Triptans and troponin: a case report

This case report describes for the first time acute coronary syndrome in a 67-year old patient after oral intake of naratriptan for migraine. So far in the literature, only sumatriptan, zolmitriptan and frovatriptan have been described to cause acute coronary syndromes

Management of Acute Coronary Syndromes During the Coronavirus Disease 2019 Pandemic: Deviations from Guidelines and Pragmatic Considerations for Patients and Healthcare Workers

Coronavirus disease 2019 (COVID-19) is forcing cardiology departments to rapidly adapt existing clinical guidelines to a new reality and this is especially the case for acute coronary syndrome pathways. In this focused review, the authors discuss how COVID-19 is affecting acute cardiology care and propose pragmatic guideline modifications for the diagnosis and management of acute coronary syndrome patients, particularly around the appropriateness of invasive strategies as well as length of hospital stay. The authors also discuss the use of personal protective equipment for healthcare workers in cardiology. Based on shared global experiences and growing peer-reviewed literature, it is possible to put in place modified acute coronary syndrome treatment pathways to offer safe pragmatic decisions to patients and staff

Coronary–aortic interaction during ventricular isovolumic contraction

In earlier work, we suggested that the start of the isovolumic contraction period could be detected in arterial pressure waveforms as the start of a temporary pre-systolic pressure perturbation (AICstart, start of the Arterially detected Isovolumic Contraction), and proposed the retrograde coronary blood volume flow in combination with a backwards traveling pressure wave as its most likely origin. In this study, we tested this hypothesis by means of a coronary artery occlusion protocol. In six Yorkshire × Landrace swine, we simultaneously occluded the left anterior descending (LAD) and left circumflex (LCx) artery for 5 s followed by a 20-s reperfusion period and repeated this sequence at least two more times. A similar procedure was used to occlude only the right coronary artery (RCA) and finally all three main coronary arteries simultaneously. None of the occlusion protocols caused a decrease in the arterial pressure perturbation in the aorta during occlusion (P > 0.20) nor an increase during reactive hyperemia (P > 0.22), despite a higher deceleration of coronary blood volume flow (P = 0.03) or increased coronary conductance (P = 0.04) during hyperemia. These results show that the pre-systolic aortic pressure perturbation does not originate from the coronary arteries

Determining the Predominant Lesion in Patients With Severe Aortic Stenosis and Coronary Stenoses: A Multicenter Study Using Intracoronary Pressure and Flow

Background: Patients with severe aortic stenosis (AS) often have coronary artery disease. Both the aortic valve and the coronary disease influence the blood flow to the myocardium and its ability to respond to stress; leading to exertional symptoms. In this study, we aim to quantify the effect of severe AS on the coronary microcirculation and determine if this is influenced by any concomitant coronary disease. We then compare this to the effect of coronary stenoses on the coronary microcirculation. Methods: Group 1: 55 patients with severe AS and intermediate coronary stenoses treated with transcatheter aortic valve implantation (TAVI) were included. Group 2: 85 patients with intermediate coronary stenoses and no AS treated with percutaneous coronary intervention were included. Coronary pressure and flow were measured at rest and during hyperemia in both groups, before and after TAVI (group 1) and before and after percutaneous coronary intervention (group 2). Results: Microvascular resistance over the wave-free period of diastole increased significantly post-TAVI (pre-TAVI, 2.71±1.4 mm Hg·cm·s−1 versus post-TAVI 3.04±1.6 mm Hg·cm·s−1 [P=0.03]). Microvascular reserve over the wave-free period of diastole significantly improved post-TAVI (pre-TAVI 1.88±1.0 versus post-TAVI 2.09±0.8 [P=0.003]); this was independent of the severity of the underlying coronary stenosis. The change in microvascular resistance post-TAVI was equivalent to that produced by stenting a coronary lesion with an instantaneous wave-free ratio of ≤0.74. Conclusions: TAVI improves microcirculatory function regardless of the severity of underlying coronary disease. TAVI for severe AS produces a coronary hemodynamic improvement equivalent to the hemodynamic benefit of stenting coronary stenoses with instantaneous wave-free ratio values <0.74. Future trials of physiology-guided revascularization in severe AS may consider using this value to guide treatment of concomitant coronary artery disease

Coronary Hemodynamics in Patients With Severe Aortic Stenosis and Coronary Artery Disease Undergoing Transcatheter Aortic Valve Replacement: Implications for Clinical Indices of Coronary Stenosis Severity.

In this study, a systematic analysis was conducted of phasic intracoronary pressure and flow velocity in patients with severe aortic stenosis (AS) and coronary artery disease, undergoing transcatheter aortic valve replacement (TAVR), to determine how AS affects: 1) phasic coronary flow; 2) hyperemic coronary flow; and 3) the most common clinically used indices of coronary stenosis severity, instantaneous wave-free ratio and fractional flow reserve. A significant proportion of patients with severe aortic stenosis (AS) have concomitant coronary artery disease. The effect of the valve on coronary pressure, flow, and the established invasive clinical indices of stenosis severity have not been studied. Twenty-eight patients (30 lesions, 50.0% men, mean age 82.1 ± 6.5 years) with severe AS and coronary artery disease were included. Intracoronary pressure and flow assessments were performed at rest and during hyperemia immediately before and after TAVR. Flow during the wave-free period of diastole did not change post-TAVR (29.78 ± 14.9 cm/s vs. 30.81 ± 19.6 cm/s; p = 0.64). Whole-cycle hyperemic flow increased significantly post-TAVR (33.44 ± 13.4 cm/s pre-TAVR vs. 40.33 ± 17.4 cm/s post-TAVR; p = 0.006); this was secondary to significant increases in systolic hyperemic flow post-TAVR (27.67 ± 12.1 cm/s pre-TAVR vs. 34.15 ± 17.5 cm/s post-TAVR; p = 0.02). Instantaneous wave-free ratio values did not change post-TAVR (0.88 ± 0.09 pre-TAVR vs. 0.88 ± 0.09 post-TAVR; p = 0.73), whereas fractional flow reserve decreased significantly post-TAVR (0.87 ± 0.08 pre-TAVR vs. 0.85 ± 0.09 post-TAVR; p = 0.001). Systolic and hyperemic coronary flow increased significantly post-TAVR; consequently, hyperemic indices that include systole underestimated coronary stenosis severity in patients with severe AS. Flow during the wave-free period of diastole did not change post-TAVR, suggesting that indices calculated during this period are not vulnerable to the confounding effect of the stenotic aortic valve

Expert recommendations on the assessment of wall shear stress in human coronary arteries : existing methodologies, technical considerations, and clinical applications

The aim of this manuscript is to provide guidelines for appropriate use of CFD to obtain reproducible and reliable wall shear stress maps in native and instrumented human coronary arteries. The outcome of CFD heavily depends on the quality of the input data, which include vessel geometrical data, proper boundary conditions, and material models. Available methodologies to reconstruct coronary artery anatomy are discussed in ‘Imaging coronary arteries: a brief review’ section. Computational procedures implemented to simulate blood flow in native coronary arteries are presented in ‘Wall shear stress in native arteries’ section. The effect of including different geometrical scales due to the presence of stent struts in instrumented arteries is highlighted in ‘Wall shear stress in stents’ section. The clinical implications are discussed in ‘Clinical applications’ section, and concluding remarks are presented in ‘Concluding remarks’ section

A HISTORICAL BACKGROUND AND REFLECTIONS OF ANCIENT GREEK, BYZANTINE, AND CYPRIOT FOLK MUSIC AND IDIOMS IN THE OPERAS OF MICHAEL HADJILOIZOU

Michael Hadjiloizou\u27s operas show the influence of Ancient Greek, Byzantine, and Cypriot folk music, all coexisting harmoniously to provide a new distinctive, unified and quite personalized compositional style. The examination of Hadjiloizou\u27s operas is primarily an ethnic musicological matter, which requires a study of his compositional ideology, as the understanding and enjoyment of the ethical expressions evident in these works requires knowledge of the historical background on which they are based. Nevertheless, as in the case of Wagner, these operas are self-contained and can be observed for what they represent as staged productions. Hadjiloizou\u27s information will be presented in two steps. First, the historical information of each of the three musical eras of the title will be told in the music of Ancient Greece and Byzantine, and Cypriot folk will be told by the similarities of each style in Mr. Hadjiloizou\u27s operas. Musical information mentioned here, will be: (1) the nature of Greek music, how it differed from modern music, and why we are attracted to the history of Greek music; (2) mythical sound events, the mythology of musical reminiscence, musical myths, timbre of ancient instruments, principles of voice production, mode(s), ancient Greek Harmoniai, scales, octave species, tonoi or tropoi, the invention of musical intervals, physical basis of sound, the birth of drama, the use of Ancient Greek music for the care of the soul, the evolution of Greek music in the Byzantine empire, and women musicians; (3) the origins of Cypriot folk song, its rhythmic elements, morphology, scales and instruments, and; (4) Hadjiloizou\u27s music and information about it as told by him

Indoor Path Planning and Navigation Of Quadrotors

Στην παρούσα διατριβή μελετάμε το πρόβλημα της πλοήγησης ενός τετράπτερου μη επανδρω- μένου αεροσκάφους σε περιβάλλον εσωτερικού χώρου. Συγκεκριμένα εστιάζουμε στη σχεδίαση ενός βέλτιστου ελεγκτή και ενός βέλτιστου εκτιμητή κατάστασης. Στη συνέχεια κάνουμε μια επίδειξη ενός αυτόνομου τετράπτερου αεροσκάφους που περιηγείται σε στατικό περιβάλλον. Ο ελεγκτής που υλοποιούμε είναι ένας γραμμικός τετραγωνικός ελεγκτής, Linear Quadratic Regulator (LQR) που έχει επεκταθεί ούτως ώστε να επιλύει το Servo-Problem. Η εκτίμηση της θέσης και της κατάστασης επιτυγχάνεται συνδυάζοντας μέσω ενός Kalman Filter, τις μετρή- σεις μίας αδρανειακής μονάδας, Inertial Measurement Unit (IMU), ενός συστήματος εντοπισμού Ultra-WideBand (UWB) και ενός αλγορίθμου μηχανικής μάθησης για τον εντοπισμό αντικει- μένων με δεδομένα που λαμβάνει από μια κάμερα. Απ’ όσο γνωρίζουμε, αυτή είναι η πρώτη εργασία που συνδυάζει αυτές τις τρεις τεχνολογίες για την υλοποίηση ενός συστήματος επε- ξεργασίας σε πραγματικό χρόνο με δυνατότητα τοποθέτησης πάνω στο μη επανδρωμένο αερο- σκάφος. Η υλοποίηση επιτυγχάνεται με μια τεχνική προσομοίωσης Hardware-in-the-loop (HIL), όπου το δυναμικό μοντέλο του τετράπτερου προσομοιώνεται σε έναν προσομοιωτή τρισδιάστα- στων ρομποτικών εφαρμογών ανοιχτού κώδικα και το σύστημα πλοήγησης υλοποιείται σε ένα ενσωματωμένο σύστημα υπολογιστή βελτιστοποιημένο για εφαρμογές τεχνιτής νοημοσύνης.In this thesis we study the problem of indoor quadrotor navigation. Specifically we focus on the design of an optimal controller, and an optimal state estimator. We then provide a working example of an autonomous quadrotor navigating through a static environment. The implemented controller is a Linear Quadratic Regulator (LQR) augmented in such a way to solve the Servo- Problem. The state estimation is achieved by coalescing via a Kalman Filter, the measurements from an Inertial Measurement Unit (IMU), an Ultra-WideBand localization system, and a monocular camera-based object detection algorithm. To the best of the author’s knowledge, this is the first work that combines these three technologies for an onboard real-time implementation of a localization mechanism. The implementation is achieved with a Hardware-in-the-loop (HIL) simulation technique, where the dynamic model of the quadrotor is simulated in an open-source 3D robotics simulator, and the navigation system is implemented on an Artificial Intelligence embedded computer. Our results show that the camera-based solution is a viable option capable of further improving the performance of the purely UWB approach.Complete