Flutter Wave Morphology of Peri-Mitral Atrial Flutters Is Mainly Determined by Right Atrial Activation: Insights From High-Resolution Mapping.

BACKGROUND: Peri-mitral atrial flutters frequently develop post-atrial fibrillation ablation or postcardiac surgery. The determinants of the flutter wave morphology on surface ECG have been less studied. METHODS: We retrospectively reviewed 24 patients with peri-mitral atrial flutters who underwent biatrial high-resolution mapping at 3 institutions with LUMIPOINT software. We analyzed the overlap between the right atrial (RA) activation time and flutter wave duration and compared the proportion of the endocardial area that was activated in both atria during the flutter wave duration. Biatrial activation patterns and interatrial conductions were also identified. RESULTS: The mean tachycardia cycle length was 264±60 ms, with RA activation time 155±45 ms (60.8±20.6% of the tachycardia cycle length), and the flutter wave duration 107±31 ms (41.6±11.7% of the tachycardia cycle length). The overlap between the RA activation time and the flutter wave duration was 102±29 ms, which takes 68.5±17.2% of the RA activation time and 95.7±9.1% of the flutter wave duration, respectively. Quantitative analysis also showed that during the flutter wave duration, more percentage of the endocardial area was activated in the RA than in the left atrium (73.0±12.7% versus 45.2±13.0%, P<0.001). We consistently observed that the RA anterior wall rightward activation corresponded to the positive component in V1 in both flutter patterns, and the RA downward activation corresponded to the positive component in the counterclockwise group or the upward activation corresponded to the negative component in the clockwise group in the inferior leads. The passive RA activation patterns were varied with spontaneous atrial scarring or previous linear ablation. CONCLUSIONS: ECG flutter wave morphology of peri-mitral atrial flutters is mainly dependent on RA activation patterns.

Circumferential pulmonary vein antrum ablation for the treatment of paroxysmal atrial fibrillation: A randomized controlled trial.

BACKGROUND: It remains unclear whether the curative result of paroxysmal atrial fibrillation (PAF) is a result of pulmonary vein (PV) isolation, PV antrum modification (PVAM), or both. We hypothesized that sufficient antrum modification (PVAM) is as important as PV isolation (PVI) for atrial fibrillation (AF) control and that PVAM can be evaluated by quantified lesion deployment using a force-sensing catheter. METHODS AND RESULTS: Patients of symptomatic PAF were randomly assigned 2:1 into a PVAM group or a circumferential PV isolation (CPVI) group. In the PVAM group, circumferential quantitative ablation evaluated by automatical VisiTag module was performed. In the CPVI group, conventional circumferential ablation was performed to achieve the end point of all-PV isolation. In total, 180 patients with PAF were enrolled and randomly assigned to either the PVAM group (n = 120) or the CPVI group (n = 60). A total of 179 patients successfully underwent ablation. In the PVAM group, 68 patients achieved all PVI (PVAM-PVI), while 51 did not (PVAM-non-PVI). At 18 months, there was no significant difference in the maintenance of sinus rhythm between the PVAM and CPVI groups (84.9 vs 79.7%, P = .382). The PVAM-PVI subgroup demonstrated a higher arrhythmia-free survival compared with the PVAM-non-PVI subgroup (92.6 vs 74.5%, P = .006) and the CPVI group (92.6 vs 79.7%, P = .036). CONCLUSIONS: The trial shows that sufficient force-sensing guided PVAM can result in satisfying outcomes in PAF patients. Notably, sufficient PVAM with all-PV isolated will further increase the success rate.

Phosphorene nanocomposite with high environmental stability and antifouling capability for simultaneous sensing of clenbuterol and ractopamine.

A series of phosphorene (BP) nanocomposites was prepared to realize simultaneous electrochemical determination of clenbuterol (CLB) and ractopamine (RAC). CLB and RAC are the most commonly used ß-agonists in animal-derived food. The BP nanohybrid was obtained by co-decoration with both mono(6-mercapto-6-deoxy)-ß-cyclodextrin and poly(3,4-ethylenedioxythiophene) nanoparticles. It displays high stability, antifouling capability, a large electrochemical active surface and good electrochemical response. The electrochemical assisted antifouling strategy was selected by further eliminating the fouling of the electrode surface using continuous cyclic voltammetry. The electrode was employed for electrochemical sensing of CLB and RAC at typical peak voltages of 0.8 and 1.0 V (vs. SCE). Responses are linear in the 0.3-90 µM concentration range for CLB, and from 0.3 to 9.4 µM for RAC under optimal conditions. The limit of detection are 0.14 and 0.12 µM, respectively. The sensor was employed for simultaneous determination of CLB and RAC in (spiked) beef, feed and bovine serum samples with acceptable recoveries. Graphical abstractAn electrochemically assisted anti-fouling method for simultaneous voltammetric nanosensing of clenbuterol (CLB) and ractopamine (RAC) in edible cattle product samples using high-stable and anti-foul phosphorene (BP) co-decorated with mono(6-mercapto-6-deoxy)-ß-cyclodextrin (S-ß-CD) and poly(3,4-ethylenedioxythiophene) (PEDOTNPs).

[Materiamedica literature study on medicinal properties and utility of four kinds of Alpinia Chinese medicines].

In order to explore the correlation between the medicinal properties，efficacy and application in the same genetic relationship，explain the scientific connotation of the medicinal properties and effects of traditional Chinese medicines(TCM)，promote the academic development of the theory of traditional Chinese medicines，and provide reference for the research and development of the traditional Chinese medicines of a same genus. In this paper, a literature study of ancient and modern works of Chinese herbal medicine was conducted to investigate the correlation between the properties, meridians tropism, efficacy and application of Alpinia officinarum， A. katsumadai， Galangae Fructus and Alpinae Oxyphyllae Fructus, four kinds of Alpinia Chinese medicines．The results showed that the similar properties of these four kinds of Alpinia Chinese medicines included that they were acrid, warm,and mainly getting into the spleen and stomach channels; the similar efficacies included that dispelling cold，relieving pain，warming stomach，anti-nausea，anti-diarrheal，reinforcing spleen to promote digestion and other effects; in application aspects, the similarities were that they were all mainly used in treatment of catching cold or spleen deficiency induced by abdominal pain，vomiting，diarrhea,diet indigestion, etc. indicating that phylogenetic relationship was closely related with the herbal properties, efficacy and application. It is an effective way to explore，collate and research traditional Chinese medicine by using plant phylogenetic relationships in exploring the internal relations and laws of TCM theories，material bases, pharmacological effects and clinical applications, also with a strong maneuverability to explain their scientific connotation.

Electrophysiological Characteristics of Bundle Branch Reentry Ventricular Tachycardia in Patients Without Structural Heart Disease.

BACKGROUND: The distinct electrophysiological features of bundle branch reentry ventricular tachycardia (VT) in patients without structural heart disease have not been systemically characterized. METHODS: Nine patients (mean age, 29.6 years) with normal left ventricular function were enrolled. Bundle branch reentry VT with right and left bundle branch block (BBB) patterns was induced in 1 and 9 patients, respectively. The right bundle was attempted to record by a 6F decapolar or quadripolar catheter. Electroanatomic mapping of the left ventricle was performed in 6 patients. In all left BBB pattern VT, the mean VT cycle length was 329.3±89.1 ms, and the median HV interval during tachycardia was longer than that of baseline (78 [73-100] versus 71 [64.5-88] ms; P=0.11). RESULTS: The H-RB interval during VT was slightly shorter (P=0.14); however, the median RB-V interval was markedly longer than that during sinus rhythm (50 [29.5-83] versus 30 [8-51] ms; P=0.043]. In 6 patients with 3-dimensional mapping of the left ventricle, a slow anterograde or retrograde conduction over left HIS-Purkinje system with normal myocardial voltage was identified. In addition, Purkinje-related VTs (1.0±1.3 types) were also induced in 5 patients. Ablation was applied in distal left BB in patients with baseline left BBB and in one narrow QRS patient with sustained Purkinje-related VT, whereas right BB was targeted in other patients. During a mean follow-up of 31.4 months, frequent premature ventricular contractions occurred in one patient, and new VT developed in the other patient. CONCLUSIONS: Bundle branch reentry VT can occur in young patients with extensive conduction disturbances within HIS-Purkinje system. Ablation targeting at the distal left BB which bifurcates into left posterior and anterior fascicle can preserve the residual atrioventricular conduction, but intensive follow-up is needed.

Late cure of focal ventricular arrhythmias post-catheter ablation: electrophysiological characteristics and long-term outcome.

PURPOSE: Late cure after a previously failed ablation of ventricular arrhythmias (VAs) is a relatively common phenomenon. The present study sought to delineate the incidence and electrophysiological characteristics of late cure in idiopathic VA patients. METHODS: Totally, 45 idiopathic VA cases (mean age 44 ± 18 years, 27 males) either failed acutely or recurred within 12 h were enrolled in this study. Based on intensive clinical observations in the acute period, 19 (42%) patients demonstrated late cure in the first week after the procedure. RESULTS: The late cure patients had significantly better acute and cumulative ablation effects during the procedure than did those without a late cure. Additionally, they had a prediction that originated from the right ventricular outflow tract, aortic-mitral continuum, and left summit area relative to other sites (13/18 vs 6/27, p < 0.01). In a median follow-up of 24 [14, 46] months, 7/19 (37%) patients had their VAs recurred. The late cure group had significantly more patients cured at long-term follow-up than those without (12/19 vs 0/26, p < 0.01). A cutoff value of the "time to eliminate VAs" > 7.0 s was able to predict a long-term recurrence of the VAs with 62.5% sensitivity and 85.7% specificity. CONCLUSIONS: The late cure of VAs occurs in more than one third of patients who have a seemingly unsuccessful ablation session, which is clustered in the first week after the procedure. However, long-term recurrence of VAs occurred in 37% of the late cure patients, emphasizing the importance of long-term follow-up.

Idiopathic isolated fibrotic atrial cardiomyopathy underlies unexplained scar-related atrial tachycardia in younger patients.

Aims: Unexplained scar-related atrial tachycardia (AT) has been frequently encountered in clinical practice. We hypothesized that idiopathic, isolated fibrotic atrial cardiomyopathy (ACM) underlies this rhythm disorder. This study was aimed to characterize the underlying substrate and to explore the aetiology of this unexplained scar-related AT. Methods and results: Twenty-six (11 men, aged 46 ± 13 years) of 52 non-surgical scar-related AT patients identified by three-dimensional voltage mapping were enrolled in this prospective observational study. Multimodality image examinations (echocardiography, cardiac magnetic resonance, 99Tc single-photon emission computed tomography), ventricular voltage mapping, and intracardiac pressure curve recording ruled out ventricular involvement. Catheter ablation was acutely successful for all the patients, and pacemaker implantation was performed in seven patients who presented sinus node dysfunction or atrial standstill after termination of the AT. In three patients with multiple AT recurrences, the diseased areas of the right atrium were resected and dechannelled via mini-invasive surgical interventions. Histological examinations revealed profound fibrosis without amyloidosis or adipose deposition. Viral and familial investigations yielded negative results. Fibrosis progression over a median of 45 (5-109) months of follow-up manifested as atrial arrhythmia recurrence in seven patients and atrial lead non-capture due to newly developed atrial standstill in two patients. Two patients suffered four ischaemic stroke events before receiving anticoagulation treatment. Conclusion: Isolated, fibrotic ACM may underlie the idiopathic scar-related ATs. This novel cardiomyopathy has unique clinical characteristics with high morbidity including stroke and warrants specific therapeutic strategies. Further investigations are required to determine the aetiology and mechanism.

Peri-mitral atrial flutter: personalized ablation strategy based on arrhythmogenic substrate.

Aims: The aim of this study is to characterize the arrhythmogenic substrate for peri-mitral atrial flutter (PMAFL), thereby determining a personalized ablation strategy to treat PMAFL. Methods and results: Thirty-six consecutive PMAFL patients (mean age: 63.8 ± 11.3, 23 males) underwent detailed three-dimensional electroanatomic mapping in left atrium (LA). The LA was divided into septal-anterior wall (SAW), posterior inferior wall (PIW), and mitral isthmus (MI) region, respectively. Ablation strategy was determined based on the endocardial bipolar voltage map. Based on electrophysiological substrates, 10, 17, and 9 cases were classified into iatrogenic, spontaneous, and no-substrate PMAFL, respectively. The mean voltage in SAW was significantly lower in spontaneous PMAFL (iatrogenic: 1.07 ± 0.66 mV; spontaneous: 0.65 ± 0.44 mV; no-substrate: 1.60 ± 0.53 mV, P <0.001), while iatrogenic PMAFL patients had the lowest voltage in MI (0.51 ± 0.23 mV vs. 1.55 ± 0.78 mV, 1.61 ± 0.56 mV, P <0.001). No low-voltage or slow conduction zone was found in the no-substrate PMAFL group. Fifteen spontaneous PMAFLs were successfully terminated by modified septal-anterior (9/10) or conventional anterior ablation line (6/7). Eight iatrogenic PMAFLs (8/10) were terminated by reinforcing the previous ablation areas. Cardioversion without PMAFL ablation was done in no-substrate PMAFL patients. After a median follow-up of 12 (7-39) months, two spontaneous PMAFL patients received redo procedures for recurrence due to "gap" conduction. Conclusions: The ablation strategy for PMAFL patients should be based on the arrhythmogenic substrate, but not the indiscriminate MI ablation. No-substrate PMAFLs during AF ablation could be monitored after cardioversion and might not need further ablation.

Prolonged Sinus Pauses upon Termination of Paroxysmal Atrial Fibrillation: Abnormal Right Atrial Electrophysiologic and Electroanatomic Findings.

The efficacy of pulmonary vein antral isolation for patients with prolonged sinus pauses (PSP) on termination of atrial fibrillation has been reported. We studied the right atrial (RA) electrophysiologic and electroanatomic characteristics in such patients. Forty patients underwent electroanatomic mapping of the RA: 13 had PSP (group A), 13 had no PSP (group B), and 14 had paroxysmal supraventricular tachycardia (control group C). Group A had longer P-wave durations in lead II than did groups B and C (115.5 ± 15.4 vs 99.5 ± 10.9 vs 96.5 ± 10.4 ms; P=0.001), and RA activation times (106.8 ± 13.8 vs 99 ± 8.7 vs 94.5 ± 9.1 s; P=0.02). Group A's PP intervals were longer during adenosine triphosphate testing before ablation (4.6 ± 2.3 vs 1.7 ± 0.6 vs 1.5 ± 1 s; P <0.001) and after ablation (4.7 ± 2.5 vs 2.2 ± 1.4 vs 1.6 ± 0.8 s; P <0.001), and group A had more complex electrograms (11.4% ± 5.4% vs 9.3% ± 1.6% vs 5.8% ± 1.6%; P <0.001). Compared with group C, group A had significantly longer corrected sinus node recovery times at a 400-ms pacing cycle length after ablation, larger RA volumes (100.1 ± 23.1 vs 83 ± 22.1 mL; P=0.04), and lower conduction velocities in the high posterior (0.87 ± 0.13 vs 1.02 ± 0.21 mm/ms; P=0.02) and high lateral RA (0.89 ± 0.2 vs 1.1 ± 0.35 mm/ms; P=0.04). We found that patients with PSP upon termination of atrial fibrillation have RA electrophysiologic and electroanatomic abnormalities that warrant post-ablation monitoring.

Efficient Discovery of Quality Control Markers for Gastrodia elata Tuber by Fingerprint-Efficacy Relationship Modelling.

INTRODUCTION: Gastrodia elata tuber (GET) has been widely used in China as a famous herbal medicine. However, the quality control markers (QCMs) for GET still need further investigation. OBJECTIVE: To develop a rational strategy based on fingerprint-efficacy relationship modelling to discover the efficacy-related QCMs, using GET as a case study. METHODOLOGY: The high-performance liquid chromatography (HPLC) fingerprints of 13 batches of GET extracts were established and 10 common peaks were structurally characterised by HPLC coupled with quadrupole time-of-flight mass spectrometry (QTOF-MS). The neuroprotective effects of GET samples were evaluated using the in vitro model of ß-amyloid peptide (Aß25-35 )-induced PC12 cell death. The fingerprint-efficacy relationship of chemical fingerprints and neuroprotective effects was linked by orthogonal projection to latent structure-discriminant analysis (OPLS-DA) model. RESULTS: The chemical combination of 5-hydroxymethyl-2-furaldehyde (5-HMF), parishin B (PB) and parishin C (PC) was discovered and confirmed as QCMs of GET by the OPLS-DA method. The selected QCMs allowed to evaluate the relative quality of GET samples. CONCLUSION: This study has demonstrated that the rational strategy based on fingerprint-efficacy relationship modelling might be generally applicable for the quality control of herbal medicines. Copyright © 2017 John Wiley & Sons, Ltd.

Catheter Ablation of Nonparoxysmal Atrial Fibrillation Using Electrophysiologically Guided Substrate Modification During Sinus Rhythm After Pulmonary Vein Isolation.

BACKGROUND: The high incidence of postprocedural atrial tachycardia reduces the absolute arrhythmia-free success rate of extensive ablation strategies to treat nonparoxysmal atrial fibrillation (NPAF). We hypothesized that a strategy of targeting low-voltage zones and sites with abnormal electrograms during sinus rhythm (SR-AEs) in the left atrium after circumferential pulmonary vein isolation and cavotricuspid isthmus ablation in patients with NPAF is superior. METHODS AND RESULTS: A total of 86 consecutive patients with NPAF were enrolled in study group. After circumferential pulmonary vein isolation, cavotricuspid isthmus ablation and cardioversion to SR, high-density mapping of left atrium was performed. Areas with low-voltage zone and SR-AE were targeted for further homogenization and elimination, respectively; 78 consecutive sex- and age-matched patients with NPAF who were treated with the stepwise approach served as the historical control group. In the study group, 92% (79/86) were successfully cardioverted after circumferential pulmonary vein isolation and cavotricuspid isthmus ablation. Among the patients converted to SR, 70% (55/79) had low-voltage zone and SR-AE and received additional ablation, whereas in 30% (24/79) without SR-AE or low-voltage zone, no further ablation was performed. During a follow-up period of >30 months, the Kaplan-Meier estimated probability to maintain SR at 24 months was 69.8% versus 51.3%. And after a single procedure, 3.5% (3/86) developed postprocedural atrial tachycardia in study group, compared with 30% (24/78) in control group (P=0.0003). CONCLUSIONS: A strategy of selective electrophysiologically guided atrial substrate modification in SR after circumferential pulmonary vein isolation and cavotricuspid isthmus ablation is clinically more effective than the stepwise approach for NPAF ablation. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov. Unique identifier: NCT01716143.

Non-contact mapping-guided ablation of ventricular arrhythmias originating from the pulmonary artery.

AIMS: To identify unique electrophysiological characteristics of pulmonary artery (PA) ventricular arrhythmias (VA) and determine long-term clinical outcomes following non-contact mapping (NCM)-guided ablation. METHODS AND RESULTS: The NCM array was deployed in consecutive patients undergoing clinically indicated ablation of outflow tract (OT) VA with left bundle branch block morphology, inferior axis and the precordial lead transition zone ≥ V3. Activation, pace and NCM mapping parameters, and electrocardiogram analysis of PA VA patients were compared with 50 patients with right ventricular OT (RVOT) or aortic coronary cusps (ACC) foci. Of 170 consecutive patients, 20 (12%) patients (8 male, 39.7 ± 12.8 years old) with PA VA were identified. Electrocardiogram morphologies of PA ventricular tachycardia (VT) (located 10.8 ± 15.1 mm above the PV) were indistinguishable from RVOT VT, particularly those arising from the septal RVOT. Pulmonary artery VT can be mapped and ablated by targeting the site of earliest activation on NCM maps, with success rates of 90% after a single procedure, without anti-arrhythmics and mean follow-up of >5 years. Pace-mapping in the PA is complicated by frequent inability to capture (P < 0.01). Small far-field atrial potentials and smaller ventricular electrograms were more frequently recorded at successful sites of ablation in the PA (P < 0.05). CONCLUSION: Non-contact mapping is a useful technique to map PA VT and ablation at sites of earliest activation above the pulmonary valve is associated with excellent long-term clinical success.

Prevention of postsurgical atrial tachycardia with a modified right atrial free wall incision.

BACKGROUND: Most postsurgical macroreentry atrial tachycardias (PS-MATs) are atriotomy related; however, underlying mechanisms and prevention remain undefined. OBJECTIVE: The purpose of the present study was to investigate the electrophysiological and histologic bases of right atriotomy incision arrhythmogenicity and whether a modified atriotomy that extends the incisional line to the tricuspid annulus (TA) and inferior vena cava (IVC) prevents PS-MAT. METHODS: Atrial arrhythmia induction and electrophysiological and histologic characteristics were studied 8 weeks after right atriotomy in 30 adult swine according to incision distance to TA or IVC (groups A, B, and C: broad, narrow, and closed corridors, respectively; group D, no-incision sham; n = 6 per group, except n = 12 for group B). RESULTS: Sustained PS-MATs were induced and mapped in the broad- and narrow-corridor groups (A, 1 of 6 [16.7%] vs B, 5 of 12 [41.7%]) but not in the closed-corridor (C) or sham (D) groups (P = .087). With 20-ms pacing cycle-length decrements (from 350 to 270 ms), mean conduction time over 20 mm at the atriotomy-to-TA corridor was 29.2 ± 2.2, 31.0 ± 4.2, 26.0 ± 1.9, and 17.0 ± 1.4 ms for 5 and 10 mm (both group B), 15 mm (group A), and sham incision (P = .017), respectively. Conduction properties correlated with histologic findings: the wider the corridor, the healthier its tissue. In group C (modified atriotomy), both corridors were replaced by dense scar with complete conduction block. CONCLUSION: Atriotomy corridor width determines conduction properties and contributes to arrhythmogenicity. A modified right atriotomy that extends to the TA and IVC prevents PS-MAT.

Idiopathic accelerated idioventricular rhythm or ventricular tachycardia originating from the right bundle branch: unusual type of ventricular arrhythmia.

BACKGROUND: Accelerated idioventricular rhythm (AIVR) or ventricular tachycardia (VT) originating from the right bundle branch (RBB) is rare and published clinical data on such arrhythmia are scarce. In this study, we will describe the clinical manifestations, diagnosis, and management of a cohort of patients with this novel arrhythmia. METHODS AND RESULTS: Eight patients (5 men; median age, 25 years) with RBB-AIVR/VT were consecutively enrolled in the study. Pharmacological testing, exercise treadmill testing, electrophysiological study, and catheter ablation were performed in the study patients, and ECG features were characterized. All RBB-AIVR/VTs were of typical left bundle-branch block morphology with atrioventricular dissociation. The arrhythmias, which demonstrated chronotropic variability, were often isorhythmic with sinus rhythm and were accelerated by physical exercise, stress, and intravenous isoprenaline infusion. The rate of RBB-AIVR/VT varied from 45 to 200 beats per minute. Two patients experienced syncope, and 3 had impaired left ventricular function. Metoprolol was proven to be the most effective drug to decelerate the arrhythmia rate and relieve symptoms. Electrophysiology study was performed in 5 patients and the earliest activation with a sharp RBB potential was localized in the mid or distal RBB area. Catheter ablation terminated the arrhythmia with subsequent RBB block morphology during sinus rhythm. During follow-up, patients' symptoms were controlled with normalization of left ventricular function either on metoprolol or by catheter ablation. CONCLUSIONS: RBB-AIVR/VT is an unusual type of ventricular arrhythmia. It can result in significant symptoms and depressed ventricular function and can be successfully treated with catheter ablation.

Mapping of focal atrial tachycardia with an uninterpretable activation map after extensive atrial ablation: tricks and tips.

BACKGROUND: Atrial tachycardias (ATs) after extensive ablation are increasingly common and challenging arrhythmias. The prolonged intra-atrial conduction time (IACT) during ATs in the milieu may complicate the mapping of focal ATs. In this present study, we aim to characterize the electrophysiological features of ATs in this unique setting and to delineate an effective mapping strategy further. METHODS AND RESULTS: In total, 13 patients (average age, 59±7 years) in a cohort of 80 patients referred for AT ablation were selected for the study. The patients all demonstrated an undistinguishable map not ready to be interpreted the 3-dimensional mapping. A total of 13 ATs were mapped with mean tachycardia cycle length of 296±70 ms. Two activation patterns were identified, which were referred to as pseudo-macroreentry and chaotic activation. The former was a focal AT originating from the vicinity of an area of conduction block with the IACT less than the window of interest duration (4 cases; IACT/window of interest ratio range, 0.93-0.98). The latter refers to a focal AT exhibiting a disorderly color mapping display with IACT exceeding the window of interest duration (9 cases; IACT/window of interest ratio range, 1.02-1.29). The IACT was determined after resetting the annotation. All ATs were successfully eliminated at the originating site. CONCLUSIONS: We delineated a series of focal ATs in the setting of a significantly prolonged IACT encountered in patients after previous extensive ablation. Two activation patterns were identified, which may help facilitate the mapping of focal ATs in this setting.

Tachycardiomyopathy complicated by focal atrial tachycardia: incidence, risk factors, and long-term outcome.

OBJECTIVE: Focal atrial tachycardias (ATs) are known to have the potential to develop tachycardiomyopathy (TCM). The aim of the study was to investigate the incidence, risk factors, and long-term outcome of TCM patients complicated by focal ATs. METHODS AND RESULTS: A total of 237 patients undergoing electrophysiological studies were enrolled, among which 216 patients were diagnosed as focal ATs. In total, 18 patients (8.3%, 13 males) were identified to have TCM. The TCM patients were younger (29.8 ± 20.1 vs. 45.9 ± 17.3; P < 0.000) and were more frequently males (13/18 vs. 80/198; P = 0.014). The ATs were more likely to be persistent (11/18 vs. 32/198; P < 0.001). There was no difference between the 2 groups in terms of the tachycardia cycle length (392 milliseconds vs. 380 milliseconds; P = 0.56) and heart rate (144 bpm vs. 156 bpm; P = 0.15). The persistence and incidence of symptoms and prevalence of structural heart disease were comparable between the groups. In a multivariable analysis, the younger age and persistent nature were independently associated with TCM. In a 56 ± 21-month follow-up, all TCM patients had improved left ventricle ejection fraction after successful catheter ablation or medical therapy (43.9 ± 5.8% vs. 61.1 ± 3.5%; P ＜ 0.05). However, 1 patient suffered sudden cardiac death due to unauthorized withdrawal of the drug and progressive heart failure. CONCLUSIONS: The incidence of TCM in focal ATs patients was 8.3%. Younger age and persistent nature were the independent risk factors of TCM. Most TCM patients had a benign outcome; however, long-term risk of sudden death does exist.

[Determination of the trace elements in Shengmai San decoction by ICP-AES].

The method for the determination of the trace elements in Shengmai San by inductively coupled plasma atomic emission spectrometry (ICP-AES) was presented. The contents and solubility of the trace elements in Shengmai San with different ginseng were compared. The recovery rates of the procedure were between 95.2% and 112.4%, and the RSDs were between 0.70% and 5.9%. When the ginseng was western genseng in the Shengmai San, the solubility of trace elements was the highest. The couple of Shengmai San was proved reasonable. The method was simple, rapid, precise, convenient and suitable for traditional Chinese medicine.