Effect of Tricaprin on Cardiac Proteome in a Mouse Model for Triglyceride Deposit Cardiomyovasculopathy.

Triglyceride deposit cardiomyovasculopathy (TGCV), a rare cardiovascular disorder caused by genetic or acquired dysfunction of adipose triglyceride lipase (ATGL), is marked by defective intracellular lipolysis that results in excessive accumulation of triglycerides (TGs) in the myocardium and coronary arteries, leading to intractable heart failure (HF). We have developed a specific treatment for TGCV using tricaprin, a medium chain TG, as part of a governmental rare disease project in Japan. We recently reported that tricaprin diet improved cardiac TG metabolism and left ventricular function in an ATGL-knockout (KO) mouse, a mouse model for TGCV. Here, we report the effect of tricaprin on the myocardial proteome of KO mice to elucidate the mechanisms of action of tricaprin at protein expression levels. We compared proteomic changes in the hearts of KO mice fed control or tricaprin diet. Tandem mass tag-based shotgun proteomics identified 1832 proteins common to all sample groups. Whole proteomic distribution in the heart was largely up-regulated in KO mice fed control diet. When using cut-off values (>1.5 or <0.67, FDR-adjusted p value<0.01), in fact, 65 proteins were up-regulated whereas only 2 proteins were down-regulated in the hearts of KO mice fed control diet. The former included proteins assigned to "Cardiac Arrhythmia", and "Cardiac Damage" reflecting HF by a toxicity function analysis. One of the latter was Ces1d, which is known to regulate intracellular TG metabolism. These proteomic changes observed in KO mice were dramatically rescued by the tricaprin diet. These results indicated that tricaprin diet ameliorated HF in a TGCV mouse model at protein expression levels and also provided important clues to understand mechanisms for the beneficial effect of tricaprin.

Randomized trial of an increased dose of calcium channel blocker or angiotensin II type 1 receptor blocker as an add-on intensive depressor therapy in type 2 diabetes mellitus patients with uncontrolled essential hypertension: the ACADEMIE Study.

There is a lack of data on how to treat hypertensive patients with diabetes when treatment with medium doses of calcium channel blocker and angiotensin II type 1 receptor blocker (ARB) is insufficient to achieve the target blood pressure (BP). A total of 121 participants with type 2 diabetes and uncontrolled essential hypertension, who were receiving medium doses of amlodipine (5 mg/day) and ARB, were enrolled. Participants were randomized to receive either a high dose of amlodipine (10 mg/day) plus a medium dose of ARB (high-AML) or a medium dose of amlodipine (5 mg/day) plus a high dose of ARB (high-ARB). The depressor effects of these two regimens were monitored using a telemonitoring home BP-measuring system. Fifty-four patients were excluded after an observation period, and the remaining 67 eligible participants were randomized into the two groups; 42 which had a record of their home BP for analysis. The change in morning home systolic and diastolic BP was greater in the high-AML than in the high-ARB (systolic BP; - 7.9 mmHg vs. + 2.7 mmHg; p = 0.0002, diastolic BP; - 3.9 mmHg vs. + 0.6 mmHg; p = 0.0007). In addition, the home systolic and diastolic BP before going to bed and office systolic BP were significantly reduced from week 0 only in the high-AML. An increased dose of amlodipine, but not ARB, reduced home morning BP in hypertensive patients with type 2 diabetes who were already receiving combination therapy with medium doses of amlodipine and ARB.

Depressor effect of the young leaves of Polygonum hydropiper Linn. in high-salt induced hypertensive mice.

A novel chymase inhibitor has been reported to have depressor effect in salt-induced hypertension. Therefore, we examined the hypothesis that chymase inhibitory dried young leaves of Polygonum hydropiper (PPH) or young leaves extract of Polygonum hydropiper (PHE) could reduce salt-induced hypertension. In this study, 8-wk old wild-type mice were allocated into three experiments and experiment I included groups, I- normal water drinking, II- high salt (2% NaCl) water (HSW) drinking, and III- HSW plus PPH (500 mg kg-1, orally) for 12-wk. Blood pressure (BP) and heart rate (HR) were measured at baseline and weekly up to wk-12. In experiment II, mice were given HSW for 12-wk followed by 8-wk treatment with PPH plus HSW (62.5, 125, 250 and 500 mg kg-1 for groups I, II, III and IV, respectively). BP and HR were measured at baseline and monthly until wk-12, following weekly for 8-wk. Experiment III comprised of four groups of mice for 12-wk HSW and 8-wk treatment with PHE plus HSW (2.5, 5, 10 and 20 mg kg-1 for groups I-IV, respectively). BP and HR were measured at baseline and monthly up to wk-12, following weekly for 8-wk. Significant reduction in BP and HR were observed in mice treated with PPH (500 mg kg-1) compared to HSW control. PPH reduced BP and HR dose dependently in hypertensive mice and the higher dose showed maximum reduction. PHE at its maximum dose (20 mg kg-1) significantly suppressed BP and HR. Over all, we found that the young leaves of Polygonum hydropiper suppressed salt-induced hypertension.

The EXPAND study: Efficacy and safety of rivaroxaban in Japanese patients with non-valvular atrial fibrillation.

AIMS: The EXPAND study examined the real-world efficacy and safety of rivaroxaban for the prevention of stroke and systemic embolism (SE) in Japanese patients with non-valvular atrial fibrillation (NVAF). METHODS AND RESULTS: This multicenter, prospective, non-interventional, observational, cohort study was conducted at 684 medical centers in Japan. A total of 7141 NVAF patients ≥20 years of age (mean, 71.6 ±â€¯9.4 years) who were being or about to be treated with rivaroxaban (10 mg/day, 43.5%; 15 mg/day, 56.5%) were followed for an average of 897.1 (±206.8) days with a high follow-up rate (99.65%). The mean CHADS2 score at baseline was 2.1 (1.3) (0-1, 37%; 2, 29%; ≥3, 34%). The total incidence rate of symptomatic stroke and SE (primary efficacy endpoint) was 1.0%/year, and 0.5%, 0.9%, and 1.7%/year for those with CHADS2 scores of 0-1, 2, and ≥3, respectively. Cumulative incidence rates for major bleeding (primary safety endpoint) and non-major bleeding (secondary safety endpoint) were 1.2%/year and 4.9%/year, respectively. Differences were noted between new and current users only for major bleeding event rate (1.7% vs. 1.1%/year, P = 0.0024). Comparisons with previous studies suggested that rivaroxaban is effective and safe for low-risk patients (0-1 CHADS2), as shown for warfarin in the XANTUS international prospective post-marketing study. CONCLUSIONS: The EXPAND study demonstrated that low dosages of rivaroxaban for Japanese NVAF patients in real-world clinical practice, including those with CHADS2 scores 0-1, resulted in low rates of stroke and SE, and major and non-major bleeding.

Efficacy and Safety of Combination Therapy Consisting of Angiotensin II Type 1 Receptor Blocker, Calcium Channel Blocker and Hydrochlorothiazide in Patients With Hypertension.

BACKGROUND: Many patients continue to have high blood pressure (BP) even after treatment with high-dose (H)-angiotensin II type 1 receptor blocker (ARB)/calcium channel blocker (CCB) or middle-dose (M)-ARB/CCB/hydrochlorothiazide (HCTZ). METHODS: Thirty-two hypertensive patients who had the use of H-ARB/CCB or M-ARB/CCB/HCTZ were enrolled in this study. We applied a changeover with a switch to H-ARB (telmisartan 80 mg/day)/CCB (amlodipine 5 mg/day or nifedipine CR 40 mg/day)/HCTZ (12.5 mg/day). RESULTS: Systolic BP (SBP) and diastolic BP (DBP) were significantly decreased in all patients and in the H-ARB/CCB and M-ARB/CCB/HCTZ groups after 3 months. Percentage (%) of patients who reached the target BP after 3 months (72%) in all patients was significantly higher than that at 0 months (19%). There were no serious adverse effects in any of the patients. CONCLUSIONS: Combination therapy with H-ARB/CCB/HCTZ was associated with a significant reduction of BP.

Evaluation of the antithrombotic abilities of non-vitamin K antagonist oral anticoagulants using the Total Thrombus-formation Analysis System®.

The Total Thrombus-formation Analysis System (T-TAS®) is a novel automated microchip flow-chamber system for the quantitative evaluation of thrombus formation under blood flow conditions. T-TAS® uses two types of microchip to evaluate thrombus formation: the AR-chip quantifies white thrombus formation and the PL-chip quantifies platelet thrombus formation. We assessed the antithrombotic abilities of various non-vitamin K antagonist oral anticoagulants (NOACs) using T-TAS®. One hundred and three consecutive patients who were hospitalized with cardiovascular diseases were enrolled. We divided the patients into 2 groups; a control group that did not receive an anticoagulant (non-AC group) and an anticoagulant group (AC group). The AC group was further divided into warfarin, dabigatran, rivaroxaban and apixaban groups. We performed common coagulation tests and evaluated the area under the flow pressure curve (AR-AUC and PL-AUC) to quantify antithrombotic ability using T-TAS® at the trough. There were no significant differences in patient characteristics between the non-AC and AC groups. Only 55.1 % of patients in the AC group achieved the target blood pressure (BP) of less than 130/80 mmHg. Compared with the non-AC group, AR-AUC was significantly decreased in the AC, warfarin, dabigatran and apixaban groups. Only the rivaroxaban group did not show a significant decrease in AR-AUC. NOACs showed a significant decrease in PL-AUC compared with the non-AC group. In conclusion, T-TAS® was a useful tool for evaluating anticoagulation activity. NOACs was significantly effective as an antiplatelet agent. BP control should be a higher priority than the selection of an anticoagulant drug, especially NOACs.

Study Design and Baseline Characteristics of the EXPAND Study: Evaluation of Effectiveness and Safety of Xa Inhibitor, Rivaroxaban for the Prevention of Stroke and Systemic Embolism in a Nationwide Cohort of Japanese Patients Diagnosed as Non-Valvular Atrial Fibrillation.

The use of rivaroxaban, a factor Xa inhibitor, has been increasing for prevention of ischemic stroke and systemic embolism in patients with non-valvular atrial fibrillation (AF) in Japan. We conducted the nationwide multicenter study, termed as the EXPAND Study, to address its effectiveness and safety in the real-world practice of patients with non-valvular AF in Japan. The EXPAND Study is a prospective, non-interventional, observational cohort study to evaluate the effectiveness and safety of rivaroxaban in non-valvular AF patients in a real-world clinical practice. A total of 7,178 patients with non-valvular AF were enrolled in 684 medical institutes between November 20, 2012 and June 30, 2014. As for the baseline demographic and clinical characteristics of 7,164 patients, the proportion of female patients was 32.2%, and those of patients with creatinine clearance < 50 mL/min and non-paroxysmal (persistent or permanent) AF were 21.8% and 55.1%, respectively. The proportions of patients complicated with hypertension, congestive heart failure, diabetes mellitus, and a history of ischemic stroke were 70.9%, 25.9%, 24.3%, and 20.2%, respectively. The proportions of patients with a CHADS2 score ≤ 1 and a CHA2DS2-VASc score ≤ 1 were 37.3% and 13.6%, respectively. They were followed up until March 31, 2016 for a mean follow-up period of approximately 2.5 years. The findings of the EXPAND Study will help to establish an appropriate treatment with rivaroxaban for Japanese patients with non-valvular AF.

Rivaroxaban, a factor Xa inhibitor, induces the secondary prevention of cardiovascular events after myocardial ischemia reperfusion injury in mice.

OBJECTIVES: Rivaroxaban has been shown to reduce overall death from cardiovascular causes in patients with recent acute coronary syndrome. Therefore, we evaluated the secondary prevention of cardiovascular events after myocardial ischemia reperfusion injury and its mechanisms in mice. METHODS: After myocardial reperfusion injury, C57BL/6J mice were randomized to receive either no treatment or treatment for 14days with low and high doses of rivaroxaban. After 7days, mice were administered tissue factor as a secondary event. RESULTS: Based on a Kaplan-Meier curve analysis, the high-dose rivaroxaban group showed a significantly higher % survival than the no-treatment group from day 7 (after the administration of tissue factor) to day 14 (at the end of the experimental period). Left ventricular (LV) ejection fraction in both the low- and high-dose rivaroxaban groups improved compared to that in the no-treatment group. Moreover, mRNA levels of interleukin-6 and collagens 1α2 and 3α1 in the LV in the high-dose group were significantly suppressed compared to those in the no-treatment group. CONCLUSIONS: Rivaroxaban improved the survival rate, probably by improving cardiac function through the reduction of inflammatory and fibrotic factors in the LV. This effect may be due to the pleiotropic effects of rivaroxaban beyond its main effect as an anti-coagulant.

Circadian variations in laboratory measurements of coagulation assays after administration of rivaroxaban or warfarin in patients with nonvalvular atrial fibrillation.

BACKGROUND: Although rivaroxaban has a relatively shorter half-life and peak and trough plasma concentrations throughout the day than warfarin, rivaroxaban has been found to be non-inferior to warfarin in preventing thromboembolic events in patients with nonvalvular atrial fibrillation (NVAF). We measured circadian variations in laboratory measurements of coagulation assays for chronic treatment with rivaroxaban or warfarin in patients with NVAF. METHODS: We included 28 consecutive patients with NVAF who were treated with rivaroxaban (n=13) or warfarin (n=15). Blood samples were collected at 6 AM, 11 AM, and 3 PM on the same day and on the next morning at 6 AM. Prothrombin time (PT), international normalized ratio of the PT (PT-INR), activated partial thromboplastin time (APTT), prothrombin fragment 1+2 (F1+2), and protein C level/activity were measured in each patient. RESULTS: PT and PT-INR were significantly and consistently lower, and the F1+2 and protein C level/activity were significantly and consistently higher throughout the day in rivaroxaban-treated patients than in warfarin-treated patients. Significant increases in PT and PT-INR were observed 3h after oral administration in the patients taking rivaroxaban in the morning, whereas, significant increases in the protein C level/activity were observed 3h after oral administration in the patients taking warfarin in the morning. CONCLUSIONS: The protein C level/activity was significantly and consistently higher in the rivaroxaban-treated patients than in the warfarin-treated patients throughout the day, which was in contrast to the findings for other coagulation assays. These findings may partly explain the specific persistent anticoagulant effects of rivaroxaban even during the trough phase of the plasma concentration.

Waon Therapy for Managing Chronic Heart Failure　- Results From a Multicenter Prospective Randomized WAON-CHF Study.

BACKGROUND: Waon therapy improves heart failure (HF) symptoms, but further evidence in patients with advanced HF remains uncertain. METHODS AND RESULTS: In 19 institutes, we prospectively enrolled hospitalized patients with advanced HF, who had plasma levels of B-type natriuretic peptide (BNP) >500 pg/ml on admission and BNP >300 pg/ml regardless of more than 1 week of medical therapy. Enrolled patients were randomized into Waon therapy or control groups. Waon therapy was performed once daily for 10 days with a far infrared-ray dry sauna maintained at 60℃ for 15 min, followed by bed rest for 30 min covered with a blanket. The primary endpoint was the ratio of BNP before and after treatment. In total, 76 Waon therapy and 73 control patients (mean age 66 years, men 61%, mean plasma BNP 777 pg/ml) were studied. The groups differed only in body mass index and the frequency of diabetes. The plasma BNP, NYHA classification, 6-min walk distance (6MWD), and cardiothoracic ratio significantly improved only in the Waon therapy group. Improvements in NYHA classification, 6MWD, and cardiothoracic ratio were significant in the Waon therapy group, although the change in plasma BNP did not reach statistical significance. No serious adverse events were observed in either group. CONCLUSIONS: Waon therapy, a holistic soothing warmth therapy, showed clinical advantages in safety and efficacy among patients with advanced HF.

Efficacy and safety of combination therapy of high-dose losartan and hydrochlorothiazide in patients with hypertension.

OBJECTIVE: We analyzed the efficacy and safety of combination therapy of high-dose losartan (100 mg/day) and hydrochlorothiazide (HCTZ, 12.5 mg/day) compared with those of the combination of high-dose telmisartan (80 mg/day) and HCTZ (12.5 mg/day). METHODS: Forty hypertensive patients who received a combination of high-dose telmisartan and HCTZ were enrolled. We applied a changeover strategy with switching from a combination of high-dose telmisartan and HCTZ to high-dose losartan and HCTZ. We divided the patients into two groups; those who achieved the target blood pressure (controlled group) and those who did not reach the target blood pressure (uncontrolled group) before the changeover and performed further analysis. RESULTS: The uncontrolled group showed a significant decrease in systolic blood pressure (SBP) (143±12 mmHg to 126±11 mmHg at three months). In addition, serum uric acid significantly decreased in all subjects, and in each of the controlled and uncontrolled groups. There were no significant changes in other biochemical parameters, such as potassium and hemoglobin A1c, at three months after the changeover in all subjects. CONCLUSION: Combination therapy with high-dose losartan and HCTZ was superior to the combination of telmisartan and HCTZ with respect to significant decreases in systolic blood pressure and serum uric acid in hypertensive patients.

Ratio of eicosapentaenoic acid to arachidonic acid is a critical risk factor for acute coronary syndrome in middle-aged older patients as well as younger adult patients.

BACKGROUND: Coronary risk factors for the onset of acute coronary syndrome (ACS), including polyunsaturated fatty acids (PUFAs), in younger adult patients may be different from those in older patients. METHODS AND RESULTS: We enrolled 578 patients who underwent coronary angiography at Fukuoka Saiseikai Hospital, and divided them into a younger adult group (YG) (<50 years, n=47) and a middle-aged older group (OG) (≥50 years, n=531). In a multivariate analysis, lower levels of high-density lipoprotein cholesterol and the ratio of eicosapentaenoic acid (EPA) to arachidonic acid (AA) (EPA/AA), and less aspirin, oral hypoglycemic agent, and calcium channel blocker (CCB) use were independent risk factors for ACS in all patients. In YG, lower levels of EPA/AA and less angiotensin II receptor blocker/angiotensin-converting enzyme inhibitor use were the independent risk factors. In OG, smoking, lower levels of EPA/AA, less aspirin and CCB use were the risk factors. While lower levels of EPA/AA was the only risk factor for ACS that was common to all patients, YG and OG, docosahexaenoic acid/AA was not associated with ACS in YG and OG. CONCLUSIONS: Lower level of EPA/AA is a common critical risk factor for ACS in middle-aged older patients as well as younger adult patients. Some of the risk factors for the onset of ACS in younger patients were different from those in older patients.

Efficacy and safety of a single-pill fixed-dose combination of high-dose telmisartan/hydrochlorothiazide in patients with uncontrolled hypertension.

OBJECTIVE: Many patients still have high blood pressure (BP) after treatment with high-dose angiotensin II type 1 receptor blockers (ARBs) or Preminent® (medium-dose of losartan (50 mg/day)/hydrochlorothiazide (HCTZ) (12.5 mg/day)). Therefore, we analyzed whether Micombi®BP (high-dose telmisartan (80 mg/day)/HCTZ (12.5 mg/day)) could provide better results with regard to efficacy and safety for patients with uncontrolled hypertension. METHODS: In total, 44 hypertensive patients (22 males, age 71±14 years) who showed uncontrolled BP despite the use of high-dose ARBs or Preminent® were enrolled in this study. We used a changeover design in which the patients were switched from high-dose ARBs or Preminent® to Micombi®BP. We analyzed BP, heart rate (HR), and biochemical parameters before and after treatment for 3 months. RESULTS: Systolic BP and diastolic BP significantly decreased (125±15/69±11 mmHg) and 85% of the patients achieved their target BP at 3 months after changeover. Patients who switched from ARBs and those who switched from Preminent® showed similar BP-lowering effects. In addition, the reductions in BP after 3 months in patients with or without chronic kidney disease and in those with or without metabolic syndrome (MetS) were also similar. There were no significant changes in HR during the study period. Although blood levels of potassium, hemoglobin A1c and uric acid (UA) significantly increased after 3 months for all of the patients, none of the patients showed serious adverse effects. CONCLUSION: High-dose telmisartan/HCTZ therapy was associated with a significant reduction in BP and helped patients achieve their target BP.

Which strategy is more effective for the treatment of cardiovascular disease: high-dose angiotensin II type 1 receptor antagonist monotherapy or combination therapy?

Angiotensin II type 1 (AT(1)) receptor antagonists (blockers) [ARBs] are highly selective for the AT(1) receptor and block the diverse effects of angiotensin II. When high BP is not controlled by low-dose ARB monotherapy, physicians need to employ another strategy, either high-dose ARB monotherapy or combination therapy with calcium channel antagonists (blockers) [CCBs], diuretics, or other agents. High-dose ARB monotherapy is more effective for decreasing proteinuria than low-dose ARB monotherapy or CCBs. Although the ARB valsartan has been shown to prevent coronary restenosis in a clinical study (Val-PREST [Valsartan for prevention of restenosis after stenting of type B2/C lesions]), it is still unclear whether ARBs help to prevent restenosis. The results reported by Peters in this issue highlight the relative efficacies of low- (80 mg/day) and high-dose valsartan (160-320 mg/day) for the prevention of in-stent restenosis after the implantation of bare-metal stents, and suggest that high-dose valsartan can reduce the in-stent restenosis rate, target lesion revascularization and target vessel revascularization rates, late lumen loss, and major adverse cardiac events rate more effectively than low-dose valsartan. A better understanding of the differences in the efficacies of high- and low-dose ARBs could be useful in the treatment of patients with cardiovascular disease and may resolve the issue of whether ARBs prevent coronary restenosis. Clinical benefits may be induced by complete blockade of the renin-angiotensin system using high-dose ARB monotherapy. Therefore, physicians need to select a strategy carefully; i.e. either high-dose ARB monotherapy or combination therapy.

Pilsicainide for atrial fibrillation.

Pilsicainide is a class IC antiarrhythmic drug, which has a pure sodium channel blocking action with slow recovery pharmacokinetics. In experimental studies, pilsicainide has a depressant effect on intra-atrial conduction and a prolonging effect on the atrial effective refractory period (ERP). In patients with paroxysmal atrial fibrillation (AF), pilsicainide significantly prolonged the ERP of the distal pulmonary vein (PV), PV-left atrium (LA) junction and LA, and the conduction time from the distal PV to the PV-LA junction. In some patients, PV-LA conduction block has been observed just before pilsicainide-induced termination of AF; this isolation of the PV may provide a new insight into the mechanism of pharmacological conversion of AF. Hybrid therapy with pilsicainide and PV isolation (by radiofrequency catheter ablation) appears to be an effective therapeutic approach for AF. The pharmacological PV isolation by pilsicainide and its suppression of focal discharges from atrial tissue may prevent the development of AF after unsuccessful ablation.

Effects of atorvastatin and apoA-I/phosphatidylcholine discs on triglyceride-rich lipoprotein subfractions as characterized by capillary isotachophoresis.

BACKGROUND: The present study examined the effects of atorvastatin and the in vitro effect of apolipoprotein (apo) A-I/phosphatidylcholine (POPC) discs on charge-based triglyceride-rich lipoprotein (TRL) subfractions in a patient with type III hyperlipoproteinemia (HLP) and the apoE2/2 phenotype. METHODS: Charge-based lipoprotein subfractions were characterized by capillary isotachophoresis (cITP). cITP analysis was performed using plasma that had been prestained with a lipophilic dye on a Beckman P/ACE MDQ system. RESULTS: Treatment with atorvastatin for 4 weeks markedly decreased the slow (s)-migrating TRL subfraction and both fast- and slow-migrating low-density lipoprotein (LDL) subfractions, but did not affect the fast (f)-migrating TRL subfraction in this patient. ApoA-I/POPC discs consisted of two major charge-based subfractions that had the mobility of cITP fTRL and sTRL. Incubation of plasma from this patient in the presence of apoA-I/POPC discs caused not only a reduction in cITP fast- and intermediate-migrating HDL and an increase in cITP sHDL but also a reduction in fTRL and sTRL and an increase in sLDL. CONCLUSION: Atorvastatin and apoA-I/POPC discs decreased cITP TRL subfractions in a complementary manner, suggesting that the combination of apoA-I/POPC discs and atorvastatin could be a promising therapeutic approach for hypertriglyceridemia.

Spontaneous onset of ventricular fibrillation in Brugada syndrome with J wave and ST-segment elevation in the inferior leads.

We report the case of a 52-year-old man with variant Brugada syndrome who was successfully resuscitated from ventricular fibrillation (VF). Resting ECG showed J wave and ST-segment elevation in the inferior leads but no coved or saddleback ST-segment elevation in the right precordial leads. Pilsicainide infusion provoked coved-type ST-segment elevation in the right precordial leads and mild ST-segment elevation 80 ms after the J point in the inferior leads. During an emergency, 12-lead ECG showed that spontaneous onset of VF was preceded by left bundle branch block and superior axis-type ventricular extrasystoles. The present case provides additional information on the site of origin of VF in patients with Brugada syndrome.

Effects of the NA+ channel blocker pilsicainide on the electrophysiologic properties of pulmonary veins in patients with atrial fibrillation.

INTRODUCTION: Na+ channel blockers are used to treat atrial fibrillation (AF). However, the effects of Na+ channel blockers on the electrophysiologic properties of pulmonary veins (PVs) are not well characterized. The aim of the present study was to evaluate the effect of the pure Na+ channel blocker pilsicainide on the PVs. METHODS AND RESULTS: PV mapping using a basket catheter was performed in 28 patients with paroxysmal AF. Twenty-eight PVs, including 20 left superior and 8 right superior PVs, were studied. Programmed stimulation was performed in the distal PV and PV-left atrial (LA) junction before and after infusion of pilsicainide (1 mg/kg). Pilsicainide significantly prolonged the effective refractory period (ERP) of the distal PV from 163 +/- 44 msec to 192 +/- 53 msec (P < 0.001), PV-LA junction from 227 +/- 48 msec to 235 +/- 52 msec (P < 0.05), and LA appendage from 225 +/- 55 msec to 245 +/- 48 msec (P < 0.05). Pilsicainide significantly prolonged the conduction time from the distal PV to PV-LA junction from 45 +/- 14 msec to 70 +/- 26 msec (P < 0.0001). In 3 of 5 patients who experienced AF termination with pilsicainide, PV-LA conduction block was observed just before AF termination. CONCLUSIONS: Pilsicainide can modify ERP heterogeneity and conduction properties in the PV and at the PV-LA junction. Because the PV and PV-LA junction have important roles as substrates for AF maintenance, pilsicainide may terminate AF by pharmacologic PV isolation.

Electrophysiologic properties of pulmonary veins assessed using a multielectrode basket catheter.

OBJECTIVES: The purpose of the present study was to evaluate the electrophysiologic properties within the pulmonary vein (PV) and at the PV-left atrial (LA) junction. BACKGROUND: It has been recognized that atrial fibrillation (AF) can originate from PVs. However, the electrophysiologic properties of the PV have not been well characterized. METHODS: Thirty-two bipolar electrograms were recorded simultaneously from a basket catheter placed in 81 PVs of 48 patients with paroxysmal AF. The programmed stimulation was performed in the distal PV and PV-LA junction. Activation maps of PVs were analyzed from episodes of spontaneous onset of AF and initiation of induced AF by a single extrastimulus. RESULTS: The effective refractory period (ERP) of the distal PV was significantly shorter than that of the PV-LA junction (177 +/- 43 vs. 222 +/- 30 ms, p < 0.0001). The conduction delay from the distal PV to the PV-LA junction was significantly longer than that from the PV-LA junction to distal PV (73 +/- 40 vs. 32 +/- 17 ms, p < 0.0001). During initiation of AF, a short coupled extrastimulus or rapid, repetitive focal activities originating from the PV formed a PV-LA reciprocating re-entrant circuit involving exit and entrance breakthrough points at the PV-LA junction. Also, an unstable re-entrant circuit within the PV was observed. CONCLUSIONS: The presence of ERP heterogeneity and anisotropic conduction properties within the PV and at the PV-LA junction may be crucial to promote re-entry formation and thus might play an important role as a substrate for the maintenance of AF.

Successful catheter ablation of ventricular tachycardia originating from the idiopathic saccular apical left ventricular aneurysm.

Left ventricular (LV) aneurysm has been recognized to frequently become a substrate of ventricular tachyarrhythmias. We report a case of a 66-year-old woman with symptomatic sustained monomorphic ventricular tachycardia (SMVT) originating from saccular apical LV aneurysm without definite underlying diseases. We performed catheter ablation using electroanatomical and conventional bipolar potential mapping. During SMVT, we found an area of fragmented potential -40 ms preceding the earliest wide QRS complex in the area of the apical LV aneurysm. Radiofrequency applications were delivered to this area. Since then, SMVT was no longer inducible by programmed electrical stimulation. The patient has remained free of VT recurrences during a subsequent 12-month follow-up period.