Nilesh Mathuria

University of Texas Health Science Center at Houston, Houston, Texas, United States

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Publications (34)130.47 Total impact

  • Nilesh Mathuria ·

    Heart rhythm: the official journal of the Heart Rhythm Society 09/2015; DOI:10.1016/j.hrthm.2015.09.013 · 5.08 Impact Factor
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    ABSTRACT: IntroductionPatients undergoing catheter ablation for ventricular tachycardia (VT) may require epicardial mapping. In patients with end stage heart failure, hybrid surgical epicardial mapping and ablation during the period of left ventricular assist device (LVAD) implantation may be considered in select patients to reduce post-LVAD ventricular tachycardia.Methods and ResultsFrom March 2009 through October 2012, 5 patients (4 men and 1 woman, age range 52–73yrs) underwent open chest electrophysiology study and epicardial mapping for recurrent ventricular tachycardia while the heart was exposed during the period of LVAD implantation. Epicardial mapping was considered if patients had recurrent VT despite failed prior endocardial ablation and/or EKG features of an epicardial exit. Activation and/or a substrate mapping approach were employed during all procedures. Three of 5 patients (60%) had acute procedural success. In all patients, VT was either eliminated or significantly reduced with epicardial ablation. One patient had mediastinal bleeding delaying sternal closure. During a follow-up period of 363±368 days, 4 patients died due to non-arrhythmic causes.Conclusions Open-chest hybrid epicardial mapping and ablation for recurrent VT is feasible and can be considered in select patients during the period of LVAD implantation.This article is protected by copyright. All rights reserved
    Journal of Cardiovascular Electrophysiology 09/2015; DOI:10.1111/jce.12839 · 2.96 Impact Factor
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    ABSTRACT: The impact of catheter ablation of ventricular tachycardia (VT) on all-cause mortality remains unknown. To examine the association between VT recurrence after ablation and survival in patients with scar-related VT. Analysis of 2,061 patients with structural heart disease referred for catheter ablation of scar-related VT from 12 international centers was performed. Data on clinical and procedural variables, VT recurrence, and mortality were analyzed. Kaplan-Meier analysis was used to estimate freedom from recurrent VT, transplant, and death. Cox proportional hazards frailty models were used to analyze the effect of risk factors on VT recurrence and mortality. One-year freedom from VT recurrence was 70% (72% in ischemic and 68% in non-ischemic cardiomyopathy). 57 (3%) patients underwent cardiac transplantation and 216 (10%) died during follow-up. At one year, the estimated rate of transplant and/or mortality was 15% (same for ischemic and non-ischemic cardiomyopathy). Transplant-free survival was significantly higher in patients without VT recurrence compared to those with recurrence (90% vs. 71%, p<0.001). In multivariable analysis, recurrence of VT after ablation showed the highest risk for transplant and/or mortality (HR 6.9 (5.3-9.0); p<0.001). In patients with EF<30% and across all NYHA classes, improved transplant-free survival was seen in those without VT recurrence. Catheter ablation of VT in patients with structural heart disease results in 70% freedom from VT recurrence, with an overall transplant and/or mortality rate of 15% at 1 year. Freedom from VT recurrence is associated with improved transplant-free survival, independent of heart failure severity. Copyright © 2015. Published by Elsevier Inc.
    Heart rhythm: the official journal of the Heart Rhythm Society 05/2015; 12(9). DOI:10.1016/j.hrthm.2015.05.036 · 5.08 Impact Factor
  • Venkatachalam Mulukutla · Wilson Lam · Leo Simpson · Nilesh Mathuria ·

    04/2015; DOI:10.1016/j.hrcr.2015.02.015
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    ABSTRACT: Vagal hyperactivity promotes atrial fibrillation (AF), which has been almost exclusively attributed to acetylcholine. Vasoactive intestinal polypeptide (VIP) and acetylcholine are neurotransmitters co-released during vagal stimulation. Exogenous VIP has been shown to promote AF by shortening action potential duration (APD), increasing APD spatial heterogeneity and causing intra-atrial conduction block. To investigate the effects of neuronally released VIP on atrial electrophysiological properties during vagal stimulation. We used a specific VIP antagonist (H9935) to uncover the effects of endogenous VIP released during vagal stimulation in canine hearts. H9935 significantly attenuated (1) the vagally induced shortening of atrial effective refractory period and widening of atrial vulnerability window during stimulation of cervical vagosympathetic trunks (VCNS) and (2) vagal effects on APD during stimulation through fat-pad ganglion plexus (VGPS). Atropine completely abolished these vagal effects during VCNS and VGPS. In contrast, VGPS-induced slowing of local conduction velocity was completely abolished by either VIP antagonist or atropine. In pacing-induced AF during VGPS, maximal dominant frequencies and their spatial gradients were reduced significantly by H9935 and, more pronouncedly, by atropine. Furthermore, VIP release in the atria during vagal stimulation was inhibited by atropine, which may account for the concealment of VIP effects with muscarinic blockade. Neuronally released VIP contributes to vagal effects on atrial electrophysiological properties and affects the pathophysiology of vagally induced AF. Neuronal release of VIP in the atria is inhibited by muscarinic blockade, a novel mechanism by which VIP effects are concealed by atropine during vagal stimulation. Copyright © 2015. Published by Elsevier Inc.
    Heart rhythm: the official journal of the Heart Rhythm Society 03/2015; 12(6). DOI:10.1016/j.hrthm.2015.03.003 · 5.08 Impact Factor
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    ABSTRACT: Percutaneous left atrial appendage (LAA) ligation using an epicardial suture system (LARIAT®, SentreHEART, Palo Alto, CA) has been used in patients with nonvalvular atrial fibrillation (AF) and contraindication to oral anticoagulation. However, complex LAA anatomy may preclude its use. We report the safety and effectiveness of compassionate use of first-generation LARIAT® device for epicardial ligation of large, complex left atrial appendages. Between January 2010 and March 2013, 93 patients with AF, high CHADS2 score, and contraindication(s) for oral anticoagulation therapy were evaluated for LAA ligation. Complex anatomy detected by 3D cardiac computed tomography CT angiography led to preclusion of 25 patients (27%). Of these, nine patients who opted for epicardial LAA ligation on compassionate grounds were studied. Mean age was 68.1 ± 8.2 years, four females, all with large LAA width (>40 mm, 45-58 mm) and additional anatomic complexities such as bilobed (two), long C-shaped-like (two), goose neck-like (one), multilobed cauliflower-like (two), cactus-like (one), and chicken wing-like (one) LAA. LAA ligation with LARIAT® was successfully performed with surgical standby in all patients. Seven patients (78%) were safely treated percutaneously and only two patients required minimally invasive thoracotomy (one due to inability to release the epicardial snare from long C-shaped LAA and other due to preexisting adhesions precluding pericardial entry). There were no major complications. Repeat trans-esophageal echocardiography at 3 months showed no remnant flow and none had stroke off Coumadin at 19.3 ± 8.2 months of follow-up. Despite a high preclusion rate, percutaneous LAA ligation may be safely and effectively performed on compassionate grounds using the first-generation LARIAT® device with surgical standby in patients with large and complex LAA.
    Journal of Interventional Cardiac Electrophysiology 01/2015; 42(1). DOI:10.1007/s10840-014-9963-2 · 1.58 Impact Factor
  • Article: Abstracts.
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    ABSTRACT: There is a paucity of data on biophysical parameters during radiofrequency ablation of scar-mediated ventricular tachycardia (VT).
    Journal of Cardiovascular Electrophysiology 06/2014; · 2.96 Impact Factor
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    ABSTRACT: Background There is a paucity of data on biophysical parameters during radiofrequency ablation of scar-mediated ventricular tachycardia (VT).Methods and ResultsData was collected from consecutive patients undergoing VT ablation with open-irrigation. Complete data was available for 372 lesions in 21 patients. The frequency of biophysical parameter changes were: >10Ω reduction (80%), bipolar EGM reduction (69%), while loss of capture was uncommon (32%). Unipolar injury current was seen in 72% of radiofrequency applications. Both EGM reduction and impedance drop were seen in 57% and a change in all 3 parameters was seen in only 20% of lesions. Late potentials were eliminated in 33%, reduced/modified in 56%, and remained after ablation in 11%. Epicardial lesions exhibited an impedance drop (90% vs 76%, p = 0.002) and loss of capture (46% vs 27%, p<0.001) more frequently than endocardial lesions. Lesions delivered manually exhibited a >10Ω impedance drop (83% vs 71%, p = 0.02) and an EGM reduction (71% vs 40%, p< 0.001) more frequently than lesions applied using magnetic navigation, although loss of capture, elimination of LPs, and a change in all 3 parameters were similarly observed.ConclusionsVT ablation is inefficient as the majority of radiofrequency lesions do not achieve more than one targeted biophysical parameter. Only one-third of RF applications targeted at LPs result in complete elimination. Epicardial ablation within scar may be more effective than endocardial lesions and lesions applied manually may be more effective than lesions applied using magnetic navigation. New technologies directed at identifying and optimizing ablation effectiveness in scar are clinically warranted.This article is protected by copyright. All rights reserved.
    Journal of Cardiovascular Electrophysiology 06/2014; 25(11). DOI:10.1111/jce.12477 · 2.96 Impact Factor
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    ABSTRACT: -The extent to which channels within scar are inter-connected is not known. The objective of the study was to evaluate the impact of local ablation of LPs on adjacent and remote areas of slow conduction with simultaneous multipolar mapping. -Analysis was performed on consecutive patients referred for ablation of scar-mediated VT with double ventricular access. Ablation was performed targeting the earliest of LPs visualized on the multipolar catheter and the impact on later LPs was recorded. In 21 patients, a multipolar catheter placed within scar visualized spatially distinct LPs. Among 39 RF applications, ablation at earlier LPs had an effect on neighboring and remote LPs in 31 (80%), with delay in 8 (21%), partial elimination in 9 (23%), and complete elimination in 14 (36%). The mean distance where an ablation impact was detected was 17.6±14.7mm (range 2mm-50mm). Among all patients, 9.7±7.8 RF applications were delivered to homogenize the targeted scar region with a mean number of 23±12 LPs targeted. -Ablation can eliminate neighboring and remote areas of slow conduction, suggesting that channels within scar are frequently inter-connected. This is the first mechanistic demonstration to show that ablation can modify electrical activity in regions of scar outside of the known radius of an RF lesion. The targeting of relatively earlier LPs can expedite scar homogenization without the need for extensive ablation of all LPs.
    Circulation Arrhythmia and Electrophysiology 10/2013; 6(6). DOI:10.1161/CIRCEP.113.000867 · 4.51 Impact Factor

  • The Journal of Heart and Lung Transplantation 04/2013; 32(4):S272. DOI:10.1016/j.healun.2013.01.713 · 6.65 Impact Factor
  • Nilesh S. Mathuria · Roderick Tung · Kalyanam Shivkumar ·
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    ABSTRACT: Management of patients with non-ischemic cardiomyopathy (NICM) and ventricular tachycardia (VT) remains challenging. The role of catheter ablation for VT continues to evolve for these patients. Recent publications have described the location of the arrhythmogenic substrate for patients with NICM to be located along the basal left ventricle on both the endocardial and epicardial surface. Additionally, predictors for identifying whether mapping the endocardium or epicardial surface of the heart have been identified for successful ablation of VT in this patient population. This chapter reviews the known arrhythmogenic substrate in NICM, characterizes the location of this substrate, and provides predictors of identifying an endocardial and/or epicardial site for successful substrate modification.
    Cardiac Mapping, 12/2012: pages 514-523; , ISBN: 9780470670460
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    ABSTRACT: BACKGROUND: Epicardial ablation has been shown to be a useful adjunct for treatment of ventricular tachycardia (VT). OBJECTIVE: To report the trends, safety and efficacy of epicardial mapping and ablation at a single center over an eight-year period. METHODS: Patients referred for VT ablation (6/2004-6/2011) were divided into three groups: ischemic cardiomyopathy (ICM), nonischemic cardiomyopathy (NICM), and idiopathic ventricular arrhythmias (VA). Scar-mediated VT patients that underwent combined epicardial and endocardial (epi-endo) mapping and ablation were compared with those that underwent endocardial ablation only (endo-only) with regards to patient characteristics, acute procedural success, 6 month and 12 month clinical outcomes. RESULTS: Amongst 144 patients referred for VT ablation, 95 patients underwent 109 epicardial procedures (94% access rate). Major complications were seen in 8 patients (8.8%) with pericardial bleeding (>80cc) in 6 cases (6.7%), although no tamponade, surgical intervention, or procedural mortality was seen. Patients with ICM who underwent a combined epi-endo ablation had improved freedom from VT compared to those with endo-only ablation at 12 months (85% vs 56%, p=0.03). In NICM patients, no differences were seen between those that underwent epi-endo ablation compared to those with endo-only ablation at 12 months (36% vs 33%, p=1.0). In idiopathic VA, only 2/17 patients were successfully ablated from the epicardium. CONCLUSIONS: In this large tertiary single-center experience, complication rates are acceptably low and improved clinical outcomes were associated with epi-endo ablation in ICM patients. NICM patients represent a growing referred population, although clinical recurrence remains high despite epicardial ablation. Epicardial ablation has a low yield in idiopathic VA.
    Heart rhythm: the official journal of the Heart Rhythm Society 12/2012; 10(4). DOI:10.1016/j.hrthm.2012.12.013 · 5.08 Impact Factor
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    Circulation Arrhythmia and Electrophysiology 10/2012; 5(5):e101. DOI:10.1161/CIRCEP.112.974626 · 4.51 Impact Factor
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    ABSTRACT: Introduction: The usefulness of unipolar electrograms (EGMs) has been reported in assessing lesion transmurality and conduction block along ablation lines. It is unknown whether unipolar and bipolar EGM characteristics predict exit block during pulmonary vein isolation (PVI) procedures. Methods and results: Twenty patients (63 ± 7 years; 14 males [70%]) undergoing PVI with a circular mapping catheter (CMC) placed outside each PV ostium were retrospectively studied. After entrance block was achieved, pacing at each bipole around the CMC was performed to assess for absence of atrial capture (exit block). Bipolar EGMs recorded before pacing were examined for voltage, duration, fractionation, and monophasic morphology. Unipolar EGMs were examined for positive and negative amplitude, PQ segment elevation, fractionation, and monophasic morphology. The association of these parameters with atrial capture (absence of exit block) at each site was analyzed. After achievement of entrance block, only 23 of 64 PV antra (36%) exhibited exit block. Unipolar EGMs at sites with persistent capture were more likely to be fractionated and had larger negative deflections. Bipolar EGMs at sites with persistent capture showed higher amplitude, longer duration, were more likely to be fractionated, and were less likely to be monophasic. In a multivariate logistic regression model, bipolar and unipolar fractionation, bipolar duration, and lack of bipolar monophasic morphology were independently associated with persistent atrial capture. Conclusion: Specific unipolar and bipolar EGM characteristics are associated with left atrium capture after PV antral isolation. These parameters might be useful in predicting the need for further ablation to achieve exit block.
    Pacing and Clinical Electrophysiology 08/2012; 35(11). DOI:10.1111/j.1540-8159.2012.03499.x · 1.13 Impact Factor
  • Nilesh Mathuria · Roderick Tung · Kalyanam Shivkumar ·
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    ABSTRACT: Management of patients with nonischemic cardiomyopathy (NICM) and ventricular tachycardia (VT) remains challenging. The role of catheter ablation for VT continues to evolve for these patients. Prior reports have described the location of the arrhythmogenic substrate for patients with NICM to be frequently located along the basal left ventricle, with an epicardial predilection. Furthermore, predictors for identifying whether mapping the endocardium or epicardial surface of the heart have been identified for improved success of VT ablation in this patient population. This chapter will review the latest advances in catheter ablation of ventricular tachycardia in patients with NICM.
    Current Cardiology Reports 07/2012; 14(5):577-83. DOI:10.1007/s11886-012-0302-x · 1.93 Impact Factor
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    ABSTRACT: Background: Radiofrequency ablation is first-line therapy for atrial flutter (AFL). There are no studies of ablation in patients with severe pulmonary arterial hypertension (PAH). Methods: Consecutive patients with severe PAH (systolic pulmonary artery pressure >60 mmHg) and AFL referred for ablation were evaluated. Patients with complex congenital heart disease were excluded. Results: A total of 14 AFL ablation procedures were undertaken in 12 patients. A total of 75% of patients were female; mean age 49 ± 12 years. SPAP prior to ablation was 99 ± 35 mmHg. Baseline 6-minute walk distance was 295 ± 118 m. ECG demonstrated a typical AFL pattern in only 42% of cases. Baseline AFL cycle length was longer in PAH patients compared to controls (295 ± 53 ms vs 252 ± 35 ms, P = 0.006). Cavotricuspid isthmus dependence was verified in 86% of cases. Acute success was obtained in 86% of procedures. SPAP decreased from 114 ± 44 mmHg to 82 ± 38 mmHg after ablation (P = 0.004). BNP levels were lower postablation (787 ± 832 pg/mL vs 522 ± 745 pg/mL, P = 0.02). Complications were seen in 14%. A total of 80% (8/10) of patients were free of AFL at 3 months; 75% (6/8) at 1 year. Conclusion: Ablation of AFL in severe PAH patients is feasible, with good short- and intermediate-term success rates. The ECG pattern is not a reliable marker of isthmus dependence. The SPAP and BNP levels may decrease postablation. AFL may be a marker of poor outcomes in patients with PAH with a 1-year mortality rate of 42% in this study. This rate is higher than expected in the general PAH population.
    Journal of Cardiovascular Electrophysiology 06/2012; 23(11). DOI:10.1111/j.1540-8167.2012.02387.x · 2.96 Impact Factor
  • Jiangli Han · Jie Cheng · Nilesh Mathuria ·
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    ABSTRACT: Thromboembolism is the crucial cause of ischemic stroke in patients with atrial fibrillation (AF). Anticoagulation therapy with vitamin K antagonists, such as warfarin, have been proven to be effective for stroke prevention in AF. Nonetheless, the use of warfarin may be limited due to increased risk of bleeding, the potential interaction with multiple foods and drugs, and the need for routine coagulation monitoring. Over the last decade anticoagulants, such as dabigatran and rivaroxaban, have been developed and have shown superiority compared to warfarin for preventing stroke in patients with nonvalvular AF in large randomized trials. In addition, on account of the risk of thrombus formation in the left atrial appendage (LAA), many nonpharmacologic approaches have been developed to reduce stroke risk in patients with AF who are not candidates for anticoagulant therapy. Surgical, epicardial, and endovascular techniques for LAA closure are being investigated currently. Both novel pharmacotherapy and nonpharmacologic approaches for stroke prevention will be detailed in this review. (PACE 2012;XX:1–11)
    Pacing and Clinical Electrophysiology 03/2012; 35(7):887-96. DOI:10.1111/j.1540-8159.2012.03367.x · 1.13 Impact Factor
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    ABSTRACT: Myocardial scars harbor areas of slow conduction and display abnormal electrograms. Pace-mapping at these sites can generate a 12-lead ECG morphological match to a targeted ventricular tachycardia (VT), and in some instances, multiple exit morphologies can result. At times, this can also result in the initiation of VT, termed pace-mapped induction (PMI). We hypothesized that in patients undergoing catheter ablation of VT, scar substrates with multiple exit sites (MES) identified during pace-mapping have improved freedom from recurrent VT, and PMI of VT predicts successful sites of termination during ablation. High-density mapping was performed in all subjects to delineate scar (0.5-1.5 mV). Sites with abnormal electrograms were tagged, stimulated (bipolar 10 mA at 2 ms), and targeted for ablation. MES was defined as >1 QRS morphology from a single pacing site. PMI was defined as initiation of VT during pace-mapping (400-600 ms). In a 2-year period, 44 consecutive patients with scar-mediated VT underwent mapping and ablation. MES were observed during pace-mapping in 25 patients (57%). At 9 months, 74% of patients who exhibited MES during pace-mapping had no recurrence of VT compared with 42% of those without MES observed (P=0.024), with an overall freedom from VT of 61%. Thirteen patients (30%) demonstrated PMI, and termination of VT was seen in 95% (18/19) of sites where ablation was performed. During pace-mapping, electrograms that exhibit MES and PMI may be specific for sites critical to reentry. These functional responses hold promise for identifying important sites for catheter ablation of VT.
    Circulation Arrhythmia and Electrophysiology 02/2012; 5(2):264-72. DOI:10.1161/CIRCEP.111.967976 · 4.51 Impact Factor
  • Nilesh Mathuria · Eric Buch · Kalyanam Shivkumar ·

    Circulation Arrhythmia and Electrophysiology 02/2012; 5(1):e18-9. DOI:10.1161/CIRCEP.111.968420 · 4.51 Impact Factor
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    Nilesh Mathuria ·

    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 01/2012; 39(4):529-31. · 0.65 Impact Factor

Publication Stats

198 Citations
130.47 Total Impact Points


  • 2013-2015
    • University of Texas Health Science Center at Houston
      Houston, Texas, United States
  • 2011-2015
    • Texas Heart Institute
      Houston, Texas, United States
  • 2010-2014
    • University of California, Los Angeles
      • Division of Cardiology
      Los Ángeles, California, United States
  • 2012
    • St. John's Episcopal Hospital
      Rockaway, New Jersey, United States
  • 2007-2009
    • Baylor College of Medicine
      • Department of Medicine
      Houston, Texas, United States