakers were retrospectively analyzed between January 2010 and December 2015 at Yokohama City University Hospital. Patients with a prior history of AF, VVI mode pacemaker, congenital heart disease, severe valvular heart disease, and cardiovascular surgery before pacemaker implantation were excluded. Among the remaining patients, 44 (21.3%) developed new AF during follow-up (mean follow-up, 1,115±651 days; range, 9-2,176 days). Patients with new-onset AF had a significantly higher CHADS2score (2.09±1.27 vs. 1.31±1.08, P<0.001) and CHA2DS2-VASc score (3.00±1.39 vs. 2.26±1.19, P<0.001) compared with those without new-onset AF. On Cox regression analysis only age at implantation was significantly correlated with new-onset AF. Interestingly, the incidence of hospitalization due to heart failure was significantly higher in the new-onset AF than in the without new-onset AF group. CONCLUSIONS: A total of 21.3% of pacemaker-implanted patients with high CHADS2and CHA2DS2-VASc scores developed new-onset AF during a mean follow-up of 3.1 years; and pacemaker-identified AF was associated with an increased risk of worsening heart failure.

Development of Atrioventricular Block and Diagnostic Value of Stored Electrograms in Patients With Sick Sinus Syndrome and Implanted Pacemaker.

BACKGROUND: The incidence of atrioventricular block (AVB) in pacemaker patients with sick sinus syndrome (SSS) is not yet known. The aim of this study was to analyze AVB episodes in SafeR mode based on stored electrograms (EGM), and determine the occurrence rate and risk factors for advanced AVB in a pacemaker population with SSS. METHODS AND RESULTS: The study included 50 consecutive patients with SSS without a history of advanced AVB who had a dual-chamber pacemaker programmed in SafeR mode. A total of 377 EGM stored in the pacemakers as AVB episodes fulfilling the second- or third-degree criterion were analyzed. Of 377 EGM, 73 EGM (19.4%) were appropriate episodes, whereas the other EGM did not show actual AVB, and showed atrial tachyarrhythmia, ventricular event in the blanking period, or premature atrial contractions with block. On EGM analysis, advanced AVB occurred in 9 patients (18%), and the occurrence rate was 11.7% per year. Moreover, on multivariate analysis ß-blocker use was an independent risk factor for advanced AVB (OR, 9.10; P=0.004). CONCLUSIONS: The occurrence rate of advanced AVB in patients with SSS is much higher than previously reported, and ß-blocker use is an independent risk factor for advanced AVB. SafeR is useful to detect latent AVB. Stored EGM, however, sometimes include inaccurately classified events.

Clinical significance of collateral superficial vein across clavicle in patients with cardiovascular implantable electronic device.

BACKGROUND: Obstruction of the access vein is a well-known complication after cardiovascular implantable electronic device (CIED) implantation. In that case, well-developed collateral superficial veins are frequently observed on the skin surface around the CIED. The aim of this study was to clarify the relationship between venous obstruction and development of a superficial vein across the clavicle. METHODS AND RESULTS: A total of 107 patients scheduled for generator replacement, device upgrade, or lead extraction were enrolled. The skin surface around the device was photographed. A 20-ml bolus of contrast medium was injected into a peripheral arm vein on the side of CIED implantation, and contrast venography was performed. Venous obstruction was defined as luminal diameter narrowing >75%. Venography showed venous obstruction in 27 patients (25.2%). There were no statistically significant differences in patient characteristics between the venous obstruction and no venous obstruction group. Of 107 patients, 44 (41.1%) had a superficial vein across the clavicle on the side of CIED implantation. The sensitivity of the presence of a superficial vein across the clavicle in the diagnosis of venous obstruction was 96.3% and specificity was 77.5% (P<0.001). CONCLUSIONS: The presence of a superficial vein across the clavicle is useful for the prediction of venous obstruction in patients with CIED.

Does reducing unnecessary right ventricular pacing improve sympathetic activity and innervation of heart in sinus node disease patients? MVP and SafeR study.

Ventricular desynchronization imposed by ventricular pacing causes regional disturbances of adrenergic innervation in the left ventricular myocardium and increases the risk of heart failure and atrial fibrillation (AF) in patients with sinus node disease (SND). As a result, decreased iodine-123 metaiodobenzylguanidine (I-(123 )MIBG) uptake occurs in patients with an implanted permanent pacemaker. Fourteen SND patients with an implanted pacemaker equipped with an algorithm for reducing unnecessary right ventricular pacing (RURVP) were enrolled. Pacemakers were programmed to RURVP mode for the first 12 weeks, and then reprogrammed to DDD for the last 12 weeks. At the end of each mode, data on cumulative percent ventricular pacing (%Vp), atrial high rate episodes (%AHR), I-(123 )MIBG myocardial scintigraphy, brain natriuretic peptide (BNP), human atrial natriuretic peptide (hANP), and myocardial damage indices typified by troponin T and C-reactive protein (CRP) were collected. %Vp was lower in RURVP than in DDD (0.2% versus 95.7%, P = 0.00098). BNP, hANP, troponin T, and CRP did not differ significantly between the pacing modes. However, I-(123 )MIBG findings of patients with full ventricular pacing in DDD improved in RURVP. In contrast, among patients without full ventricular pacing in DDD, their I-(123 )MIBG findings did not differ significantly between the pacing modes. In SND patients with normal cardiac function and intact atrioventricular conduction, the reduction of %Vp in RURVP was due to the reduction of ineffective pacing and fusion pacing in DDD. Therefore, these 2 types of pacing do not affect cardiac pump function.

Successful implantation of left ventricular lead for a cardiac resynchronization therapy defibrillator through a persistent left superior vena cava using the anchor balloon technique.

A 69-year-old woman was referred for upgrading implantable cardioverter defibrillator (ICD) to cardiac resynchronization therapy defibrillator (CRT-D) because of symptomatic heart failure due to dilated cardiomyopathy. Her electrocardiogram showed left bundle branch block and echocardiography showed severe left ventricular dysfunction. Venography confirmed the presence of persistent left superior vena cava (PLSVC), and occlusion of innominate vein and the coronary sinus (CS) ostium. We tried to insert the left ventricular (LV) lead through the PLSVC. Because the PLSVC was narrow, there was concern that insertion of the guiding catheter through the PLSVC might cause vascular damage. Therefore, we planned to implant the LV lead without a guiding catheter. Although the LV lead did not advance to the CS due to the acute angle, using a second wire (buddy wire system), the tip of the first wire was trapped by an inflated balloon delivered by a second wire (anchor balloon technique). This technique allowed us to reinforce the support of the other wire. The LV lead was easily advanced along with the fixed first wire and was delivered to the lateral vein of the CS. Thus, we successfully performed minimally invasive implantation of an LV lead through a PLSVC approach. .

A case report of pulmonary vein isolation with radiofrequency catheter using superior vena cava approach in patient with paroxysmal atrial fibrillation and inferior vena cava filter.

BACKGROUND: Transseptal puncture and pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) are generally performed via the inferior vena cava (IVC). However, in cases where the IVC is inaccessible, a specific strategy may be needed. CASE SUMMARY: An 86-year-old woman with paroxysmal AF and an IVC filter in situ was referred to our hospital for ablation therapy. An IVC filter for pulmonary embolism and deep venous thrombosis had been implanted 15 years prior, therefore we selected a transoesophageal echocardiography (TOE)-guided transseptal puncture using a superior vena cava (SVC) approach. After the single transseptal puncture, we performed fast anatomical mapping, voltage mapping by multipolar mapping catheter, and then PVI by contact force-guided radiofrequency catheter using a steerable sheath. Following the ablation, bidirectional conduction block between the four pulmonary veins and the left atrium was confirmed by both radiofrequency and mapping catheter. No complications occurred and no recurrence of AF was documented in the 12 months after the procedure. DISCUSSION: When performing a transseptal puncture during AF ablation, an SVC approach, via access through the right internal jugular vein, enables the sheath to directly approach the left atrium without angulation and improves operability of the ablation catheter. Combining the use of general anaesthesia, TOE, a steerable sheath, and contact force-guided ablation may contribute to achieving minimally invasive PVI with a single transseptal puncture via an SVC approach.

Successful screening of sleep-disordered breathing using a pacemaker-based algorithm in Japan.

BACKGROUND: Recent pacemakers with transthoracic impedance sensors have a specific algorithm identifying sleep apnea (SA). Our aim was to evaluate the algorithm in Japanese patients. METHODS: Consecutive patients implanted with a pacemaker with sleep apnea monitoring algorithm at our hospital were enrolled prospectively. After implantation, patients underwent polysomnography (PSG). The respiratory disturbance index measured by pacemaker (RDI-PM) was extracted in the morning after PSG. RESULTS: Forty-five patients were recruited; 78% of patients underwent overnight PSG completely, and among them RDI-PM was invalid for one patient. Then the analysis was performed in 34 patients. Moderate/severe SA (apnea hypopnea index, AHI≥15events/h) and severe SA (AHI≥30events/h) by PSG were diagnosed in 65% and 41% of patients. The mean AHI-PSG and RDI-PM were 30.4±22.6 and 21.7±14.2events/h, respectively. There was a significant positive correlation between AHI-PSG and RDI-PM (r=0.543; p=0.001). The correlation was stronger in the severe SA group (r=0.664; p=0.010), in a group whose apnea index was higher than hypopnea index (r=0.822; p=0.002), and in a group whose central sleep apnea (CSA) index was higher than obstructive sleep apnea index (r=0.977; p<0.001). RDI-PM cut-off value for identifying severe SA was 22 (area under the curve, 0.682; sensitivity, 64%; specificity, 75%). CONCLUSIONS: The pacemaker-based algorithm is a useful screening tool for SA in Japanese individuals, especially in the severe SA group, apnea-dominant group, and CSA-dominant group.

Right-sided cardiac resynchronization therapy with defibrillator implantation in a patient with corrected transposition of great arteries and persistent left superior vena cava.

Patients with corrected transposition of great arteries (c-TGA) are generally known to develop atrioventricular block, systemic right ventricular dysfunction, and tricuspid regurgitation over time, which are associated with tachyarrhythmia and progressive heart failure. A 76-year-old man had been diagnosed with c-TGA. He developed a cardiopulmonary arrest while playing tennis, and an automated external defibrillator detected ventricular fibrillation (VF). Immediate cardiopulmonary resuscitation and intensive treatment were performed. He fully recovered without neurological sequelae. QRS duration was 172 ms. Echocardiography showed marked dysfunction and dyssynchrony of the systemic right ventricle (systemic right ventricular end-diastolic diameter/end-systolic diameter = 73/60 mm, systemic right ventricular ejection fraction = 34%). For secondary prevention and treatment of progressive heart failure, cardiac resynchronization therapy with defibrillator (CRT-D) implantation was recommended. Venography via the left cubital superficial vein revealed a persistent left superior vena cava (PLSVC) and giant coronary sinus that did not connect with the right superior vena cava (SVC). Because of the acute angle between the PLSVC and great cardiac vein, we selected a right-sided approach via the right SVC. We were finally able to deliver a coronary sinus lead to the lateral vein. CRT-D implantation can be achieved even in patients with c-TGA and PLSVC. .

Significance of change in serum bilirubin in predicting left ventricular reverse remodeling and outcomes in heart failure patients with cardiac resynchronization therapy.

BACKGROUND: Research on the correlation of serum bilirubin level with cardiac function as well as outcomes in heart failure patients with cardiac resynchronization therapy (CRT) has not yet been reported. The aim of this study was to analyze the relationship between change in serum bilirubin level and left ventricular reverse remodeling, and also to clarify the impact of bilirubin change on clinical outcomes in CRT patients. METHODS: We evaluated 105 consecutive patients who underwent CRT. Patients who had no serum total-bilirubin data at both baseline and 3-9 months' follow-up or had died less than 3 months after CRT implantation were excluded. Accordingly, a total of 69 patients were included in the present analysis. The patients were divided into two groups: decreased bilirubin group (serum total-bilirubin level at follow-up≤that at baseline; n=48) and increased bilirubin group (serum total-bilirubin level at follow-up>that at baseline; n=21). RESULTS: Mean follow-up period was 39.3 months. In the decreased bilirubin group, mean left ventricular end-systolic diameter decreased from 54.5mm to 50.2mm (p=0.001) and mean left ventricular ejection fraction increased significantly from 29.8% to 37.0% (p=0.001). In the increased bilirubin group, there was no significant change in echocardiographic parameters from baseline to follow-up. In Kaplan-Meyer analysis, cardiac mortality combined with heart failure hospitalization in the increased bilirubin group was significantly higher than that in the decreased bilirubin group (log-rank p=0.018). Multivariate Cox regression analysis revealed that increased bilirubin was an independent predictor of cardiac mortality combined with heart failure hospitalization (OR=2.66, p=0.023). CONCLUSIONS: The change in serum bilirubin is useful for assessment of left ventricular reverse remodeling and prediction of outcomes in heart failure patients with CRT.

Shock Lead Dislodgement Related To Its Small Hair-Pin Curve In A Pocket -A Case Of Ratchet Syndrome.

There have been few reports about ratchet syndrome. We report a case of ratchet syndrome caused by small hair-pin curve of lead that triggered the lead retract itself. A 69-year-old man with a past history of inferior wall myocardial infarction, presented with progressive congestive heart failure. He underwent implantation of cardiac resynchronization therapy with an implantable cardiac defibrillator (CRTD) at our hospital. At 33 days after implantation, shock lead dislodgement was revealed. X-ray showed that the lead tip was in left subclavian vein, leaving its screw out, and a large part of the proximal portion of the lead was retracted into the pocket, while the other two leads remained in appropriate positions and the device had not rotated. An X-ray series showed that a hair-pin curve had been expanding gradually from just after implantation. In this case, relatively stiff shock lead was markedly bent and expanded the curve in the pocket, and ratchet-like movement occurred. We here report a new type of ratchet syndrome.

Impact of renal insufficiency on long-term clinical outcome in patients with heart failure treated by cardiac resynchronization therapy.

BACKGROUND: Renal insufficiency is recognized as a predictor of mortality and adverse outcome in heart failure (HF) patients. However, the long-term clinical outcome of cardiac resynchronization therapy (CRT) in Japanese HF patients with renal insufficiency remains uncertain. METHODS: We evaluated 67 consecutive patients who underwent CRT at our hospital. The patients were divided into two groups according to a baseline estimated glomerular filtration rate (e-GFR) cut-off value of 50ml/min, which is defined as the time at which patients should be referred to a nephrologist, by the Japanese Society of Nephrology. Follow-up echocardiographic findings and renal function were examined at 3-6 months after CRT. Then, we compared long-term clinical outcomes between the two groups, and analyzed the effect of CRT on renal function, echocardiographic parameters and cardiac survival. RESULTS: During a mean follow-up period of 30.3 months, patients with advanced renal insufficiency (e-GFR<50ml/min) had significant higher all-cause mortality (log-rank p=0.033) and higher cardiac mortality combined with HF hospitalization (log-rank p=0.017) than patients with e-GFR≥50ml/min. Multivariate analysis revealed that advanced renal insufficiency was an independent predictor of cardiac mortality combined with HF hospitalization (odds ratio=3.01, p=0.008). Subgroup analysis in the baseline advanced renal insufficiency group revealed that patients with preserved renal function by CRT (<10% reduction in e-GFR) had a higher rate of decrease of left ventricular end-systolic diameter (-14.0% vs. -0.8%, p=0.023) and lower cardiac mortality combined with HF hospitalization (log-rank p=0.029) compared with patients with deterioration of renal function (≥10% reduction in e-GFR). CONCLUSIONS: The present study suggests that advanced renal insufficiency is quite useful for the prediction of worsening clinical outcomes in HF patients treated by CRT. Preservation of renal function by CRT brings about better cardiac survival through prevention of adverse cardiac events, even in HF patients with advanced renal insufficiency.