Diagnosis Of Tachycardia Research Articles

NEW ELECTROCARDIOGRAPHIC CRITERIA FOR DIFFERENTIAL DIAGNOSIS OF TACHYCARDIAS WITH ADVANCED QRS COMPLEXES ACCORDING TO THE TYPE OF BLOCKADE OF LEFT BUNDLE OF HIS

Aim. To evaluate standard 12-lead electrocardiogram (ECG) indices for the differential diagnosis of left bundle branch block (LBBB) tachycardias.Material and Methods. The study analyses 244 ECG indices in 63 retrospective patients (85 males and 39 females aged 50±12 years) with LBBB type tachycardias. The electrophysiological study identified ventricular tachycardias (VT) (VT group, n=20), supraventricular tachycardias (SVT) with LBBB (SVT+LBBB group, n=23) or antidromic SVTs (WPW group, n=20). Unifactorial, multifactorial, and ROC analyses were performed to develop diagnostic ECG algorithms. The prognostic accuracy of the algorithms was subsequently evaluated in a prospective group of patients with LBBB tachycardias (n=57).Results. ECG signs of LBBB VTs were as follows: 1) the presence of the initial R wave in the lead aVL; 2) the absence of a split (M-shaped) R wave in the lead I; and 3) the S wave duration in the lead V1≤100 ms. For antidromic LBBB tachycardias, the ECG signs were as follows: 1) the duration of the R waves in the lead V2≥45 ms; 2) the absence of a split R waves (M-shaped) in the lead I; and 3) the duration of the R wave in the lead aVL>30 ms. The accuracy of the algorithm for diagnosis of VT with LBBB was 95% (sensitivity of 97%, specificity of 92%). The accuracy of the algorithm for diagnosis of antidromic tachycardias was 84% (sensitivity rate of 65%, specificity rate of 100%).Conclusion. Our data showed new very powerful criteria for differential diagnosis between various LBBB tachycardias even in comparison with well-known ECG algorithms of Wellens, Brugada, Griffith, Scheinman, Vereckei, Sasaki, et al.

NEW ELECTROCARDIOGRAPHIC CRITERIA FOR DIFFERENTIAL DIAGNOSIS OF TACHYCARDIAS WITH ADVANCED QRS COMPLEXES ACCORDING TO THE TYPE OF BLOCKADE OF LEFT BUNDLE OF HIS

Aim. To evaluate standard 12-lead electrocardiogram (ECG) indices for the differential diagnosis of left bundle branch block (LBBB) tachycardias.Material and Methods. The study analyses 244 ECG indices in 63 retrospective patients (85 males and 39 females aged 50±12 years) with LBBB type tachycardias. The electrophysiological study identified ventricular tachycardias (VT) (VT group, n=20), supraventricular tachycardias (SVT) with LBBB (SVT+LBBB group, n=23) or antidromic SVTs (WPW group, n=20). Unifactorial, multifactorial, and ROC analyses were performed to develop diagnostic ECG algorithms. The prognostic accuracy of the algorithms was subsequently evaluated in a prospective group of patients with LBBB tachycardias (n=57).Results. ECG signs of LBBB VTs were as follows: 1) the presence of the initial R wave in the lead aVL; 2) the absence of a split (M-shaped) R wave in the lead I; and 3) the S wave duration in the lead V1≤100 ms. For antidromic LBBB tachycardias, the ECG signs were as follows: 1) the duration of the R waves in the lead V2≥45 ms; 2) the absence of a split R waves (M-shaped) in the lead I; and 3) the duration of the R wave in the lead aVL>30 ms. The accuracy of the algorithm for diagnosis of VT with LBBB was 95% (sensitivity of 97%, specificity of 92%). The accuracy of the algorithm for diagnosis of antidromic tachycardias was 84% (sensitivity rate of 65%, specificity rate of 100%).Conclusion. Our data showed new very powerful criteria for differential diagnosis between various LBBB tachycardias even in comparison with well-known ECG algorithms of Wellens, Brugada, Griffith, Scheinman, Vereckei, Sasaki, et al.

A scoring algorithm for the accurate differential diagnosis of regular wide QRS complex tachycardia.

The differential diagnosis of regular wide QRS complex tachycardia (RWQRST) remains the subject of numerous publications, all of which aim at diagnosis during the acute phase. Although an accurate diagnosis is necessary to make long-term decisions, it often leads to invasive testing. Criteria with high positive predictive values (PPVs) for diagnosis can be obtained by analyzing the electrocardiogram (ECG) data during RWQRST and comparing them with these data at baseline. By assigning points to these criteria, a scoring algorithm to accurately diagnose numerous patients can be obtained. A total of 352 consecutive patients with RWQRST were included. Two electrophysiologists blind to patient condition analyzed the 16 criteria considered as having high PPVs. A total of 149 (42.3%) cases were supraventricular tachycardia (SVT), and 203 (57.7%) cases were ventricular tachycardia (VT). A higher percentage of patients with VT had structural heart disease (86.7%vs 16.1%). Seven of the 16 criteria analyzed had PPVs>95%, and each criterion was assigned a score. A final score of -1 was indicative of SVT (PPV 98%); a score of 1 was indicative of VT (PPV 98%); and a score of ≥2 was indicative of VT (PPV 100%). A score of ≠0 was obtained for 51.7% of all cases of tachycardia, making it possible to reach a highly accurate diagnosis in approximately half of all cases. No cases of VT scored -1, and no cases of SVT scored ≥2. The current scoring system stands out for its high PPV (98%) and specificity (98%), enabling an accurate diagnosis for more than half of the patients.

CATECHOLAMINE-INDUCED CARDIOMYOPATHY IN THE POSTPARTUM PATIENT

There are several conditions that can cause cardiomyopathy (CM) in the postpartum period. Diagnosis of the etiology of CM can have important implications in management and prognosis of these patients. A 30 year old female with recent diagnosis of supraventricular tachycardia (SVT) presented with

Improving Electrocardiography Diagnostic Accuracy in Emergency Medical Services Personnel

BackgroundAccuracy of electrocardiogram (ECG) interpretation is important for identification of ST-elevation myocardial infarction (STEMI) by Emergency Medical Services (EMS) personnel who recognize STEMI in the field and activate the coronary catheterization laboratory. According to previous research, there is improvement in diagnosis of STEMIs for healthcare providers who read an average of > 20 ECGs per week. This study evaluated the effectiveness of online ECG modules on improving diagnostic accuracy. MethodsEMS personnel received 25 ECGs per week to interpret via an online program. Diagnostic accuracy was assessed for improvement via completion of an ECG evaluation package before and after the intervention. Job satisfaction data were collected to determine the impact of the educational initiative. ResultsA total of 64 participants completed the study. Overall, there was an improvement in ECG diagnostic accuracy from 50.8% to 61.2% (95% confidence interval [CI], 7.7-13.2; P < 0.0001). Specifically, there was significant improvement in the diagnosis of STEMI (8.5%; 95% CI, 4.9-12.3; P < 0.003) and supraventricular tachycardia (39.0%; 95% CI, 17.2-60.8; P < 0.008), with a trend toward improvement in all other diagnoses. These effects were sustained to 3 months (9.6%; 95% CI, 6.4-12.7; P < 0.0001). Improvement was seen regardless of employment experience and training. There was no significant impact on job satisfaction. ConclusionsECG exposure remains an important factor in improving the accuracy of ECG diagnosis in EMS personnel. Online education modules provide an easily accessible way of improving ECG interpretation with the opportunity for positive downstream effects on patient outcomes and resource use.

Accuracy of smartphone-based ECG for the diagnosis of various cardiac arrhythmias

Diagnosis of cardiac arrhythmias can be challenging due to their frequent transient nature. Smartphone-based ECG has previously been studied for atrial fibrillation (AF) diagnosis. However, data is lacking regarding diagnostic accuracy of smartphone-based ECGs for other frequent arrhythmias. To assess the accuracy of Alivecor smartphone-based ECG (AECG) device for the diagnosis of various bradyarrhythmias or tachyarrhythmias. Hospitalized patients were eligible for inclusion if they had any of the following arrhythmias: AF, atrial tachycardia/flutter (AT), sinus rhythm with frequent atrial premature depolarizations (APD), sinus rhythm with frequent ventricular premature depolarizations (VPD), sinus tachycardia > 120 beats/min, sinus bradycardia < 40 beats/min, high-degree atrioventricular (AV) block, atrioventricular node reentrant tachycardia (AVNRT) and ventricular tachycardia (VT). Reference twelve-lead ECG were recorded, and the corresponding one-lead AECG was independently interpreted by four blinded electrophysiologists. Seventy-three patients (57 men; aged 72 ± 14 years) were included. For the diagnosis of bradyarrhythmias, AECG had a sensitivity and specificity of 75%–95% for sinus bradycardia, and 52%–98% for AV block. For atrial tachyarrhythmias, sensitivites and specificites were good for APD (83%–97%), AF (82%–87%), and sinus tachycardia (86%–98%), whereas sensitivity was poor for AT (49%–93%) and AVNRT (10%–99%), with very frequent confusion between them. For ventricular tachyarrhythmias, sensitivities and specificities were 70%–95% for VPD, and 89%–100% for VT ( Table 1 , Fig. 1 ). AECG is accurate for the diagnosis of sinus bradycardia, sinus tachycardia, APD, VPD, AF and VT. However, AV block, AT and AVNRT were poorly diagnosed by AECG, with a low sensitivity and very frequent confusion between AT and AVRNT.

Case Report: Direct Vagal Stimulation as Alternative Electrophysiological Procedure in the Diagnosis of Tachycardias During Electrophysiological Study

Case Report: Direct Vagal Stimulation as Alternative Electrophysiological Procedure in the Diagnosis of Tachycardias During Electrophysiological Study

Is obstructive sleep apnea associated with ventricular tachycardia? A retrospective study from the National Inpatient Sample and a literature review on the pathogenesis of Obstructive Sleep Apnea.

Obstructive sleep apnea (OSA) is a known independent risk factor for a multiple cardiovascular morbidities and mortality. The association of OSA and ventricular arrhythmias is less well understood. The aim of this analysis is to study the relationship between OSA and ventricular tachyarrhythmias. OSA is associated with increased ventricular arrhythmias. Data from the national inpatient sample (NIS) 2012 to 2014, were reviewed. Discharges associated with OSA were identified as the target population using the relevant ICD-9-CM codes. The primary outcome was a diagnosis of ventricular tachycardia (VT) in the OSA population. Secondary outcomes include the rate of ventricular fibrillation (VF) and cardiac arrest. Multivariable analyses were performed to examine the association of VT with multiple potential confounding clinical variables. Of 18 013 878 health encounters, 943 978 subjects (5.24%) had a diagnosis of OSA. VT and VF were more prevalent among patients with OSA compared to those without a diagnosis of OSA (2.24% vs 1.16%; P < 0.001 and 0.3% vs 0.2%; P < 0.001, respectively). Odds ratio for cardiac arrest in OSA group was not statistically significant (1, 95% confidence interval 0.97-1.02, P < 0.76). In unadjusted analyses, all examined comorbidities were significantly more common in those with OSA, including diabetes mellitus, hypertension, chronic kidney disease, acute coronary syndrome, and heart failure. OSA is associated with increased rates of ventricular tachyarrhythmia.

Arrhythmia induction using isoproterenol or epinephrine during electrophysiology study for supraventricular tachycardia

Electrophysiology study (EPS) is an important part of the diagnosis and workup for supraventricular tachycardia (SVT). Provocative medications are used to induce arrhythmias, when they are not inducible at baseline. The most common medication is the β1-specific agonist, isoproterenol, but recent price increases have resulted in a shift toward the nonspecific agonist, epinephrine. We hypothesize that isoproterenol is a better induction agent for SVT during EPS than epinephrine. We created a retrospective cohort of 131 patients, who underwent EPS and required medication infusion with either isoproterenol or epinephrine for SVT induction. The primary outcome was arrhythmia induction. Successful induction was achieved in 71% of isoproterenol cases and 53% of epinephrine cases (P = 0.020). Isoproterenol was significantly better than epinephrine for SVT induction during EPS (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.14-4.85; P = 0.021). There was no difference in baseline variables or complications between the two groups. Other variables associated with successful arrhythmia induction included a longer procedure duration and atrioventricular nodal re-entry tachycardia as the clinical arrhythmia. In a multivariable model, isoproterenol remained significantly associated with successful induction (OR, 2.57;95% CI, 1.002-6.59; P = 0.05). Isoproterenol was significantly better than epinephrine for SVT arrhythmia induction. However, epinephrine was safe and successfully induced arrhythmias in the majority of patients who received it. Furthermore, when atropine was added in epinephrine-refractory cases, in a post hoc analysis there was no difference in arrhythmia induction between medications. Cost savings could thus be significant without compromising safety.

PCV85 - The Impact of the Centers for Medicare and Medicaid Services (CMS) 2016 Update to the Two-Midnight Rule On Inpatient/Outpatient Status and Length of Stay for Cardiac Ablation Procedures

CMS released an update to the 2013 2-midnight rule, effective for 2016, expanding a physician’s ability to admit patients under Medicare Part A who are expected to require less than two midnights of hospital care. We sought to quantify the impact of this change on rates of inpatient admissions and lengths of stay (LOS) for patients having cardiac catheter ablation. These procedures had high rates of extended observational outpatient stays based on the original rule. Patient-level de-identified hospital records from 2013-2016 were extracted from the MedAssets hospital database. Visits for adults (age 18+) with a primary diagnosis of atrial fibrillation, atrial flutter, ventricular tachycardia, or supraventricular tachycardia and a procedure code for catheter ablation of the associated arrhythmia were included, provided that they did not have additional codes for AV node ablation, endoscopic or surgical ablation, surgical left atrial appendage exclusion, valve surgery, or cardiac implant. The primary outcomes were inpatient/outpatient visit status and LOS by insurance type (Medicare/commercial) and year. A total of 11,398 commercial and 15,430 Medicare ablation visits met all inclusion criteria. The percentage of inpatient visits remained constant from 2015 to 2016 for patients with commercial insurance (32.4% to 32.7%, p=0.8511) but increased for those with Medicare (45.0% to 50.0%, p=0.0002). Similarly, the percentage of patients with single night LOS remained constant from 2015 to 2016 for the commercially insured (30.1% and 30.1%, p=0.9714) while decreasing for Medicare patients (25.5% to 20.2%, p<0.0001). In cardiac catheter ablation patients, the change to the CMS 2-midnight rule increased the percentage of Medicare patients admitted as inpatients and staying two or more nights. This increase impacts hospital reimbursement rates and patient eligibility for Medicare payment of skilled nursing care upon discharge.

Trends and predictors of implantable cardioverter defibrillator implantation after sudden cardiac arrest: Insight from the national inpatient sample.

Implantable cardioverter defibrillator (ICD) has a class IA indication in survivors of sudden cardiac arrest (SCA) provided no reversible cause is identified. We sought to determine trends and predictors of ICD implant in SCA patients from a national sample of the United States population. Data were gathered from National Inpatient Sample (NIS) from January 2003 to December 2014. All patients≥18 years of age with a primary discharge diagnosis of SCA, ventricular fibrillation (VF), ventricular flutter, and ventricular tachycardia (VT) were included. Patients died during hospitalization, had a previous ICD implant, and with a reversible cause of SCA were excluded. Primary outcome of interest was rate of new ICD implant at discharge. Logistic regression analysis was then performed to determine predictors for ICD implantation. A total of 176,876 patients were identified to have SCA, VF, ventricular flutter, and VT. After applying exclusion criteria, we were left with 22,054 patients. Out of this, 6,908 (31%) patients were implanted with an ICD prior to discharge. There was a linear trend toward reduced ICD utilization over our study period (40% in 2003vs 25% in 2014, P trend = 0.0004). Advanced age, black race, and chronic renal disease are independently associated with low ICD utilization. We found low trend of ICD implant in survivors of SCA without any reversible cause. There is a need to identify etiologies behind low ICD utilization in this vulnerable group who are at most risk for a subsequent SCA.

Influence of advancing age on clinical presentation, treatment efficacy and safety, and long-term outcome of inducible paroxysmal supraventricular tachycardia without pre-excitation syndromes: A cohort study of 1960 patients included over 25 years.

AimTo investigate the influence of increasing age on clinical presentation, treatment and long-term outcome in patients with inducible paroxysmal supraventricular tachycardia (SVT) without pre-excitation syndromes.MethodsClinical and electrophysiological study (EPS) data, as well as long-term clinical outcome (mean follow-up 2.4±4.0 years) were collected in patients referred for regular tachycardia with inducible SVT during EPS without pre-excitation.ResultsAmong 1960 referred patients, 301 patients (15.4%) were aged ≥70 (70–97). In this subset, anticoagulants were prescribed in 49 patients following an erroneous diagnosis of atrial tachycardia and 14 were previously erroneously diagnosed with ventricular tachycardia because of wide QRS. Ablation was performed more frequently in patients ≥70 despite more frequent failure and complications. During follow-up, higher risks of AF, stroke, pacemaker implantation and death were observed in patients ≥70 whereas SVT recurrences were similar in both age groups. In multivariable analysis, age ≥70 was independently associated with higher risks of SVT-related adverse events prior to ablation (OR = 1.93, 1.41–2.62, p<0.001), conduction disturbances (OR = 11.27, 5.89–21.50, p<0.001), history of AF (OR = 2.18, 1.22–3.90, p = 0.009) and erroneous diagnosis at baseline (OR = 9.14, 5.93–14.09, p<0.001) as well as high rates of procedural complications (OR = 2.13, 1.19–3.81, p = 0.01) and ablation failure (OR = 1.68, 1.08–2.62, p = 0.02). In contrast, age ≥70 was not significantly associated with a higher risk of AF in multivariable analysis.ConclusionsA sizeable proportion of patients with inducible SVT without pre-excitation syndromes are elderly. These patients exhibit higher risks of erroneous tachycardia diagnosis prior to EPS as well as failure and/or complication of ablation, but similar risk of SVT recurrence. These results support performing transesophageal EPS in most patients and intracardiac EPS in selected patients. EPS may furthermore prove useful in elderly patients with regular tachycardia, mainly by avoiding treatment based on an erroneous diagnosis.

Correlation between the sudden jump-like increases of the atrio-Hisian interval induced during burst atrial pacing and during programmed atrial stimulation in patients with atrioventricular nodal reentrant tachycardia

PurposeTo study the correlation between the sudden prolongations of the atrio-Hisian (AH) interval with ≥50 ms during burst and programmed atrial stimulation, and to define whether the AH jump during burst atrial pacing is a reliable diagnostic criterion for dual AV nodal physiology. MethodsRetrospective data on 304 patients with preliminary ECG diagnosis of AV nodal reentrant tachycardia (AVNRT), confirmed during electrophysiological study, was analyzed for the presence of AH jump during burst and programmed atrial stimulation, and for correlation between the pacing modes for inducing the jump. Wilcoxon signed-ranks test and Spearman's bivariate correlation coefficient were applied, significant was P-value <0.05. ResultsThe population was aged 48.5 ± 15.7 (12-85) years; males were 38.5%. AH jump occurred during burst atrial pacing in 81% of the patients, and during programmed stimulation – in 78%, P = 0.366. In 63.2% AH jump was induced by both pacing modes; in 17.8% – only by burst pacing; in 14.8% – only by programmed pacing; in 4.2% there was no inducible jump. There was negative correlation between both pacing modes, ρ = –0.204, Р<0.001. ConclusionBurst and programmed atrial stimulation separately prove the presence of dual AV nodal physiology in 81 and 78% of the patients with AVNRT, respectively. There is negative correlation between the two pacing modes, allowing the combination of the two methods to prove diagnostic in 95.8% of the patients.

Ventrikuläre Herzrhythmusstörungen

Ventricular arrhythmias include awide range of potentially benign single ventricular premature contractions to ventricular tachycardia and ventricular fibrillation with arisk for sudden cardiac death. The diagnosis of ventricular arrhythmia is made by 12-lead electrocardiogram, 24 h Holter monitoring, an external or implantable loop recorder, or during in-hospital monitoring. Especially the diagnosis of wide complex tachycardias is challenging in terms of differentiating between ventricular tachycardia and supraventricular tachycardia with aberrant atrioventricular conduction. After documentation of ventricular arrhythmias, diagnostic work-up with respect to structural or electrical cardiomyopathy is mandatory followed by risk stratification for sudden cardiac death. Therapeutic options for treatment of ventricular arrhythmias range from pharmacological therapy and interventional procedures such as catheter ablation and implantable devices. The current article provides an overview of the diagnosis of ventricular tachycardia and underlying cardiomyopathies. Furthermore, medical and interventional therapies are described. In addition, the indications for implantable and wearable defibrillators are presented.

One symptom, two arrhythmias: the rare and the even rarer

BackgroundWolff-Parkinson-White (WPW) syndrome and idiopathic left ventricular tachycardia (ILVT) are rare and up to now the coexistence of both entities has rarely been reported.In patients with ventricular preexcitation the underlying mechanism of paroxysmal tachycardia most likely is atrioventricular reentrant tachycardia (AVRT). However, without ECG documentation of the tachycardia diagnosis of the underlying mechanism cannot be made due to similar clinical presentation of AVRT and ILVT.Case presentationWe report a case of a two-staged occurrence of two rare arrhythmias in a young adult, who was admitted to our hospital twice within 6 months because of paroxysmal tachycardia. WPW syndrome and ILVT as underlying arrhythmias have been diagnosed and were ablated successfully.ConclusionsThis case highlights the diagnostic defiance of rare tachycardia entities and the paramount importance of ECG documentation and analysis of all available tachycardia ECGs.

EP04.35: Prenatal diagnosis of fetal idiopathic ventricular tachycardia treated with maternal intravenous magnesium: a case report

Supporting information can be found in the online version of this abstract Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

R-Wave Peak Time at Lead II in Adults With Ventricular Premature Beats, Bundle Branch Block and Left Anterior Fascicular Block

BackgroundRecently, the R-wave peak time (RWPT) at lead II was reported to be a helpful and simple tool for differentiating wide QRS complex tachycardias with a RWPT ≥ 50ms for ventricular tachycardia diagnosis. Our previous study showed that the duration of RWPT at lead II in adults was ≈29ms. However, the effects of ventricular premature beats (VPBs), bundle branch block (BBB) or left anterior fascicular block (LAFB) on RWPT at lead II remain unknown. MethodsThe study was conducted in the First Affiliated Hospital of Shantou University Medical College in Southern China. Adults with VPBs, BBB or LAFB were included. RWPT at lead II was determined. ResultsCompared with the control groups, the right BBB, LAFB, RWPT were longer in groups with left BBB and VPBs. Compared with the group with left BBB, the group with VPBs had a significantly longer RWPT at lead II (54.20 ± 18.52 versus 84.76 ± 16.38ms, P < 0.01). ConclusionOur study showed that there is a significant difference in the RWPT at lead II between groups with left BBB, ventricular premature beat, right BBB and LAFB. A RWPT of 50ms may be optimal to differentiate between ventricular tachycardia and supraventricular tachycardia with right left BBB and LAFB, but not with left BBB.

Antenatal antiarrhythmic treatment for fetal tachyarrhythmias: a study protocol for a prospective multicentre trial

IntroductionSeveral retrospective or single-centre studies demonstrated the efficacy of transplacental treatment of fetal tachyarrhythmias. Our retrospective nationwide survey showed that the fetal therapy will be successful at an overall rate...

Catheter ablation of accessory pathway: 14-year trends in utilization and complications in adults in the United States

BackgroundThe aim of this study was to determine the temporal trends in utilization of catheter ablation of accessory pathways in the United States. MethodsAll patients from the Nationwide Inpatient Sample (NIS) ≥18years of age with a primary diagnosis of anomalous atrioventricular excitation syndrome (International Classification of Diseases, Ninth Edition, Clinical Modification [ICD-9-CM] code 426.7) were included in the study. Patients who underwent catheter ablation were identified using ICD-9-CM procedure code 37.34. Patients with a concomitant diagnosis of atrial fibrillation, atrial flutter, atrial tachycardia or ventricular arrhythmias were excluded from the analysis. Annual hospital volume was identified using unique hospital identification number and was divided into tertiles for further analysis. ResultsA total of 11,601 catheter ablations for anomalous atrioventricular excitation syndrome were studied from 1998 to 2011. The mean length of stay was 1.8days (median 1day). The utilization trends of accessory pathway ablation have steadily declined from 3.9 ablation procedures/million US population in 1998–1999 to 2.5 ablation procedures/million US population in 2010–2011. The second tertile (adjusted OR 0.41; 95% CI 0.20–0.83, p=0.01) and third tertile (adjusted OR 0.39; 95% CI 0.18–0.85, p=0.02) of hospital volume were associated with reduction in cardiac complications as compared to first tertile of hospital volume. Advanced age (OR 1.02, 95% CI 1.01–1.04, p=0.002) was independent predictor of cardiac complications. There were no in-hospital deaths. ConclusionDespite decline in ablation trends, it still remains a relatively safe procedure associated with low morbidity and no mortality.

Atrial and ventricular activation sequence after ventricular induction/entrainment pacing during fast–slow atrioventricular nodal reentrant tachycardia: New insight into the use of V-A-A-V for the differential diagnosis of supraventricular tachycardia

The atrial and ventricular response observed immediately after cessation of ventricular induction/entrainment pacing is commonly analyzed to discriminate atrial tachycardia from other supraventricular tachycardias during electrophysiologic studies. However, the response in fast-slow atrioventricular nodal reentrant tachycardia (F/S-AVNRT) remains poorly investigated. The purpose of this study was to analyze the atrial andventricular activation patterns after ventricular pacing in F/S-AVNRT. We enrolled 28 patients with F/S-AVNRT incorporating a typical slow pathway (typ-F/S-AVNRT) and 9 patients with F/S-AVNRT incorporating a superior slow pathway (sup-F/S-AVNRT). The V-A-A-V response was observed in 14 patients (38%) with F/S-AVNRT, more commonly in patients with sup-F/S-AVNRT than in those with typ-F/S-AVNRT (89% vs 21%, P = .0003). The underlying mechanisms included (1) a double atrial response (DAR) in 13 patients; (2) an anterograde block at the lower common pathway once after ventricular pacing in 2 patients; and (3) a pseudo-A-A-V response in 2 patients. The DAR was characterized by a V-A-A-V interatrial interval that was 55 ± 60 ms shorter than the tachycardia cycle length, whereas the block at the lower common pathway or infrahisian block had a V-A-A-V interatrial interval that was almost equal to or longer than the tachycardia cycle length. The V-A-A-V activation sequence immediately after ventricular induction/entrainment pacing is observed in patients with F/S-AVNRT, particularly in patients with sup-F/S-AVNRT, and is caused by multiple mechanisms, including a DAR, which is the major etiology.