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Vagal nerve stimulation (VNS) has been shown to have antiarrhythmic effects, but many of these benefits were demonstrated in the setting of vagal nerve decentralization. The purpose of this study was to evaluate the role of afferent fiber activation during VNS on efferent control of cardiac hemodynamic and electrophysiological parameters. In 37 pigs a 56-electrode sock was placed over the ventricles to record local activation recovery intervals (ARIs), a surrogate of action potential duration. In 12 of 37 animals atropine was given systemically. Right and left VNS were performed under six conditions: both vagal trunks intact ( n = 25), ipsilateral right ( n = 11), ipsilateral left ( n = 14), contralateral right ( n = 7), contralateral left ( n = 10), and bilateral ( n = 25) vagal nerve transection (VNTx). Unilateral VNTx significantly affected heart rate, PR interval, Tau, and global ARIs. Right VNS after ipsilateral VNTx had augmented effects on hemodynamic parameters and increase in ARI, while subsequent bilateral VNTx did not significantly modify this effect (%change in ARI in intact condition 2.2 ± 0.9% vs. ipsilateral VNTx 5.3 ± 1.7% and bilateral VNTx 5.3 ± 0.8%, P < 0.05). Left VNS after left VNTx tended to increase its effects on hemodynamics and ARI response ( P = 0.07), but only after bilateral VNTx did these changes reach significance (intact 1.1 ± 0.5% vs. ipsilateral VNTx 3.6 ± 0.7% and bilateral VNTx 6.6 ± 1.6%, P < 0.05 vs. intact). Contralateral VNTx did not modify VNS response. The effect of atropine on ventricular ARI was similar to bilateral VNTx. We found that VNS activates afferent fibers in the ipsilateral vagal nerve, which reflexively inhibit cardiac parasympathetic efferent electrophysiological and hemodynamic effects.

BACKGROUND: To evaluate the impact of changes in the filtered QRS duration (fQRS) on signal‐averaged electrocardiograms (SAECGs) from pre‐ to postimplantation on the clinical outcomes in nonischemic heart failure (HF) patients under cardiac resynchronization therapy (CRT). METHODS: We studied 103 patients with nonischemic HF and sinus rhythm who underwent CRT implantation. SAECGs were obtained within 1 week before and 1 week after implantation and narrowing fQRS was defined as a decrease in fQRS from pre‐ to postimplantation. Echocardiography was performed before and 6 months after CRT implantation. The primary outcome was death from any cause. The secondary outcomes were hospitalization due to worsened HF and occurrence of ventricular tachyarrhythmias. RESULTS: Of the 103 CRT patients, 53 (51%) showed narrowing fQRS. Left ventricular end‐diastolic volume and end‐systolic volume were significantly reduced (both p

AimsThe effects of inotropic agents on left ventricular (LV) synchrony in heart failure patients are still unknown. The purpose of this study was to investigate the effects of dobutamine on LV mechanical dyssynchrony and LV systolic performance in patients with dilated cardiomyopathy (DCM) and a narrow QRS using real-time three-dimensional echocardiography (RT3DE).Methods and resultsThirty-three patients with idiopathic DCM and a narrow QRS underwent low-dose dobutamine stress echocardiography (LDSE) with RT3DE. A time-global LV volume curve and time-regional LV volume curves were derived from RT3DE. Regional LV stroke volumes were summed in each stage, and the dobutamine-induced increase in the sum of regional LV stroke volumes was considered as the sum of regional contractile reserve. Systolic dyssynchrony index (SDI) was calculated as follows: (standard deviation of time to minimal volume for regional LV segments)×100/RR duration. Among the 33 patients, low-dose dobutamine increased global LV stroke volume (SV) in 28 (85%), but decreased global LVSV in the remainder (15%). The sum of regional contractile reserve was modestly correlated with the dobutamine-induced increase in global LVSV (R=0.57, p

Objective To evaluate the impact of diastolic dysfunction on the outcome of atrial fibrillation (AF) ablation. Methods Eighty consecutive patients with drug-refractory symptomatic AF who underwent AF ablation were enrolled (65 males, 58±10years, 65 paroxysmal AF, 15 persistent AF). All patients underwent extensive pulmonary vein isolation with a double lasso technique using CARTO MERGE. Diastolic dysfunction was defined as a ratio of the mitral inflow early filling velocity to the velocity of the early medial mitral annular ascent of >10. The clinical and echocardiographic data were compared between the patients with and without diastolic dysfunction, and between the patients with and without AF recurrences after the AF ablation. Results Twenty-nine out of all the patients (36.3%) had diastolic dysfunction. Compared with the patients without diastolic dysfunction, the patients with diastolic dysfunction had higher brain natriuretic peptide (p=0.001) and C-reactive protein (p=0.023) levels, and a larger left atrial diameter (P=0.019). The AF-free rate after a single or repeat AF ablation procedure in the patients with diastolic dysfunction was lower than that in those without diastolic dysfunction (p=0.005 and p=0.013 by the log-rank test, respectively). In the univariate analysis, the patients with persistent AF and diastolic dysfunction were likely to have AF recurrences after a single AF ablation. The multivariate analysis indicated diastolic dysfunction as the only independent predictor of an AF recurrence after a single AF ablation (P=0.023). Conclusion The patients with diastolic dysfunction had a worse outcome of the AF ablation not only for a single procedure but also a repeat procedure.

The guidelines suggest that an adjuvant substrate modification in addition to pulmonary vein isolation (PVI) may be needed for persistent atrial fibrillation (PerAF) assuming that catheter ablation is less successful for PerAF than paroxysmal AF (PAF). To revisit the above assumption, we compared the outcome of the same catheter ablation strategy between PAF and PerAF.Two hundred and thirty-three consecutive patients (mean age 60 ± 10 years, 53 PerAF and 8 long-lasting PerAF) without structural heart disease underwent catheter ablation of AF by the same strategy using an empiric thoracic vein isolation (a wide circumferential PVI plus empiric superior vena cava isolation) as a major part of the strategy without any adjuvant substrate modification. The duration of AF in the patients with PerAF was 6 ± 4 months. During 25 ± 10 months of follow-up after single procedures, 71 (30%) patients had atrial tachyarrhythmia recurrences without antiarrhythmic drugs. A Kaplan-Meier analysis of the recurrence-free survival rate after a single procedure and after repeat procedures revealed no significant difference between the patients with PAF and those with PerAF (log-rank, P = 0.38 and P = 0.27, respectively). A Cox regression multivariate analysis of the variables including the age, gender, PerAF, body mass index, left ventricular ejection fraction, and left atrial volume index demonstrated that none of the variables were an independent predictor of an atrial tachyarrhythmia recurrence after a single ablation procedure.In patients without underlying heart disease, the procedural outcome of an empiric thoracic vein isolation is comparable for PAF and PerAF.

Many patients with successful atrial flutter (AFL) ablation will develop atrial fibrillation (AF) during follow-up. This study aimed to determine whether prolonged interatrial conduction time (IACT) is associated with risk for new-onset AF after ablation of isolated, typical AFL.Participants were 80 consecutive patients who underwent successful radiofrequency ablation of isolated, typical AFL from 2004 to 2012. Patients with any history of AF prior to AFL ablation were excluded. IACT was defined as the interval from the earliest onset of the P-wave on the ECG to the latest activation in the coronary sinus catheter during sinus rhythm measured after AFL ablation. New-onset AF was identified from 12-lead ECGs, 24-hour ambulatory monitoring, and device interrogations.During a mean follow-up of 4.1 ± 2.5 years after successful AFL ablation, 22 patients (27.5%) developed new-onset AF. Cox regression multivariate analysis demonstrated that IACT was the independent predictor of new-onset AF after AFL ablation (hazard ratio: 1.03; 95% confidence interval: 1.00-1.06; P = 0.02). IACT was accurate in predicting new-onset AF (AUC = 0.70). The optimal cut-off point of IACT for predicting new-onset AF was 120 milliseconds (sensitivity 47.6%, specificity 89.8%). Kaplan-Meier curves showed that new-onset AF after AFL ablation was significantly higher in patients with IACT ≥120 milliseconds than in patients with IACT120 milliseconds (P = 0.0016).Prolonged IACT predicted new-onset AF after ablation of isolated AFL. This finding may contribute to guiding decisions regarding the maintenance of anticoagulation after AFL ablation.

Summary Objectives The purpose of this study was to explore the possibility of using our novel echocardiographic index of inefficient left ventricular (LV) contraction in patient selection for cardiac resynchronization therapy (CRT). Methods Forty consecutive patients with LV ejection fraction ≤35% were divided into 2 groups, 9 CRT candidates and 31 non-CRT candidates based on conventional criteria. A global LV time–area curve and regional LV time–area curves in 6 radial sectors were obtained using two-dimensional echocardiography in the short-axis view with speckle tracking. Fractional inefficient contraction (FIC, %) was calculated as follows: (1 − global LV area change/sum of regional LV area changes) × 100. LV dyssynergy and dyssynchrony were quantified as the standard deviations of minimal values of circumferential speckle-tracking strain and their timings in the 6 sectors, respectively. Results There was no significant difference in LV dyssynchrony between CRT candidates and non-CRT candidates (79 ± 61 ms vs. 58 ± 26 ms, respectively). In contrast, FIC was significantly larger in CRT candidates than in non-CRT candidates (15.7 ± 11.0% vs. 5.4 ± 3.5%, respectively, p = 0.0018), with less overlap between groups. FIC showed a positive correlation with dyssynchrony (r = 0.64) and a negative correlation with dyssynergy (r = −0.42). Conclusions Our novel echocardiographic index of inefficient LV contraction, which increases with more dyssynchrony or less dyssynergy, may prove more useful in patient selection for CRT than other indices that focus on LV temporal dyssynchrony alone.

Aims To evaluate the feasibility of integrating three-dimensional images created by intra-procedural cone-beam computed tomography (CBCT) into three-dimensional electroanatomical maps (EAM) and compare its accuracy with that of pre-procedural multi-slice CT (MSCT). Methods and results In 24 patients with drug-refractory atrial fibrillation (AF), atriography using CBCT with pulmonary arterial contrast injection was performed at the beginning of the AF ablation procedure. Intra-procedural CBCT images and pre-procedural MSCT images were individually imported into the EAM system and compared their integration accuracy (point-to-surface distance) of each image and EAM just before ablation. The CBCT images were assessed qualitatively and quantitatively in comparison with MSCT images. All CBCT images were graded as optimal or useful in delineating the left atrium–pulmonary vein anatomy and were successfully integrated with the EAM. Overall, integration accuracy was similar for CBCT and MSCT. However, in 11 patients, the MSCT was performed 5 or more days prior to EAM, resulting in significantly shorter surface-to-point distance in CBCT than that in MSCT ( P = 0.047). Radiation exposure with CBCT was significantly reduced compared with MSCT ( P < 0.001). Conclusion It is feasible to integrate CBCT image into EAM, and the integration is relatively accurate. Intra-procedural atriography by CBCT may replace pre-procedural MSCT as the imaging source for image integration.

Sympathoexcitation is associated with ventricular arrhythmogenesis. The aim of this study was to determine the role of thoracic dorsal root afferent neural inputs to the spinal cord in modulating ventricular sympathetic control of normal heart electrophysiology. We hypothesize that dorsal root afferent input tonically modulates basal and evoked efferent sympathetic control of the heart. A 56-electrode sock placed on the epicardial ventricle in anesthetized Yorkshire pigs ( n = 17) recorded electrophysiological function, as well as activation recovery interval (ARI) and dispersion in ARI, at baseline conditions and during stellate ganglion electrical stimulation. Measures were compared between intact states and sequential unilateral T1–T4 dorsal root transection (DRTx), ipsilateral ventral root transection (VRTx), and contralateral dorsal and ventral root transections (DVRTx). Left or right DRTx decreased global basal ARI [Lt.DRTx: 369 ± 12 to 319 ± 13 ms ( P < 0.01) and Rt.DRTx: 388 ± 19 to 356 ± 15 ms ( P < 0.01)]. Subsequent unilateral VRTx followed by contralateral DRx+VRTx induced no further change. In intact states, left and right stellate ganglion stimulation shortened ARIs (6 ± 2% vs. 17 ± 3%), while increasing dispersion (+139% vs. +88%). There was no difference in magnitude of ARI or dispersion change with stellate stimulation following spinal root transections. Interruption of thoracic spinal afferent signaling results in enhanced basal cardiac sympathoexcitability without diminishing the sympathetic response to stellate ganglion stimulation. This suggests spinal dorsal root transection releases spinal cord-mediated tonic inhibitory control of efferent sympathetic tone, while maintaining intrathoracic cardiocentric neural networks.

The safety and efficacy of an empiric superior vena cava isolation (SVCI) in addition to circumferential pulmonary vein isolation (CPVI) in patients with paroxysmal atrial fibrillation (PAF) have not been clarified. A total of 186 consecutive patients who underwent catheter ablation of PAF were included. All patients underwent a CPVI. Patients in the first half underwent an additional SVCI only if SVC-triggered AF or rapid SVC activity was observed during the procedure (n = 93, as-needed SVCI, group I), and those in the second half underwent an empirical SVCI after the CPVI (n = 93, empiric SVCI, group II). The CPVI was successfully performed in all patients. An SVCI was performed in 8 of 93 patients (9%) in group I and 81 of the 93 patients (87%) in group II. In the remaining 12 patients in group II, an SVCI was not performed because of the lack of SVC potentials. During a mean follow-up of 27 ± 12 months, the atrial tachyarrhythmia recurrence rate after a single ablation procedure in the patients in group II was lower than that in group I (44% vs 23%, p = 0.035). A Cox regression multivariate analysis demonstrated that an empiric SVCI was an independent predictor of an atrial tachyarrhythmia recurrence after a single ablation procedure (odds ratio: 0.57, 95% confidence interval 0.31 to 0.999; p = 0.049). Neither sinus node injury nor any injury to the phrenic nerve was observed. In conclusion, an empiric SVCI in addition to the CPVI improved the outcome of AF ablation in patients with PAF without any additional adverse effects.

Background Myocardial infarction (MI) induces remodeling in stellate ganglion neurons (SGNs). Objective We investigated whether infarct site has any impact on the laterality of morphologic changes or neuropeptide expression in stellate ganglia. Methods Yorkshire pigs underwent left circumflex coronary artery (LCX; n=6) or right coronary artery (RCA; n=6) occlusion to create left- and right-sided MI, respectively (control: n=10). At 5 ± 1 weeks after MI, left and right stellate ganglia (LSG and RSG, respectively) were collected to determine neuronal size, as well as tyrosine hydroxylase (TH) and neuropeptide Y immunoreactivity. Results Compared with control, LCX and RCA MIs increased mean neuronal size in the LSG (451 ± 25 vs 650 ± 34 vs 577 ± 55 μm 2 , respectively; P = .0012) and RSG (433 ± 22 vs 646 ± 42 vs 530 ± 41 μm 2 , respectively; P = .002). TH immunoreactivity was present in the majority of SGNs. Both LCX and RCA MIs were associated with significant decreases in the percentage of TH-negative SGNs, from 2.58% ± 0.2% in controls to 1.26% ± 0.3% and 0.7% ± 0.3% in animals with LCX and RCA MI, respectively, for LSG ( P = .001) and from 3.02% ± 0.4% in controls to 1.36% ± 0.3% and 0.68% ± 0.2% in LCX and RCA MI, respectively, for RSG ( P = .002). Both TH-negative and TH-positive neurons increased in size after LCX and RCA MI. Neuropeptide Y immunoreactivity was also increased significantly by LCX and RCA MI in both ganglia. Conclusion Left- and right-sided MIs equally induced morphologic and neurochemical changes in LSG and RSG neurons, independent of infarct site. These data indicate that afferent signals transduced after MI result in bilateral changes and provide a rationale for bilateral interventions targeting the sympathetic chain for arrhythmia modulation.

Background— T-peak to T-end interval (Tp-e) is an independent marker of sudden cardiac death. Modulation of Tp-e by sympathetic nerve activation and circulating norepinephrine is not well understood. The purpose of this study was to characterize endocardial and epicardial dispersion of repolarization (DOR) and its effects on Tp-e with sympathetic activation. Methods and Results— In Yorkshire pigs (n=13), a sternotomy was performed and the heart and bilateral stellate ganglia were exposed. A 56-electrode sock and 64-electrode basket catheter were placed around the epicardium and in the left ventricle (LV), respectively. Activation recovery interval, DOR, defined as variance in repolarization time, and Tp-e were assessed before and after left, right, and bilateral stellate ganglia stimulation and norepinephrine infusion. LV endocardial and epicardial activation recovery intervals significantly decreased, and LV endocardial and epicardial DOR increased during sympathetic nerve stimulation. There were no LV epicardial versus endocardial differences in activation recovery interval during sympathetic stimulation, and regional endocardial activation recovery interval patterns were similar to the epicardium. Tp-e prolonged during left (from 40.4±2.2 ms to 92.4±12.4 ms; P P P P R =0.86). Of note, norepinephrine infusion did not increase DOR or Tp-e. Conclusions— Regional patterns of LV endocardial sympathetic innervation are similar to that of LV epicardium. Tp-e correlated with whole heart DOR during sympathetic nerve activation. Circulating norepinephrine did not affect DOR or Tp-e.

Myocardial infarction (MI) induces neural and electrical remodeling at scar border zones. The impact of focal MI on global functional neural remodeling is not well understood. Sympathetic stimulation was performed in swine with anteroapical infarcts (MI; n = 9) and control swine ( n = 9). A 56-electrode sock was placed over both ventricles to record electrograms at baseline and during left, right, and bilateral stellate ganglion stimulation. Activation recovery intervals (ARIs) were measured from electrograms. Global and regional ARI shortening, dispersion of repolarization, and activation propagation were assessed before and during sympathetic stimulation. At baseline, mean ARI was shorter in MI hearts than control hearts (365 ± 8 vs. 436 ± 9 ms, P < 0.0001), dispersion of repolarization was greater in MI versus control hearts (734 ± 123 vs. 362 ± 32 ms2, P = 0.02), and the infarcted region in MI hearts showed longer ARIs than noninfarcted regions (406 ± 14 vs. 365 ± 8 ms, P = 0.027). In control animals, percent ARI shortening was greater on anterior than posterior walls during right stellate ganglion stimulation ( P = 0.0001), whereas left stellate ganglion stimulation showed the reverse ( P = 0.0003). In infarcted animals, this pattern was completely lost. In 50% of the animals studied, sympathetic stimulation, compared with baseline, significantly altered the direction of activation propagation emanating from the intramyocardial scar during pacing. In conclusion, focal distal anterior MI alters regional and global pattern of sympathetic innervation, resulting in shorter ARIs in infarcted hearts, greater repolarization dispersion, and altered activation propagation. These conditions may underlie the mechanisms by which arrhythmias are initiated when sympathetic tone is enhanced.

Background— Radiofrequency ablation for ventricular tachycardia is an established therapy. Use of chemical agents for scar homogenization represents an alternative approach. The purpose of this study was to characterize the efficacy of collagenase (CLG) application on epicardial ventricular scar homogenization. Methods and Results— Myocardial infarcts were created in Yorkshire pigs (n=6) by intracoronary microsphere injection. After 46.6±4.3 days, CLG type 2, type 4, and purified CLG were applied in vitro (n=1) to myocardial tissue blocks containing normal myocardium, border zone, and dense scar. Histopathologic studies were performed to identify the optimal CLG subtype. In vivo high-density electroanatomic mapping of the epicardium was also performed, and border zone and dense scar surface area and late potentials were quantified before and after CLG-4 application (n=5). Of the CLG subtypes tested in vitro, CLG-4 provided the best scar modification and least damage to normal myocardium. During in vivo testing, CLG-4 application decreased border zone area (21.3±14.3 to 17.1±11.1 mm 2 , P =0.043) and increased dense scar area (9.1±10.3 to 22.0±20.6 mm 2 , P =0.043). The total scar area before and after CLG application was 30.4±23.4 and 39.2±29.5 mm 2 , respectively ( P =0.08). Late potentials were reduced by CLG-4 application (28.8±21.8 to 13.8±13.1, P =0.043). During CLG-4 application (50.0±15.5 minutes), systolic blood pressure and heart rate were not significantly changed (68.0±7.7 versus 61.8±5.3 mmHg, P =0.08; 77.4±7.3 versus 78.8±6.0 beats per minute, P =0.50, respectively). Conclusions— Ventricular epicardial scar homogenization by CLG-4 application is feasible and effective. This represents the first report on bioenzymatic ablation of arrhythmogenic tissue as an alternative strategy for lesion formation.

Background: Enhanced cardiac sympathetic tone has been associated with ventricular arrhythmias and sudden cardiac death. The spinal cord is an important integrative region of afferent and efferent pathways that participate in cardiovascular regulation. The purpose of this study is to investigate the role of spinal processing of cardiac afferent information on ventricular electrophysiology during cardiac sympathoexcitation. Methods: Female Yorkshire pigs (n=5) underwent surgical exposure of the heart and left stellate ganglion (LSG) through thoractomy as well as the dorsal and ventral roots of the spinal cord through laminectomy. A 56-electrode sock was placed over the ventricles to record epicardial electrograms. Animals underwent LSG stimulation in intact, after dorsal root transaction (DRTx), and followed by ventral root transaction (DVRTx). Activation recovery intervals (ARIs) were measured at each electrode before and during LSG stimulation. Results: With intact roots LSG stimulation resulted in significant global ARI shortening by 12.9% (p Conclusion: Spinal afferent pathways play an inhibitory role in sympathoexcitation of ventricle induced by LSG stimulation. This finding provides insight into the mechanism underlying the beneficial effects of thoracic epidural anesthesia in reducing ventricular arrhythmias.

Purpose: Implantable Cardioverter Defibrillator (ICD) prevents sudden cardiac death in high risk patients with heart failure (HF). Worsening renal function (WRF) is associated with mortality in patients with myocardial infarction or HF, but its effect on lethal arrhythmia is unknown. We evaluated the influence of WRF on the occurrence of arrhythmic events in patients with nonischemic HF and ICD. Methods: A total of 286 nonischemic HF patients who underwent ICD implantation between 1990 and 2007 were studied. Estimated Glomerular Filtration Rate (eGFR) was calculated using the Modification of Diet in Renal Disease. Renal dysfunction was defined as eGFR 2 and WRF was defined as 15mL/min/1.73m 2 per year. Differences in arrhythmia recurrences according to the eGFR and WRF were compared by Kaplan-Meier survival curves. Results: During a mean follow-up time of 2.2+/−1.0 years, 94 (33%) of 286 patients (mean age; 57+/−15 years, 72% male) experienced appropriate ICD shock therapy. There was a significantly higher cumulative rate of appropriate ICD shock therapy (p Conclusion: WRF is associated with increased rate of arrhythmic event in nonischemic HF patients. Especially, those patients with low LVEF and WRF experience more frequent ICD shocks.

Abnormal early septal motion observed in patients with left bundle brunch block (LBBB) has been explained as a difference in right-to-left ventricular pressure. The interventricular septum was thought to be displaced passively into the LV because the right ventricle contracts prior to the LV and the right ventricular pressure exceeds the LV pressure during early systolic phase. Assuming that this theory is right, the interventricular septal wall would be stretched and shown positive strain value in circumferential and longitudinal directions during early systolic phase. We investigated the mechanism of the early septal motion with LBBB using speckle tracking imaging (STI). Methods: Systolic septal motion on the middle LV portion level was analyzed in 44 patients with complete LBBB (mean QRS duration 166 ± 35 ms) using M-mode echocardiography and speckle tracking imaging (STI). Time from onset of QRS configuration to peak circumferential strain and longitudinal strain were measured in parasternal short axis and apical views by STI. Furthermore, 20 healthy individuals (mean QRS duration 84 ± 6 ms) were also analyzed. Changes in LV pressure and septal strain were simultaneously measured to evaluate the relationship between them in 6 patients with LBBB. Results: Septal displacement into the LV was early and abrupt on M-mode echocardiograms from all patients with LBBB. During this displacement, the STI of the interventricular septum of all patients showed negative strain in both the circumferential and longitudinal directions. Furthermore, early septal displacement almost coincided with peak negative strain. Time to peak septal strain in LBBB patients was significantly shorter than in normal controls in the circumferential (296 ± 80 vs. 356 ± 30 ms; p < 0.05) and longitudinal (317 ± 104 vs. 369 ± 17 ms; p < 0.05) directions. The peak of septal negative strain was followed by an increase in LV pressure in all patients. Conclusion: Early motion of the interventricular septum is provoked by its active contraction in LBBB. The septal contraction starts very early and almost isotonically toward a very low load. However, further shortening is suppressed by a subsequently increased load of pressure elevation due to the contraction of other LV segments.

Percutaneous balloon pericardiotomy and intrapericardial instillation seemed to be less invasive and effective treatments for refractory pericardial effusion. A 65-year-old man who suffered from refractory pericardial effusion associated with gastric cancer and had been hospitalized three times for pericardiocentesis, complained of dyspnea at rest and visited our emergency room. Echocardiography showed a large amount of pericardial effusion all around the heart and signs of cardiac tamponade. Percutaneous balloon pericardiotomy was performed and pericardial effusion turned to pleural effusion. We performed left thoracocentesis. One week later, massive pericardial effusion localized only around the right heart appeared, and pericardiocentesis was performed again. After another month, pericardial effusion around right heart appeared again and intrapericardial instillation with OK-432 (Picibanil) was tried. After the procedure, the pericardial effusion did not increase, and he has had few symptoms for 2 months as an outpatient.

A 60-year-old female had sudden onset of syncope. The emergency service noticed that she suffered cardiopulmonary arrest (ventricular fibrillation: VF). After defibrillation in the ambulance, she was transported to our emergency department. Electrocardiography monitoring showed QT prolongation. Serum potassium level was extremely low at 1.8 mEq/l. Although potassium and lidocaine were administered, it was difficult to maintain appropriate electrolyte balance and prevent VF after admission, so temporary overdrive pacing was required. She was diagnosed as having primary aldosteronism after laboratory and imaging examinations. VF was otherwise uncontrollable so a cardioverter defibrillator was implanted on the 24th hospital day. Laparoscopic adrenalglandectomy was performed about 1 month later. After the surgery, serum potassium level remained at an appropriate level without medication. No severe neurological deficits were found at discharge from our hospital.

Introduction: We compared the effectiveness of left ventricular (LV) only pacing with standard biventricular (BiV) pacing by a novel electrogram-based algorithm for atrioventricular (AV) optimization (SMART-AV®, Boston scientific, Minnesota). Methods: 20 patients with NYHA class ≥2 heart failure, LV ejection fraction (LVEF) ≤35% and QRS duration ≥120 ms were implanted with Cognis® (Boston scientific, Minnesota) for CRT and divided into two groups as follows: LV group (13 patients) with LV only pacing and BiV group (7 patients) with standard BiV pacing by SMART-AV® algorithm. LV volumes and systolic function were assessed with echocardiography at baseline and 6 months. A reduction in LV end systolic volume (LVESV) ≥15% was defined as responder. Results: There were no significant differences in baseline characteristics between LV group and BiV group. Although LVESV was significantly decreased in both groups 6 months after pacing, LVEF was improved only in LV group. Responder was higher in LV group than BiV group but there was no statistical significance (76.9% vs 41.9%, P=0.15). There were also no significant differences in reduction of LVESV and change in LVEF. Conclusion: Left ventricular only pacing for patients with intrinsic AV conduction by SMART-AV® algorithm is effective as well as standard BiV pacing.

Aim: The device leads perforating the myocardium are contraindicated for percutaneous lead extraction (LE). The purpose of this study is to investigate the usefulness of multidetector computed tomography (MDCT) or angiography to identify the perforating lead before LE. Methods: Among consecutive 44 patients underwent LE, we performed MDCT in 30 patients and angiography of RA, RV in 31 patients. The images were investigated to assess the possibility of lead perforation. Results: In 9 patients, the tip of the leads seemed protruding from the myocardium (RV apex n=7, RA appendage n=2). LE was performed under the thoracotomy in 6 patients with possible perforation, considering for the risk of cardiac tamponade. In 6 patients (67%) with possible perforation, the percutaneous LE was succeeded without any complications. In 3 patients (33%), the leads were surgically extracted. In cases with thoracotomy, surgical observation revealed that 2 RA and 1 RV leads were sticking out of the myocardium, but covered with pericardium and fat pad (pseudo-perforation). Two RA leads underwent surgical removal, but the RV lead was safely extracted by percutanous technique. Conclusion: Though the percutaneous LE was safely performed even in most patients with the findings of pseudo-perforation, we have to pay attention not to make the complications in these patients.

Background: Effect of upgrade from permanent right ventricular (RV) apical pacing to biventricular (BiV) pacing has not yet delineated. Aims: The aim of this study is to investigate the role of upgrade from RV pacing to BiV pacing. Methods: Sixty four patients with NYHA>class 2 heart failure and LV ejection fraction (LVEF) 130 msec) and group-B (upgrade to BiV pacing in 24 patients with bradycardia and paced-QRS>150 msec). The LV volume and systolic function were assessed with echocardiography at baseline and 6 months after implantation of a cardiac resynchronization (CRT) device. A reduction in LV end systolic volume (LVESV)>15% was defined as responder. Results: LVESV reduced significantly in group-A (204.7 ml to 181.6 ml, P

Backgrounds: Some specific CRT devices can sense the left ventricular (LV) activation and inhibit the LV pacing to prevent R on T. However, only a little is known about the trouble caused by this function. We experienced some patients who had the persistent inhibition of the LV pacing in the setting of biventricular pacing. Methods: The occurrence of LV pacing inhibition (LPI) was investigated in consecutive 68 patients, who underwent the implantation of CRTDs with LV pacing protection (LVPP) function. LV sensing, LVPP and the RV sense-triggered LV pacing were activated in all the patients. Results: The persistent RV only pacing with the LPI was observed in 5 patients, despite the pacing setting was biventricular (n=4) or LV only (n=1). In 2 patients, the far-field atrial sensing caused the LPI, and one of them had the LV lead dislodgement. In the other 3 patient, oversensed T-wave or automatic prolongation of PVARP following PMT detection, concealed the atrial sensing. and the conducted RV to LV interval became shorter than the LV protection interval, and it caused the persistent LPI. Conclusion: Though the LVPP is useful in avoiding the risk of R on T, it possibly causes the persistent LPI in some specific situation.

Aims: Bacteria culture examinations are important to identify the bacteria and its focus of infection in patients with device infection. The aim of this study was to investigate the relationship between results of culture and clinical symptoms in patients with local pocket infection. Methods and Results: Between January 2005 and June 2010, 42 patients (mean age 61 yr; male n=33) were diagnosed of device infection in our hospital. Twenty four (57%) patients had only local inflammatory changes or erosion at generator-pocket site without blood stream infection and a vegetation-like mass adherent to the leads at initial echocardiological assessment. Among them, 17 (71%) patients had a positive pocket tissue culture. Lead cultures after lead extraction procedure were more frequently positive in patients with positive tissue culture than in patients with negative tissue culture (47% (8/17) vs 29% (2/7)). Additionally, there was no difference in results of pocket tissue culture between patients with and without fistula or discharge at the generator-pocket site. Conclusion: Bacteria culture examinations revealed that pocket infection extended to the leads in about half of patients who had only local inflammatory changes or erosion at generator-pocket site without any signs of systemic infection at initial assessment.

Background: According to HRS guideline revised in 2009, Cardiovascular Implantable Electronic Device (CIED) pocket infection became class I indication for complete system removal. In many institutions, conservative treatments such as antimicrobial therapy, local debridement and relocation of the pacemaker pocket have been considered for the complex lead extraction procedure. The purpose of this study is to evaluate the characteristics of infection in patients with CIED infections. Methods: The pre-operative clinical, microbiological, echocardiographic conditions were analyzed in a retrospective cohort including all consecutive 39 patients diagnosed CIED infections between February 2006 and September 2010. Results: The patients were divided into 2 groups, with local pocket infection (Group I=35) and with elevated CRP·WBC without local pocket infection (Group II=4). Among the patients underwent TEE (Group I=24, Group II=4), the vegetation-like masses (VLMs) were observed in 46% and 75% in each group. Though the blood cultures were positive only in 7.7%, the lead cultures were positive in 58% in Group I. And among 11 patients with VLMs in Group I, 9 patients underwent the lead cultures and it was positive in 56%. In Group II, the blood cultures were positive in 75%. Conclusions: Since the appearance of VLMs is not uncommon in patients with local pocket infection, complete system removal should be considered.

Background: It had been reported that atrial fibrillation (AF) recurrence immediately after ablation of AF may be caused by acute inflammatory changes after ablation and does not always means long-term AF recurrence. However, the pre-procedural clinical background of that is unclear. Aim: To clarify the clinical background of patients who had AF recurrences within 3-days after ablation (immediate AF recurrence) and the impact of immediate AF recurrences on the long-term outcome. Method: The study included 113 patients (aged 23–78 years; 80% men) with symptomatic drug-resistant paroxysmal (n=89) or persistent AF (n=24) who underwent extensive pulmonary vein ablation. All patients were followed up for more than 3-months (mean 530 days) after the first ablation. Result: Eighteen patients (16%) had immediate AF recurrences (Group-A), 5 (4%) had early recurrences 4–30 days after ablation (Group-B), and the remaining 90 (80%) had no AF recurrences within 1 month after ablation (Group-C). Compared with Group-C, Group-A had more persistent AF patients (p=0.03), higher brain natriuretic peptide levels (p=0.047), larger left atrial volume (p=0.012) and higher E/e′ ratio which is an indicator of left ventricular diastolic dysfunction (p=0.006). The AF free rates after the first AF ablation without anti-arrhythmic drugs in Group-C was superior to that in Group-A and Group-B (P

Aims: Venous obstruction following cardiac electronic device implantation sometimes causes a challenge in lead revision or device upgrade. The aim of this study was to determine the predictors of venous obstruction after transvenous device implantation. Methods and Results: Between April 2004 and April 2011, contrast venography was performed in 77 patients who needed lead revision or device upgrade. Sixteen (21%) of them had venous obstruction, including 8 patients with total obstruction and 8 patients with partial obstruction. No significant differences between obstructed and non-obstructed patients were seen for age, sex, atrial fibrillation, dilated cardiomyopathy, numbers of the leads, antiplatelet/anticoagulant drugs, and time from initial implantation to lead revision or device upgrade. In univariate analysis, low body weight and low body surface area (BSA) were associated with an increased risk of venous obstruction (P=0.036, 55.4 vs 62.3 kg, and P=0.035, 1.57 vs 1.68 m2, respectively). Multivariate logistic regression analysis showed that BSA was a predictor of venous obstruction (OR: 0.58, 95% CI: 0.36–0.96, P=0.034). This means 1.7-fold risk of venous obstruction per 0.1 m2 decrease of BSA. Conclusion: The incidence of venous obstruction following cardiovascular electronic device implantation was not rare. In this study, BSA had negative correlation with risk of venous obstruction.

Background: Hypertrophic cardiomyopathy (HCM) tends to demonstrate advanced remodeling of the left atrium, which may cause a poor outcome of ablation for atrial fibrillation (AF). Aim: To assess the efficacy of the catheter ablation of AF in patients with HCM. Methods and Results: This study included 12 patients (9 male, aged 59+7 years) with symptomatic drug-resistant paroxysmal (n=5), persistent (n=6) or long-standing persistent AF (n=1) who underwent extensive pulmonary vein isolation (EPVI). Of the 12 patients, 5 had hypertrophic obstructive cardiomyopathy. The average ejection fraction was 54+13% and average left atrial volume index (LAVI) was 49±12 ml/m2. During a mean follow-up of 483±197 days, 8 patients (67%) had an AF recurrence without any anti-arrhythmic drugs (AADs). Of those patients, three were maintained in sinus rhythm (SR) with AADs, and six underwent a second ablation procedure. After the second ablation procedure, two patients remained in SR without any AADs, and two were maintained in SR with AADs after the second ablation procedure. The final AF-free rate without any AADs was 50% (6/12) and final AF-free rate with AADs was 83% (10/12). Conclusion: AF recurrences after the first EPVI were high in the patients with HCM. A repeat ablation procedure and AADs were often necessary to obtain a favorable outcome.

Aim: Transvenous cardiovascular implantable electronic devices (CIEDs) implantation in patients with complex congenital heart disease (CCHD) is challenging because of their complex anatomy. We report our experience of CIEDs implantation in CCHD patients. Methods: CCHD patients underwent the CIEDs implantation, were analyzed retrospectively. Results: We implanted CIEDs (pacemaker n=19, ICD n=5, CRT-D n=2) in consecutive 26 CCHD patients (mean 25 y.o.) from 1994 to 2011. The underlying heart diseases were tricuspid atresia (n=2) and single RV (n=1) both after Fontan operation, single LV (n=1) underwent the septation, truncus arteiosus communis underwent Rastelli (n=1), transposition of great ateries (TGA) (n=9) and corrected TGA (n=12; SLL n=9, IDD n=3). Twelve patients with TGA and corrected TGA underwent atrial switch (n=6) or double switch (n=6) operation. The pacing leads were successfully positioned with favorable sensing and pacing threshold in all patients, transvenously, without major complications. In 2 patients with cTGA, we successfully positioned the leads at the LV apex and in the coronary vein for the resynchronization of anatomical RV. The lead revision was required during the follow-up period, due to the lead dislodgement (n=2) and the lead fracture (n=2). Conclusion: Transvenous implantation of CIEDs was safely performed and feasible even in patients with CCHD and sometimes with atrio-ventricular discordance.

Background: Sleep-disordered breathing (SDB) is common and increases mortality rate independently in patients with heart failure (HF). Furthermore, current research suggests that SDB might be an independent predictor of life-threatening ventricular arrhythmias. However, it is still unknown whether SDB have a role to play in electrophysiological background in patient with HF. We assessed the hypothesis that SDB plays an important role in electrophysiological background and contributes to the risk of life-threatening ventricular arrhythmia in patients with HF. Methods: We performed both sleep study and electrophysiologic study in consecutive 33 HF patients and analyzed the relationship between SDB and electrophysiologic data such as AV conduction, ventricular effective refractory period and the inducibility of sustained ventricular tachycardia or fibrillation. All patients had an ejection fraction 10 events/hour on the sleep study. Results: SDB was diagnosed in 22 of 33 patients (67%). There were no statistical differences between patients with and without SDB in baseline characteristics with respect to age, male gender, NYHA class, left ventricular ejection fraction, underlying cardiac disease and medications. AV nodal conduction and ventricular effective refractory period were not significantly differences among two groups. However, the induciblity of ventricular tachyarrhythmia was significantly higher in patients with SDB than those without SDB (73%vs.27%, p=0.013). Conclusions: The present study suggests that SDB can be a risk factor of malignant ventricular arrhythmias without affecting ventricular refractory period in patients with HF.