Publications by authors named "Ashish Nabar"

24 Publications

  • Page 1 of 1

Professor Hein JJ Wellens, In memoriam.

Indian Pacing Electrophysiol J 2020 Sep - Oct;20(5):213-214. Epub 2020 Aug 6.

LTMG Hospital, Mumbai, India.

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http://dx.doi.org/10.1016/j.ipej.2020.07.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7517541PMC
August 2020

A case report: metastatic complete heart block.

Eur Heart J Case Rep 2018 Dec 29;2(4):yty131. Epub 2018 Nov 29.

Department of Cardiology, Seth GS Medical College, KEM Hospital, Achary Dhonde MargParel, Mumbai, Maharashtra, India.

Background: Though primary malignant tumours of the heart are rare, secondary metastatic affection of the heart is quite common. Common presentations include pericardial effusion, obstruction of inflow and outflow tracts and arrhythmias, most notably tachyarrhythmias, and very rarely complete heart blocks (CHBs).

Case Summary: A 28-year-old man suffering from carcinoma of the tongue underwent a surgery in the form of radical hemimandibulectomy. He presented with recurrent syncope and CHB with broad complex escape rhythm. After performing echocardiography, he was found to have malignant infiltration of the interventricular septum. This was confirmed by performing cardiac positron emission tomography (PET). It was decided that a permanent pacemaker would then be implanted. Post-implantation of permanent pacemaker patient succumbed to massive haemoptysis after 5 days.

Discussion: Although CHBs are rare in malignancy and careful assessment of ECGs especially looking for first degree heart blocks which may progress to CHB later on is prudent. One must rule out hypercalcaemia as it is a reversible cause of CHB. Careful echocardiogram can show hyper enhancement on interventricular septum and presence of pericardial effusion. Further imaging like cardiac magnetic resonance imaging or cardiac PET is confirmatory.
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http://dx.doi.org/10.1093/ehjcr/yty131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6426093PMC
December 2018

Professor of Cardiology, SGPGIMS, Lucknow, Uttar Pradesh.

J Assoc Physicians India 2016 08;64(8 Suppl):11-15

Senior Resident, Department of Cardiology, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra.

Atrial fibrillation (AF) is the most common supraventricular tachycardia and its incidence increases with age. The pathophysiology of AF has been studied extensively and is a subject of continuing research. The primary pathologic change seen in AF is progressive fibrosis of the atria and hence structural remodeling, is the mainstay in many forms of AF. Dilation of the atria can be due to almost any structural abnormality of the heart which includes valvular heart disease, hypertension or congestive heart failure. Electrical remodeling promotes AF by acting on fundamental arrhythmia mechanism: focal ectopic activity and reentry. Rapidly firing foci initiating paroxysmal AF arise most commonly from the atrial myocardial sleeves that extend into pulmonary veins. The evolution of AF from paroxysmal to persistent to permanent forms through atrial remodeling can be caused by the arrhythmia itself and/or progression of underlying heart disease. The development of functional reentry substrates contribute to persistent AF. AF-related reentry is currently thought to occur through two main concepts: (1) the leading- circle concept and (2) spiral wave reentry. The multiple wavelets hypothesis, particularly in advanced structural and electrical remodelling are present, maintains AF survival, causing the most frequent common final pathway in sustained AF.
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August 2016

Percutaneous tricuspid valvotomy for pacemaker lead-induced tricuspid stenosis.

Indian Heart J 2015 Dec 14;67 Suppl 3:S115-6. Epub 2016 Jan 14.

Seth GS Medical College and KEM Hospital, Parel, Mumbai, India.

Permanent pacemaker lead-induced tricuspid regurgitation is extremely uncommon. We report a patient with severe tricuspid stenosis detected 10 years after permanent single chamber pacemaker implantation in surgically corrected congenital heart disease. The loop at the level of the tricuspid valve may have caused endothelial injury and eventually led to stenosis. Percutaneous balloon valvotomy for such stenosis has not been reported from India.
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http://dx.doi.org/10.1016/j.ihj.2015.06.033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4798980PMC
December 2015

A survey of cardiac implantable electronic device implantation in India: By Indian Society of Electrocardiology and Indian Heart Rhythm Society.

Indian Heart J 2016 Jan-Feb;68(1):68-71. Epub 2016 Jan 18.

Railway Hospital, Byculla, Mumbai, India.

Background: There is limited data regarding the demographics and type of cardiac implantable electronic device (CIED) in India.

Aim: The aim of this survey was to define trends in CIED implants, which included permanent pacemakers (PM), intracardiac defibrillators (ICD), and cardiac resynchronization therapy pacemakers and defibrillators (CRT-P/D) devices in India.

Methods: The survey was the initiative of the Indian Society of Electrocardiology and the Indian Heart Rhythm Society. The type of CIED used, their indications, demographic characteristics, clinical status and co-morbidities were collected using a survey form over a period of 1 year.

Results: 2117 forms were analysed from 136 centers. PM for bradyarrhythmic indication constituted 80% of the devices implanted with ICD's and CRT-P/D forming approximately 10% each. The most common indication for PM implantation was complete atrio-ventricular block (76%). Single chamber (VVI) pacemakers formed 54% of implants, majority in males (64%). The indication for ICD implantation was almost equal for primary and secondary prevention. A single chamber ICD was most commonly implanted (65%). Coronary artery disease was the etiology in 58.5% of patients with ICD implants. CRT pacemakers were implanted mostly in patients with NYHA III/IV (82%), left ventricular ejection fraction <0.35 (88%) with CRT-P being most commonly used (57%).

Conclusion: A large proportion of CIED implants in India are PM for bradyarrhythmic indications, predominantly AV block. ICD's are implanted almost equally for primary and secondary prophylaxis. Most CRT devices are implanted for NYHA Class III. There is a male predominance for implantation of CIED.
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http://dx.doi.org/10.1016/j.ihj.2015.06.037DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4759489PMC
January 2017

Classical Cardiovascular Manifestations of Marfan Syndrome.

J Assoc Physicians India 2015 Jul;63(7):65-7

Presence of multiple cardiovascular manifestations of the Marfan syndrome in the same patient is not commonly encountered. We present a 49 year-old lady with this syndrome who presented with decompensated heart failure. Evaluation revealed presence of extensive Stanford type A aortic dissection alongwith severe aortic and mitral incompetence. However, the patient declined surgery and was discharged on medical management. At a year's follow-up, she had dyspnea of NYHA class II with persistent cardiovascular findings.
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July 2015

Bilateral Superior Venae Cavae With Crisscross Atrial Drainage.

Circulation 2015 Dec;132(23):e365-8

From Department of Cardiology, Seth G. S. Medical College & King Edward VII Memorial Hospital, Acharya Donde Marg, Parel, Mumbai, India (S.P.T., A.A.N., P.G.K.); Infinity Medical Centre, Parel, Mumbai, India (H.B.T.); and Department of Radiology, Global Hospital, Parel, Mumbai, India (A.S.U.).

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http://dx.doi.org/10.1161/CIRCULATIONAHA.115.018898DOI Listing
December 2015

Subvalvular apparatus and adverse outcome of balloon valvotomy in rheumatic mitral stenosis.

Indian Heart J 2015 Sep-Oct;67(5):428-33. Epub 2015 Aug 8.

Department of Cardiac Pathology, King Edward VII Memorial Hospital and Seth G S Medical College, Mumbai 400012, India.

Background: Balloon mitral valvotomy (BMV) is a well-established therapeutic modality for rheumatic mitral stenosis (RMS). However, there are chances of procedural failure and the more ominous post-procedural severe mitral regurgitation. There are only a few prospective studies, which have evaluated the pathogenic mechanisms for these major complications of BMV, especially in relation to the subvalvular apparatus (SVA) pathology.

Methods: All symptomatic patients of RMS suitable for BMV by echocardiographic criteria in a span of 1 year were selected. In addition to the standard echocardiographic assessment of RMS (Wilkins score and score by Padial et al.), a separate grading and scoring system was assigned to evaluate the severity of the SVA pathology. The SVA score was 'I', when none of the two SVAs had severe disease, 'II' when one of the two SVAs has severe disease, and 'III' when both SVAs had severe disease. With these scoring systems, the outcomes of BMV (successful procedure, failure, and post-procedural mitral regurgitation) were analyzed. Emergency valve replacement was performed depending on clinical situation, and in cases of replacement, the pathology of the excised mitral valves were compared with echocardiographic findings.

Results: Of the 356 BMVs performed in a year, 43 patients had adverse outcomes in the form of failed procedure (14 patients) and mitral regurgitation (29 patients). Forty-one among these had a SVA score of III. The sensitivity and specificity of the MR score was lesser than the SVA score (sensitivity 0.34 vs. 1.00, specificity 0.92 vs. 0.99, respectively). The mitral valvular morphology in 39 patients who underwent post-procedural valve replacements correlated well with echocardiography findings.

Conclusion: It is important to assess the degree of SVA pathology in the conventional echocardiographic assessment for RMS, as BMV would have adverse events when both SVAs were severely diseased.
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http://dx.doi.org/10.1016/j.ihj.2015.06.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4593808PMC
December 2016

An interesting case of an absent right-sided AV connection with an atrioventricular septal defect and double-outlet left atrium.

Eur Heart J Cardiovasc Imaging 2014 Oct 22;15(10):1181. Epub 2014 May 22.

Department of Cardiology, Seth G.S. Medical College and King Edward VII Memorial Hospital, Acharya Donde Marg, Parel, Mumbai, Maharashtra 400012, India.

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http://dx.doi.org/10.1093/ehjci/jeu092DOI Listing
October 2014

Supracardiac total anomalous pulmonary venous drainage with giant superior vena cava aneurysm: a rare combination.

J Am Coll Cardiol 2014 May 26;63(19):e51. Epub 2014 Mar 26.

Department of Cardiology, King Edward Memorial Hospital, Mumbai, India.

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http://dx.doi.org/10.1016/j.jacc.2013.11.071DOI Listing
May 2014

Differential cyanosis and clubbing sparing a single limb.

J Am Coll Cardiol 2014 Apr 19;63(14):e33. Epub 2014 Feb 19.

Department of Cardiology, Seth G. S. Medical College and The King Edward VII Memorial Hospital, Mumbai, India.

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http://dx.doi.org/10.1016/j.jacc.2013.11.058DOI Listing
April 2014

Left main trunk connecting to superior vena cava via aneurysmal coronary artery fistula.

Eur Heart J Cardiovasc Imaging 2014 Jul 20;15(7):752. Epub 2014 Jan 20.

Department of Cardiology, King Edward Memorial Hospital, CVTC Building, E. Borges Road, Parel, Mumbai, Maharashtra 422012, India.

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http://dx.doi.org/10.1093/ehjci/jet281DOI Listing
July 2014

Can carbonated lime drink intake prior to myocardial perfusion imaging with Tc-99m MIBI reduce the extracardiac activity that degrades the image quality and leads to fallacies in interpretation?

Clin Nucl Med 2010 Mar;35(3):160-4

Radiation Medicine Centre, Bhabha Atomic Research Centre, Tata Memorial Centre Annexe, Jerbai Wadia Road, Parel, Mumbai, India.

Background: During myocardial perfusion imaging with Tc-99m sestamibi, intestinal and hepatic radiotracer activity commonly interfere with visualization of the inferior wall of the myocardium leading to difficulties in interpretation. This study was undertaken to assess if carbonated lime drink ingestion prior to imaging prevents the said interference and improves the quality of images.

Materials And Methods: The study group comprised 33 consecutive patients including 26 males (age range: 30-80 years) and 7 females (42-62 years) who were referred for myocardial perfusion imaging. Of 33 patients, 21 (18 males, 3 females) were imaged at rest, 5 patients (3 males, 2 females) underwent physical stress, and 7 patients (5 males, 2 females) had pharmacological stress with adenosine. Five to 10 minutes after intravenous injection of 296 to 444 MBq (8-12 mCi) Tc-99m MIBI, anterior, and left anterior oblique (LAO) 45 degree planar views were acquired with a gamma camera using LEHR collimator. Each view was acquired for 100 seconds in a 256 x 256 matrix in all patients. Thereafter each patient was administered about 250 mL of a carbonated lime drink and repeat views were acquired within 5 minutes with the same parameters. Quantitative assessment of counts in the inferior wall of myocardium (M) to those in adjacent abdomen (A) was performed on both pre- and postintervention studies by drawing an ROI of about 50 +/- 5 pixels. M/A ratios were recorded for each patient in both the groups. The student t test was performed to evaluate the significance of difference between pre- and postintervention images. P < 0.05 was considered significant. All patients underwent myocardial perfusion single photon emission computed tomography.

Results: It was found that the inferior wall of the myocardium was better visualized, and there was no interference from gut or hepatic tracer activity in postintervention planar and single photon emission computed tomography reconstructed views as compared with preintervention images in all patients. The M/A ratio expressed as mean +/- SD was significantly higher in the postintervention group, viz. 2.19 +/- 0.71 in the anterior and 2.07 +/- 0.70 in the LAO45 views as compared with those of preintervention values of 1.50 +/- 0.59 in the anterior and 1.41 +/- 0.49 in the LAO 45 views, respectively (P < 0.001).

Conclusion: We conclude that intake of carbonated lime drink is a simple and an effective technique to improve the image quality of the inferior wall of the myocardium on myocardial perfusion imaging with Tc-99m MIBI. This technique may also help in reducing the time interval between injection of radiotracer and imaging, which is otherwise delayed in routine practice.
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http://dx.doi.org/10.1097/RLU.0b013e3181cc63a1DOI Listing
March 2010

Ablation of atrial flutter: block (isthmus conduction) or not a block, that is the question?

Authors:
Ashish Nabar

Indian Pacing Electrophysiol J 2002 Jul 1;2(3):85-90. Epub 2002 Jul 1.

Department of Cardiology, Academic Hospital Maastricht, P. Debyelaan 25, Post box 5800, 6202 AZ, Maastricht, The Netherlands.

It is important to identify residual slow conduction and minimize the chance of resumption of conduction after right atrial isthmus ablation to reduce the chance of recurrence of atrial flutter (AFL). The aim of this article is to discuss the best possible way of confirming a bi-directional isthmus conduction (BIC) block after ablation of an isthmus-dependent AFL. A combination of activation and double potential mapping seems to be the most practical way of acutely confirming the BIC block.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1564056PMC
July 2002

Excerpts from electrophysiology sessions at the European Society of Cardiology Congress 2002-Berlin.

Authors:
Ashish Nabar

Indian Pacing Electrophysiol J 2003 Jan 1;3(1):41-3. Epub 2003 Jan 1.

Department of Cardiology, Academic Hospital Maastricht, P. Debyelaan 25, 6202 AZ, Maastricht, The Netherlands.

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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1555631PMC
January 2003

Temporal patterns of electrical remodeling in canine ventricular hypertrophy: focus on IKs downregulation and blunted beta-adrenergic activation.

Cardiovasc Res 2006 Oct 25;72(1):90-100. Epub 2006 Jul 25.

Department of Cardiology, Cardiovascular Research Institute Maastricht, Maastricht University and Academic Hospital Maastricht, PO Box 5800, 6202 AZ, Maastricht, The Netherlands.

Objectives: Electrical remodeling in cardiac hypertrophy often involves the downregulation of K+ currents, including beta-adrenergic (beta-A)-sensitive IKs. Temporal patterns of ion-channel downregulation are poorly resolved. In dogs with complete atrioventricular block (AVB), we examined (1) the time course of molecular alterations underlying IKs downregulation from acute to chronic hypertrophy; and (2) concomitant changing responses of repolarization to beta-adrenergic receptor (beta-AR) stimulation.

Methods And Results: Serial left-ventricular (LV) biopsies were collected from anesthetized dogs during sinus rhythm (SR; control) and at 3, 7 and 30 days of AVB. KCNQ1 mRNA and protein decreased within 3 days (protein expression 58 +/- 10% of control), remaining low thereafter. beta1-AR mRNA and protein decreased more gradually to 53 +/- 8% at 7 days. In chronic-AVB LV myocytes, IKs -tail density was reduced: 1.4 +/- 0.3 pA/pF versus 2.6 +/- 0.4 pA/pF in controls. beta-A enhancement of IKs was reduced. Isoproterenol shortened action-potential duration in control cells, while causing heterogeneous repolarization responses in chronic AVB. beta-A early afterdepolarizations were induced in 4 of 13 chronic-AVB cells, but not in controls. In intact conscious dogs, isoproterenol shortened QTc at SR (by -8 +/- 3% from 295 ms), left it unaltered at 3 days AVB (+1 +/- 3% from 325 ms) and prolonged QTc at 30 days (+6 +/- 3% from 365 ms).

Conclusions: Profound decrease of KCNQ1 occurs within days after AVB induction and is followed by a more gradual decrease of beta1-AR expression. Downregulation and blunted beta-A activation of IKs contribute to the loss of beta-A-induced shortening of ventricular repolarization, favoring proarrhythmia. Provocation testing with isoproterenol identifies repolarization instability based on acquired channelopathy.
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http://dx.doi.org/10.1016/j.cardiores.2006.07.015DOI Listing
October 2006

Variable patterns of septal activation in patients with left bundle branch block and heart failure.

J Cardiovasc Electrophysiol 2003 Feb;14(2):135-41

Department of Cardiology, Academic Hospital Maastricht, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands.

Introduction: Little is known about the septal activation pattern in patients with heart failure and left bundle branch block (LBBB-HF).

Methods And Results: The right ventricular (RV) and left ventricular (LV) activation patterns of 12 patients (mean age 67 +/- 11 years) with LBBB-HF and 5 patients (mean age 45 +/- 14) with normal hearts were studied during sinus rhythm using a three-dimensional mapping system. The etiology of HF was myocardial infarction (n = 4) or idiopathic dilated cardiomyopathy (n = 8). In patients with LBBB-HF, endocardial activation usually started before the onset of the surface QRS complex on the RV free wall. Latest RV activation occurred in the basal region, and total RV activation time was longer than in patients with normal hearts. In patients with LBBB-HF, the left septum was activated via slowly conducting LBB or via right-to-left transseptal conduction. In both patients with LBBB-HF and those with normal hearts, latest LV activation occurred either in the posterior or posterolateral-basal region. Conduction velocity was slower in the peri-scar region, in patients with previous myocardial infarct and globally slow, in patients with idiopathic dilated cardiomyopathy.

Conclusion: The two types of left septal activation observed in patients with LBBB-HF may have consequences for biventricular hemodynamic performance. Conduction slowing along the LV, regionally or globally, suggests a contribution outside the specific conduction system in the ECG pattern of LBBB.
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http://dx.doi.org/10.1046/j.1540-8167.2003.02421.xDOI Listing
February 2003

Echocardiographic predictors of survival in patients undergoing radiofrequency ablation of postinfarct clinical ventricular tachycardia.

J Cardiovasc Electrophysiol 2002 Jan;13(1 Suppl):S118-21

Department of Cardiology, Academic Hospital Maastricht, The Netherlands.

Introduction: The aim of this study was to determine the predictive value of echocardiographic parameters of systolic left ventricular (LV) dysfunction for survival in a group of patients with "mappable" ventricular tachycardia (VT) after myocardial infarction who underwent radiofrequency ablation (RFA) of their clinical VT(s).

Methods And Results: RFA of at least one inducible, "mappable," and clinical VT was attempted in 61 patients. In total, 63 (79%) of 80 target clinical VTs were ablated successfully, such that clinical VT(s) were noninducible in 49 (80%) of 61 patients. At the last recorded follow-up (range 2 to 98 months; mean 21 +/- 20), nonfatal VT recurrences were observed in 11 (22%) patients; 10 (16%) patients died. On univariate analysis, a higher LV end-diastolic volume (LVEDV; P = 0.008) and, by multivariate analysis, applying backward selection of variables, older age (P = 0.03) with a higher LVEDV (P = 0.003) predicted patients more likely to die. When age and LV ejection fraction (LVEF) were excluded, LV end-systolic diameter (LVESD; P = 0.007) was the most significant predictor of survival.

Conclusion: In our patient population with postinfarct VT who underwent RFA of mappable clinical VT(s), LVEF did not predict survival. In this group of patients with overall low mean LVEF (<35%), older age together with higher LVEDV and LVESD predicted patients who were more prone to die. LV size rather than LVEF correlated with survival.
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http://dx.doi.org/10.1111/j.1540-8167.2002.tb01965.xDOI Listing
January 2002
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