Comparison of the electrophysiological properties of the pulmonary veins between paroxysmal and persistent atrial fibrillation.

Background: The role of the pulmonary veins (PVs) as triggers in atrial fibrillation (AF) is well-known; however, their detailed electrophysiological properties have not been thoroughly examined. Objective: This study aimed to investigate the electrophysiological properties of the PVs between paroxysmal AF (pAF) and persistent AF (perAF). Methods: Prior to catheter ablation in patients with pAF (n = 51) and perAF (n = 41), a voltage map of the left atrium and PVs was created under sinus rhythm, and the area of the myocardial sleeves in the PVs and their electrophysiological characteristics, including the pacing threshold and effective refractory period (ERP), were compared between the two groups. Results: Compared with perAF, the myocardial sleeves of PVs for pAF were significantly larger for all PVs. The ERP for perAF was significantly shorter than that for pAF for all PVs. The pacing threshold for perAF was significantly higher than that for pAF for the right and left superior PVs. Conclusion: In patients with perAF, a decrease in the normal myocardial sleeves and a shortening of the ERP were observed for all PVs. Those changes in the electrophysiological properties of the PVs might be related to the persistence of AF.

The target ablation index values for electrical isolation of the superior vena cava.

PURPOSE: The ablation index (AI), developed as a radiofrequency (RF) catheter ablation composite component endpoint, which incorporates contact force (CF), time, and power in a weighted formula, has been reported to be useful for a durable pulmonary vein isolation (PVI) to treat atrial fibrillation (AF). No study has reported the target AI value for the SVC isolation (SVCI). In this study, we aimed to investigate the target AI for the SVCI. METHODS: Thirty-six AF patients who underwent an initial SVCI were enrolled. Ablation was performed at 556 points. The sites where dormant conduction was induced or additional ablation was needed were defined as touch up sites (n = 36). We compared the energy deliver time, power, generator impedance (GI) drop, local bipolar voltage, contact force (CF), force-time integral (FTI), and AI between the touch up sites and the no touch up sites (n = 520). RESULTS: The FTI and AI were significantly lower at the touch up sites (touch up sites vs. no touch up sites; FTI, 126.5 [99.3-208.8] vs. 244 [184-340.8], p < 0.0001; AI, 350.1 ± 43.6 vs. 277.2 ± 21.8, p < 0.0001). The median value of the AI at the no touch up sites was 350, and no reconnections were seen where the minimum AI value was more than 308. Most of the touch up sites were located in the anterior wall and lateral wall (anterior wall, 20/36 sites [55.6%]; lateral wall, 10/36 sites [27.8%]; septal wall, 6/36 sites [16.7%]; posterior wall, 0/36sites [0.0%]). CONCLUSION: The target AI value for the SVCI should be 350, and at least 308 would be needed.

Effects of uninterrupted dabigatran on the intensity of anticoagulation during atrial fibrillation ablation.

BACKGROUND: Uninterrupted dabigatran during atrial fibrillation (AF) ablation is now established as the standard therapy. However, there are few reports on the effects of uninterrupted dabigatran on the intensity of anticoagulation during AF ablation. METHODS: We retrospectively analyzed 247 consecutive patients who underwent AF ablation in our hospital from January 2017 to December 2018. Patients who took warfarin or uninterrupted direct oral anticoagulants (DOACs) except for dabigatran were excluded. 89 patients underwent ablation with uninterrupted dabigatran (uninterrupted group, male 71, mean age 59.6 ± 14.0) and 124 with interrupted DOACs (interrupted group, male 105, mean age 56.9 ± 12.9) during AF ablation. The initial ACT level, proportion of ACT levels of more than 300 s, and total amount of heparin were compared. Furthermore, the incidence of procedure complications was also evaluated. RESULTS: The initial ACT levels were significantly higher in the uninterrupted group, and the total number of ACTs of more than 300 s was significantly higher in the uninterrupted group (uninterrupted vs. interrupted; initial ACT level, 315.6 ± 59.8 vs. 264.5 ± 48.6, p < .001; total number of ACTs ≧300, n [%], 304/ 484 [62.8 %] vs. 372/745 [49.9%], p < .001). The total amount of heparin during procedure was significantly lower in the uninterrupted group (uninterrupted group vs. interrupted group; 12966 ± 4773 vs. 16371 ± 5212, p < .001). There was no significant difference in the incidence of complications between the two groups. CONCLUSIONS: In the catheter ablation of AF, uninterrupted dabigatran would be useful to obtain a stable anticoagulation status during the entire procedure.

Improvement of left ventricular function after successful radiofrequency catheter ablation in persistent atrial fibrillation with preserved left ventricular ejection fraction: a comprehensive echocardiographic assessment using two-dimensional speckle tracking analysis.

BACKGROUND: A limited number of studies have investigated the effects of radiofrequency catheter ablation (RFCA) on left ventricular (LV) function and the left atrial (LA) size in patients with atrial fibrillation (AF). The purpose of this study was to conduct a comprehensive assessment of LV function in patients with AF with preserved left ventricular ejection fraction (LVEF) before and after RFCA. METHOD: A total of 30 consecutive patients with no recurrences after RFCA for persistent AF (age, 57.7 ± 8.4 years) were enrolled. Transthoracic echocardiography was performed at the baseline and 6 months after the final RFCA using speckle tracking derived LV strain analysis. RESULTS: After RFCA, we measured decreases in the LA volume index (33.7 ± 10.4 ml/m2 vs. 24.6 ± 8.6 ml/m2, p < 0.0001), while we observed improvements in systolic indices such as LVEF (56.8 ± 9.8% vs. 65.1 ± 9.1%, p < 0.0001), global longitudinal strain (- 16.8 ± 4.4% vs. - 18.8 ± 3.4%, p = 0.0055) and twist (8.12 ± 3.66° vs. 12.33 ± 6.75°, p = 0.0050), and also in diastolic indices such as strain rate during early diastole (SRE) (0.73 ± 0.10 s-1 vs. 1.32 ± 0.29 s-1, p < 0.0001) and early transmitral inflow velocity (E)/SRE (1.11 ± 0.36 m vs. 0.61 ± 0.19 m, p < 0.0001). Logistic regression analysis showed that ΔE/SRE was a contributing factor for improvement in LVEF (odds ratio 126.9; p = 0.021). CONCLUSION: In persistent AF with preserved LVEF, further improvement in LVEF and reverse remodeling of the LA are achieved after RFCA. LV filling pressure may play significant roles in the mechanisms.

Observational Study of Infective Endocarditis at a Community-based Hospital: Dominance of Elderly Patients with Comorbidity.

Objective The purpose of this study was to present the recent clinical profiles and the real-world management of infective endocarditis (IE). Methods All medical records of patients with IE were reviewed retrospectively for their clinical data, including clinical presentation, laboratory results, blood cultures, echocardiographic findings, treatments and complications. Using the clinical data collected, we calculated the EuroSCORE II, the European risk score for adult cardiac surgery, the Charlson Comorbidity Index as a surrogate of comordibity, and the Katz Index as a surrogate of frailty. Results Thirty-eight patients were identified as having IE (24 men, age: 71.8±13.1 years). Congestive heart failure occurred in 16 patients (42%), stroke in 14 (50%), and systemic embolism in 5 (13%). The EuroSCORE II and Charlson Comorbidity Index were high (7.7±5.8% and 5.5±2.8%, respectively). The Katz Index was fair (5.5±1.4) before the onset but deteriorated to 2.8±2.7 at the time of establishing the diagnosis of IE (p<0.001). Early surgery was performed in 22 cases (61%). In-hospital death occurred in 10 cases (26%). A EuroSCORE II ≥9%, Staphylococcus aureus etiology, and a Charlson Comorbidity Index were suggested as determinants of in-hospital death (hazard ratios: 173.60, 9.31, 1.57, respectively). In contrast, early surgery was suggested as a determinant of the survival (hazard ratio: 0.04). The Charlson Comorbidity Index was also suggested as a determinant for selecting conservative management (odds ratio: 1.40). Conclusion Comorbidity may influence the treatment selection and outcome of elderly patients with IE.

The impact of left ventricular deformation and dyssynchrony on improvement of left ventricular ejection fraction following radiofrequency catheter ablation in Wolff-Parkinson-White syndrome: A comprehensive study by speckle tracking echocardiography.

PURPOSE: The purpose of this study was to evaluate left ventricular (LV) deformation and LV dyssynchrony in patients with Wolff-Parkinson-White (WPW) syndrome and to identify the factors that affect the efficacy of radiofrequency catheter ablation (RFCA). METHODS: Thirty patients (26 men, mean age 40 ± 12 years) with WPW syndrome were prospectively recruited for this study. They underwent 2-dimensional transthoracic echocardiography with speckle tracking analysis before RFCA and again within 48 hours after RFCA. Control group consisted of 15 age and sex-matched healthy volunteers. RESULTS: The patients had significantly lower LV ejection fraction (LVEF), global longitudinal strain (Sl ), and global circumferential strain (Sc ) compared with healthy controls (64% ± 8% vs 68% ± 5%, P = .049; -17.6% ± 3.2% vs -19.9% ± 3.3%, P = .037, -15.2% ± 2.5% vs -19.4% ± 2.5%, P < .0001, respectively). Patients had a significantly higher dyssynchrony index relative to healthy controls (58.4 ± 49.0 ms vs 36.4 ± 31.1 ms, P = .031). After RFCA, there was a significant increase in LVEF and global Sc (68% ± 8% vs 64% ± 8%, P = .005; -17.3% ± 2.0% vs -15.2% ± 2.5%, P < .0001, respectively), along with a significant decrease in the dyssynchrony index (36.9 ± 36.3 ms vs 58.4 ± ms, P < .001) relative to the baseline values. Logistic regression revealed that the baseline dyssynchrony index was a predictor of LVEF improvement after RFCA (odds ratio: 1.060, P = .038). CONCLUSION: In WPW syndrome, impaired LV circumferential deformation can be restored by RFCA with concomitant improvement in LV dyssynchrony and LVEF.

Primary Mural Endocarditis Without Valvular Involvement.

Primary mural endocarditis is an extremely rare infection in which nonvalvular endocardial involvement is seen without any cardiac structural abnormalities such as ventricular septal defects. The rapid and precise diagnosis of this disease remains challenging. We present 2 cases (67- and 47-year-old male patients) of pathologically confirmed primary mural endocarditis that could have been detected by initial transthoracic echocardiography in the emergency department. Transthoracic echocardiography and transesophageal echocardiography play critical roles in the early recognition and confirmation of primary mural endocarditis.

Cardiac Asystole Triggered by Temporal Lobe Epilepsy with Amygdala Enlargement.

A 25-year-old previously healthy man was hospitalized for syncope. While standing, he suddenly lost consciousness, followed by a generalized tonic clonic seizure. An electrocardiogram demonstrated asystole. No cardiac abnormalities were detected on the echocardiogram, cardiac magnetic resonance imaging (MRI), positron emission tomography, or a coronary angiogram. An electrophysiological study showed normal sinus node and atrioventricular node function. An electroencephalogram revealed small spike waves in the fronto-temporal region. Brain MRI demonstrated a left-sided amygdala enlargement. To the best of our knowledge, this is the first case of temporal lobe epilepsy with an amygdala enlargement that induced cardiac asystole.

A novel cardiac ryanodine receptor gene (RyR2) mutation in an athlete with aborted sudden cardiac death: a case of adult-onset catecholaminergic polymorphic ventricular tachycardia.

Sudden cardiac death (SCD) in athletes <35 years of age are mostly due to congenital or acquired cardiac malformations or hypertrophic cardiomyopathy. However, ion channelopathies such as catecholaminergic polymorphic ventricular tachycardia (CPVT) or long-QT syndromes, which are less frequently observed, are also potential pathogenesis of SCD in young athletes. CPVT is an inherited arrhythmia that is induced by physical or emotional stress and may lead to ventricular fibrillation syncope or SCD. Here, we report a case of athlete woman with adult-onset CPVT and aborted SCD who has a novel missense mutation (K4392R) in the cardiac RyR2 gene.

'Honeycomb appearance' on three-dimensional transthoracic echocardiography as the landmark of left ventricular non-compaction: two case reports.

INTRODUCTION: Left ventricular non-compaction is a rare congenital heart disease, and is most commonly diagnosed via two-dimensional echocardiography according to echocardiographic criteria. Recently, transthoracic three-dimensional echocardiography has become available in the clinical setting. CASE PRESENTATION: We present two isolated cases of left ventricular non-compaction from Japan (in an 84-year-old woman and 47-year-old man) that were confirmed by two-dimensional echocardiography, contrast-enhanced two-dimensional echocardiography, three-dimensional echocardiography and cardiac magnetic resonance imaging. In both cases, three-dimensional echocardiography successfully demonstrated the trabecular meshwork of the left ventricle, referred to as a 'honeycomb appearance'. CONCLUSIONS: Three-dimensional echocardiography has the advantage of visualizing an en-face view of the trabecular meshwork, which is not possible with two-dimensional echocardiography. We further emphasize the clinical utility of three-dimensional echocardiography, which is not limited to just the observation of the trabeculations and inter-trabecular recesses, but can also visualize the trabecular meshwork with a 'honeycomb appearance'.

Newly developed mobile mass superimposed on mitral annulus calcification in patient with cerebral infarction: Documentation of a unique embolic source.

Mitral annulus calcification (MAC) has been recognized as a potent risk factor to cause cerebral infarction. There has been suggested possible linkage between mass on MAC and systemic embolic events. We report a case of cerebral infarction with newly developed mobile mass superimposed on MAC.

Beneficial effects of nifedipine on vasodilator response to acetylcholine in coronary and brachial arteries in the patients with coronary artery disease.

BACKGROUND: Nifedipine has been reported to improve endothelial function. However, there are few simultaneous studies on the effects of nifedipine on coronary and peripheral endothelial function in humans. METHODS: To investigate the effects of nifedipine on endothelial function in coronary artery (CA) and brachial artery (BA) in coronary artery disease (CAD), we measured vasodilator responses of CA and BA to acetylcholine (ACh, endothelium-dependent dilation) in 13 patients (63+/-10 years old) with CAD before and after sublingual administration of nifedipine 10 mg. To measure blood flow, a Doppler guidewire was inserted into the major branch of CA and the left BA. ACh was infused at 10(-7) mol/l for 3 min into CA and at 15.0 microg/ml for 5 min into BA, respectively. The vasodilator response to ACh was assessed by the ratio of ACh-induced flow/baseline flow (CAVR index, the ratio of CA flow changed by ACh; BAVR index, the ratio of BA flow changed by ACh). RESULTS: Nifedipine significantly increased both the CAVR and BAVR index:CAVR index, from 1.33+/-0.54 to 1.76+/-0.52 (32%) and BAVR index, from 1.74+/-0.83 to 2.18+/-0.93 (25%), respectively, p<0.05. In addition, nifedipine-induced changes in CAVR tended to correlate with those of BAVR (r=0.42. p=0.06). CONCLUSIONS: Acute administration of nifedipine improves both coronary and brachial artery vasodilator responses to ACh. Nifedipine improves coronary and peripheral endothelial function in patients with CAD.

Comparable prognostic value of vasodilator response to acetylcholine in brachial and coronary arteries for predicting long-term cardiovascular events in suspected coronary artery disease.

BACKGROUND: Vasodilator response to acetylcholine (ACh) (ie, endothelium-dependent dilation) is impaired in the peripheral and coronary circulation of patients with coronary risk factors and coronary artery disease (CAD). There is a close relationship of vasodilator response to ACh in both the coronary artery (CA) and the brachial artery (BA), but the comparative prognostic importance of these responses has not been fully investigated in relatively low-risk suspected CAD. METHODS AND RESULTS: The flow responses of both the CA and BA were measured in 70 patients with suspected CAD, excluding patients with triple-vessel disease and known peripheral or cerebrovascular disorders. A Doppler guidewire was placed into a major branch of the CA and a proximal portion of the left BA. ACh was infused at 10(-8), 10(-7) and 10(-6) mol/L for 3 min into the CA and at 7.5, 15, and 30 mug/min for 5 min into BA. The flow response was obtained by multiplying the average peak velocity by the cross-sectional area from quantitative angiography. Vasodilator response to ACh was assessed by the ratio of ACh-induced flow/baseline flow, expressed as coronary blood flow index (CBFI) or brachial blood flow index (BBFI). There were 39 CAD patients (61 +/- 8 years old) and 31 normal coronary patients (NL, 58 +/- 11 years old) who were followed up for 53 +/- 17 months. Eleven patients had coronary events (CE) during this period: 1 case of nonfatal myocardial infarction and 10 cases of unstable angina. A strong correlation between CBFI and BBFI was observed at middle-and high-doses of ACh (r=0.72, p<0.0001, 15 microg/min vs 10(-7) mol/L; r=0.76, p<0.0001, 30 microg/min vs 10(-6) mol/L). Kaplan-Meier analysis, using the best cut-off values obtained from receiver-operating characteristic curves for CE, revealed that both CBFI and CAFI were significant predictors for CE. CONCLUSIONS: The BA vasodilator response to optimal ACh dosage can be used as a surrogate prognostic predictor for coronary endothelial function tests in patients with suspected CAD.

Close relationship between the vasodilator response to acetylcholine in the brachial and coronary artery in suspected coronary artery disease.

BACKGROUND: Vasodilator response to acetylcholine (endothelium-dependent dilation) is impaired in the peripheral and coronary circulation in patients with coronary artery disease (CAD). The purpose of this study is to investigate if the vasodilator response to acetylcholine in the brachial artery (BA) correlates with the same response in the coronary artery (CA). STUDY: We measured the flow responses of BA and CA in 57 patients with suspected CAD. Doppler guidewire was placed into the proximal portion of the left BA and the major branch of CA. Acetylcholine was infused at 7.5, 15, and 30 mug/min for 5 min into BA and at 10(-8), 10(-7), 10(-6) M for 3 min into CA, respectively. The flow was calculated by multiplying average peak velocity by cross sectional areas obtained from quantitative angiography. Vasodilator response to acetylcholine was assessed by ratio of acetylcholine-induced flow/baseline flow. RESULTS: A total of 33 CAD patients (CAD group, 61+/-8 years old) and 24 normal coronary patients (NL group, 57+/-12 years old) were investigated. A strong correlation between the vasodilator response to acetylcholine in BA and CA was observed in both CAD and NL groups, only at two moderate doses of acetylcholine (CAD group, r=0.64, p<0.001, NL group, r=0.87, p<0.001, 15 microg/min vs. 10(-7) M; CAD group, r=0.68, p<0.001, NL group, r=0.72, p<0.001, 30 microg/min vs. 10(-6) M). No significant correlation was obtained during low dose acetylcholine infusion. CONCLUSIONS: The brachial artery vasodilator response to optimal acetylcholine doses is a useful surrogate for coronary endothelial function studies.

Provocation of microvessel spasm by low-dose acetylcholine in patients with suspected coronary artery disease--two case reports.

Endothelial dysfunction plays an important role in the pathogenesis of cardiac syndrome X, and intracoronary low-dose acetylcholine infusion is a widely used diagnostic modality for studying the coronary artery endothelial function. The authors herein report 2 cases of cardiac syndrome X with coronary artery endothelial dysfunction and microvessel spasm. The findings of non-invasive testing were positive for ischemia. Coronary angiograms appeared entirely normal in both cases. However, the intracoronary infusion of low-dose (1.5-15 microg/minute) acetylcholine demonstrated an impairment of the coronary blood flow response and consequently provoked an ST-segment elevation in an electrocardiogram. The coronary angiograms showed no spasm in the epicardial arteries. These patients are thus suggested to have cardiac syndrome X with microvessel spasms associated with coronary artery endothelial dysfunction.

Effect of chronic oral supplementation with vitamins on the endothelial function in chronic smokers.

Cigarette smoking has been associated with endothelial dysfunction including impaired endothelium-dependent flow-mediated dilation (FMD). In cigarette smokers, increased oxygen-derived free radicals have been suspected of being one of the major causes of endothelial dysfunction, owing possibly to the inactivation of nitric oxide by free radicals. Vitamins C and E are widely used antioxidant vitamins, which have also been reported to effectively improve the endothelial function in several conditions. To test the effect of moderate-term oral antioxidant vitamin supplementation on the endothelial function in smokers, the authors evaluated the combined effect of vitamins C and E, administered in normal dosages, on FMD in young male smokers. A prospective interventional study was performed. In 15 healthy male subjects (mean age, 24.4 +/-2.5 years old). They studied FMD in the brachial artery by using high-resolution ultrasound. The vascular effects of moderate-term oral supplementation with vitamin C (1.0 g/day) and vitamin E (500 mg/day) were determined during reactive hyperemia, which causes endothelium-dependent FMD. They performed a vascular function study 3 times including before vitamin supplement, after 25 days of vitamin supplement, and 4 weeks after the cessation of the vitamin supplement. The flow-mediated dilator response measurements were repeated twice a day before vitamin supplements, and the repeatability obtained from these measurements was found acceptable (variability of FMD <2%). The oral antioxidant vitamin supplement significantly restored FMD (3.8 +/-2.2% vs 5.9 +/-2.5%; p<0.05), however, this effect disappeared 4 weeks after the vitamin supplementations ended. The combined usual dosage of vitamins C and E supplements was found to improve the endothelial function in chronic smokers.