Changes in estimated glomerular filtration rate before and after the first visit for atrial fibrillation.

BACKGROUND: Although the development of atrial fibrillation (AF) and the progression of chronic kidney disease are known to be interrelated, it remains unclear when and how renal function changes during the clinical course of AF. METHODS: This study retrospectively enrolled 131 patients who were able to collect data on estimated glomerular filtration rate (eGFR) at least five times during the 500 days before and 500 days after the first visit (baseline) of new-onset AF, respectively. To investigate the temporal relationship between the development of AF and the beginning of worsening renal function (WRF), a piecewise regression model was applied to the eGFR time series data. The time point at which the slopes of the two regression lines changed (inflection -point), the slope before and after the inflection-point (ß1 and ß2, respectively), and the difference in slope (Δß) were estimated. The presence of WRF was defined as having the inflection-point at which both Δß and ß2 were < - 0.0083 mL/min/1.73 m2/day (corresponding to 3.03 mL/min/1.73 m2/year), and the corresponding the inflection-point was defined as the beginning of WRF. RESULTS: WRF was detected in 54 (41.2%) patients. The beginning of WRF were distributed at various times, but most frequently (23 of 54 patients) within 100 days before and after baseline. The presence of WRF was not associated with age, heart failure, or baseline eGFR, but was associated with positive ß1 (odds ratio 30.5, 95% confidence interval 11.1-83.9, P < 0.01). CONCLUSION: In nearly half of AF patients with WRF, the beginning of WRF was observed within a few months before or after the first visit for AF. Patients with a positive eGFR slope before the onset of AF are more likely to develop WRF after the onset of AF, suggesting that potential kidney damage may be underlying.

Catheter Ablation of Refractory Ventricular Fibrillation Storm After Myocardial Infarction.

BACKGROUND: Ventricular fibrillation (VF) storm after myocardial infarction (MI) is a life-threatening condition that necessitates multiple defibrillations. Catheter ablation is a potentially effective treatment strategy for VF storm refractory to optimal medical treatment. However, its impact on patient survival has not been verified in a large population. METHODS: We conducted a multicenter, retrospective observational study involving consecutive patients who underwent catheter ablation of post-MI refractory VF storm without preceding monomorphic ventricular tachycardia. The target of ablation was the Purkinje-related ventricular extrasystoles triggering VF. The primary outcome was in-hospital and long-term mortalities. Univariate logistic regression and Cox proportional-hazards analysis were used to evaluate clinical characteristics associated with in-hospital and long-term mortalities, respectively. RESULTS: One hundred ten patients were enrolled (age, 65±11years; 92 men; left ventricular ejection fraction, 31±10%). VF storm occurred at the acute phase of MI (4.5±2.5 days after the onset of MI during the index hospitalization for MI) in 43 patients (39%), the subacute phase (>1 week) in 48 (44%), and the remote phase (>6 months) in 19 (17%). The focal triggers were found to originate from the scar border zone in 88 patients (80%). During in-hospital stay after ablation, VF storm subsided in 92 patients (84%). Overall, 30 (27%) in-hospital deaths occurred. The duration from the VF occurrence to the ablation procedure was associated with in-hospital mortality (odds ratio for each 1-day increase, 1.11 [95% CI, 1.03-1.20]; P=0.008). During follow-up after discharge from hospital, only 1 patient developed recurrent VF storm. However, 29 patients (36%) died, with a median survival time of 2.2 years (interquartile range, 1.2-5.5 years). Long-term mortality was associated with left ventricular ejection fraction <30% (hazard ratio, 2.54 [95% CI, 1.21-5.32]; P=0.014), New York Heart Association class ≥III (hazard ratio, 2.68 [95% CI, 1.16-6.19]; P=0.021), a history of atrial fibrillation (hazard ratio, 3.89 [95% CI, 1.42-10.67]; P=0.008), and chronic kidney disease (hazard ratio, 2.74 [95% CI, 1.15-6.49]; P=0.023). CONCLUSIONS: In patients with MI presenting with focally triggered VF storm, catheter ablation of culprit triggers is lifesaving and appears to be associated with short- and long-term freedom from recurrent VF storm. Mortality over the long-term follow-up is associated with the severity of underlying cardiovascular disease and comorbidities in this specific patient population.

Particular Morphology of Inferior Pulmonary Veins and Difficulty of Cryoballoon Ablation in Patients With Paroxysmal Atrial Fibrillation.

BACKGROUND: The CRYO-Japan PMS study indicated that cryoballoon ablation (Cryo-Abl) has a lower acute success rate of pulmonary vein isolation (PVI) for the right and left inferior PVs (RIPV and LIPV, respectively) than for the superior PVs. This study aimed to determine if the orientation and position of the inferior PVs are related to the difficulty of acute success of PVI.Methods and Results:We investigated 30 consecutive patients who underwent Cryo-Abl. A "difficult PV" was defined as the requirement for >2 cooling applications and/or touch-up ablation to achieve PVI. We measured the ventral angle between the vertical line and the direction of each PV trunk (PV angle) on the transverse plane of enhanced CT images. PV position was defined as the difference in the levels between the bottom of the RIPVs and the non-coronary cusp of the aorta. PV angle <105° and PV position <1.250 mm were independent factors of difficult RIPV isolation (PV angle: odds ratio (OR)=23.80, confidence interval (CI) -3.15528 to -0.53622, P=0.002; PV position: OR=12.14, CI -2.77301 to -0.23160, P=0.014). PV position <16.875 mm was also related to the difficulty of LIPV isolation (OR=5.78, CI -1.77095 to -0.09474, P=0.027). CONCLUSIONS: RIPV with ventral orientation may require difficult maneuvers to advance an ablation system towards it. Low take-off of the inferior PVs may cause non-coaxial configuration of balloon catheters towards the direction of these veins.

A novel method to estimate blood flow velocity in the left atrial appendage using enhanced computed tomography: role of Hounsfield unit density ratio at two distinct points within the left atrial appendage.

Low blood flow velocity in the left atrial appendage (LAA) indicates a high risk of thromboembolism. Although transesophageal echocardiography (TEE) has been the standard method with which to evaluate the LAA blood flow velocity, a clinically noninvasive method is desired. We hypothesized that the ratio of the Hounsfield unit (HU) density at two distinct points within the LAA represents the blood flow velocity in the LAA. We retrospectively investigated 60 consecutive patients with atrial fibrillation (paroxysmal type, n = 29) who underwent enhanced computed tomography (CT) and TEE. The peak emptying flow velocity in the LAA (LAAPV) was evaluated using TEE. HU density was measured at proximal and distal sites of the LAA (LAAp and LAAd) on CT images. The LAAd/LAAp ratio was correlated with the LAAPV (P < 0.01, r = 0.69). Among several indices, the HU ratio was the most significant parameter associated with the LAAPV (ß = 0.469, CI 28.602-68.286, P < 0.001). Receiver-operating characteristic analysis (area under the curve, 0.91) demonstrated that an HU density ratio cutoff of 0.32 discriminated a low LAAPV (<25 cm/s) with sensitivity of 90% and specificity of 84%. Flow velocity of the LAA can be estimated by the HU density ratio at distal and proximal sites within the LAA. Our method might be a feasible substitution for TEE to discriminate patients with a reduced LAAPV.

Ectopies from the superior vena cava after pulmonary vein isolation in patients with atrial fibrillation.

Episodes of atrial fibrillation (AF) are mainly initiated by triggers from pulmonary veins (PVs). The superior vena cava (SVC) has been identified as a second major substrate of non-PV foci, but the electrophysiologic features of the SVC have not been fully investigated. We hypothesized that SVC ectopies are suppressed by predominant features of PV ectopies and tend to appear after PV isolation (PVI). We evaluated the electrophysiological characteristics and clinical implications of SVC ectopies in patients with AF during catheter ablation using high-dose isoproterenol and the atrial overdrive pacing maneuver. The manifestation patterns and modes of onset (coupling interval and appearance interval) of ectopies from both the PVs and SVC were investigated. 205 patients were enrolled [153 males and 52 females; mean age 64 ± 10 years; paroxysmal in 143 patients (69.8 %), persistent in 40 (19.5 %), and long-standing persistent in 22 patients (10.7 %)]. Before PVI, PV ectopies were detected in 182/205 patients (89 %). SVC ectopies were rarely observed before PVI but were significantly more frequent after the completion of PVI (3/205 vs. 14/205 patients, p = 0.011). The coupling interval (CI) and % CI (CI/preceding the A-A interval × 100) of PV ectopies were significantly shorter than those of SVC ectopies (211 ± 78 vs. 282 ± 106 ms, p = 0.021, and 34 ± 9 vs. 51 ± 17 %, p < 0.001, respectively). The appearance intervals of the PV ectopies were shorter than those of the SVC ectopies (6.3 ± 4.0 vs. 10.7 ± 6.7 s, p = 0.030). During repeat procedures, PVs with reconnection to the left atrium were less frequently observed in patients with SVC firing than in patients without SVC firing (1.7 ± 1.5 vs. 2.9 ± 1.1 PVs, p = 0.029). We demonstrated that PVI tends to manifest SVC ectopies with less spontaneous activity and that an elimination of predominant ectopies from the PVs may affect appearance of SVC ectopy.

Simultaneous existence of sustained double chamber tachycardias originating from the aortic sinus of Valsalva.

Monomorphic ventricular tachycardia is basically a benign phenomenon in patients without structural heart disease. The focal source of the tachycardia is usually located in the right ventricular outflow tract and more rarely in the left ventricular outflow tract. Aortic sinus of Valsalva (ASV) is a well-known source of atrial and ventricular tachycardias. We report a case with simultaneous existence of sustained atrial and ventricular tachycardias originating from ASV, which was successfully treated with radiofrequency catheter ablation.

A proposed interval for evaluation of renal function during anticoagulation therapy using direct oral anticoagulants in patients with atrial fibrillation.

BACKGROUND: Direct oral anticoagulants (DOACs) have been used to prevent cardiogenic embolism in patients with atrial fibrillation (AF). No evidence has been established for the follow-up renal function evaluation intervals. We hypothesized that a proposed follow-up interval of renal function can be estimated by patient's baseline characteristics including creatinine clearance (CCr). METHODS: We conducted a single-center retrospective study at Kindai University Hospital from May 2011 to December 2017. Patients were screened and they were enrolled if baseline CCr of ≥50 mL/min. To provide a periodical synchronization for measurements of CCr in all patients, these were evaluated at four different time points (approximately at 3, 6, 9, and 12 months). Primary endpoint was defined as a CCr value of <50 mL/min during the follow-up period. We analyzed associations between the cumulative risk for renal endpoint and baseline characteristics by the Kaplan-Meier method and the Cox proportional hazards model. RESULTS: Renal endpoint was associated with age (95% CI: 0.07 to 0.21, p<0.01), body weight (95% CI: -0.09 to -0.01, p<0.01), CCr (95% CI: -0.18 to -0.07, p<0.01), and CHA2DS2-VASc score (95% CI: 0.14 to 0.63, p<0.01). Combining baseline CCr of <60 mL/min and other risk factors, acceptable intervals for 5% risk levels were 78 days (age ≥75 years old), 100 days (CHA2DS2-VASc score of> 4 points), and 90 days (body weight <60kg), respectively. Under conditions of baseline CCr of <60 mL/min, age ≥75 years old, CHA2DS2-VASc score of> 4 points, or body weight <60 kg, an increased risk of renal endpoints is 4.85, 3.29, 1.24, 2.44 fold, respectively. CONCLUSIONS: We propose a risk-stratified follow-up interval for renal evaluation in patients with AF and DOACs therapy according to a combination of baseline CCr and other risk factors.

Rhythm control should be better for the management of patients with atrial fibrillation and heart failure--rhythm control vs. rate control: which is better in the management of atrial fibrillation? (Rhythm-side).

The incidence of atrial fibrillation (AF) increases with advancing NHYA cardiac functional class, and it significantly affects the cardiac function of a failing heart. In such situations, clinicians should aim to maintain sinus rhythm in these patients with heart failure (HF) in order to improve their prognosis. However, according to various randomized clinical studies demonstrating the non-superiority of rhythm control over rate control, many clinicians seem to prefer to take the line of least resistance (ie, rate control). Curative catheter ablation mainly based on isolation procedure of the pulmonary veins in patients with AF and HF has demonstrated a significant improvement in left ventricular function, even in the presence of adequate ventricular rate control before the ablation. On the other hand, ablation and biventricular pacing therapy, which is an extreme rate control strategy, has not shown any beneficial effects for these patients. Therefore, a regular RR interval with an appropriate cycle length only is not sufficient to improve cardiac performance, and maintenance of sinus rhythm, which restores atrial contraction and the atrioventricular synchrony, is thought to be essential for an improvement in HF. Thoughtful clinicians should do their best to find a way to keep HF patients in sinus rhythm.

Cardiac resynchronization therapy to prevent life-threatening arrhythmias in patients with congestive heart failure.

Various clinical data demonstrate that cardiac resynchronization therapy (CRT) provides a favorable structural as well as electrical remodeling. The CArdiac Resynchronization-Heart Failure study, which tested the pure effect of CRT (using CRT devices without the capability of defibrillation) clearly showed a significant reduction in the total mortality by partly preventing sudden cardiac death. The antiarrhythmic effects of CRT are explained, at least in part, by ionic and genetic modulation of ventricular myocytes. It has been revealed in animal experiments to mimic disorganized ventricular contraction that CRT reverses down-regulation of certain K(+) channels and abnormal Ca(2+) homeostasis in the failing heart. However, CRT can be proarrhythmic in some particular cases especially in the early phase of this therapy. According to our study, proarrhythmic effects after CRT can be observed in approximately 10% of patients. The relatively high incidence of the proarrhythmic effects of CRT may promote a trend toward selecting CRT-D rather than CRT-P.

Impact of atrial fibrillation/flutter on outcomes of patients with implantable cardioverter defibrillators: A sub-analysis of the Nippon Storm study.

BACKGROUND: Implantable cardioverter-defibrillator and cardiac resynchronization therapy using a defibrillator (ICD/CRT-D) are established means of reducing mortality due to ventricular arrhythmia. Although atrial fibrillation/flutter (AF) is the most common cardiac arrhythmia in patients with heart disease, the impact of AF on the prognosis of patients with ICD/CRT-D remains controversial. METHODS AND RESULTS: We analyzed data from the Nippon Storm Study, a prospective observational study of 1570 patients that was conducted at 48 Japanese ICD centers. We allocated 1549 participants to AF and non-AF groups, compared their clinical data at the time of enrollment, and monitored the incidences of mortality, hospitalization, and appropriate and inappropriate ICD/CRT-D therapy during a median 28 months. When the AF (n = 257, 16.6%) and non-AF-(n = 1292, 83.4%) groups were compared, the AF group was older (67.7 vs. 61.4 years; p<0.0001), and had lower left ventricular ejection fraction (38.0 ± 17.0% vs. 43.5 ± 18.9%; p<0.0001). During follow up, mortality was significantly higher in the AF than the non-AF group (p<0.0001). In multivariate analysis, AF was significantly associated with all-cause mortality [p = 0.013; hazard ratio (HR)=1.62]. Inappropriate ICD/CRT-D therapy occurred in 40/257 patients (15.6%) and AF was associated with a higher prevalence of inappropriate ICD/CRT-D therapy (p<0.0001; HR=2.25). CONCLUSION: The presence of AF at ICD/CRT-D implantation carries subsequent independent risks of 1.62-fold for death and 2.25-fold for inappropriate therapy.

A novel method to demonstrate thrombus formation of the left atrial appendage in patients with persistent atrial fibrillation by cardiac computed tomography.

BACKGROUND: Transesophageal echocardiography (TEE) is currently the gold standard technique for diagnosing left atrial appendage (LAA) thrombi. Cardiac computed tomography (CT) has been expected to become an alternative method to TEE; however, a reliable quantitative evaluation method has not been established. METHODS AND RESULTS: We enrolled 177 patients with persistent atrial fibrillation who underwent both cardiac CT and TEE before catheter ablation. The patients were classified into two groups according to the TEE results: the thrombus group (13 patients) and non-thrombus group (164 patients). The Hounsfield unit (HU) density at the proximal LAA (LAAp) and distal LAA (LAAd) was measured on cardiac CT images. The LAAd/LAAp HU ratio and standard deviation of HU density (HU-SD) at the LAAd were evaluated. We created an algorithm by decision tree analysis to predict LAA thrombus formation using the HU ratio and HU-SD. Definite absence of LAA thrombus (Category-I) was diagnosed for 139 patients by combining the first and second branching of the decision tree (Category-Ia: HU ratio of ≥0.26, Category-Ib: HU ratio of <0.26, HD-SD of ≥26.94). Definite presence of LAA thrombus (Category-Ⅱ) was diagnosed for 3 patients using the third branching of the decision tree (Category-Ⅱ: HU ratio of <0.26 and HU-SD of <13.85). Highly possibility of LAA thrombus (Category-III), but not definite, was diagnosed for the remaining 35 patients; therefore, these patients required diagnostic TEE. The diagnostic accuracy of this algorithm was 0.95. CONCLUSION: We have proposed a reliable algorithm to diagnose LAA thrombus formation using the HU ratio and HU-SD.

Comparison of second appropriate defibrillator therapy occurrence in patients implanted for primary prevention and secondary prevention - Sub-analysis of the Nippon Storm Study.

BACKGROUND: Patients with implantable cardioverter defibrillator (ICD) use for primary prevention (primary prevention patients) of sudden cardiac death have lower incidence of appropriate ICD therapy (app-Tx) compared with those with ICD use for secondary prevention (secondary prevention patients). However, detail analysis of a second app-Tx after a first app-Tx is still lacking. OBJECTIVE: This study aimed to compare the incidence of a second app-Tx in primary vs secondary prevention patients. METHODS: We conducted sub-analysis of the Nippon Storm Study, which was a prospective, observational study involving 985 patients with structural heart disease (left ventricular ejection fraction ≤ 50%). Of these, we selected 251 patients (62 ± 14 years old, 82% men) who experienced at least one appropriate ICD therapy, and compared occurrence of a second app-Tx between primary (n = 116) and secondary (n = 135) prevention patients. RESULTS: There was no significant difference in the incidence of a second app-Tx between primary and secondary prevention patients (the cumulative incidence for a second app-Tx was 59% at 1 year and 79% at 3 years in primary prevention patients vs the cumulative incidence for the second app-Tx was 59% at 1 year and 75% at 3 years in secondary prevention patients).Additionally, we evaluated the incidence of a second app-Tx according to basal structural disease (ischemic and non-ischemic cardiomyopathy) and found no significant difference between primary and secondary prevention patients. CONCLUSION: Once app-Tx occurs, primary prevention patients acquire the high risk of subsequent ventricular arrhythmias because there is a comparable incidence of a second app-Tx in secondary prevention patients.

Impact of beta-blocker use on the long-term outcomes of heart failure patients with chronic obstructive pulmonary disease.

AIMS: The number of patients with both chronic obstructive pulmonary disease (COPD) and heart failure (HF) is increasing in Asia, and these conditions often coexist. We previously revealed a tendency of beta-blocker underuse among patients with HF with reduced ejection fraction (HFrEF) and COPD in Asian countries other than Japan. Here, we evaluated the impact of cardio-selective beta-blocker use on the long-term outcomes of patients with HF and COPD. METHODS AND RESULTS: Among the 5232 patients with HFrEF (left ventricular ejection fraction of <40%) prospectively enrolled from 11 Asian regions in the ASIAN-HF registry, 412 (7.9%) had a history of COPD. We compared the clinical characteristics and long-term outcomes of the patients with HF and COPD according to the use and type of beta-blockers used: cardio-selective beta-blockers (n = 149) vs. non-cardio-selective beta-blockers (n = 124) vs. no beta-blockers (n = 139). The heart rate was higher, and the outcome was poorer in the no beta-blocker group than in the beta-blocker groups. The 2 year all-cause mortality was significantly lower in the non-cardio-selective beta-blocker group than in the no beta-blocker group. Further, the cardiovascular mortality significantly decreased in the non-cardio-selective beta-blocker group before (hazard ratio: 0.36; 95% confidence interval: 0.18-0.73; P = 0.004) and after adjustments (hazard ratio: 0.37; 95% confidence interval: 0.19-0.73; P = 0.005), but not in the cardio-selective beta-blocker group. CONCLUSIONS: Beta-blockers reduced the all-cause mortality of patients with HFrEF and COPD after adjusting for age and heart rate, although the possibility of selection bias could not be completely excluded due to multinational prospective registry.

Long-term effects of non-retrieved inferior vena cava filters on recurrences of venous thromboembolism in cancer and non-cancer patients: From the COMMAND VTE registry.

BACKGROUND: There is a paucity of data comparing the long-term outcomes after inferior vena cava (IVC) filters placement for patients with acute venous thromboembolism (VTE) between those with and without active cancer. METHODS: In the COMMAND VTE Registry, we evaluated the effects of IVC filter use on the long-term clinical outcomes stratified by the presence and absence of active cancer. RESULTS: Among 2,626 patients with acute symptomatic VTE, there were 604 patients with active cancer, and 2022 patients without active cancer. IVC filters were placed and not retrieved in 455 patients (17%) in the entire cohort, in 150 patients (24.8%) in the active cancer stratum, and in 305 patients (15.1%) in the non-cancer stratum. In the entire cohort, non-retrieved IVC filter placement was not associated with a lower adjusted risk for PE recurrence (HR 0.59, 95% CI 0.30-1.15, P = 0.122), but with an increased adjusted risk for DVT recurrence (HR 2.27, 95% CI 1.43-3.60, P<0.001). In the non-cancer stratum, the non-retrieved IVC filter placement was associated with a decreased risk for PE (HR 0.29, 95% CI 0.09-0.93, P = 0.037), but not with an increased risk for DVT (HR 1.73, 95% CI 0.89-3.38, P = 0.108), while in the active cancer stratum, it was associated with an increased risk for DVT (HR 2.47, 95% CI 1.24-4.91, P = 0.010), but not with a decreased risk for PE (HR 0.82, 95% CI 0.34--1.96, P = 0.650). CONCLUSIONS: There were some differences in the risk-benefit balance between VTE patients with and without active cancer.

Early transient recurrence of ventricular fibrillation after catheter ablation of premature ventricular contraction from Purkinje fibers in two patients with myocardial infarction.

Catheter ablation (CA) targeting premature ventricular contraction (PVC) from Purkinje fibers can be an effective therapy for refractory ventricular fibrillation (VF) after myocardial infarction (MI). We experienced two cases in which catheter ablation targeting PVC initiating VF after percutaneous coronary intervention (PCI) in post-MI patients was effective despite transient early recurrences of VF. The first patient (a 68-year-old woman with MI) developed drug-refractory VF 3 days after PCI to the left anterior descending artery (LAD) and left circumflex artery. CA targeting Purkinje potential preceding PVC at the infarcted area eliminated both the PVCs and VF. Three days after the procedure, the VF attacks relapsed by a different type of PVC. However, the VF responded to conventional treatments and disappeared thereafter. In the second patient (an 83-year-old woman with old MI), refractory VF attacks occurred after PCI to the LAD. CA targeting Purkinje potential preceding two distinct types of PVC successfully suppressed the VF. Although the VF relapsed 2 days after CA, it was suppressed by conventional treatment and disappeared the next day. .

Cardiac memory-induced T wave change during complete atrioventricular block in a patient with inferior acute myocardial infarction.

Cardiac memory is an electrocardiographic manifestation of transient T wave abnormalities, which is observed after abrupt interruption of abnormal ventricular activation. We report a case with preexisting complete left bundle branch block in whom cardiac memory was induced. This cardiac memory was induced by normalization of QRS morphology after development of complete atrioventricular block due to acute inferior myocardial infarction. .

Intravenous amiodarone homogeneously prolongs ventricular repolarization in patients with life-threatening ventricular tachyarrhythmia.

BACKGROUND: The most critical adverse effects of class III drugs are marked QT prolongation and torsade de pointes. Even though intravenous amiodarone (iv-Amio) is a representative class III drug, it peculiarly inhibits both clinical ventricular tachycardia/fibrillation (VT/VF) and proarrhythmic effects. To test the hypothesis that iv-Amio homogeneously prolongs repolarization, we evaluated electrocardiographic changes before and during short-term amiodarone therapy, focusing closely on the ventricular dispersion of repolarization. METHODS: Twenty-seven consecutive patients treated with iv-Amio for VT/VF as a first-line antiarrhythmic therapy were enrolled in this study. Twelve-lead electrocardiography was recorded before and during amiodarone therapy to evaluate the following electrocardiographic intervals: R-R, QRS, QT, QRS to T-peak (QTp), and T-peak to T-end (Tp-e; as an index of dispersion of repolarization). Repolarization indices were corrected to the heart rate by Bazett's method (QTc, c-QTp, c-Tp-e). RESULTS: Amiodarone suppressed VT/VF in 19/27 (70%) patients without conferring any proarrhythmic effect. The QTc, c-QTp, and R-R interval were significantly prolonged during amiodarone (476±45ms vs 511±45ms, p<0.05; 338±40ms vs 364±35ms, p<0.05; 762±272ms vs 870±189ms, p<0.05; respectively), whereas the c-Tp-e and QRS durations did not change significantly (139±33ms vs 145±41ms, p=0.25; 96±20ms vs 97±21ms, p=0.33; respectively). CONCLUSIONS: Iv-Amio homogeneously prolongs repolarization and properly inhibits original VT/VF recurrence without inducing torsade de pointes.

Efficacy and feasibility of the submuscular implantation technique for an implantable cardiac electrical device.

BACKGROUND: A common complication associated with implantable cardiac electrical device implantation compromises skin lesions caused by overstretching just above a buried device that is relatively large in size. Apart from affecting the cosmetic appearance in some patients, a compromised blood supply to the skin may also lead to ischemic necrosis, which is an important complication. We describe a novel procedure for the implantation of implantable cardiac electrical devices generators under the pectoralis major muscle to avoid such skin-related complications. METHODS: Twenty-one patients were referred to plastic surgeon for surgical support for the secondary replacement of implantable cardiac electrical devices. In all cases, the leads and devices had been implanted under the skin. We decided to perform device implantation under the pectoralis major muscle, which was highly recommended in all these patients. RESULTS: In Japan, leanness is determined on the basis of body mass index less than 18.5, and 11 patients out of 21 (52%) were considered to be lean. The surgeon's participation in the procedure for implantable cardiac electrical device implantation did not exceed 5 minutes in total. CONCLUSIONS: We consider that the novel method of sub-pectoralis major muscle device implantation described here minimizes the risk of the skin breakdown and improves the patient's quality of life.

Electrical storm in patients with brugada syndrome is associated with early repolarization.

BACKGROUND: Electrical storms (ESs) in patients with Brugada syndrome (BrS) are rare though potentially lethal. METHODS AND RESULTS: We studied 22 men with BrS and ES, defined as ≥3 episodes/d of ventricular fibrillation (VF) and compared their characteristics with those of 110 age-matched, control men with BrS without ES. BrS was diagnosed by a spontaneous or drug-induced type 1 pattern on the ECG in the absence of structural heart disease. Early repolarization (ER) was diagnosed by J waves, ie, >0.1 mV notches or slurs of the terminal portion of the QRS complex. The BrS ECG pattern was provoked with pilsicainide. A spontaneous type I ECG pattern, J waves, and horizontal/descending ST elevation were found, respectively, in 77%, 36%, and 88% of patients with ES, versus 28% (P<0.0001), 9% (P=0.003), and 60% (P=0.06) of controls. The J-wave amplitude was significantly higher in patients with than without ES (P=0.03). VF occurred during undisturbed sinus rhythm in 14 of 19 patients (74%), and ES were controlled by isoproterenol administration. All patients with ES received an implantable cardioverter defibrillator and over a 6.0±5.4 years follow-up, the prognosis of patients with ES was significantly worse than that of patients without ES. Bepridil was effective in preventing VF in 6 patients. CONCLUSIONS: A high prevalence of ER was found in a subgroup of patients with BrS associated with ES. ES appeared to be suppressed by isoproterenol or quinidine, whereas bepridil and quinidine were effective in the long-term prevention of VF in the highest-risk patients.