Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Ioannis Felekos is active.

Publication


Featured researches published by Ioannis Felekos.


Rheumatology | 2013

Myocardial ischaemia without obstructive coronary artery disease in rheumatoid arthritis: hypothesis-generating insights from a cross-sectional study

Konstantinos Toutouzas; Petros P. Sfikakis; Antonios Karanasos; Constantina Aggeli; Ioannis Felekos; George D. Kitas; E. Zampeli; Athanase D. Protogerou; Christodoulos Stefanadis

OBJECTIVE RA is associated with increased cardiovascular events, reportedly to equal diabetes mellitus (DM). The presence of myocardial ischaemia was assessed in asymptomatic high-risk RA patients and compared with patients with DM and a healthy control group. METHODS Eighteen consecutive non-diabetic RA patients without known cardiovascular disease who developed a new carotid atheromatic plaque during the last 3 years were matched 1:1 for traditional cardiovascular risk factors with asymptomatic type 2 DM patients and 1:2 with asymptomatic non-RA, non-DM control subjects. After dobutamine stress contrast echocardiography with wall-motion and perfusion evaluation, coronary angiography was performed in those with positive stress tests. RESULTS Ischaemia by echocardiography was found in 67% of RA patients; this was significantly higher than controls (31%, P = 0.019) but comparable to those with DM (78%, P = 0.71). Angiography performed in eight consenting RA patients was normal in four, revealed non-flow-limiting coronary atheromatic lesions in two and significant lesions in two patients. RA patients with ischaemia had CRP serum levels significantly higher by six-fold compared with those with normal stress echocardiography. CONCLUSION Asymptomatic RA patients may display myocardial ischaemia at similar levels to DM patients but with low prevalence of obstructive coronary artery disease. Microvascular abnormalities associated with increased inflammatory response may account for these findings. Their exact nature and significance require further evaluation.


International Journal of Cardiology | 2013

Myocardial mechanics for the early detection of cardiac sarcoidosis

Constantina Aggeli; Ioannis Felekos; Dimitris Tousoulis; Elias Gialafos; Aggeliki Rapti; Christodoulos Stefanadis

Background: Speckle tracking has emerged as valuable tool for comprehensive assessment of regional myocardial function, providing angle-independent measurements of ventricular strain. Aim of this study was to evaluate left ventricular (LV) function in patients with newly diagnosed sarcoidosis, utilizing the novel method of 2D speckle tracking. Methods: Forty one patients with sarcoidosis and unremarkable medical history of cardiovascular disease, as well as 20 healthy age- and gender-matched controls underwent echocardiographic study. Apical 4-,2-,3- chamber as well as short axis acquisitions were made. In addition to conventional 2D, Doppler and TDI measurements, speckle tracking echocardiography was applied and LV global longitudinal strain was derived from the obtained images. Moreover, LV base and apex rotation angles were assessed from which LV twist was derived. Results: The mean age of patients (17 men) was 41 ± 6.5 years old. Compared with controls, patients had similar conventional 2D and Doppler measurements. TDI revealed increased E/E9 in the patient group vs control group (8.72 ± 1.65 vs 4.6 ± 1.32, p Conclusions: Speckle tracking echocardiography revealed impaired strain and rotational indices, implying elevated filling pressures of the left ventricle. This may represent a sign of myocardial involvement in patients with sarcoidosis. Therefore deformation imaging could be valuable adjunct for screening.


Heart | 2012

In vivo measurement of plaque neovascularisation and thermal heterogeneity in intermediate lesions of human carotid arteries

Konstantinos Toutouzas; Maria Drakopoulou; Constantina Aggeli; Charalampia Nikolaou; Ioannis Felekos; Haralampos Grassos; Andreas Synetos; Konstantinos Stathogiannis; Antonis Karanasos; Eleftherios Tsiamis; Elias Siores; Christodoulos Stefanadis

Objectives Both neoangiogenesis and inflammation contribute in atherosclerosis progression. Contrast-enhanced ultrasound (CEUS) provides visualisation of plaque neovascularisation. Microwave radiometry (MR) allows in vivo non-invasive measurement of temperature of tissues, reflecting inflammatory activation. We assessed the association of carotid plaque temperature, measured by MR, with plaque neovascularisation assessed by CEUS in intermediate lesions. Methods Consecutive patients with coronary artery disease and carotid atherosclerosis underwent carotid ultrasound imaging, CEUS and MR. Plaque texture, plaque surface and plaque echogenicity were analysed. Contrast enhancement (CE) by CEUS was defined as the % percentage of signal intensity difference, prior and post contrast infusion. Thermal heterogeneity (ΔT) was assigned as maximal temperature along the carotid artery minus minimum. Results Eighty-six carotid arteries of 48 patients were included. Fatty plaques had higher CE% and ΔT compared with mixed and calcified (p<0.01 for all comparisons). Heterogeneous plaques had higher CE% and ΔT compared with homogenous (p<0.01 for all comparisons). Plaques with irregular surface had higher CE% and ΔT compared with plaques with regular (p<0.01 for all comparisons). There was a good correlation between ΔT and CE (R=0.60, p<0.001). Conclusions Carotid plaque neovascularisation on CEUS examination is associated with increased thermal heterogeneity and ultrasound characteristics of plaque vulnerability in intermediate lesions.


Interactive Cardiovascular and Thoracic Surgery | 2012

Tricuspid regurgitation after successful mitral valve surgery

Vasiliki Katsi; Leonidas Raftopoulos; Constantina Aggeli; Ioannis Vlasseros; Ioannis Felekos; Dimitrios Tousoulis; Christodoulos Stefanadis; Ioannis Kallikazaros

The tricuspid valve (TV) is inseparably connected with the mitral valve (MV) in terms of function. Any pathophysiological condition concerning the MV is potentially a threat for the normal function of the TV as well. One of the most challenging cases is functional tricuspid regurgitation (TR) after surgical MV correction. In the past, TR was considered to progressively revert with time after left-sided valve restoration. Nevertheless, more recent studies showed that TR could develop and evolve postoperatively over time, as well as being closely associated with a poorer prognosis in terms of morbidity and mortality. Pressure and volume overload are usually the underlying pathophysiological mechanisms; structural alterations, like tricuspid annulus dilatation, increased leaflet tethering and right ventricular remodelling are almost always present when regurgitation develops. The most important risk factors associated with a higher probability of late TR development involve the elderly, female gender, larger left atrial size, atrial fibrillation, right chamber dilatation, higher pulmonary artery systolic pressures, longer times from the onset of MV disease to surgery, history of rheumatic heart disease, ischaemic heart disease and prosthetic valve malfunction. The time of TR manifestation can be up to 10 years or more after an MV surgery. Echocardiography, including the novel 3D Echo techniques, is crucial in the early diagnosis and prognosis of future TV disease development. Appropriate surgical technique and timing still need to be clarified.


European Journal of Echocardiography | 2011

Value of real-time three-dimensional adenosine stress contrast echocardiography in patients with known or suspected coronary artery disease

Constantina Aggeli; Ioannis Felekos; George Roussakis; Christina Kazazaki; Stauroula Lagoudakou; Panagiota Pietri; Dimitrios Tousoulis; Christos Pitsavos; Christodoulos Stefanadis

AIM The aim of this study was to evaluate the feasibility of myocardial wall-motion and perfusion assessment using contrast echocardiography during real-time three-dimensional (RT3D) adenosine stress test, and compare its diagnostic accuracy with the two-dimensional (2D) method using coronary angiography as reference. METHODS AND RESULTS Patients with known or suspected coronary artery disease (CAD) have been submitted to adenosine stress contrast echocardiography and coronary angiography, within a 1-month period. Two-dimensional apical four, two, and three chamber, as well as three-dimensional (3D) pyramidal full-volume data sets were acquired at rest and at peak stress. The 17-segment division of the left ventricle was used and each segment was evaluated based on wall motion and perfusion. Sixty patients (age: 60.1 ± 8.5 years, 38 men) were enrolled, i.e. 1020 segments were evaluated at rest and at peak stress. Wall-motion analysis per patient revealed that the sensitivity and specificity of 2D to detect CAD were 80 and 82% and of RT3D echocardiography were 82 and 64%, respectively, whereas in the per patient perfusion analysis the respective percentages were 88, 64% for 2D and 90, 73% for RT3D. Regarding left anterior descending artery and right coronary system, there seems to be no statistical significant difference in terms of wall-motion and perfusion evaluation between the two modalities. CONCLUSIONS Real-time 3D adenosine stress echocardiography is a feasible and valuable technique to evaluate myocardial wall motion and perfusion in patients with suspected CAD, despite existing problems concerning lower spatial and temporal resolution when compared with 2D echocardiography.


Current Pharmaceutical Design | 2012

Ultrasound Contrast Agents: Updated Data on Safety Profile

Constantina Aggeli; Ioannis Felekos; Gerasimos Siasos; Dimitris Tousoulis; Christodoulos Stefanadis

Contrast echocardiography represents a major technological advancement in the constantly evolving field of cardiovascular imaging. Over the last twenty years numerous studies have been published, illustrating the incremental value of contrast implementation into a variety of clinical scenarios. However, serious concerns have been raised about contrast safety profile, mainly based on postmarketing observational data and several animal studies. The latter have investigated contrast bio effects under experimental conditions that are not consistent with daily clinical practice. On the other hand, numerous clinical trials with large registries have proven otherwise. Not only contrast agents are efficient, but they also demonstrate a remarkable safety profile. So the question is: should we fear contrast utilization or should we consider them as an adjunctive and indispensable clinical tool for daily bedside practice?


International Journal of Cardiology | 2015

Real-time three-dimensional echocardiography: never before clinical efficacy looked so picturesque.

Constantina Aggeli; Ioannis Felekos; Stelios Kastellanos; Vassiliki Panagopoulou; Evangelos Oikonomou; Eleftherios Tsiamis; Dimitris Tousoulis

Over the years echocardiography has served the clinical cardiologist in a variety of clinical scenarios, assisting in patient diagnostic and therapeutic managements. With the advent of novel imaging modalities we now experience the renascence of imaging. As a result, the field of cardiovascular medicine is strongly connected to imaging, which in turn requires thorough knowledge of each modalitys distinct advantages and limitations. In this concise review we present up-to-date knowledge with regard to real-time three-dimensional echocardiography and its implementation in clinical practice.


Cardiovascular Ultrasound | 2010

Echocardiographic imaging of tricuspid and pulmonary valve abnormalities in primary ovarian carcinoid tumor

Constantina Aggeli; Ioannis Felekos; Christina Kazazaki; Dimitrios Giannopoulos; Athanasios Kartalis; Christos Pitsavos; Christodoulos Stefanadis

Carcinoid is a rare malignancy originating from enterochromaffin cells and is clinically characterized by flushing, diarrhea and bronchospasm, due to secretion of vasoactive substances. A dreaded complication is carcinoid heart disease, which mainly affects right cardiac chambers, resulting in thickened, immobile and retracted tricuspid and pulmonary valves. In the current report, a case of a 60-year old female presenting with symptoms of right heart failure is described. Transthoracic two-dimensional and real-time three-dimensional echocardiography findings, as well as biochemical markers, including pro-BNP and NT-pro-BNP, were consistent with carcinoid syndrome. The histological diagnosis of carcinoid was confirmed after surgical resection of an ovarian mass.


Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques | 2018

Global longitudinal strain and long-term outcomes in asymptomatic extracardiac sarcoid patients with no apparent cardiovascular disease

Ioannis Felekos; Constantina Aggeli; Elias Gialafos; Vasileios Kouranos; Aggeliki Rapti; Petros P. Sfikakis; Nikolaos Koulouris; Dimitris Tousoulis

Global longitudinal strain (GLS) is increasingly accepted as a predictor of mortality in various clinical settings. This study tested the hypothesis that GLS is associated with increased event rate in patients with extracardiac sarcoidosis, who have no overt symptoms of cardiovascular disease and preserved ejection fraction (EF).


Current Pharmaceutical Design | 2012

Contrast echocardiography: an update on clinical applications.

Constantina Aggeli; Ioannis Felekos; Eleftherios Tsiamis; Konstantinos Toutouzas; Christodoulos Stefanadis

Contrast echocardiography is considered by many as the Holy Grail for the assessment of heart disease, including coronary artery disease, structural abnormalities and cardiomyopathies. Although contrast agents have been severely criticized at times, they are now officially implemented into an extended variety of clinical applications, as illustrated by the American and European echocardiographic societies published consensus statements. The current review highlights contrast major clinical applications under the light of current literature data.

Collaboration


Dive into the Ioannis Felekos's collaboration.

Top Co-Authors

Avatar

Constantina Aggeli

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Christodoulos Stefanadis

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Dimitrios Tousoulis

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Konstantinos Toutouzas

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Dimitris Tousoulis

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Emmanouil Poulidakis

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Athanasios Angelis

National and Kapodistrian University of Athens

View shared research outputs
Top Co-Authors

Avatar

Erifili Venieri

National and Kapodistrian University of Athens

View shared research outputs
Researchain Logo
Decentralizing Knowledge