Ken Takarada

J-waves in patients with an acute ST-elevation myocardial infarction who underwent successful percutaneous coronary intervention: prevalence, pathogenesis, and clinical implication

AIMS The prevalence, clinical significance, and pathogenesis of J-waves were studied in the patients with an ST-elevation myocardial infarction (MI) after percutaneous coronary intervention (PCI). METHODS AND RESULTS One hundred and fifty-two consecutive patients with an acute ST-elevation MI were included. The mean age was 68.6 ± 13.5 years, and 78.3% of the patients were male. Following successful PCI, 12-lead electrocardiograms (ECGs) were monitored, and J-waves were measured 1 week after the MI and analysed in relation to the location of the MI and arrhythmias. Clinical and ECG parameters were compared between the groups with and without J-waves. The rate dependency of the J-wave amplitude was analysed in the conducted atrial premature beats (APBs). J-waves were present in 60.5% (≥0.1 mV) or 48.9% (≥0.2 mV) of the 152 patients. The J-waves were more often located in the inferior leads and more frequently in an inferior MI. The presence of J-waves was associated with ventricular arrhythmias, including ventricular fibrillation. The J-wave amplitude increased in the conducted APB, mechanistically suggesting a phase 3 block. CONCLUSION Many patients in the early recovery phase after an acute MI had J-waves. This ECG phenomenon was associated with an increased incidence of ventricular arrhythmias. The tachycardia-dependent augmentation of the J-wave amplitude suggested a mechanistic role of conduction delay.

Second-generation cryoballoon ablation without the use of real-time recordings: A novel strategy based on a temperature-guided approach to ablation

BACKGROUND The achievement of -40°C within the first 60 seconds during cryoenergy applications has proven to independently predict durable pulmonary vein (PV) isolation in the setting of second-generation cryoballoon (CB-A; Medtronic, Minneapolis, MN) ablation. OBJECTIVE We sought to evaluate a strategy based on the attainment of the specific parameter of -40°C within the first 60 seconds during cryoenergy applications in the setting of CB-A ablation without the use of an inner lumen mapping catheter (Achieve, Medtronic) for the visualization of real-time recordings. METHODS A total of 52 patients having undergone CB ablation for paroxysmal atrial fibrillation (AF) between 1 February 2015 and 30 June 2015 who underwent a temperature-guided approach based on achieving -40°C within 60 seconds without real-time recordings (wire group) were compared with a cohort of 52 propensity score-matched patients having undergone CB ablation performed with an inner lumen mapping catheter (Achieve group). All PVs were checked for electrical isolation at the end of the procedure with a circular mapping catheter in the wire group. RESULTS Electrical isolation could be obtained in all patients in the Achieve group and in 99% of PVs in the wire group. Freedom from AF without antiarrhythmic drugs at a mean follow-up of 12.4 ± 3.0 months did not significantly differ between both groups (85% vs 88%, respectively; P = .56). CONCLUSION A temperature-guided approach based on achieving -40°C within 60 seconds is effective in producing PV isolation and affords freedom from AF at 12-month follow-up in 85% of patients affected by paroxysmal AF after a 3-month blanking period.

The association between obesity and acute myocardial infarction is age- and gender-dependent in a Japanese population

Controversies concerning the association between obesity and acute myocardial infarction (AMI) are still ongoing in Japan. We investigated the association between obesity defined by body mass index of 25 kg/m2 or higher and AMI by a case–control study using data from 1199 AMI cases and 4056 apparently healthy controls. The analysis was performed in age- and sex-matched samples of 621 case–control pairs younger than 80 years and in crude samples aged 40–79 years divided into 10-year age groups. Prevalence of obesity, diabetes, current smoking, hypertension, and hypercholesterolemia were compared between cases and controls, and a multivariable odds ratio (OR) of AMI was calculated for each risk factor in various age groups. The OR (95 % confidence interval (CI)) of AMI for obesity was 1.63 (1.23–2.17), P = 0.0008 in men younger than 80 years; 2.65 (1.41–5.00), P = 0.0025 in women younger than 80 years; 2.23 (1.46–3.41), P = 0.0002 in men aged 59 years or younger; 1.34 (0.90–2.01), P = 0.1510 in men aged 60–79 years; and 2.98 (1.56–5.71), P = 0.0010 in women aged 60–79 years using paired samples. The OR (95 % CI) of AMI for obesity was 4.92 (2.53–9.58), P < 0.0001 in men aged 40–49 years; 1.54 (1.07–2.21), P = 0.0197 in men aged 50–59 years; 1.07 (0.69–1.66), P = 0.7717 in men aged 60–69 years; 2.24 (1.20–4.20), P = 0.0118 in men aged 70–79 years; 2.48 (1.12–5.48), P = 0.0245 in women aged 60–69 years; and 3.05 (1.46–6.37), P = 0.0029 in women aged 70–79 years using crude samples. The association between obesity and AMI was age- and gender-dependent in a Japanese population.

Efficacy and safety of the second generation cryoballoon ablation for the treatment of paroxysmal atrial fibrillation in patients over 75 years: a comparison with a younger cohort

Aims In this double centre, retrospective study, we aimed to analyse the 1-year efficacy and safety of cryoballoon ablation (CB-A) in patients older than 75 years compared with those younger than 75-years old. Methods and results Fifty-three consecutive patients aged 75 years or older with drug-resistant paroxysmal AF (PAF) who underwent pulmonary vein isolation (PVI) by the means of second generation CB-A, were compared with 106 patients aged <75 years. The mean age in the study group (>75 years) was 78.19 ± 2.7 years and 58.97 ± 8.5 in the control group. At 1-year follow-up the global success rate was 83.6% and did not significantly differ between older (10/53) and younger patients (16/106) (81.1 vs. 84.9%, P = 0.54). Transient phrenic nerve palsy was the most common complication which occurred in eight patients in the younger group and in three in the older group (7.5 vs. 5.7%, respectively, P = 0.66). Conclusions The results of our study showed that CB-A for the treatment of PAF is a feasible and safe procedure in elderly patients, with similar success and complications rates when compared with a younger population.

Role of Electrocardiographic Tpeak-Tend for the Prediction of Ventricular Arrhythmic Events in the Brugada Syndrome

Some previous studies have proposed the electrocardiographic Tpeak-Tend (TpTe) as a possible predictor of ventricular arrhythmic events in patients with Brugada syndrome (BrS). We sought to analyze the association between the parameters of repolarization dispersion (TpTe, TpTe/QT, TpTe dispersion, QTc, and QTd) and ventricular fibrillation/sudden cardiac death in a large cohort of patients with type 1 BrS. A total of 448 consecutive patients with BrS (men 61%, age 45 ± 16 years) with spontaneous (n = 96, 21%) or drug-induced (n = 352, 79%) type 1 electrocardiogram were retrospectively included. At the time of the diagnosis or during a mean follow-up of 93 ± 47 months (median 88 months), 43 patients (9%) documented ventricular arrhythmias. No significant difference was observed in TpTe, TpTe/QT, maximum TpTe, and TpTe dispersion between asymptomatic patients and those with syncope and malignant arrhythmias. TpTe/QT ratio did not also significantly differ between patients with ventricular fibrillation/sudden cardiac death and those asymptomatic ones. In conclusion, TpTe was not significantly prolonged in those patients with type 1 BrS presenting with unexplained syncope or malignant arrhythmic events during follow-up.

Long-term outcome of pulmonary vein isolation in patients with paroxysmal atrial fibrillation and Brugada syndrome

Aims The therapeutical management of atrial fibrillation (AF) in the setting of Brugada syndrome (BS) might be challenging as many antiarrhythmic drugs (AADs) with sodium channel blocking properties might lead to to the development of ventricular arrhythmias. This study sought to evaluate the clinical outcome in a consecutive series of patients with BS having undergone pulmonary vein (PV) isolation by means of radiofrequency (RF) or cryoballoon (CB) ablation and the efficacy of catheter ablation for preventing inappropriate interventions delivered by implantable cardioverter defibrillators (ICD) on a 3-year follow up. Methods and results Twenty-three consecutive patients with BS (13 males; mean age was 47 ± 18 years) having undergone PV isolation for drug-resistant paroxysmal AF were enrolled. Eleven patients (48%) had an ICD implanted of whom four had inappropriate shocks secondary to rapid AF. Over a mean follow-up period of 35.0 ± 25.4 months (median 36 months) the freedom from AF recurrence after the index PV isolation procedure was 74% without AADs. Patients with inappropriate ICD interventions for AF did not present futher ICD shocks after AF ablation. No major complications occurred. Conclusion Catheter ablation is a valid therapeutic choice for patients with BS and paroxysmal AF considering the high success rates, the limitations of the AADs and the safety of the procedure, and it should be taken into consideration especially in those patients presenting inappropriate ICD shocks due to rapid AF.

Single freeze per vein strategy with the second-generation cryoballoon for atrial fibrillation: a propensity score-matched study between 180- and 240-s application time in a large cohort of patients

Aims The single-freeze strategy using the second-generation cryoballoon (CB-A, Arctic Front Advance, Medtronic, Minneapolis, MN, USA) has been reported to be as effective as the recommended double-freeze approach in several single-centre studies. In this retrospective, international, multicentre study, we compare the 3-min single-freeze strategy with the 4-min single-freeze strategy. Methods and results Four hundred and thirty-two patients having undergone pulmonary vein isolation (PVI) by means of CB-A using a single-freeze strategy were considered for this analysis. A cohort of patients who were treated with a 3-min strategy (Group 1) was compared with a propensity score-matched cohort of patients who underwent a 4-min strategy (Group 2). Pulmonary vein isolation was successfully achieved in all the veins using the 28-mm CB-A. The procedural and fluoroscopy times were lower in Group 1 (67.8 ± 17 vs. 73.8 ± 26.3, P < 0.05; 14.9 ± 7.8 vs. 24.2 ± 10.6 min, P < 0.05). The most frequent complication was PNP, with no difference between the two groups (P = 0.67). After a mean follow-up of 13 ± 8 months, taking into consideration a blanking period of 3 months, 85.6% of patients in Group 1 and 87% of patients in Group 2 were free from arrhythmia recurrence at final follow-up (P = 0.67). Conclusion There is no difference in acute success, rate of complications, and freedom from atrial fibrillation recurrences during the follow-up between 3-min and 4-min per vein freeze strategies. The procedural and fluoroscopy times were significantly shorter in 3-min per vein strategy.

Dynamicity of J waves during coronary intervention and angiography in a patient with non-Q inferior myocardial infarction

Slurs or notches at the terminal portion of the QRS complexes are called J waves, which may be associated with myocardial ischemia. We describe our experience with a case of a patient with acute inferior myocardial infarction in whom J waves were observed in the inferior leads with ST‐segment elevation. The coronary artery was completely occluded, and during percutaneous intervention, ST‐segment elevation was normalized first, followed by the disappearance of the J waves after full revascularization. On follow‐up coronary angiography (CAG), the J waves in the inferior leads reappeared during the right CAG. The J waves were associated with an alteration of the electrical axis. J waves developing in association with myocardial ischemia seemed to be more sensitive to ischemia and might represent a depolarization abnormality.

Impact of an additional right pulmonary vein on second-generation cryoballoon ablation for atrial fibrillation: a propensity matched score study

PurposeCryoballoon (CB) technology in the context of anatomical pulmonary vein (PV) variants might hypothetically hamper successful PV isolation (PVI). Our aim was to assess the impact of a right middle PV (RMPV) in the setting of second-generation cryoballoon (CB advance—CB-A), on procedural parameters and on mid-term follow-up.MethodsConsecutive patients with AF presenting RMPV (RMPV+) at the pre-procedural computed tomography who underwent PVI by CB-A were enrolled. Comparison with propensity score-matched patients without RMPV (RMPV−) was performed. Acute procedural parameters and clinical follow-up were assessed.ResultsA total of 240 patients (80 RMPV+) were included in the analysis. Twelve of 80 (15%) RMPV+ patients underwent a direct cryo-application in this variant and accomplished the isolation without phrenic nerve palsy, whereas in 25 of 80 (31%) RMPV+ patients, the RMPVs were not targeted directly nor indirectly (by co-occlusion during application at a major PV). At a median follow-up of 17.3 [interquartile range 11.3–26.5] months, there was no significant difference in AF-free survival between RMPV+ and RMPV− patients (78.8 vs 78.1%, P = 1.00), and the recurrence of atrial arrhythmias among patients with versus without an intentional or indirect cryo-application to the RMPV was not different (22 vs 20%, P = 1.00).ConclusionsMid-term outcome after CB-A ablation did not differ between RMPV+ and RMPV− patients. Within RMPV+ patients, outcome was similar between those with versus without a cryo-application (either direct or indirect) to the additional vein.

Continuous monitoring after second-generation cryoballoon ablation for paroxysmal atrial fibrillation in patients with cardiac implantable electronic devices

BACKGROUND The second-generation cryoballoon (CB) is effective in achieving pulmonary vein isolation. Continuous monitoring would eliminate any over- or underestimated freedom from atrial fibrillation (AF) postablation. OBJECTIVE The purpose of this study was to differentiate between arrhythmias occurring after cryoballoon ablation (CBA), detecting true AF in symptomatic patients and detecting silent subclinical AF. METHODS Between June 2012 and January 2015, 54 patients with a preexisting cardiac implantable electronic device (CIED) who had undergone CBA for paroxysmal atrial fibrillation (PAF) were included in our retrospective study. Regular CIED controls, physical examination, and ECG recordings were performed by an experienced cardiologist blinded to the ablation procedure. Data on any hospitalization during follow-up were gathered. Patients were encouraged to note all clinical symptoms during follow-up. RESULTS Continuous monitoring showed a success rate of 83.3% after 1 year and 75.93% after 3 years of follow-up. During the first year, 68% of episodes of palpitations after ablation were due to sinus tachycardia, nonsustained ventricular tachycardia, or supraventricular tachycardia. AF recurrence was detected in 15.6% of asymptomatic patients during follow-up. Total AF burden post-CBA had decreased to 0.64% ± 4.34% (P <.001) during long-term follow-up of 3.3 years. CONCLUSION Although this is a selected group of patients with a preexisting CIED, continuous monitoring showed freedom from AF in 83.3% of patients post-CBA after 1 year and 75.93% after 3 years of follow-up.