Effect of Limb Salvage by Excimer Laser Angioplasty Plus Low-Pressure Balloon Inflation in Chronic Limb-Threatening Ischemia Patients with Infrapopliteal Vessel Disease.

Background: Patients with chronic limb-threatening ischemia (CLTI) often exhibit long, diffuse, totally occluded and heavily calcified infrapopliteal (IP) lesions. This study evaluated limb salvage after peripheral excimer laser atherectomy (PELA) plus low-pressure balloon inflation (LPBI) without stent deployment in CLTI patients with severe IP disease. Methods: We retrospectively evaluated 70 consecutive patients with 109 IP vessels who underwent PELA plus LPBI from 2010 to 2013. Technical success was defined as at least one IP straight-line flow being achieved below the malleolus. Binary logistic regression was performed to identify factors associated with 6-month limb salvage. Results: Of the 109 IP vessels, 100 (91.7%) were totally occluded, and none of the patients received a stent. Of the 70 patients, 20% were octogenarians, and 85.8% had a Rutherford-Becker class 5 and 6. The technical success rate was 87.1% and 6-month limb salvage rate was 78.6%. Rutherford score was negatively correlated with clinical success (adjusted odds ratio 0.24; p = 0.028). No immediate major cardiovascular events were recorded during admission. Conclusions: PELA plus LPBI may be a treatment option for complex IP lesions in patients with CLTI. Higher Rutherford class was correlated with a lower 6-month limb salvage rate. However, a large-scale study with a control group is needed to clarify our results.

Increased Risk of Venous Thromboembolism in Women with Uterine Leiomyoma: A Nationwide, Population-Based Case-Control Study.

BACKGROUND: Venous thromboembolism (VTE) is a sex-specific disease that has different presentations between men and women. Women with uterine leiomyoma can present with VTE without exhibiting the traditional risk factors. We investigated the relationship between a history of uterine leiomyoma and the risk of VTE using the National Health Insurance Research Database (NHIRD). METHODS: We conducted a retrospective, nationwide, population-based case-control study using the NHIRD. We identified 2,282 patients with diagnosed VTE and 392,635 subjects without VTE from 2000 to 2013. After development of an age and index diagnosis year frequency-matched model and propensity score-matched model, 2 models with a case-to-control ratio of 1 to 4 were established. Using the diagnosis of uterine leiomyoma as the exposure factor, conditional logistic regression was performed to examine the association between uterine leiomyoma and VTE. Multiple logistic regression analysis was used to investigate the joint effect of uterine leiomyoma and comorbid diseases on the risk of VTE. RESULTS: A strong association was observed between uterine leiomyoma and VTE in the overall patient model, frequency-matched model and propensity score-matched model [p < 0.0001, odds ratio (OR): 1.547; p = 0.0005, OR: 1.486; p = 0.0405, OR: 1.26, respectively]. In the subgroup analyses, women with uterine leiomyoma who were ≥ 45 years old were less likely to experience VTE, but women with uterine leiomyoma and anemia, cancer, coronary artery disease or heart failure were more likely to experience VTE. CONCLUSIONS: Women with uterine leiomyomas have an increased risk of developing VTE, especially during reproductive periods or in the presence of specific diseases.

Atrial fibrillation originating from superior vena cava with atrial flutter-electrocardiogram pattern.

BACKGROUNDS: Substrate property is related to the genesis and maintenance of atrial fibrillation (AF). The aim of the study was to investigate the impact of substrate property on the electrocardiogram (ECG) in patients with AF originating from the superior vena cava (SVC). METHODS AND RESULTS: Seventy-six patients with AF originating from SVC who underwent catheter ablation were included from 2004 to 2013. Of these patients, 16 had a presentation of atrial flutter (AFL)-pattern ECG during AF (group 1), and 60 patients did not (group 2). There was no significant difference in clinical characteristics between the groups. The percentage of low voltage zone (LVZ) in SVC below the level of pulmonary artery in group 1 was significantly larger than that in group 2. The polarities of the flutter wave in 12-lead ECG were compared with another 26 subjects with reverse typical AFL. The ECG morphology was characterized by negative or biphasic P waves in lead V1 in most of the patients in group 1 (62.5%), which was analogous to that in reverse typical AFL. The negative polarity of flutter waves in aVL might distinguish SVC AF with an AFL-pattern from reverse typical AFL. CONCLUSION: The ECG characteristics of AF originating from SVC can mimic atypical AFL. LVZ in the SVC may be associated with the presentation of AFL-pattern ECG.

Novel electrophysiological characteristics of atrioventricular nodal continuous conduction curves in atrioventricular nodal re-entrant tachycardia with concomitant cavotricuspid isthmus-dependent atrial flutter.

AIMS: The detailed electrophysiological characteristics of patients with both atrioventricular nodal re-entrant tachycardia (AVNRT) and atrial flutter (AFL) have not been clarified. This study investigated the related electrophysiological differences in a large series of patients undergoing radiofrequency catheter ablation of AVNRT. METHODS AND RESULTS: A total of 1063 clinically documented AVNRT patients underwent catheter ablation were enrolled. Before the slow pathway (SP) ablation, 61 patients (5.7%) had inducible sustained cavotricuspid isthmus (CTI)-dependent AFL (Group 1), and the others (94.3%) without inducible sustained CTI-dependent AFL were defined as Group 2. The electrophysiological characteristics of these two groups and effect of the SP ablation on the inducibility of AFL were assessed. In Group 1, 36 patients (59%) had inducible/sustained AFL after the ablation of AVNRT and required a CTI ablation. The Group 1 patients had more AVNRT with continuous atrioventricular (AV) node function curves (P < 0.001, odds ratio = 7.55 [3.70-16.7], multivariate regression), and a younger age (P = 0.02, odds ratio = 1.02 [1.003-1.03], multivariate regression) than Group 2. The other characteristics were comparable between the two groups. The long-term follow-up (64.9 ± 34.9 months) revealed that the recurrence of AFL/atrial fibrillation was similar between the two groups (P > 0.05). CONCLUSION: Atrioventricular nodal re-entrant tachycardia patients with concomitant CTI-dependent AFL had more continuous AV node function curves. Forty-one per cent of these patients had non-inducible AFL after the SP ablation, indicating a slow conduction isthmus in the triangle of Koch area.

Thermal characteristics of aluminum nanoparticles and oilcloths.

Exothermic behavior of aluminum nanoparticles (ANP) in aqueous medium of various pH values and oilcloths (OC) composed of linseed oil, SAE 10W-40 engine oil, or SAE 20W-50 engine oil in cotton or nylon was studied. The experimental results revealed that for ANP hydrolysis, a deviation of pH value from 7 yielded a decrease in onset temperature (Tonset), peak temperature, no return temperature, self-accelerating decomposition temperature, time to T(onset), time to maximum rate (TMRad), and activation energy. Also, reaction order and frequency factor increased as pH value deviating from 7. For decomposition of oily materials, Tonset of OC was lower than that of pure oil, suggesting that cotton and nylon enhanced the combustibility of the three oils. Besides, total enthalpy of OC was larger than that of the corresponding pure oil. Nylon-based OC produced larger total enthalpy than cotton-based OC, while the latter yielded shorter oxidative induction time (OIT) than the former. Moreover, reasonable discrepancy between experimentally determined OIT and theoretically estimated TMRad was obtained. Hydrolysis of damped ANP and decomposition of OC could be derived from heat accumulation, leading to release of a considerable amount of thermal energy at relatively low Tonset.

Ventricular arrhythmias originating from the cardiac crux and the basal inferior segment of the interventricular septum in the patients with structural heart diseases: characteristics, mapping, and electrophysiological properties.

PURPOSE: There are few reports describing ventricular arrhythmias (VAs) from the crux and the corresponding endocardial site, i.e., the basal inferior segment of the interventricular septum (IVS). We aimed to investigate a distinct clinical group of VAs arising from the endocardium at this area in patients with structural heart diseases (SHD). METHODS: We included 17 patients with SHD and clinically documented VAs. Thirteen patients underwent endocardial mapping only. Three patients underwent both epicardial and endocardial approaches and one had only epicardial mapping. Eighteen VAs were identified, 14 focal and 4 reentrant VAs, confirmed by entrainment. RESULTS: There were 2 VAs from the crux, 5 VAs from the corresponding endocardial site in the right ventricle (RV), and 11 from the site in the left ventricle (LV). Compared with the VAs from RV endocardium, VAs from LV endocardium had a higher R wave in V3 than V2 (V2R/V3R ratio, 1.83 ± 0.84 vs. 0.86 ± 0.38, P = 0.008) and a higher V3 transition ratio percentage (2.16 ± 2.07 vs. 0.58 ± 0.62, P = 0.008). Combining all 16 patients with endocardial mapping, there were also lower bipolar voltages (1.21 ± 1.05 vs. 3.10 ± 2.65 mv, P < 0.0001), lower unipolar voltages (4.05 ± 1.92 vs. 5.75 ± 2.90 mv, P < 0.0001), and longer local electrocardiogram (EGM) lateness (157.6 ± 47.9 vs.140.3 ± 52.5 ms, P = 0.0001) in the dominant chambers. CONCLUSIONS: In VAs from the crux and the corresponding endocardial site, the complete ECG V2R/V3R ratio and V3 transition ratio percentage could differentiate the VAs from the RV or LV endocardium. The lower unipolar, bipolar voltage mapping, and longer EGM lateness are helpful to identify the abnormal substrate in the endocardium in these patients.

The Interaction Effects of Meteorological Factors and Air Pollution on the Development of Acute Coronary Syndrome.

This study investigated the interaction effects of meteorological factors and air pollutants on the onset of acute coronary syndrome (ACS). Data of ACS patients were obtained from the Taiwan ACS Full Spectrum Registry and comprised 3164 patients with a definite onset date during the period October 2008 and January 2010 at 39 hospitals. Meteorological conditions and air pollutant concentrations at the 39 locations during the 488-day period were obtained. Time-lag Poisson and logistic regression were used to explore their association with ACS incidence. One-day lag atmospheric pressure (AP), humidity, particulate matter (PM2.5, and PM10), and carbon monoxide (CO) all had significant interaction effects with temperature on ACS occurrence. Days on which high temperatures (>26 °C) and low AP (<1009 hPa) occurred the previous day were associated with a greater likelihood of increased incidence of developing ACS. Typhoon Morakot was an example of high temperature with extremely low AP associated with higher ACS incidence than the daily average. Combinations of high concentrations of PM or CO with low temperatures (<21 °C) and high humidity levels with low temperatures were also associated with increased incidence of ACS. Atmospheric pollution and weather factors have synergistic effects on the incidence of ACS.

Novel electrocardiogram and electrophysiological findings for differentiating idiopathic left posterior papillary muscle and left posterior fascicular ventricular arrhythmias.

PURPOSE: Differentiation between idiopathic left posterior fascicular ventricular arrhythmias (LPF-VAs) and posterior papillary muscle (PPM) VAs is of clinical value. This study aimed to develop an algorithm to distinguish PPM-VAs from LPF-VAs. METHODS: This study enrolled 73 consecutive cases, including 31 with PPM-VAs and 42 with LPF-VAs, undergoing successful ablation by using 3D mapping and intracardiac echography to confirm the origin of the VAs. Electrocardiographic and electrophysiological parameters were compared between two groups. RESULTS: The 12-lead electrocardiography of the PPM-VAs was characterized by a longer QRS duration than that in LPF-VAs (154.4 ± 14.5 vs. 132.3 ± 13.1 ms, P < 0.001). A QRS duration ≥133 ms was observed in all patients (100%) with PPM-VAs and 13/42 (31.0%) patients with LPF-VAs. The conduction duration from the earliest left ventricular activation site of the VA to the proximal right bundle branch (VA-RBB) was longer in patients with PPM-VAs than LPF-VAs (51.3 ± 12.2 vs. 23.6 ± 7.7 ms, P < 0.001). Based on the ROC analysis, a VA-RBB >36 ms was recognized in 28/31 patients with PPM-VAs (90.3%) and 2/42 with LPF-VAs (4.8%). An algorithm incorporating a QRS duration of ≥133 ms with a conduction duration of a VA-RBB of >36 ms could yield a sensitivity of 90.3% and specificity of 100% for discriminating PPM-VAs from LPF-VAs. CONCLUSIONS: The novel algorithm incorporating a QRS duration of ≥133 ms with a conduction duration of the VA-RBB of >36 ms could be useful in differentiating PPM-VAs from LPF-VAs.

Impact of aortic encroachment to left atrium on non-pulmonary vein triggers of atrial fibrillation.

BACKGROUND: Aortic dilatation was frequently observed in patients with atrial fibrillation (AF) and non-pulmonary vein (PV) triggers are important for mapping and ablation of AF. We hypothesized that the aortic encroachment area over left atrium (LA) could contribute to the local substrate characteristics. METHODS: We studied 32 consecutive patients of AF (age=57.34±8.07, male=30), including 26 paroxysmal and 6 persistent AFs. Anatomic relationship between LA and aorta, and electrophysiological characteristics of the encroachment areas were investigated. IRB approval was taken. RESULTS: The LA bipolar voltage (mean 0.49±0.26mV) was lower at aortic encroached area compared to global LA (mean 1.52±0.48mV) and it was statistically significant (p<0.001). There was a linear correlation between the voltages of LA and distance from the aorta to the aortic encroachment area of LA (p<0.001, R=0.616). Non-PV triggers were observed in 34.37% (n=11) of total patients. The initiation of AF in aortic encroached area was seen in 45.45% (n=5) of non-PV trigger and 15.62% of total patients. All the patients were followed up for 6months and 4 (14.81%) out of 27 patients without trigger at aortic encroached site of LA and 1 (20%) out of 5 patients with trigger at aortic encroached site of LA had recurrence of AF. CONCLUSION: The aorta contributed to low voltages on its encroachment area over the anterior wall of LA. Non-pulmonary vein triggers originating from the aortic encroachment area were found in 15.62% of total patients. Careful evaluation of the anatomical relationship between LA and aorta is important during AF ablation for a better long term outcome.

The Different Substrate Characteristics of Arrhythmogenic Triggers in Idiopathic Right Ventricular Outflow Tract Tachycardia and Arrhythmogenic Right Ventricular Dysplasia: New Insight from Noncontact Mapping.

BACKGROUND: The aim of this study was to investigate the different substrate characteristics of repetitive premature ventricular complexed (PVC) trigger sites by the non-contact mapping (NCM). METHODS: Thirty-five consecutive patients, including 14 with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC) and 21 with idiopathic right ventricular outflow tract tachycardia (RVOT VT), were enrolled for electrophysiological study and catheter ablation guided by the NCM. Substrate and electrogram (Eg) characteristics of the earliest activation (EA) and breakout (BO) sites of PVCs were investigated, and these were confirmed by successful PVC elimination. RESULTS: Overall 35 dominant focal PVCs were identified. PVCs arose from the focal origins with preferential conduction, breakout, and spread to the whole right ventricle. The conduction time and distance from EA to BO site were both longer in the ARVC than the RVOT group. The conduction velocity was similar between the 2 groups. The negative deflection of local unipolar Eg at the EA site (EA slope3,5,10ms values) was steeper in the RVOT, compared to ARVC patients. The PVCs of ARVC occurred in the diseased substrate in the ARVC patients. More radiofrequency applications were required to eliminate the triggers in ARVC patients. CONCLUSIONS/INTERPRETATION: The substrate characteristics of PVC trigger may help to differentiate between idiopathic RVOT VT and ARVC. The slowing and slurred QS unipolar electrograms and longer distance from EA to BO in RVOT endocardium suggest that the triggers of ARVC may originate from mid- or sub-epicardial myocardium. More extensive ablation to the trigger site was required in order to create deeper lesions for a successful outcome.

Different characteristics and electrophysiological properties between early and late recurrences after acute successful catheter ablation of idiopathic right ventricular outflow tract arrhythmias during long-term follow-up.

BACKGROUND: Radiofrequency catheter ablation (RFCA) is an effective therapeutic strategy in eliminating drug-refractory idiopathic right ventricular outflow tract ventricular arrhythmias (RVOT VAs). It remains unclear what factors affect early and late VA recurrences after ablation. OBJECTIVE: The aim of our study was to elucidate the differences between early and late recurrences after acute successful RFCA of RVOT VAs in a long-term follow-up. METHODS: A total of 220 patients with acute successful RFCA of RVOT VAs were enrolled. Detailed clinical characteristics and assessments by noninvasive and invasive electrophysiology study were explored to predict the overall, early (≤1 year), and late VA (>1 year) recurrences. RESULTS: During a mean follow-up of 34.15 ± 33.74 months, 45 of 220 patients (20.5%) documented recurrence of RVOT VAs after the initial RFCA. Of these patients, 26 patients (57.8%) with recurrent VAs showed similar morphology, and 19 (42.2%) were different. Patients with recurrent VAs were associated with a higher incidence of hypertension, higher systolic blood pressure, identification of foci by pace mapping alone, shorter earliest activation time, more radiofrequency pulses required, and VA originating from the anterior free wall. Multivariate analysis demonstrated that mapping strategy and shorter earliest activation time preceding VA were associated with early recurrences (hazard ratio [HR] 2.26; 95% confidence interval [CI] 1.49-3.42; P < .001; and HR 0.91; 95% CI 0.85-0.98; P = .008, respectively), whereas hypertension was associated with late recurrence (HR 3.48; 95% CI 1.34-9.07; P = .001). CONCLUSION: RFCA is an effective strategy in the elimination of RVOT VAs. However, early and late recurrences occur commonly. Patients with early and late VA recurrences demonstrated nonuniform patterns of clinical characteristics and electrophysiological properties.