Sou Takenaka

Calorie restriction reduced blood pressure in obesity hypertensives by improvement of autonomic nerve activity and insulin sensitivity.

Summary: Association between obesity and hypertension has been well recognized. A reduction in the body weight of overweight hypertensive patients is a recommended lifestyle modification. The purpose of our study is to examine the relationship of insulin sensitivity and autonomic nervous activity with reduction of blood pressure by the calorie restriction. We evaluated the heart rate variability, nocturnal change of blood pressure and insulin resistance before and after a short‐term low‐calorie diet in 12 overweight essential hypertensives. After a week of standard diet (2000 kcal), 2 weeks of low‐calorie diet (800 kcal) with normal sodium content induced a significant reduction in body mass index, triglyceride, fasting immunoreactive protein, homeostasis model assessment as an index of insulin resistance, and urinary excretion of sodium and potassium. Systolic blood pressure was significantly reduced both in daytime and night‐time after the low‐calorie diet (daytime, 134.5 ± 6.0 to 122.0 ± 4.1 mmHg; night‐time, 126.8 ± 5.2 to 113.4 ± 7.2 mmHg). In daytime, diastolic blood pressure was also reduced (90.3 ± 2.1 to 88.1 ± 4.8 mmHg). Although heart rate was not significantly reduced, a rise of high frequency in night‐time (346 ± 82 to 572 ± 108 ms2) and a fall of low frequency/high frequency in daytime (3.5 ± 0.4 to 2.6 ± 0.1) was significant after a low‐calorie diet. In conclusion, weight loss by low‐calorie diet with a constant intake of sodium, reduced blood pressure in obese hypertensives by improvement of vagal nervous activity and insulin resistance.

The impact of lesion length and vessel size on outcomes after sirolimus-eluting stent implantation for in-stent restenosis

Objectives: We evaluated the predictors of recurrent restenosis and the impact of lesion length and vessel size on outcomes in patients treated with routine sirolimus-eluting stent (SES) implantation for in-stent restenosis (ISR) of bare-metal stent (BMS). Methods: In this study, 250 consecutive patients with 275 lesions after SES implantation for ISR of BMS were enrolled. Follow-up angiogram was obtained in 239 patients with 258 lesions eight months after implantation (follow-up rate: 95.6%). We compared characteristics of patients and lesions between the two groups (the recurrent restenosis group and the no-restenosis group). Results: Recurrent restenosis was angiographically documented in 43 lesions (16.7%). Recurrent restenosis was found in 30.4% with small vessel lesions (reference diameter of less than 2.5 mm, 92 lesions) and 23% with the diffuse type lesions (106 lesions). Seventy-two per cent of patients had a focal pattern of recurrent restenosis. Previously recurrent ISR lesions (odds ratio (OR) 1.94, 95% confidence interval (CI) 0.94 to 4.06, p = 0.05), reference diameter of less than 2.5 mm (OR 2.41, CI 1.05 to 5.41, p = 0.03), diffuse type restenosis (OR 4.48, CI 2.12 to 9.94, p = 0.0001) and dialysis patients (OR 4.72, CI 1.42 to 15.7, p = 0.01) were independent predictors of recurrent restenosis. Conclusions: Small vessels, diffuse type restenosis and dialysis patients were still the predictors of recurrent restenosis in patients treated with SES for ISR of BMS.

Non‐SCN5A Related Brugada Syndromes: Verification of Normal Splicing and Trafficking of SCN5A Without Exonic Mutations

Recently, it has been reported that under 20% of Brugada syndrome cases are linked to SCN5A mutations. The purpose of this study was to clarify whether abnormalities other than exonic mutations, such as splicing disorders, decreased mRNA expression levels, or membrane transport abnormalities of SCN5A, play a role in the pathogenesis of Brugada syndrome.

Coronary Sinus Morphology in Patients with Posteroseptal Atrioventricular Accessory Pathways

Background: There have been numerous reports about coronary sinus (CS) anomalies related to posteroseptal accessory pathways (APs). The purpose of this study was to explore the diameter and morphology of CS in patients with posteroseptal APs.

Progress of Sinus Bradycardia in Patients with Bradycardia-Tachycardia Syndrome: One-Year Follow-Up

Background and Objectives: The progression of sinus node dysfunction is believed slowly. In patients with permanent pacemaker for bradycardia-tachycardia syndrome, pacing should operate only during the periods of slow atrial and ventricular rates. Methods: We studied 10 consecutive patients who had received permanent pacemaker implantation for bradycardia-tachycardia syndrome. Serial changes in percentage of atrial pacing were evaluated at 1 month, 6 months and 12 months after the procedure. Results: Four of 10 patients required more than 90% pacing at 12 month follow-up. Two required less than 10% during the follow-up periods. In other 2 patients, percentage of atrial pacing was going up during the follow-up. One patient was shifted to atrial fibrillation. Conclusion: In patients with bradycardia-tachycardia patients, sinus bradycardia became also progressing.

Reverse Left Atrial Remodeling after Radiofrequency Catheter Ablation for Non-Paroxysmal Atrial Fibrillation

Background & Objectives: Restoration and maintenance of regular rhythm can be achieved by radiofrequency catheter ablation (RFCA) in patients with non-paroxysmal atrial fibrillation (non-PAF). However, it still remains undetermined whether this reversal is accompanied with amelioration of atrial function, which is associated with reduced risk of subsequent thromboembolic events. Methods: We studied 19 consecutive patients (age: 60±12 years) who had received RFCA for non-PAF. Serial changes in left atrial (LA) size and contraction were evaluated with echocardiography at baseline, 2 weeks, 3 months and 12 months after the procedure. Results: Fourteen of 19 patients had recovered and maintained regular rhythm during the follow-up. LA size and biplane volume index reduced over the time (p<0.01 and p<0.01, respectively). Atrial contractibility, assessed by time-velocity integral of atrial wave and atrial filling fraction (p<0.05 and p<0.05, respectively), was improved after the procedure. In addition, atrial compliance, assessed by peak systolic strain of LA inferior and septal wall (p<0.001 and p<0.001, respectively), was also improved over the time. These improvements of LA function were accompanied with that of left ventricular ejection fraction (p<0.001). Conclusion: Restoration and maintenance of regular rhythm achieved by RFCA was associated with reduction in atrial size and volume as well as improvement in contraction. Our findings may encourage usefulness of RFCA for non-PAF, expecting risk of reduction of subsequent thlomboembolic events.

Ventricular Premature Beats Originated from the Posterior Cardiac Vein

A 60-year-old male suffered from dyspnea on effort. He had a ventricular premature beats (VPCs) with QRS complex of right bundle branch morphology and superior axis, which resulting in a poor left ventricular function. The origin of these VPCs was the epicardium of left ventricular along the posterior cardiac vein. A Radiofrequency current delivery applied at that vein eliminated VPCs. He remained free of any arrhythmias after the procedure, and his left ventricular function was increasing.

Stent placement to stabilize the left ventricular lead in the coronary sinus

Recently, cardiac resynchronization therapy (CRT. has been established as an effective treatment for drug‐resistant heart failure with left ventricular dyssynchrony in patients with a New York Heart Association class (NYHA. of III‐IV. Many cases have already been treated with CRT in Japan, however, some challenges still remains, such as difficult placement of the left ventricular (LV. lead at the target site, high threshold values even after successful placement of the LV lead, and the need to reposition of the LV lead due to diaphragmatic stimulation regardless of an appropriate threshold value. In particular, those cases with high threshold values at a distal site or those in which the lead is placed at a proximal site because of diaphragmatic stimulation are prone to lead dislodgement, and re‐operation may be required. We report on a patient in whom stabilization of the LV lead was obtained by placing a coronary stent in the coronary sinus wall which resulted in an improved clinical course.

Pathological Findings of Cavotricuspid Isthmus Tissue Eighteen Days after Radiofrequency Catheter Ablation for Typical Atrial Flutter

A 75‐year‐old man with a prior myocardial infarction, who underwent a coronary artery bypass graft, suffered from typical atrial flutter. He underwent a cavotricuspid linear catheter ablation. Eighteen days after the ablation, he suddenly died. A transmural ablation line was created between the inferior vena cava and tricuspid annulus. Transmural loss of the cardiomyocytes and small clusters of coagulative necrosis were observed. Evidence of edema and a patchy hemorrage remained in the extracellular space.

The differences between posteroseptal and the other atrioventricular accessory pathways: the coronary sinus morphology and the conduction over accessory pathways

62.2±4.5 mV, p<0.0t), maximal diastolic potential (80.4±2.2 vs. 58.7±5.4 mV, p<0.05), dV/dt (156.6±12.7 vs. 26.4±6.5 V/sec, p<0.05), and ADPg0 (208.3±7.2 vs. 145.2±7.4 ms, p<0.01), consistent with slow conduction and unidirectional block occurred in the BZ. In conclusion, sustained monomorphic VTs developed after MI were due to functional spiral wave reentry or anatomic macroreentry around the infarction area. Both types of reentries involved in the BZ with delayed conduction and unidirectional block. Background: Increased left atdal volume (LAV) is associated with a higher risk of recurrent atdal fibdllation (AF) and atdal arrhythmias. Two-dimensional (2-D) transthorecic echocardio- graphy is validated as a reliable method by which to assess LAV compared to cine-computed tomography (cine-CT). Using the biplane method of disks, LAV measured by transthoracic echocardiography is well correlated with that obtained by cine-CT, but under estimates the LAV by 20-32%. Magnetic electroanatomic mapping (MEAM) is valuable for defining the ana- tomic location of catheter-based electrophysiologic recordings by creating a detailed shell of the endocardial anatomy in three-dimensional that can help guide focal AF ablation. We sought to validate the accuracy of volume measurements by MEAM by compadng MEAM LAV measurements against those measured by two-dimensionaJ transthoracic echocardiogrephy. Methods: Forty-seven patients underwent 2-D echocardiography and detailed MEAM of the left atdum (LA). The entire LA was mapped with 78-224 distinct points (mean 126 ± 37) acquired dudng atdal end-diastole, MEAM measurement of LAV was computed by using the built-in volume function of the Biosense TM system. The LAV was assessed using 2-D tran- sthoraclc echocardiography by the biplane methods of disks. The endocardial outlined was digitally traced in the apical 4-chamber and 2-chamber views at end-atrial diastole with exclu- sion of the pulmonic veins and appendage. Results: The LAV by 2-D echocardiography was 92.7 + 25.9 cc versus the LAV by MEAM which was 125.4 + 28,4 cc. There is good correlation between the results of echocardio- graphy and MEAM (r=0.90, p<0.001) for LAV, although the average value obtained by echocardiography is about 26% lower than that obtained by MEAM. Conclusions: Magnetic electroanatomic catheter mapping appears to be a retiable method by which to assess LAV. The results of MEAM correlate well with the echocardiographic assessments of LAV. Echocardiography underestimates LAV by a similar percentage when compared to MEAM as it does when compared to cine-CT. MEAM may prove useful in track- ing LAV with repeat mapping procedures and helping to plan post.ablative management. Bmckorounds: There were few reports about the differences between posteroseptal and the other atdoventdcular accessory pathways lAPs) in anatomy and electrophysiology. Methods: The size and shape of coronary sinus (CS) were measured in 21 patients with posteroseptal APs (11 right and 10 Jeff posteroseptal wall), 83 with the other APs (63 left lateral, 13 right lateral, 7 right anteroseptal wall) and 25 control subjects after CS angiogra- phy. CS diameter and morphoiogic features were measured. In 38 patients with APs, we investigated the electrophysiological charactedstics about anterograde and retrograde con- duction over APs, Rssults: The proximal CS in patients with posteroseptal APs was larger than in those with the other APs and the control (13.8 +/- 1.3 mm vs. 10.9 +/- 2.1 mm (p < 0.001) and 9.7 +/- 1.5 mm (p < 0.001), respectively). At a distance of 5 mm from the CS ostium, the CS mea- sured 10.8 +/- 0.8 mm, compared with 8.9 +/- 1.9 mm (p < 0.05) and 8.2 +/- 1.8 mm (p < 0.01). The dilatation persisted 10 mm into the CS, with the measurement of 8.6 +/- 1.2 mm, compared with 7.5 +/- 1.8 mm (p<0.05) and 7.2 +/- 1.7 mm (p<0.05). There were no differ- ences in these distal diameter, tn 67% of patients with posteroseptal APs, the proximal CS had the wind-cone appearance. This morphology was found in 16% of patients with the other APs. In all of control subjects and 84% of patients with the other APs, the CS was the tubular. Only 1 patient with a posteresaptal AP had retrograde and anterograde decremen- tal conduction over the AP. Three patients with postereseptal APs, 2 with left lateral, 2 with dght rataral and 1 with anteroseptal had only retmgrada conduction. Posteroseptal APs with dacramental conduction were located only in the right side. C.onclusions: The larger size of proximal CS was a structural characteristics in patients with posterosaptal APs. The appearance of proximal CS was like a wind-cone in these patients. Right posteroseptal APs were prone to have the high incidences of decremental conduction. These findings may have a clue to trace arrthythmia pathogenesis to its origin.