Imperial College London

DrViasMarkides

Faculty of MedicineNational Heart & Lung Institute

Honorary Clinical Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7351 8619v.markides

 
 
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Assistant

 

Dr Tom Wong +44 (0)20 7351 8619

 
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Location

 

Chelsea WingRoyal Brompton Campus

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Summary

 

Publications

Publication Type
Year
to

165 results found

Panikker S, Virmani R, Kolodgie F, Jarman J, Mantziari L, Haldar SK, Foran JP, Markides V, Wong Tet al., 2015, Insights into the anatomical sites of acute left atrial appendage reconnection after successful electrical isolation, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 948-948, ISSN: 0195-668X

Conference paper

Panikker S, Jarman JWE, Mantziari L, Nicol E, Haldar SK, Hussain W, Foran JP, Markides V, Wong Tet al., 2015, A novel, safe and effective modality of treating persistent atrial fibrillation: concomitant left atrial appendage electrical isolation and device occlusion, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 567-567, ISSN: 0195-668X

Conference paper

Mantziari L, Butcher C, Kontogeorgis A, Panikker S, Roy K, Markides V, Wong Tet al., 2015, The utility, efficacy and safety of a new rapid high-resolution mapping system in the catheter ablation of atrial and ventricular arrhythmias in humans, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 1058-1059, ISSN: 0195-668X

Conference paper

Mantziari L, Butcher C, Kontogeorgis A, Panikker S, Roy K, Markides V, Wong Tet al., 2015, The use of a new rapid high resolution mapping system in the validation of linear lesions, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 560-561, ISSN: 0195-668X

Conference paper

Farag M, Okafor O, Niespialowska-Steuden M, Artman B, Markides V, Gorog DAet al., 2015, Patients who revert to atrial fibrillation after cardioversion demonstrate impaired thrombotic status, Congress of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 392-392, ISSN: 0195-668X

Conference paper

Niespialolwska-Steuden M, Markides V, Okafor O, Farag M, Spinthakis N, Cisecka M, Gorog DA, Collins Pet al., 2015, IMPROVEMENT IN ENDOGENOUS THROMBOLYTIC STATUS FOLLOWING SUCCESSFUL ABLATION OF ATRIAL FIBRILLATION, British-Cardiac-Society (BCS) Annual Conference on Hearts and Genes, Publisher: BMJ PUBLISHING GROUP, Pages: A30-A30, ISSN: 1355-6037

Conference paper

Farag M, Okafor O, Niespialowska-Steuden M, Artman B, Markides V, Gorog Det al., 2015, EFFECT OF ELECTRICAL CARDIOVERSION ON THROMBOTIC STATUS, British-Cardiac-Society (BCS) Annual Conference on Hearts and Genes, Publisher: BMJ PUBLISHING GROUP, Pages: A32-A32, ISSN: 1355-6037

Conference paper

Sabashnikov A, Weymann A, Haldar S, Soliman RFB, Fatullayev J, Jones D, Hussain W, Choi Y-H, Zeriouh M, Dohmen PM, Popov A-F, Markides V, Wong T, Bahrami Tet al., 2015, Position of totally thoracoscopic surgical ablation in the treatment of atrial fibrillation: An alternative method of conduction testing, Medical Science Monitor Basic Research, Vol: 21, Pages: 76-80, ISSN: 2325-4394

Recent advances in surgical techniques and understanding of the pathophysiology of atrial fibrillation has led to the development of a less invasive thoracoscopic surgical treatment including video-assisted bilateral pulmonary vein isolation using bipolar radiofrequency ablation clamps. More recently, the same operation became possible via a totally thoracoscopic approach.In this paper we describe technical aspects of the thoracoscopic approach to surgical treatment of AF and discuss its features, benefits and limitations. Furthermore, we present a new alternative technique of conduction testing using endoscopic multi-electrode recording catheters.An alternative electrophysiological mapping strategy involves a multi-electrode recording catheter designed primarily for percutaneous endocardial electrophysiologic mapping procedure. According to our initial experience, the recordings obtained from the multi-electrode catheters positioned around the pulmonary veins are more accurate than the recordings obtained from the multifunctional ablation and pacing pen.The totally thoracoscopic surgical ablation approach is a feasible and efficient treatment strategy for atrial fibrillation. The conduction testing can be easily and rapidly performed using a multifunctional pen or multi-electrode recording catheter.

Journal article

Jarman JWE, Panikker S, Das M, Wynn GJ, Ullah W, Kontogeorgis A, Haldar SK, Patel PJ, Hussain W, Markides V, Gupta D, Schilling RJ, Wong Tet al., 2015, Relationship Between Contact Force Sensing Technology and Medium-Term Outcome of Atrial Fibrillation Ablation: A Multicenter Study of 600 Patients, JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Vol: 26, Pages: 378-384, ISSN: 1045-3873

Journal article

Niespialowska-Steuden M, Markides V, Okafor O, Farag M, Spinthakis N, Artman B, Gorog DAet al., 2015, ATRIAL FIBRILLATION ABLATION IMPROVES GLOBAL THROMBOTIC STATUS THROUGH ENDOGENOUS THROMBOLYSIS, AS EARLY AS 3 MONTHS POST ABLATION, Scientific Session of the American-College-of-Cardiology (ACC), Publisher: ELSEVIER SCIENCE INC, Pages: A421-A421, ISSN: 0735-1097

Conference paper

Ismail TF, Panikker S, Markides V, Foran JP, Padley S, Rubens MB, Wong T, Nicol Eet al., 2015, CT imaging for left atrial appendage closure: A review and pictorial essay, JOURNAL OF CARDIOVASCULAR COMPUTED TOMOGRAPHY, Vol: 9, Pages: 89-102, ISSN: 1934-5925

Journal article

Panikker S, Virmani R, Sakakura K, Kolodgie F, Francis DP, Markides V, Walcott G, McElderry HT, Wong Tet al., 2015, Left atrial appendage electrical isolation and concomitant device occlusion: A safety and feasibility study with histologic characterization, HEART RHYTHM, Vol: 12, Pages: 202-210, ISSN: 1547-5271

Journal article

Panikker S, Lord J, Jarman J, Foran JP, Haldar S, Jones DG, Salukhe T, Clague JR, Markides V, Wong Tet al., 2014, 45Real world experience left atrial appendage closure provides superior cost benefits relative to new and established oral anticoagulants., Europace, Vol: 16 Suppl 3

Recent evidence supports left atrial appendage closure (LAAC) as a cost-effective alternative to warfarin. However these findings, based on clinical trial populations, may not be generalisable to clinical practice. The cost-impact of a real world experience of LAAC compared with warfarin, dabigatran, rivaroxaban, apixaban, aspirin and no therapy in patients with nonvalvular atrial fibrillation (NVAF) is unknown.

Journal article

Cooklin M, Sporton S, Lovell M, Kanagaratnam P, Lowe M, Markides V, Mason M, Whitbread Met al., 2014, 71Does triage of patients diagnosed by paramedics with ventricular tachycardia directly to arrhythmia centres improve patient care?, Europace, Vol: 16 Suppl 3

The impact of triaging patients with selected arrhythmia emergencies diagnosed by ambulance paramedics directly to centres capable of delivering specialist care 24 hrs a day (24/7) has not been measured. Triage of patients diagnosed by the London Ambulance Service (LAS) with ventricular tachycardia (VT) directly to arrhythmia centres was evaluated and compared to standard care.

Journal article

Panikker S, Jarman J, Lord J, Foran JP, Haldar S, Jones DG, Salukhe T, Clague JR, Markides V, Wong Tet al., 2014, Cost impact of left atrial appendage occlusion to prevent stroke in patients with nonvalvular atrial fibrillation, Annual Meeting of the European-Society-of-Cardiology (ESC), Publisher: OXFORD UNIV PRESS, Pages: 1075-1076, ISSN: 0195-668X

Conference paper

Jarman JWE, Wong T, Kojodjojo P, Spohr H, Davies JER, Roughton M, Francis DP, Kanagaratnam P, O'Neill MD, Markides V, Davies DW, Peters NSet al., 2014, Organizational Index Mapping to Identify Focal Sources During Persistent Atrial Fibrillation, JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Vol: 25, Pages: 355-363, ISSN: 1045-3873

Journal article

Jones DG, Johar S, Wang J, Markides V, Wong Tet al., 2014, Atrial Tachycardia after AF Ablation: An Alternate Mechanism?, PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY, Vol: 37, Pages: 375-378, ISSN: 0147-8389

Journal article

Haldar S, Jarman JWE, Panikker S, Jones DG, Salukhe T, Gupta D, Wynn G, Hussain W, Markides V, Wong Tet al., 2013, Contact force sensing technology identifies sites of inadequate contact and reduces acute pulmonary vein reconnection: A prospective case control study, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 168, Pages: 1160-1166, ISSN: 0167-5273

Journal article

Jones DG, Jarman JWE, Lyne JC, Markides V, Gatzoulis MA, Wong Tet al., 2013, The safety and efficacy of trans-baffle puncture to enable catheter ablation of atrial tachycardias following the Mustard procedure: A single centre experience and literature review, INTERNATIONAL JOURNAL OF CARDIOLOGY, Vol: 168, Pages: 1115-1120, ISSN: 0167-5273

Journal article

Jones DG, Haldar SK, Jarman JWE, Johar S, Hussain W, Markides V, Wong Tet al., 2013, Impact of Stepwise Ablation on the Biatrial Substrate in Patients With Persistent Atrial Fibrillation and Heart Failure, CIRCULATION-ARRHYTHMIA AND ELECTROPHYSIOLOGY, Vol: 6, Pages: 761-768, ISSN: 1941-3149

Journal article

Mantziari L, Suman-Horduna I, Gujic M, Jones DG, Wong T, Markides V, Foran JP, Ernst Set al., 2013, Use of Asymmetric Bidirectional Catheters with Different Curvature Radius for Catheter Ablation of Cardiac Arrhythmias, PACE-PACING AND CLINICAL ELECTROPHYSIOLOGY, Vol: 36, Pages: 757-763, ISSN: 0147-8389

Journal article

Richardson JA, Hayward C, Khanna A, Williams O, Markides V, Wong T, Sharma RK, Clague JR, Cowie MR, Lyon ARet al., 2013, Predictive value of future ventricular arrhythmic risk in patients with chronic heart failure from annual remote telemonitoring, EUROPEAN JOURNAL OF HEART FAILURE, Vol: 12, Pages: S247-S247, ISSN: 1388-9842

Journal article

Niespialowska-Steuden M, Markides V, Jones D, Collins P, Hussain W, Wong T, Gorog Det al., 2013, CATHETER ABLATION FOR ATRIAL ARRHYTHMIAS RAPIDLY IMPROVES THROMBOTIC PROFILE OVER AND ABOVE THERAPEUTIC ANTICOAGULATION, 62nd Annual Scientific Session of the American-College-of-Cardiology, Publisher: ELSEVIER SCIENCE INC, Pages: E275-E275, ISSN: 0735-1097

Conference paper

Jones DG, Haldar SK, Hussain W, Sharma R, Francis DP, Rahman-Haley SL, McDonagh TA, Underwood SR, Markides V, Wong Tet al., 2013, A randomized trial to assess catheter ablation versus rate control in the management of persistent atrial fibrillation in heart failure, J Am Coll Cardiol, Vol: 61, Pages: 1894-1903, ISSN: 1558-3597

OBJECTIVES: This study sought to compare catheter ablation with rate control for persistent atrial fibrillation (AF) in heart failure (HF). BACKGROUND: The optimal therapy for AF in HF is unclear. Drug-based rhythm control has not proved clinically beneficial. Catheter ablation improves cardiac function in patients with HF, but impact on physiological performance has not been formally evaluated in a randomized trial. METHODS: In a randomized, open-label, blinded-endpoint clinical trial, adults with symptomatic HF, radionuclide left ventricular ejection fraction (EF) </=35%, and persistent AF were assigned to undergo catheter ablation or rate control. Primary outcome was 12-month change in peak oxygen consumption. Secondary endpoints were quality of life, B-type natriuretic peptide, 6-min walk distance, and EF. Results were analyzed by intention-to-treat. RESULTS: Fifty-two patients (age 63 +/- 9 years, EF 24 +/- 8%) were randomized, 26 each to ablation and rate control. At 12 months, 88% of ablation patients maintained sinus rhythm (single-procedure success 68%). Under rate control, rate criteria were achieved in 96%. The primary endpoint, peak oxygen consumption, significantly increased in the ablation arm compared with rate control (difference +3.07 ml/kg/min, 95% confidence interval: 0.56 to 5.59, p = 0.018). The change was not evident at 3 months (+0.79 ml/kg/min, 95% confidence interval: -1.01 to 2.60, p = 0.38). Ablation improved Minnesota score (p = 0.019) and B-type natriuretic peptide (p = 0.045) and showed nonsignificant trends toward improved 6-min walk distance (p = 0.095) and EF (p = 0.055). CONCLUSIONS: This first randomized trial of ablation versus rate control to focus on objective exercise performance in AF and HF shows significant benefit from ablation, a strategy that also improves symptoms and neurohormonal status. The effects develop over 12 months, consistent with progressive amelioration of the HF syndrome. (A Randomised Trial to Assess Cat

Journal article

Jones DG, Haldar SK, Sharma R, Rahman-Haley SL, Francis DP, McDonagh TA, Mattar W, Underwood R, Hussain W, Markides V, Wong Tet al., 2012, A Randomised Trial to Assess Catheter Ablation versus Rate Control in the Management of Persistent Atrial Fibrillation in Chronic Heart Failure, Scientific Sessions of the American-Heart-Association, Publisher: LIPPINCOTT WILLIAMS & WILKINS, Pages: 2788-2788, ISSN: 0009-7322

Conference paper

Haldar S, Jarmin J, Panikker S, Jones D, Salukhe T, Hussain W, Markides V, Wong Tet al., 2012, The Use of Contact Force Data during Pulmonary Vein Isolation Translates into Improved Clinical Outcomes for Atrial Fibrillation Ablation Patients, CIRCULATION, Vol: 126, ISSN: 0009-7322

Journal article

Sharma S, Sandler B, Cristopoulos C, Saraf S, Markides V, Gorog DAet al., 2012, Temporary transvenous pacing: endangered skill, EMERGENCY MEDICINE JOURNAL, Vol: 29, Pages: 926-927, ISSN: 1472-0205

Journal article

Jarman JW, Wong T, Kojodojojo P, Sophr H, Davies JE, Roughton M, Francis DP, Kanagaratnam P, Markides V, Davies DW, Peters NSet al., 2012, Spatiotemporal behavior of high dominant frequency during paroxysmal and persistent atrial fibrillation in the human left atrium., Circ Arrhythm Electrophysiol., Vol: 4, Pages: 650-658

BACKGROUNDSites of high dominant frequency (DF(peak)) are thought to indicate the location of drivers of atrial fibrillation (AF), but characterization of their spatiotemporal distribution and stability, critical to their relevance as targets for catheter ablation, requires simultaneous global mapping of the left atrium.METHODS AND RESULTS:Noncontact electrograms recorded simultaneously from 256 left atrial sites during spontaneous AF were analyzed. After subtraction of the ventricular component, fast Fourier transform identified the DF at each site. Focal areas of DF(peak) were defined as those having a DF >20% above all neighboring sites. Twenty-four patients with spontaneous AF (11 paroxysmal and 13 persistent) were studied. In paroxysmal AF, sites of DF(peak) (mean DF, 11.6±2.9 Hz) were observed in 100% of patients (present during 65% of the mapping period). In contrast, DF(peak) was detected in only 31% of patients with persistent AF (P<0.001) and for only 5% of the mapping period (P<0.001). In both groups, locations of DF(peak) varied widely in both consecutive and separated segments of AF (κ coefficient range, -0.07-0.22). Activation sequences around sites of DF(peak) did not demonstrate centrifugal activation that would be expected from focal drivers.CONCLUSIONS:Focal areas of high DF are more frequent in paroxysmal than persistent AF, are spatiotemporally unstable, are not the source of centrifugal activation, and are not, therefore, indicative of fixed drivers of AF. In the absence of spatiotemporal stability, the success of ablation at sites of DF(peak) cannot be explained by elimination of fixed drivers.

Journal article

Jarman JWE, Lascelles K, Wong T, Markides V, Clague JR, Till Jet al., 2012, Clinical experience of entirely subcutaneous implantable cardioverterdefibrillators in children and adults: cause for caution, EUROPEAN HEART JOURNAL, Vol: 33, Pages: 1351-1359, ISSN: 0195-668X

Journal article

Niespialowska-Steuden MM, Markides V, Gorog DA, 2012, Novel antithrombotic agents for atrial fibrillation, PHARMACOLOGY & THERAPEUTICS, Vol: 134, Pages: 345-354, ISSN: 0163-7258

Journal article

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