Atrial Tachycardias After "Multiple" Previous Ablations for Tachyarrhythmias: Treatment by Anti-arrhythmic Drugs or Additional Ablation?

Pulmonary vein (PV) isolation (PVI) ablation as the first-line therapy for atrial fibrillation (AF) and repeat PVIs for patients who had symptomatic improvement with the index PVI but who develop AF recurrence are directed by practice guidelines. How many catheter ablation (CA) procedures constitute the definition of "multiple" ablations is not known. Whether atrial tachyarrhythmias (AF, atrial tachycardia [AT], atrial flutter [AFL]) that occur post-ablation are due entirely to the proarrhythmic effects of CA or a continuum of the arrhythmia spectrum from the underlying atriopathy is debatable. Herein, we describe a case of a 65-year-old man with a CHA2DS2-VASc score of 5 points who suffered from atrial tachyarrhythmias for which seven CA procedures were performed. Because of symptomatic and drug-refractory AT/AFL that failed cardioversions, he requested another ablation procedure. During the eighth procedure, high-density three-dimensional electroanatomic mapping, including Coherent and Ripple mapping (CARTO® 3; Biosense Webster, Diamond Bar, CA, USA), of AT/AFL was performed. Small discrete areas of relatively viable tissue within an extensively scarred left atrium and a macro-re-entrant circuit with early-meets-late activation between the left atrial anterior wall and the right superior PV were found. Radiofrequency ablation performed at this site resulted in the termination of the tachycardia, and bidirectional conduction block across the line was achieved. On clinical follow-ups and rhythm monitoring by an implantable loop recorder, the patient remained in sinus rhythm with significant clinical improvement. Our case suggests that, in patients with prior multiple CAs, additional clinically indicated ablation should be performed using high-density mapping to accurately identify arrhythmia mechanisms, elucidate the disease substrate, and restore the sinus rhythm successfully.

Are antiarrhythmic agents indicated in premature ventricular complex-induced cardiomyopathy and when?

INTRODUCTION: Premature ventricular complexes (PVCs) are the most common ventricular arrhythmia that are encountered in the clinical practice. Recent data suggests that high PVC burden may lead to the development of PVC-induced cardiomyopathy (PVC-CM) even in patients without structural heart disease. Treatment for effective suppression of PVCs, can reverse PVC-CM. Both antiarrhythmic drugs (AADs) and catheter ablation (CA) are recognized treatment modalities for any cardiac arrhythmias. However, with increasing preference of CA, the role of AADs needs further defining regarding their efficacy, safety, indications and patient selection to treat PVC-CM. METHODS: To ascertain the role of AADs to treat PVC-CM; whether they are indicated to treat PVC-CM, and if so, when, we interrogated PubMed and other search engines for English language publications with key words premature ventricular complexes (PVCs), cardiomyopathy, anti-arrhythmic drugs, catheter ablation, and pharmacological agents. All publications were carefully reviewed and scrutinized by the authors for their inclusion in the review paper. For illustration of cases, ethical standard was observed as per the 1975 Declaration of Helsinki, and the patient was treated as per the prevailing standard of care. Informed consent was obtained from the patient for conducting the ablation procedure. RESULTS: Our literature search specifically the pharmacological treatment of PVC-CM with AADs revealed significant paradigm shift in treatment approach for PVCs and PVC-induced cardiomyopathy. No major large, randomized control trials of AADs versus CA for PVC-CM were found. We found that beta-blockers and calcium channel blockers are particularly effective in the treatment of PVCs originating from right ventricular outflow tract. For Class Ic AADs - flecainide and propafenone, small clinical studies showed Class Ic AADs to be effective in PVC suppression, but their usage was not recommended in patients with significant coronary artery disease. Mexiletine was found to have modest effect on PVC suppression. Studies showed sotalol to significantly reduce PVCs frequency in patients receiving both low and high doses. Studies also showed amiodarone to have higher successful PVC suppression, but not recommended as a first-line treatment for patients with idiopathic PVCs in the absence of symptoms and left ventricular dysfunction. For dronedarone, no major clinical data were available. CONCLUSIONS: Based on the available data in the literature, we conclude that AADs play important role in the treatment of PVC-induced cardiomyopathy. However, appropriate patient selection criteria are vitally important, and in general terms AADs are indicated or polymorphic PVCs, epicardial PVCs; and when CA procedure is contraindicated, or not feasible or failed.

Open-window mapping for ablation of Wolff-Parkinson-White syndrome related hemodynamically unstable tachycardia.

During catheter ablation (CA) of tachycardia, conventional point-by-point mapping may be hindered due to hemodynamic instability. We performed open-window mapping (CARTO, Biosense Webster, USA) in a patient who developed hemodynamic instability during orthodromic atrioventricular reciprocating tachycardia (AVRT) and unwarranted induction of AVRT during attempts to map accessory pathway (AP) with ventricular pacing. With over 11,000 points acquired rapidly, the system accurately identified AP at the mitral valve (MV) annulus where the application of single radiofrequency (RF) lesion promptly eliminated AP's conduction. Our case illustrates the utility of open-window mapping for the ablation of AVRT.

Persistently abnormal device-detected thoracic impedance and OptiVol fluid index related to breast reconstruction surgery.

With significant correlation shown between intrathoracic impedance and intrathoracic fluid volume, the utility of OptiVol fluid index (Medtronic, Minneapolis, MN, USA) in the management of patients with heart failure has been well-described. Although intrathoracic impedance is mainly affected by the changes in the intrathoracic fluid volume, a "false-positive" OptiVol fluid index can occur in the absence of overt congestive heart failure. We present a case of false positive Optivol fluid index elevation in a woman following breast reconstruction surgery.

One year outcomes of atrial fibrillation ablation: Contemporary analysis of the United States Nationwide Readmission Database.

BACKGROUND: Data on long-term outcomes of catheter ablation (CA) for atrial fibrillation (AF) in outside of clinical trials settings are sparse. OBJECTIVE: We aimed to assess outcomes and readmissions at 1 year following admission for CA for AF. METHODS: Utilizing the Nationwide Readmissions Database (2016-2018), we identified patients with CA among all patients with a primary admission diagnosis of AF, and a control group by propensity score match adjusted for age, sex, comorbidities, CHA2DS2-VASc scores, and the hospital characteristics. The primary outcome was a composite of unplanned heart failure (HF), AF and stroke-related readmissions, and death at 1 year, and secondary outcomes were hospital outcomes and all-cause readmission rates. RESULTS: The study cohort consisted of 29,771 patients undergoing CA and 63,988 controls. Patients undergoing CA were younger with lower CHA2DS2-VASc scores and less comorbidities. Over a follow-up of 170 ±1.1 days, the primary outcome occurred in 5.2% in CA group and 6.0% of controls (hazard ratio [HR] and 95% confidence interval [CI]: 0.86 [0.76-0.94], p = .002). CA affected AF and stroke related readmission, but showed no effect on HF and mortality outcome. Male sex (HR: 0.83 [0.74-0.94], p = .03), younger age (HR: 0.71 [0.61-0.83], p < .001], and lower CHA2DS2-VASc scores (HR: 0.68 [0.55-0.84], p < .001) were associated with lower risk of primary outcome with CA. CONCLUSION: In this study, CA for AF was associated with significantly lower AF and stroke-related admissions, but not to HF or all-cause readmission. Better outcomes were seen among males, younger patients, and in patients with less comorbidities and low CHA2DS2-VASc scores.

Implications of "slower" ventricular tachycardia on clinical management and detection and therapy function of implantable cardioverter defibrillators.

Sophisticated dual-chamber atrioventricular and rate-responsive pacing therapies, cardiac resynchronization therapy (CRT), detection and therapies for ventricular tachycardia and fibrillation (VT/VF) form some major components of multitask functions of current implantable cardioverter defibrillators (ICDs). Appropriate programming of these devices is necessary for them to perform all such tasks precisely. In this report, we describe a case of a patient with Chagas cardiomyopathy with marked cardiomegaly, scarred ventricles, prior epicardial and endocardial ablations and on antiarrhythmic pharmacotherapy for VT, who presented with symptomatic wide complex tachycardia at a slower rate than definition of VT, and in whom programming for detection and therapy for "slow" VT could not be performed due to default technological limitation of the CRT-D.

Cardiac resynchronization therapy in patients with heart failure and narrow QRS complexes (≤ 130 ms): role of speckle tracking echocardiography and different interventricular (VV) pacing intervals.

PURPOSE: Response to cardiac resynchronization therapy (CRT) in patients with heart failure with reduced ejection fraction (HFrEF) depends on the degree of correction of interventricular (VV) electromechanical dyssynchrony between the left and right ventricles (LV, RV). Wide (> 130 ms [ms]) QRS interval is used as a qualifying ECG parameter for CRT device implantation. In this study, we aimed to evaluate myocardial strain (S) and myocardial strain patterns (SP) and strain rate (SR) by speckle tracking echocardiography (STE) and mechanical characteristics at different VV intervals in acute settings and long-term outcome from "sequential LV-RV" pacing programming in patients with narrow (< 130 ms) and wide (> 130 ms) QRS complexes as a basis for extending CRT in select patients with narrow QRS. METHODS: From a previously established cohort of patients who had undergone CRT device implantation, we identified patients with narrow (< 130 ms) and wide (> 130 ms) QRS complexes, groups A and B respectively. In all patients, we assessed myocardial SP and SR by STE, and mechanical characteristics at VV intervals: "LV Off," "VV0," "VV60," and "RV Off" to provide "RV-only," "simultaneous BiV," "sequential LV-RV," and "LV-only" pacing in the acute settings, and subsequently long-term clinical outcomes with CRT devices programmed to VV60. We compared acute STE characteristics and long-term clinical outcomes between the groups. RESULTS: The study cohort comprised 271 patients (age 69.2 ± 10.3 years [mean ± SD], male-60%). Group A (n = 69) and group B (n = 202) were well matched for the clinical variables, including distribution of patients with ischemic versus non-ischemic cardiomyopathies. QRS width and left ventricular ejection fraction (LVEF) in groups A and B were 120.1 ± 12.3 ms and 152.1 ± 12.9 ms (p < 0.05), and 22.3 ± 9.4%, and 23.3 ± 10.2% (p = not significant [NS]). With VV0, VV60, and LV-only timings, corresponding LVEF rates in the acute settings were 31.45 ± 10.9%, 40.08 ± 8.3%, and 44.32 ± 7.98% (p < 0.01) in group A, and 38.94 ± 8.5%, 46.91 ± 7.33%, and 49.9 ± 8.94% (p < 0.01) in group B, and accounted for similar incremental percentage increase in LVEF compared to baseline in group A (43.2 ± 51.7%, 80.9 ± 61.4%, and 93.4 ± 65.6% respectively) and group B (67.3 ± 82.0%, 100.6 ± 94.3%, and 112.9 ± 95.7% respectively) (p = NS). Abnormal SP and SR were consistently observed with RV pacing that improved with VV60 and LV-only pacing in both groups. Strain scores at different VV timings were similar between the groups (p = NS). At 1-year follow-up, LVEF improved from 22.4 ± 8.0% to 39.8 ± 11.5% (p ≤ 0.001) for the total cohort with similar increments observed in both groups (p = NS). There were fewer NYHA III-IV class patients at 1 year in both groups. CONCLUSIONS: Comparable myocardial SP and SR characteristics and LVEF improvement with VV60 and LV-only pacing in the acute setting and long-term outcome of CRT by "sequential LV-RV" pacing seen in patients with both narrow and wide QRS duration suggest that CRT device implantation may be justified in select patients with HFrEF and narrow QRS duration (< 130 ms) who have demonstrable dyssynchrony and abnormal myocardial SP and SR characteristics.

Safety and complications of catheter ablation for atrial fibrillation: Predictors of complications from an updated analysis the National Inpatient Database.

BACKGROUND: Catheter ablation is increasingly employed in the management of atrial fibrillation (AF). Data regarding safety of ablation of AF is largely derived from controlled clinical trials. OBJECTIVES: The aim of this study was to analyze safety and complications of AF ablation performed in a "real world" setting outside of clinical trials, and obtain insights on predictors of complications. METHODS: We utilized the National Inpatient Sample database, to identify all patients who underwent AF ablations between 2015 and 2017 using International Classification of Disease-Tenth revision codes. Complications were defined as per the Agency for Health Care Research and Quality Guidelines. Statistical tests including multivariate logistic regression were performed to determine predictors of complications. RESULTS: Among 14,875 cases of AF ablation between 2015 and 2017, a total of 1884 complications were identified among 1080 (7.2%) patients. Patients with complications were likely to be older and female with a higher burden of comorbidities. A 27% increase in complications was observed from 2015 to 2017, driven by an increase in pericardial complications. Multivariate regression analysis revealed that pulmonary hypertension (adjusted odds ratio [aOR]: 1.99, p = .041) and chronic kidney disease (CKD; aOR: 1.67, p = .024), were independent predictors of complications. Centers with higher procedural volumes were associated with lower complication rates. CONCLUSIONS: Complication rates related to AF ablations remain substantially high. Presence of pulmonary hypertension and CKD are predictive of higher procedural complications. Furthermore, hospital procedure volume is an important factor that correlates with complication rates.

Myocardial strain characteristics at different interventricular pacing timings: implications for device programming and long-term clinical outcomes in patients with cardiac resynchronisation therapy.

AIMS: Response to cardiac resynchronisation therapy (CRT) in patients with heart failure depends on the degree of correction of electromechanical dyssynchrony between the left and right ventricles (LV, RV). It is not known whether chronic programming of interventricular (VV) intervals based on characterisation of myocardial strain at different pacing intervals performed acutely would have better long-term clinical outcomes. We hence aimed to evaluate this relationship between speckle tracking strain patterns and rates at different VV intervals and long-term clinical outcomes of programmed VV pacing in patients with CRT in a prospective, longitudinal follow-up study. METHODS: We assessed echocardiographic effects, myocardial strain patterns and rates in acute settings at VV intervals; 'LV Off', 'VV0', 'VV60' and 'RV Off' to provide 'RV-only', 'simultaneous BiV', 'sequential LV-RV' and 'LV-only' pacing respectively in 338 patients (age, 67.5 ± 10.3 years; male, 70%) with CRT. Thereafter, devices were programmed chronically to VV60, and long-term clinical outcomes were assessed. RESULTS: With VV0, VV60 and LV only pacing, LVEF improved to 33.6 ± 12.3%, 40.0 ± 11.4% and 42.6 ± 11.2%, respectively, from 23.7 ± 10.2% at baseline (p < .001). Incremental improvement in strain occurred with VV0, VV60 and LV only pacing; greatest with LV only pacing. At 1 year, 23% patients had NYHA III-IV compared to 96% at baseline (p < .001). CONCLUSIONS: In patients with CRT, different VV timings show significant differences in acute myocardial strain patterns and rates, and LVEF. These changes are markedly favourable with LV-only and sequential LV-RV pacing, the latter with chronic programming also results in long-term clinical improvement.

Low-dose rituximab as an adjuvant therapy in pemphigus.

BACKGROUND: Pemphigus is a chronic autoimmune blistering disease where systemic steroids and immunosuppressants are the mainstay of therapy, but long-term treatment with these agents is associated with many side effects. Rituximab, a chimeric monoclonal anti-CD20 antibody, in low doses has shown efficacy as an adjuvant to reduce the dose of steroids. AIM: To study the clinical efficacy and safety of low-dose rituximab as an adjuvant therapy in pemphigus. METHODS: Fifty patients with extensive pemphigus were selected, who either had recalcitrant pemphigus, were steroid dependent, had relapsed after pulse therapy, had anti-desmoglein levels >20, had contraindications to conventional treatment or wanted to avoid conventional treatment and its side effects. Two doses of rituximab (500 mg) were given 2 weeks apart and patients were regularly followed up every 2 weeks for 3 months and then monthly upto 2 years. Complete blood counts, liver function tests, renal function tests, skin biopsy, direct immunofluorescence and desmoglein levels were checked before and after rituximab administration. Pre-rituximab chest X-ray and electrocardiograph were also obtained. RESULTS: At 3 months, 41 (82%) patients showed complete remission. Nine (18%) patients had partial remission. After 6-12 months, 20 (40% of enrolled patients) continued to be in remission and were off all systemic therapy and the remaining 19 (38%) were continuing to take low doses of steroids with or without other adjuvant immunosuppressants and 2 (4%) had to be given another 2 doses of rituximab and subsequently could be managed with low-dose steroids. Of the 9 patients in partial remission at 3 months, after 6-12 months 5 (10% of the total) were completely off treatment and went into complete remission and 4 (8%) were on additional treatment out of which 2 (4%) had to be given 2 additional doses of rituximab and were in partial remission with low-dose therapy at the end of 12 months. One patient developed urticaria as a side effect. Another developed herpes zoster. CONCLUSION: Our results show that low-dose rituximab is a well-tolerated and beneficial adjuvant therapy in recalcitrant pemphigus which helps reduce both the severity of disease as well as the dose of steroids and immunosuppressants.

Pacing to prevent atrial fibrillation.

PURPOSE OF REVIEW: Pacemakers are frequently implanted in patients with atrial fibrillation. Many patients with pacemakers also develop atrial fibrillation. Over a period of time, through many studies on different pacing modes, sites, and algorithms, significant insights have been gained in the field of treatment and prevention of atrial fibrillation. The purpose of this review is to discuss some aspects of the scientific basis, current standards and possible future research related to cardiac pacing for prevention of atrial fibrillation. RECENT FINDINGS: Trials involving pacing at the alternative pacing site per se or in combination with specific algorithms for prevention of atrial fibrillation have not shown consistent results. Recently, a new generation of antitachycardia pacing therapies has brought on a new optimism with promising outcome data of reduction in permanent atrial fibrillation, cardiovascular hospitalizations, and mortality. SUMMARY: Multiple trials and clinical observational studies of different pacing methods and algorithms, with the exception of newer therapies in conjunction with atrial pacing algorithms, have not been shown to prevent atrial fibrillation. Hence, while permanent pacing is indicated for sinus node dysfunction and conduction abnormalities in patients with or without atrial fibrillation, the prevailing data in the literature does not support implantation of a permanent pacemaker for prevention of atrial fibrillation per se.

Nodal and infranodal atrioventricular conduction block: electrophysiological basis to correlate the ECG findings.

A 68-year-old woman with a history of dilated non-ischemic cardiomyopathy presented with syncope. The index ECG showed sinus rhythm with left bundle branch block. On telemetry episodes of sinus rhythm with narrower QRS complexes conduced in 2:1 pattern were noted. Invasive electrophysiological study was performed to determine cause of syncope. Normal conduction up to the AV node with an AH interval of 79 ms (normal = 55-125 ms) was observed. However, every alternate sinus beat was blocked after the inscription of His deflection (infra-Hisian block). The narrow beats conducted through the His bundle with HV intervals of 54 ms (normal = 35-55 ms). When 1:1 conduction resumed further abnormality of the His-Purkinje conduction system became evident with a QRS morphology that of an LBBB and prolongation of HV interval (HV = 96 ms). Criteria to differentiate nodal versus infranodal block based on electrophysiological properties of the nodal and infranodal system are discussed.

Chagas disease in Latin American immigrants with dilated cardiomyopathy in New York City.

Chagas disease-associated cardiomyopathy is clinically similar to other causes of cardiomyopathy and, therefore, the diagnosis can be easily overlooked. We found a 13% point prevalence of Chagas disease in a sample of New York City immigrants with dilated cardiomyopathy.

Reuse of explanted permanent pacemakers donated by funeral homes.

Poor patients in developing countries may not receive permanent pacemakers (PPMs) even as lifesaving measures because of their high cost. In this report we examined whether PPMs that were explanted and donated by funeral homes in the United States could be safely and effectively reused in indigent patients in India. With permission from the deceased patients' families, 121 PPMs were explanted and donated by funeral homes for reuse. These PPMs were sterilized and sent for implantation in needy and indigent patients at a charity hospital in Mumbai, India. From the pool of donated 121 PPMs, 53 (88%, 11 single-chamber PPMs, 21%, and 42 dual-chamber PPMs, 79%) were acceptable for reuse and implanted (37 new implants, 70%, and 16 for battery/generator replacement, 30%) in 53 patients (mean ± SD 64 ± 10 years old, 28 women, 53%). Indications for PPM implantation were complete heart block (n = 27, 51%) and sick sinus syndrome (n = 26, 49%). All patients were alive and well postoperatively. No significant complications including infections or device failures occurred over 19 to 1,827 days (mean 661) of follow-up. Of 40 patients (75%) who were followed locally, 4 (10%) died because of nonpacemaker-related causes; time to death was 121 to 750 days (mean 430) after PPM implantation. All except 2 patients (5%) reported marked improvement in their symptoms. There were only 4 patients (8%) who were previously employed, and all were able to resume their manual labor work. Also, of the women, 27 patients (96%) reported improvement in symptoms enabling them to resume regular household chores as housewives after PPM implantation. In conclusion, with proper device sterilization and handling protocols, reuse of explanted PPMs in poor patients in developing countries is safe and effective. Implantation of donated PPMs can not only save lives but also improve quality of life of needy poor patients.

Long-term outcome following successful pulmonary vein isolation: pattern and prediction of very late recurrence.

BACKGROUND: Despite encouraging results of pulmonary vein isolation (PVI) ablation for atrial fibrillation (AF), it is unclear whether there is genuine cure or there is an important attrition rate. We sought to determine the long-term outcome of the initial responders who experienced a prolonged AF-free complete response. METHODS: From a series of 350 consecutive patients who underwent PVI for AF, 264 patients (75%) (males 71%, age 57 +/- 12 years, paroxysmal AF 87%) who demonstrated >or=1 year AF-free follow-up on no antiarrhythmic drugs were followed for 1-5 years. RESULTS: During 28 +/- 12 months follow-up, 23 of 264 (8.7%) patients had recurrence of AF. The actuarial recurrence at 2 years postablation was 5.8% and increased to 25.5% at 5 years. Compared with long-term responders, more patients with late recurrence had hypertension (HR = 2.18, P = 0.009) and hyperlipidemia (HR = 4.01, P = 0.0005). Among 18 patients with recurrent AF necessitating repeat PVI, 15 (83%) required re-isolation of > 1 PV and 28 of 45 (58%) PVs showed reconnection. All PVs were re-isolated and five (28%) patients had additional linear ablation. All 15 patients became AF-free again. CONCLUSIONS: Although most patients following PVI remain AF-free, some patients develop "late" recurrence of AF. The "late" recurrence patients are more likely to have hypertension and hyperlipidemia. Most late recurrences are associated with PV reconnections. Our observations emphasize the importance of continued long-term vigilance for AF recurrence, and also raise concerns regarding the need for long-term anticoagulation therapy.

Dexmedetomidine related cardiac arrest in a patient with permanent pacemaker; a cautionary tale.

Dexmedetomidine (Precedex), an alpha-2 adrenergic receptor agonist is frequently and safely used as sedative agent during surgical procedures. We report a case of a 76-year-old woman who developed cardiac arrest from the use of dexmedetomidine during pacemaker lead extraction procedure.