The clinical applications of cardiogoniometry in cardiovascular disease

Cardiogoniometry (CGM) is a method of 3-dimensional electrocardiographic assessment which has primarily been investigated to evaluate its role in diagnosing patients with suspected coronary artery disease (CAD). Previous work has suggested it has considerable diagnostic ability at identifying patients with both stable CAD and those with acute coronary syndrome (ACS). However, previous studies which investigated the diagnostic performance of CGM in stable CAD did not use robust measures to accurately identify patients with physiologically significant coronary ischaemia. Furthermore, although the ability of CGM to identify specific lesions in stable CAD has been evaluated, to the best of our knowledge no research has been performed to assess the ability of CGM to detect the site of the culprit lesion in patients with non-ST elevation myocardial infarction. The first two studies of this thesis aim to address these two questions about the role of CGM in patients with CAD.Cardiac resynchronisation therapy (CRT) is a treatment used in patients with heart failure and left bundle branch block which attempts to restore synchronous contraction of the ventricles by pacing both the left and right ventricle together. Unfortunately, 25% of patients do not gain a clinical benefit from CRT, such patients are classed as ‘non-responders’. Many methods have been proposed to optimise CRT for ‘non-responders’, however, no specific optimisation method has yet been identified which significantly improves the long term benefit of CRT in non-responders. The detailed spatial and temporal information on cardiac electrical activity that CGM provides suggests that CGM may have a role in the optimisation of CRT. The aim of the third study in this thesis is to evaluate whether CGM can detect changes to CRT pacing settings, in view of developing a method of CRT optimisation using CGM

Electrocardiologic and related methods of non-invasive detection and risk stratification in myocardial ischemia: state of the art and perspectives

Background: Electrocardiographic methods still provide the bulk of cardiovascular diagnostics. Cardiac ischemia is associated with typical alterations in cardiac biosignals that have to be measured, analyzed by mathematical algorithms and allegorized for further clinical diagnostics. The fast growing fields of biomedical engineering and applied sciences are intensely focused on generating new approaches to cardiac biosignal analysis for diagnosis and risk stratification in myocardial ischemia

Review of processing pathological vectorcardiographic records for the detection of heart disease

Vectorcardiography (VCG) is another useful method that provides us with useful spatial information about the electrical activity of the heart. The use of vectorcardiography in clinical practice is not common nowadays, mainly due to the well-established 12-lead ECG system. However, VCG leads can be derived from standard 12-lead ECG systems using mathematical transformations. These derived or directly measured VCG records have proven to be a useful tool for diagnosing various heart diseases such as myocardial infarction, ventricular hypertrophy, myocardial scars, long QT syndrome, etc., where standard ECG does not achieve reliable accuracy within automated detection. With the development of computer technology in recent years, vectorcardiography is beginning to come to the forefront again. In this review we highlight the analysis of VCG records within the extraction of functional parameters for the detection of heart disease. We focus on methods of processing VCG functionalities and their use in given pathologies. Improving or combining current or developing new advanced signal processing methods can contribute to better and earlier detection of heart disease. We also focus on the most commonly used methods to derive a VCG from 12-lead ECG.Web of Science13art. no. 85659

Comparison of efficiency of cardiogoniometry and exercise-ECG test in diagnostics of stable coronary artery disease in women

Cilj ovog istraživanja bio je ispitati učinkovitost kardiogoniometrije, novije, neinvazivne metode u dijagnostici koronarne bolesti u žena i usporediti je s ergometrijom, koristeći koronarografiju kao referentnu metodu. Metode i materijali: Riječ je o unicentričnom, prospektivnom istraživanju sastavljenom od serije slučajeva u koje su bile uključene žene sa simptomima stabilne angine pektoris kojima je učinjena koronarografija. Ergometrija, izvedena prema protokolu po Bruceu, kao i kardiogoniometrija izvedene su prije koronarografije. Klinički značajna koronarna bolest je definirana kao stenoza > 70% jedne ili više koronarnih arterija. Rezultati: U istraživanje je uključeno 114 uzastopnih bolesnica s medijanom dobi 64,0 (58,0- 71,0), od kojih su 32 (28,1%) imale koronarnu bolest. Kardiogoniometrija je pokazala ukupnu učinkovitost 74,6% s osjetljivošću 75,0% (95% CI 56,6-88,5%) i specifičnošću 74,4% (95% CI 63,6-83,4%). Ergometrija je pokazala ukupnu učinkovitost 45,1% s osjetljivošću 68,1% (95% CI 42,7-83,6%) i specifičnošću 36,6% (95% CI 25,2-50,3%). Kardiogoniometrija je pokazala veću učinkovitost u usporedbi s ergometrijom (p< 0,001). Patološki nalaz kardiogoniometrije je bio povezan s gotovo 9 puta većim rizikom koronarne bolesti (omjer rizika 8,7, 95% CI 3.4-22.3, p< 0,001), koji je ostao značajan i nakon prilagodbe za dob i hipokineziju. Zaključak: Kardiogoniometrija je neinvazivna metoda, jednostavna za korištenje i bez rizika komplikacija, koja je pokazala visoku učinkovitost u dijagnostici stabilne koronarne bolesti u žena i superiornost u odnosu na ergometriju. Kardiogoniometrija bi mogla postati dio dijagnostičkog algoritma za probir žena sa stabilnom koronanom bolesti te je pogodna za korištenje u primarnoj zdravstvenoj zaštiti, osobito u žena koje ne mogu podnijeti/izvršiti fizičko opterećenje.Aim of this study was to investigate the efficiency of cardiogoniometry, a novel, non-invasive method, in diagnosing coronary artery disease (CAD) in women and compare it with exercise- ECG test, by using coronary angiography as a reference method. Methods and materials: It was a single-centre, case-series study including consecutive female patients with stable angina pectoris symptoms undergoing coronary angiography. Exercise- ECG test, done according to the Bruce protocol, and cardiogoniometry were obtained prior to coronary angiography. Clinically significant CAD has been defined as one or more coronary lesions with > 70% stenosis. Results: Study included 114 consecutive female patients with median age of 64.0 (58.0-71.0), out of which 32 (28.1%) had CAD. Cardiogoniometry yielded a total accuracy of 74.6% with a sensitivity of 75.0% (95% CI 56.6 - 88.5%) and specificity of 74.4% (95% CI 63.6-83.4%). Exercise-ECG test yielded a total accuracy of 45.1% with a sensitivity of 68.1% (95% CI 42.7- 83.6%) and specificity 36.6% (95% CI 25.2-50.3%). CGM showed higher accuracy than exercise-ECG test (p< 0.001). Pathological cardiogoniometry was associated with almost 9 times higher risk for CAD (OR 8.7, 95% CI 3.4-22.3, p< 0.001), which remained significant after adjustment for age and hypokinesia. Conclusion: Cardiogoniometry is a non-invasive, easy-to-use and risk-free method which showed high efficiency in diagnosing stable CAD in women and is superior to exercise-ECG test. Cardiogoniometry could be introduced as a part of the diagnostic algorithm of screening women for stable CAD and is suitable for use in the primary setting, especially in women unable to undergo stress-testing

Comparison of efficiency of cardiogoniometry and exercise-ECG test in diagnostics of stable coronary artery disease in women

Cilj ovog istraživanja bio je ispitati učinkovitost kardiogoniometrije, novije, neinvazivne metode u dijagnostici koronarne bolesti u žena i usporediti je s ergometrijom, koristeći koronarografiju kao referentnu metodu. Metode i materijali: Riječ je o unicentričnom, prospektivnom istraživanju sastavljenom od serije slučajeva u koje su bile uključene žene sa simptomima stabilne angine pektoris kojima je učinjena koronarografija. Ergometrija, izvedena prema protokolu po Bruceu, kao i kardiogoniometrija izvedene su prije koronarografije. Klinički značajna koronarna bolest je definirana kao stenoza > 70% jedne ili više koronarnih arterija. Rezultati: U istraživanje je uključeno 114 uzastopnih bolesnica s medijanom dobi 64,0 (58,0- 71,0), od kojih su 32 (28,1%) imale koronarnu bolest. Kardiogoniometrija je pokazala ukupnu učinkovitost 74,6% s osjetljivošću 75,0% (95% CI 56,6-88,5%) i specifičnošću 74,4% (95% CI 63,6-83,4%). Ergometrija je pokazala ukupnu učinkovitost 45,1% s osjetljivošću 68,1% (95% CI 42,7-83,6%) i specifičnošću 36,6% (95% CI 25,2-50,3%). Kardiogoniometrija je pokazala veću učinkovitost u usporedbi s ergometrijom (p< 0,001). Patološki nalaz kardiogoniometrije je bio povezan s gotovo 9 puta većim rizikom koronarne bolesti (omjer rizika 8,7, 95% CI 3.4-22.3, p< 0,001), koji je ostao značajan i nakon prilagodbe za dob i hipokineziju. Zaključak: Kardiogoniometrija je neinvazivna metoda, jednostavna za korištenje i bez rizika komplikacija, koja je pokazala visoku učinkovitost u dijagnostici stabilne koronarne bolesti u žena i superiornost u odnosu na ergometriju. Kardiogoniometrija bi mogla postati dio dijagnostičkog algoritma za probir žena sa stabilnom koronanom bolesti te je pogodna za korištenje u primarnoj zdravstvenoj zaštiti, osobito u žena koje ne mogu podnijeti/izvršiti fizičko opterećenje.Aim of this study was to investigate the efficiency of cardiogoniometry, a novel, non-invasive method, in diagnosing coronary artery disease (CAD) in women and compare it with exercise- ECG test, by using coronary angiography as a reference method. Methods and materials: It was a single-centre, case-series study including consecutive female patients with stable angina pectoris symptoms undergoing coronary angiography. Exercise- ECG test, done according to the Bruce protocol, and cardiogoniometry were obtained prior to coronary angiography. Clinically significant CAD has been defined as one or more coronary lesions with > 70% stenosis. Results: Study included 114 consecutive female patients with median age of 64.0 (58.0-71.0), out of which 32 (28.1%) had CAD. Cardiogoniometry yielded a total accuracy of 74.6% with a sensitivity of 75.0% (95% CI 56.6 - 88.5%) and specificity of 74.4% (95% CI 63.6-83.4%). Exercise-ECG test yielded a total accuracy of 45.1% with a sensitivity of 68.1% (95% CI 42.7- 83.6%) and specificity 36.6% (95% CI 25.2-50.3%). CGM showed higher accuracy than exercise-ECG test (p< 0.001). Pathological cardiogoniometry was associated with almost 9 times higher risk for CAD (OR 8.7, 95% CI 3.4-22.3, p< 0.001), which remained significant after adjustment for age and hypokinesia. Conclusion: Cardiogoniometry is a non-invasive, easy-to-use and risk-free method which showed high efficiency in diagnosing stable CAD in women and is superior to exercise-ECG test. Cardiogoniometry could be introduced as a part of the diagnostic algorithm of screening women for stable CAD and is suitable for use in the primary setting, especially in women unable to undergo stress-testing

Erfassung und Auswertung nichtinvasiver kardiovaskulärer dynamischer und morphologischer Parameter

The assessment of the autonomic function of cardiovascular regulation has been proven as a potential marker for the diagnosis and risk stratification in patients with cardiovascular disease in several clinical studies. So far most of these studies focussed either on the analysis of the rhythm or the morphology of cardiovascular signals, but not on the interaction of these components.The aim of this thesis was the analysis of the variability of the morphologic ECG and NIBP components as well as the interaction with rhythmic characteristics of these signals. Furtheron, the method of Laser Doppler Flowmetry for the detection of an altered microcirculation as a periphere component of cardiovascular regulation was examined. Therefore, established methods as well as newly developed algorithms were introduced, discussed and validated applying simulated as well as real patient data. With these analysis several significantly modified indices of cardiovascular regulation were found in patients with AF recurrence after cardioversion as well as in patients suffering from schizophrenia. These results could help to understand the increased risk for the occurence and progression of cardiovascular disease of these patients.Die Bedeutung der autonomen Regulation des Herz-Kreislauf-Systems wurde in verschiedenen klinischen Studien, die sich auf die erweiterte Diagnostik und prognostische Risikoerkennung von Patienten mit kardiovaskulären Krankheiten fokussiert haben, bereits vielfach nachgewiesen. Bisherige Analysen beschränkten sich meist auf die separate Betrachtung des Rhythmus oder der Morphologie verschiedener kardiovaskulärer Signale, ohne die Interaktionen dieser Komponenten miteinander zu betrachten.Im Rahmen dieses Promotionsvorhabens wurden umfangreiche Analysen zur zeitlichen Variabilität morphologischer Eigenschaften des EKG und der nichtinvasiven kontinuierlichen Blutdruckkurve sowie deren Interaktion mit rhythmischen Charakteristika dieser Signale durchgeführt. Des Weiteren wurden die Möglichkeiten der Laser-Doppler-Flowmetrie zur Erkennung von Veränderungen der Mikrozirkulation als periphere Zielgröße der Herz-Kreislauf-Regulation untersucht. Hierzu wurden zum einen etablierte Verfahren zur Bewertung der autonomen Herz-Kreislauf-Regulation angewandt und zum anderen neue Algorithmen besonders zur Interaktionsanalyse zwischen zwei Signalen entwickelt und in umfangreichen Untersuchungen an simulierten und realen Daten getestet und validiert.Mittels dieser Methoden konnten geeignete Parameter zur Erkennung von Veränderungen des Herz-Kreislauf-Systems von Patienten mit Schizophrenie sowie Patienten mit rezidivierendem Vorhofflimmern aufgezeigt werden. Hierauf aufbauend wurden Schlussfolgerungen gezogen, welche zum Verständnis für das erhöhte Risiko für das Auftreten bzw. die Progression einer kardiovaskulären Erkrankung bei diesen Patienten beitragen können

Análise remota do eletrocardiograma para detecção de eventos isquêmicos

The evolution of technologies for remote services delivery over the Internet unveils a new frontier in the development of the knowledge needed to implement health prevention measures. In this study, a computational tool was conceived for the remote analysis of multiple lead electrocardiograms. As a proof of concept, a method for detecting ST-T segment changes related to ischemic episodes in remote computing is proposed. The architecture combines only open source software that allows incremental object-oriented programming and support multiuser services via the Web, focusing on system evolution within the academic world. The technique used to detect ischemic events favored low computational cost and storage of both data and metadata in a database. It was anchored in a method of interpolation by weighted least squares and histograms, capable of detecting the positions of the QRS complexes, and the respective positions of J points and T waves. These points were used as borderline positions in obtaining representative under curve areas for the subsequent detection of ischemic events in the leads present in the research file. After assessment with engineering students, we conclude that the platform, architecture, and programming techniques provide a satisfactory tool for ischemic event management that can be used to develop new biomedical signal processing techniques that support the risk assessment of myocardial dysfunction.A evolução das tecnologias para entrega de serviços remotos pela Internet revela uma nova fronteira no desenvolvimento do conhecimento necessário para implementar medidas de prevenção da saúde. Neste estudo, uma ferramenta computacional foi concebida para a análise remota de eletrocardiogramas de múltiplas derivações. Como prova de conceito, um método é proposto para detectar alterações no segmento ST-T relacionadas a episódios isquêmicos através da computação remota. A arquitetura combina apenas software de código aberto que permite programação incremental orientada a objetos e oferece suporte a serviços multiusuário via Web, com foco na evolução do sistema no mundo acadêmico. A técnica utilizada para detectar eventos isquêmicos favoreceu o baixo custo computacional e armazenamento de dados e metadados em um Banco de Dados. Foi ancorado em um método de interpolação por mínimos quadrados ponderados e histogramas, capazes de detectar as posições dos complexos QRS e as respectivas posições dos pontos J e ondas T. Esses pontos foram usadas como posições limítrofes na obtenção de áreas representativas sob curvas para a subsequente detecção de eventos isquêmicos nas derivações presentes no arquivo de pesquisa. Após avaliação junto a discentes de engenharia, concluímos que a plataforma, arquitetura e técnicas de programação fornecem uma ferramenta satisfatória para o gerenciamento de eventos isquêmicos, a qual pode ser usada para o desenvolvimento de novas técnicas de processamento de sinais biomédicos que objetivem apoiar a avaliação de risco de disfunção miocárdic

Cardiogoniometric parameters for detection of coronary artery disease at rest as a function of stenosis localization and distribution

Cardiogoniometry (CGM), a spatiotemporal electrocardiologic 5-lead method with automated analysis, may be useful in primary healthcare for detecting coronary artery disease (CAD) at rest. Our aim was to systematically develop a stenosis-specific parameter set for global CAD detection. In 793 consecutively admitted patients with presumed non-acute CAD, CGM data were collected prior to elective coronary angiography and analyzed retrospectively. 658 patients fulfilled the inclusion criteria, 405 had CAD verified by coronary angiography; the 253 patients with normal coronary angiograms served as the non-CAD controls. Study patients--matched for age, BMI, and gender--were angiographically assigned to 8 stenosis-specific CAD categories or to the controls. One CGM parameter possessing significance (P < .05) and the best diagnostic accuracy was matched to one CAD category. The area under the ROC curve was .80 (global CAD versus controls). A set containing 8 stenosis-specific CGM parameters described variability of R vectors and R-T angles, spatial position and potential distribution of R/T vectors, and ST/T segment alterations. Our parameter set systematically combines CAD categories into an algorithm that detects CAD globally. Prospective validation in clinical studies is ongoing