The coronary artery calcium score correlates with left atrial low-voltage area: Sex differences.

INTRODUCTION: In patients with coronary artery disease, a high coronary artery calcium score (CACS) correlates with atrial fibrillation (AF); however, the association between left atrial (LA) remodeling progression and coronary arteriosclerosis is unclear. This study aimed to evaluate the relationship between LA remodeling progression and the CACS. METHODS: This retrospective study enrolled 148 patients with AF (paroxysmal AF, n = 94) who underwent catheter ablation. Voltage mapping for the left atrium and coronary computed tomography for CACS calculations were performed. The ratio of the LA low-voltage area (LA-LVA), defined by values less than 0.5 mV divided by the total LA surface without pulmonary veins, was calculated. Patients with LA-LVA (<0.5 mV) >5% and ≤5% were classified as the LVA (n = 30) and non-LVA (n = 118) groups, respectively. Patient characteristics and CACS values were compared between the two groups. RESULTS: LA volume, age, CHA2 DS2 VASc score, and percentage of female patients were significantly higher, and the estimated glomerular filtration rate was lower in the LVA group than in the non-LVA group. The CACS was significantly higher in the LVA group (248.4 vs. 13.2; p = .001). Multivariate analysis identified the LA volume index and CACS as independent predictors of LA-LVA (<0.5 mV) greater than 5%. The areas under the receiver operating characteristic curves for predicting LA-LVA (<0.5 mV) greater than 5% with CACS were 0.695 in the entire population, 0.782 in men, and 0.587 in women. CONCLUSION: Progression of LA remodeling and coronary artery calcification may occur in parallel. A high CACS may indicate advanced LA remodeling, especially in men.

Quality of life improvements by durable pulmonary vein isolation in patients with atrial fibrillation.

INTRODUCTION: Successful pulmonary vein isolation (PVI) can improve the quality of life (QOL) of patients with atrial fibrillation (AF). However, the role of durable PVI for such QOL improvement is not known. The aim of this study was to clarify the effectiveness of durable PVI in improving the QOL of patients with AF. METHODS AND RESULTS: We assessed 119 patients who underwent PVI (age 66.4 ± 9.6 years, 104 paroxysmal AF). A scheduled electrophysiological study was performed 6 months after the first PVI session-regardless of recurrence of AF-to assess the durability of PVI and to identify and re-isolate reconnected pulmonary veins. QOL scores were evaluated by an AF-specific QOL questionnaire and checked at baseline, 6 months, and 1 year after the first session. In patients without AF recurrence (nonrecurrence group, n = 93), the scores at 6 months improved compared with those at baseline; conversely, the scores did not improve in patients with AF recurrence (n = 26). Nevertheless, the scores at 1 year improved compared with those at 6 months in both groups. Within the nonrecurrence group, the score difference between 6 months and baseline was higher in the durable PVI group (n = 58) than that in the nondurable PVI group (n = 35). CONCLUSIONS: The QOL of AF patients improved by the resumption of sinus rhythm following PVI. Patients with durable PVI had increased QOL scores compared with those with nondurable PVI. The durability of PVI may achieve further improvements in the QOL of patients with AF.

Comparison of touch-up ablation rate and pulmonary vein isolation durability between hot balloon and cryoballoon.

INTRODUCTION: This study aimed to compare touch-up ablation (TUA) rates and pulmonary vein isolation (PVI) durability of hot balloon ablation (HBA) and cryoballoon ablation (CBA) in paroxysmal atrial fibrillation (PAF) patients. METHODS: In total, 137 PAF patients were enrolled in the study. Among them, 59 underwent two HBA procedures at 6-month intervals and 78 patients underwent two CBA sessions, both regardless of atrial fibrillation recurrence. Propensity score matching was performed to estimate similar patient characteristics between the HBA and CBA groups. RESULTS: Each group comprised of 46 matched patients for comparison. The TUA rate at the first session was higher for HBA (49 of 184 PVs) than for CBA (20 PVs) (P = .01), with the highest incidence at the left superior pulmonary vein (LSPV). The rates of PVI durability at the second session performed 7 months later were similar between HBA (168 of 184 PVs) and CBA (162 PVs) groups. The PVI durability rate at the TUA sites of the first session was higher for HBA than for CBA (41 of 49 PVs vs 10 PVs, respectively; P = .01). Fifty percent of the patients underwent HBA at 73°C for the LSPV. HBA performed at 73°C yielded a lower TUA rate than that at 70°C (16 of 23 PVs vs 7 of 23 PVs; P = .008). CONCLUSIONS: While PVI durability was similar between HBA and CBA, the TUA rate was higher for HBA than for CBA, especially on the LSPV. For LSPV, HBA at a balloon temperature of 73°C may reduce the TUA rate.

Characteristics of ventricular intracardiac electrograms of ventricular tachycardias originating from the epicardia in patients with an implantable cardioverter defibrillator.

INTRODUCTION: While characteristic waveforms of 12-lead electrocardiograms have been reported to predict the epicardial origin of ventricular tachycardia (VT), it has not been fully examined whether ventricular intracardiac electrograms (VEGMs) recorded from the implantable cardioverter defibrillator (ICD) via telemetry can determine the origin of VT or not. The aim of this study was to investigate the VEGM characteristics of VT originating from the epicardia. METHOD AND RESULTS: Intracardiac VEGMs of the induced VTs, with detected sites of origin during the VT study, were recorded in 15 (23 VTs) of the 46 patients. The characteristics of the 23 VTs were evaluated using far-field and near-field VEGMs recorded via telemetry. Five of 23 VTs were found to be focused on the epicardial site (epi group) and 18 VTs were focused on the endocardium (endo group). VTs of the epi group had longer VEGM duration in far-field EGM than those of the endo group (epi group: 240 ± 49 ms vs endo group: 153 ± 45 ms; P = 0.002) and the duration from the onset to the peak of VEGM was also longer than that of the endo group (epi group: 153 ± 53 ms vs endo group: 63 ± 28 ms; P < 0.001). There was no difference in the V wave duration in tip-ring EGM between both groups (epi group: 122 ± 52 ms vs endo group: 98 ± 6 ms; P = 0.377). CONCLUSION: Evaluation of intracardiac VEGM before VT ablation may be helpful to predict the epicardial origin of VT in patients with an ICD.

Genotype-Phenotype Correlation of SCN5A Mutation for the Clinical and Electrocardiographic Characteristics of Probands With Brugada Syndrome: A Japanese Multicenter Registry.

BACKGROUND: The genotype-phenotype correlation of SCN5A mutations as a predictor of cardiac events in Brugada syndrome remains controversial. We aimed to establish a registry limited to probands, with a long follow-up period, so that the genotype-phenotype correlation of SCN5A mutations in Brugada syndrome can be examined without patient selection bias. METHODS: This multicenter registry enrolled 415 probands (n=403; men, 97%; age, 46±14 years) diagnosed with Brugada syndrome whose SCN5A gene was analyzed for mutations. RESULTS: During a mean follow-up period of 72 months, the overall cardiac event rate was 2.5%/y. In comparison with probands without mutations (SCN5A (-), n=355), probands with SCN5A mutations (SCN5A (+), n=60) experienced their first cardiac event at a younger age (34 versus 42 years, P=0.013), had a higher positive rate of late potentials (89% versus 73%, P=0.016), exhibited longer P-wave, PQ, and QRS durations, and had a higher rate of cardiac events (P=0.017 by log-rank). Multivariate analysis indicated that only SCN5A mutation and history of aborted cardiac arrest were significant predictors of cardiac events (SCN5A (+) versus SCN5A (-): hazard ratio, 2.0 and P=0.045; history of aborted cardiac arrest versus no such history: hazard ratio, 6.5 and P<0.001). CONCLUSIONS: Brugada syndrome patients with SCN5A mutations exhibit more conduction abnormalities on ECG and have higher risk for cardiac events.

Usefulness of epicardial impedance evaluation for epicardial mapping and determination of epicardial ablation site for ventricular tachycardia: A pilot study.

BACKGROUND: During epicardial mapping, determination of appropriate ablation sites in low voltage areas (LVA) is challenging because of large epicardial areas covered by adipose tissue. OBJECTIVE: To evaluate the impedance difference between epicardial fat and the epicardial LVA using multiple detector computed tomography (MDCT). METHODS: We enrolled patients who underwent ventricular tachycardia (VT) ablation via the epicardial approach after endocardial ablation failure. After the procedure, MDCT-derived images of epicardial fat were loaded to the mapping system. Then, all points acquired during sinus rhythm were retrospectively superimposed and analyzed. RESULTS: This study included data from 7 patients (62.5 ± 3.9 years old) who underwent eight epicardial VT ablation procedures. After the procedure, MDCT-derived images of epicardial fat were registered in eight procedures. Retrospective analysis of 1,595 mapping and 236 ablation points was performed. Of the 1,595 mapping points on the merged electroanatomical and epicardial fat maps, normal voltage area (NVA) and low voltage area (LVA) without fat had lower impedance than those with fat (NVA without fat 182 ± 46 Ω vs. NVA with fat 321 ± 164.0 Ω, P  =  0.001, LVA without fat 164 ± 69 Ω vs. LVA with fat 248 ± 89 Ω, P  =  0.002). Of the 236 ablation points, initial impedance before ablation was higher on epicardial fat than on epicardial LVA without fat (134 ± 16 Ω vs. 156 ± 28 Ω, P  =  0.01). CONCLUSIONS: Real time epicardial impedance evaluation may be useful to determine effective epicardial ablation sites and avoid adipose tissue. However, the number of patients in the present study is limited. Further investigation with a large number of patients is needed to confirm our result.

Life-Threatening Ventricular Arrhythmia and Brugada-Type ST-Segment Elevation Associated With Acute Ischemia of the Right Ventricular Outflow Tract.

BACKGROUND: Brugada-type ECG (Br-ECG) is occasionally observed during acute myocardial ischemia of the right ventricular outflow tract (RVOT). No studies have explored, however, the association of ventricular tachyarrhythmia and development of Br-ECG due to acute ischemia of the RVOT.Methods and Results:The study included 13 consecutive patients with acute ischemia of the RVOT during coronary catheterization. Patients were divided into 2 groups: those with Br-ECG (group B) and those without (group N). The proportion of male patients was higher in group B than in group N (100% vs. 25%, P<0.01), and VT/VF developed in only patients with Br-ECG (group B). In group B, VT/VF was observed in patients without pre-existing organic change in the conus/right ventricular (RV) branch of the right coronary artery and no VT/VF was seen in patients with organic coronary stenosis despite Br-ECG. CONCLUSIONS: Acute myocardial ischemia of the RVOT caused Br-ECG predominantly in male patients and subsequent development of VT/VF in some patients. VT/VF was seen in patients without any obstructive lesion but arrhythmic events were not observed in RVOT ischemia in the case of pre-existing coronary occlusion or stenosis of the conus or RV branch, suggesting the effects of precondition.

Sodium Bicarbonate-Ascorbic Acid Combination for Prevention of Contrast-Induced Nephropathy in Chronic Kidney Disease Patients Undergoing Catheterization.

BACKGROUND: Sodium bicarbonate and ascorbic acid have been proposed to prevent contrast-induced nephropathy (CIN). The present study evaluated the effect of their combined use on CIN incidence.Methods and Results:We prospectively enrolled 429 patients with chronic kidney disease (CKD: baseline estimated glomerular filtration rate <60 mL/min/1.73 m2) prior to elective coronary catheterization. CIN was defined as absolute (≥0.5 mg/dL) or relative (≥25%) increase in serum creatinine within 72 h. In the saline hydration (n=218) and combined sodium bicarbonate+ascorbic acid (n=211) groups, a total of 1,500-2,500 mL 0.9% saline was given before and after the procedure. In addition, the combination group received 20 mEq sodium bicarbonate and 3 g ascorbic acid i.v. before the procedure, followed by 2 g ascorbic acid after the procedure and a further 2 g after 12 h. There were no significant differences between the basic characteristics and contrast volume in the 2 groups. CIN occurred in 19 patients (8.7%) in the saline group, and in 6 patients (2.8%) in the combined treatment group (P=0.008). CONCLUSIONS: Combined sodium bicarbonate and ascorbic acid could prevent CIN following catheterization in CKD patients.

Genetic defects in a His-Purkinje system transcription factor, IRX3, cause lethal cardiac arrhythmias.

AIM: Ventricular fibrillation (VF), the main cause of sudden cardiac death (SCD), occurs most frequently in the acute phase of myocardial infarction: a certain fraction of VF, however, develops in an apparently healthy heart, referred as idiopathic VF. The contribution of perturbation in the fast conduction system in the ventricle, the His-Purkinje system, for idiopathic VF has been implicated, but the underlying mechanism remains unknown. Irx3/IRX3 encodes a transcription factor specifically expressed in the His-Purkinje system in the heart. Genetic deletion of Irx3 provides a mouse model of ventricular fast conduction disturbance without anatomical or contraction abnormalities. The aim of this study was to examine the link between perturbed His-Purkinje system and idiopathic VF in Irx3-null mice, and to search for IRX3 genetic defects in idiopathic VF patients in human. METHODS AND RESULTS: Telemetry electrocardiogram recording showed that Irx3-deleted mice developed frequent ventricular tachyarrhythmias mostly at night. Ventricular tachyarrhythmias were enhanced by exercise and sympathetic nerve activation. In human, the sequence analysis of IRX3 exons in 130 probands of idiopathic VF without SCN5A mutations revealed two novel IRX3 mutations, 1262G>C (R421P) and 1453C>A (P485T). Ventricular fibrillation associated with physical activities in both probands with IRX3 mutations. In HL-1 cells and neonatal mouse ventricular myocytes, IRX3 transfection up-regulated SCN5A and connexin-40 mRNA, which was attenuated by IRX3 mutations. CONCLUSION: IRX3 genetic defects and resultant functional perturbation in the His-Purkinje system are novel genetic risk factors of idiopathic VF, and would improve risk stratification and preventive therapy for SCD in otherwise healthy hearts.

Early repolarization pattern and its day-to-day dynamic change as markers for ventricular fibrillation in patients with vasospastic angina.

AIMS: An early repolarization (ER) pattern is a risk factor for ventricular fibrillation (VF) in certain diseases. However, it is unclear whether this association holds for patients with vasospastic angina (VSA). Moreover, the reported long-term follow-up of implantable cardioverter defibrillator (ICD) therapy for VSA patients is limited to 3 years. This study aimed to clarify the relation between ER and VF in patients with VSA and to investigate the long-term outcomes of ICD therapy. METHODS AND RESULTS: This retrospective, observational survey evaluated 265 consecutive VSA patients, including 21 with VF. Their electrocardiogram findings and clinical course were analysed over a mean follow-up of 5.5 ± 3.3 years. Early repolarization was observed in 64 patients (24.2%) and was more frequent in patients with VF history than those without (P = 0.001). Early repolarization was independently associated with VF history. During follow-up, four patients had VF recurrences. Ventricular fibrillation recurrence was higher in patients with ER (log-rank, P = 0.018) or VF history (log-rank, P < 0.001) than those without. Among patients with ER, day-to-day variations in ER (P = 0.003) and notching of ER pattern (P = 0.03) were associated with VF history. Cases with day-to-day variation showed a higher incidence of VF recurrence during follow-up (log-rank, P = 0.007). During long-term follow-up, 23.5% of patients with an ICD received appropriate shock therapy. CONCLUSION: The presence of ER, especially with day-to-day variation, can help predict VF recurrence in VSA patients. Implantable cardioverter defibrillator implantation is a reasonable approach for the secondary prevention of VF in high-risk VSA patients.

Transient sinus node dysfunction following sinus node artery occlusion due to radiofrequency catheter ablation of the septal superior vena cava-right atrium junction.

We performed catheter ablation to septal superior vena cava (SVC)-right atrium (RA) junction rapid firing in a 57-year-old man with paroxysmal atrial fibrillation. He later experienced transient sinus node dysfunction resulting from injury to the sinus node artery (SNA), which branched only from the proximal region of the left circumflex artery. The direction of the SNA should be considered during catheter ablation at the septal SVC-RA junction, especially if the sinus node is supplied by only one SNA from the right coronary artery or the left circumflex artery.

Unmasking Brugada-type electrocardiogram on deep inspiration.

BACKGROUND: Electrocardiogram (ECG) recorded at the upper intercostal lead positions is recommended as an additional diagnostic clue for Brugada syndrome (BrS), but similar recording conditions to unmask ECG signs have not been explored. METHODS AND RESULTS: We evaluated the diagnostic usefulness for unmasking ECG signs of BrS using recordings at the upper intercostal lead position, on deep inspiration and on standing. In 34 patients (mean age, 49±14 years; 30 male) with diagnosed and suspected BrS, ECG type and ST-elevation in leads V1-V3 recorded at a higher position by 1 rib from the standard position (3ICS), and at standard lead positions (4ICS) on deep inspiration (DI test) and on standing (Stand test) were compared with the conventional lead positions (baseline). While type 1 ECG had been documented in 17 of 34 patients on at least 1 occasion in the past, only 4 had the sign at baseline during the study. Twenty patients had type 1 on 3ICS recording, 18 on DI test, and 6 on Stand test. Among 17 patients without previous documentation of spontaneous type 1, 7 had type 1 on 3ICS recording, 6 on DI test, and 1 on Stand test. CONCLUSIONS: ECG recording on deep inspiration is useful to unmask diagnostic signs of BrS and has similar accuracy to 3ICS recording.

J wave and fragmented QRS formation during the hyperacute phase in Takotsubo cardiomyopathy.

BACKGROUND: The J wave and fragmented QRS (fQRS) on electrocardiography are suggested to be closely related to cardiac arrhythmogenesis. Takotsubo cardiomyopathy (TTC) occasionally causes fatal cardiac conditions including life-threatening ventricular arrhythmia. There has been, however, only 1 case report describing the J wave in TTC, and fQRS has not been reported thus far in relation to clinical courses and prognosis. METHODS AND RESULTS: J wave and fQRS formation were investigated in 31 consecutive patients with TTC. Nine patients (29%) had J waves and/or fQRS (group A), whereas the remaining 22 did not (group B). The J wave (4 patients), fQRS (4 patients), or both (1 patient) appeared transiently during the hyperacute phase. Left ventricular ejection fraction was significantly lower in group A. Summed defect score of single-photon emission computed tomography using iodine 123 beta-methyl-p-iodophenyl-pentadecanoic acid, and creatine kinase MB isozyme (CKMB) were significantly higher in group A. On multivariate analysis CKMB was a significant indicator of J wave or fQRS. Moreover, the J wave was a significant indicator for cardiac death and/or ventricular tachyarrhythmia (odds ratio, 11.5; P=0.026). CONCLUSIONS: Patients with TTC frequently had J waves and/or fQRS during the hyperacute phase, and which were associated with myocardial damage. J wave was also an indicator for cardiac death and/or ventricular tachyarrhythmia. J waves and fQRS may be useful markers for myocardial damage.

Clinical effectiveness of tolvaptan in patients with acute decompensated heart failure and renal failure: design and rationale of the AQUAMARINE study.

PURPOSE: Over half of all admitted acute decompensated heart failure (ADHF) patients have renal failure. Although diuretics represent the mainstay of treatment strategy even in this population, there are unmet needs for safer and more effective treatment. Tolvaptan is a vasopressin-2 receptor antagonist, and we hypothesized that adding tolvaptan to standard diuretic therapy would be more effective in ADHF patients with renal function impairment. METHODS: The Answering question on tolvaptan's efficacy for patients with acute decompensated heart failure and renal failure (AQUAMARINE) is a multicenter, randomized controlled clinical trial, which will enroll 220 patients from 17 hospitals in Japan. ADHF patients whose estimated glomerular filtration rate is above 15 and below 60 mL/min/1.72 m(2) will be randomly assigned within 6 h after admission to usual care with furosemide or tolvaptan add-on therapy. Primary endpoint is achieved urine output within 48 h. Secondary endpoints include dyspnea relief measured by 7-points Likert scale, incidence of worsening renal function, dose of furosemide used within 48 h, and changes of brain natriuretic peptide. CONCLUSION: This study is the first multicenter study in Japan to evaluate clinical effectiveness of tolvaptan add-on therapy in ADHF patients with renal failure. The results of this study address the treatment strategy of this high-risk population (UMIN Clinical Trial Registry Number: UMIN000007109).

Ablation of swallowing-induced atrial tachycardia affects heart rate variability: a case report.

A 47-year-old man underwent slow pathway ablation for slow-fast atrioventricular nodal reentrant tachycardia. Following the procedure, he felt palpitations while swallowing, and swallowing-induced atrial tachycardia was diagnosed. Swallowing-induced atrial tachycardia arose from the right atrium-superior vena cava junction and was cured by catheter ablation. After the procedure, the patient's heart rate variability changed significantly, indicating suppression of parasympathetic nerve activity. In this case, swallowing-induced atrial tachycardia was related to the vagal nerve reflex. Analysis of heart rate variability may be helpful in elucidating the mechanism of swallowing-induced atrial tachycardia.

Macroreentrant atrial tachycardia in patients without previous atrial surgery or catheter ablation: clinical and electrophysiological characteristics of scar-related left atrial anterior wall reentry.

INTRODUCTION: Macroreentrant atrial tachycardia (MRAT) has been described most frequently in patients with prior cardiac surgery. Left atrial tachycardia and flutter are common in patients who undergo atrial fibrillation ablation; however, few reports describe left atrial MRAT involving the regions of spontaneous scarring. Here, we describe left atrial MRAT in patients without prior cardiac surgery or catheter ablation (CA) and discuss the clinical and electrophysiological characteristics of tachycardia and outcome of CA. METHODS AND RESULTS: An electrophysiological study and CA were performed in 6 patients (3 men; age 76 ± 6 years) with MRAT originating from the left atrial anterior wall (LAAW). No patient had a history of cardiac surgery or CA in the left atrium. Spontaneous scars (areas with bipolar voltage ≤ 0.05 mV) were observed in all patients. The activation map showed a figure-eight circuit with loops around the mitral annulus (4 counterclockwise and 2 clockwise) and a low-voltage area with LAAW scarring. The mean tachycardia cycle length was 303 ± 49 milliseconds. The conduction velocity was significantly slower in the isthmus between the scar in the LAAW and the mitral annulus than in the lateral mitral annulus (0.17 ± 0.05 m/s vs 0.94 ± 0.35 m/s; P = 0.003). Successful ablation of the isthmus caused interruption of the tachycardia and rendered it noninducible in all patients. CONCLUSION: Spontaneous LAAW scarring is an unusual cause of MRAT, showing activation patterns with a figure-eight configuration. Radiofrequency CA is a feasible and effective treatment in such cases.

Coronary artery fistula with a giant aneurysm treated by percutaneous transradial embolization.

Coronary artery fistulas are rare anomalies that are very rarely accompanied by an aneurysm. The minimally invasive method of percutaneous transradial embolization, using a thin guiding catheter, was used to treat a coronary artery fistula with an associated giant aneurysm. This technique, not previously described for this type of application, is presented as a case report. The successful outcome of this procedure demonstrated that transradial coronary interventions are useful for treating coronary artery fistulas with an associated giant aneurysm, especially in patients at high risk for conventional surgery or transfemoral interventions.

Prevalence and electrophysiological characteristics of typical atrial flutter in patients with atrial fibrillation and chronic obstructive pulmonary disease.

AIMS: Chronic obstructive pulmonary disease (COPD) is one of the important underlying diseases of atrial fibrillation (AF). However, the prevalence and electrophysiological characteristics of typical atrial flutter (AFL) in patients with AF and COPD remain unknown. The purpose of the present study was to investigate those characteristics. METHODS AND RESULTS: We investigated 181 consecutive patients who underwent catheter ablation of AF. Twenty-eight patients were diagnosed with COPD according to the Global Initiatives for Chronic Obstructive Lung Disease (GOLD) criteria. Forty patients with no lung disease served as a control group. We analysed the electrophysiological characteristics in these groups. Typical AFL was more common in the COPD group (19/28, 68%) than in the non-COPD group (13/40, 33%; P = 0.006). The prevalence of AFL increased with the severity of COPD: 4 (50%) of 8 patients with GOLD1, 13 (72%) of 18 patients with GOLD2, and 2 (100%) of 2 patients with GOLD3. Atrial flutter cycle length and conduction time from the coronary sinus (CS) ostium to the low lateral right atrium (RA) during CS ostium pacing before and after the cavotricuspid isthmus ablation were significantly longer in the COPD group than in the non-COPD group (285 vs. 236, 71 vs. 53, 164 vs. 134 ms; P = 0.009, 0.03, 0.002, respectively). CONCLUSION: In COPD patients with AF, conduction time of RA was prolonged and typical AFL was commonly observed.