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Dive into the research topics where Ioannis Germanakis is active.

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Featured researches published by Ioannis Germanakis.


Ultrasound in Obstetrics & Gynecology | 2011

Temporal and Spatial Performance of Vector Velocity Imaging in the Human Fetal Heart

H. Matsui; Ioannis Germanakis; Elena Kulinskaya; Helena M. Gardiner

To assess the spatial and temporal performance of fetal myocardial speckle tracking, using high‐frame‐rate (HFR) storing and Lagrangian strain analysis.


Pediatric Cardiology | 2006

The impact of fetal echocardiography on the prevalence of liveborn congenital heart disease

Ioannis Germanakis; Stavros Sifakis

Fetal echocardiography allows for early detection of congenital heart disease, and pregnancy termination may be an option in cases of complex defects. In the current study, the most important factors contributing to the diagnosis and termination of affected pregnancies are reviewed and their combined effect on the future prevalence of liveborn congenital heart disease is evaluated. The relative reduction of the prevalence of the most severe forms of congenital heart disease is estimated as the product of the probability that (1) a fetal cardiac screening is performed (pevaluation), (2) an affected pregnancy is detected (Pdetection), (3) pregnancy termination is decided following antenatal diagnosis (Pdecision). In areas where termination of pregnancy is a realistic and supported option, a universal sonographic screening of all pregnancies (Pevaluation = 1), with an average reported sensitivity of 35% and a termination rate of 43% following antenatal diagnosis, would result in a 15% overall reduction of the prevalence of the most severe forms of congenital heart disease. However, wide variability exists regarding the defect-specific estimates (2–50% prevalence relative reduction) due to considerable differences in the reported diagnostic sensitivity and termination rates associated with each heart defect. If an earlier diagnosis could be achieved, which is reported to be associated with an average 1.4-fold increased probability of termination, the overall reduction of the prevalence of congenital heart disease could approach 21%. As the skills of obstetric and pediatric cardiology sonographers improve, fetal echocardiography is expected to have a substantial impact on the future epidemiology of liveborn congenital heart disease.


Pediatric Blood & Cancer | 2008

Troponins and natriuretic peptides in the monitoring of anthracycline cardiotoxicity

Ioannis Germanakis; Nikol Anagnostatou; Maria Kalmanti

Anthracycline‐related cardiotoxicity has a substantial negative impact on long‐term survivors of childhood cancer. The detection of cardiotoxicity is currently based on echocardiography or radionuclide angiography. However, as they depict only the final outcome of myocardial injury in terms of reduced heart contractility, heart specific biomarkers of myocardial destruction or dysfunction could be advantageous by allowing for an earlier detection of cardiotoxicity. In the present study, the usefulness of cardiac troponins and natriuretic peptides, the most commonly used biomarkers of myocardial destruction and ventricular dysfunction respectively, to detect and to predict the development of anthracycline cardiotoxicity has been reviewed. Pediatr Blood Cancer 2008;51:327–333.


Fetal Diagnosis and Therapy | 2012

Assessment of Fetal Myocardial Deformation Using Speckle Tracking Techniques

Ioannis Germanakis; Helena M. Gardiner

Objective: To report the current status of speckle tracking techniques in evaluation of fetal myocardial deformation. Methods: A variety of non-Doppler ultrasound methods are available using offline analysis of standard four-chamber and short axis views of the heart. Results: Most reports have used techniques developed for the measurement of strain and strain rate in the adult heart and produced conflicting descriptions of gestational changes in strain. Myocardial velocities usually reflect mean modal velocities and are lower than the peak velocities obtained using Doppler techniques. Conclusions: In the fetus, most current methods of acquisition result in frame rates that are too low, and the fetal heart size is too small to achieve reliable measures of fetal myocardial deformation.


Fetal Diagnosis and Therapy | 2012

Myocardial Strain Abnormalities in Fetal Congenital Heart Disease Assessed by Speckle Tracking Echocardiography

Ioannis Germanakis; H. Matsui; Helena M. Gardiner

Objectives: To compare myocardial deformation patterns in fetuses with congenital heart disease (CHD) with our reference range using speckle tracking echocardiography. Methods: We prospectively stored and analyzed 4-chamber loops of 28 fetuses with CHD (median gestation 27 weeks, range 20.9–37.0). The peak longitudinal left (LVs) and right (RVs) ventricular free wall Lagrangian strain and LV/RV strain ratio were measured from Syngo VVI software- (Siemens) derived original coordinates. Strain values from the first examination were compared with normative data from the same population using ANOVA with post hoc tests and serial examinations described in 14 fetuses. Results: Simple shunt lesions (0.82) and shunts with pulmonary stenosis or atresia (0.93) had reduced mean LV/RV strain ratios compared to normal fetuses (1.01; 95% CI 0.97–1.05). Fetuses with hypoplastic left heart had the lowest (0.29), and those with Ebstein the highest (1.55), LV:RV ratio. Serial measurements showed increased LVs in aortic coarctation and aortic stenosis, but not in one developing important mitral regurgitation. Increased right ventricular loading in a fetus developing pulmonary regurgitation was associated with increasing RVs. Conclusions: Myocardial strain reflects the changing physiology of fetal CHD. Speckle tracking might be a useful tool to study the progress of myocardial function in affected fetuses.


Fetal Diagnosis and Therapy | 2012

Fetal Longitudinal Myocardial Function Assessment by Anatomic M-Mode

Ioannis Germanakis; Spyridon Pepes; Stavros Sifakis; Helena M. Gardiner

Aim: To evaluate the feasibility of offline anatomic M-mode (AMM) to study fetal atrioventricular annulus long-axis displacement (LAD) and compare its performance against real-time conventional M-mode (MM). Material and Methods: Paired AMM and MM LAD studies were recorded prospectively in 54 fetuses, and performance was compared. Insonation angles were less than 30° in all but 4 cases. The overall feasibility of AMM was tested in a composite total sample of 91 normal singleton pregnancies (median gestational age 23+6 weeks, range 12–36). AMM LAD was measured by placement of a virtual M-mode line on digitally stored raw data of fetal 4-chamber video loops. We studied annulus LAD at the lateral mitral (left ventricle; LV), proximal mitral (intraventricular septum; IVS), and lateral tricuspid (right ventricle; RV) myocardial segments. We compared LAD and its regression with gestational age measured using both methods in paired studies and AMM in the whole cohort. Results: Annulus LAD was measured using AMM, in all cases and segments, irrespective of cardiac axis alignment to the ultrasound beam. Good correlation existed between AMM and MM (RV r = 0.901, LV r = 0.899, IVS r = 0.815, p < 0.001). AMM recorded higher LAD values than MM in RV [mean 6.17 (SD 1.46) vs. 5.82 (SD 1.74) mm, p = 0.002] and LV [mean 4.18 (SD 1.11) vs. 3.98 (SD 1.12), p = 0.007]. Both methods showed LAD in RV > LV > IVS and a significant gestational increase in LAD values in all segments (p < 0.001) Conclusions: AMM permits offline evaluation of fetal longitudinal myocardial function in routinely obtained 2D fetal heart images with similar values to conventional MM in paired studies recorded <30°.


Acta Paediatrica | 2008

Digital phonocardiography as a screening tool for heart disease in childhood

Ioannis Germanakis; Sven Dittrich; Rousa Perakaki; Maria Kalmanti

Aim: To evaluate the performance of experienced cardiologists by use of digital phonocardiography for the correct identification of heart disease and innocent murmurs in children.


Acta Paediatrica | 2006

Clarithromycin treatment and QT prolongation in childhood

Ioannis Germanakis; Emmanouil Galanakis; Fragiskos I. Parthenakis; Panos E. Vardas; Maria Kalmanti

The effect of clarithromycin on the QT interval was studied in a group of 28 children treated for respiratory tract infections. QTc was measured before and following 24 h of treatment. A modest (average 22 ms, 95% CI 14–30 ms) but significant QTc prolongation (p<0.001) was observed, with seven cases having a QTc >440 ms during treatment (including a single case with QTc >460 ms).


Pediatric Blood & Cancer | 2005

PREVALENCE OF FACTOR V LEIDEN AND OTHER THROMBOPHILIC TRAITS AMONG CRETAN CHILDREN WITH MALIGNANCY

Eftichia Stiakaki; Ioannis Germanakis; Caterina Sfyridaki; Nikos Katzilakis; Vasiliki Danilatou; Maria Kalmanti

The prevalence of thrombophilic traits, which might further enhance the risk of thrombotic complications in children treated for cancer, varies significantly among different populations.


Acta Paediatrica | 2013

Skills of primary healthcare physicians in paediatric cardiac auscultation

Ioannis Germanakis; Eleni Petridou; George Varlamis; Ioannis L. Matsoukis; Kiriaki Papadopoulou-Legbelou; Maria Kalmanti

To evaluate the performance of primary healthcare physicians in paediatric cardiac auscultation and the impact of a multimedia‐based teaching intervention.

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Helena M. Gardiner

Memorial Hermann Healthcare System

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H. Matsui

Imperial College London

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