Thesis (M. Phil.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 133-160).

Thesis (MCur)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: The importance of maintaining maternal wellbeing during the antenatal period is mandatory to the mother and the baby. Although asymptomatic maternal tachycardia could be seen as part of the physiological changes during pregnancy, it could also be a sign of a serious underlying condition. Previous studies have shown that maternal deaths could occur in women with pre-existing cardiac conditions (Naidoo, Desai & Moodley, 2002:17). The concern that many conditions associated with maternal tachycardia pass through the health care system without being noticed or investigated motivated the researcher to undertake this study. The study aimed to determine the prevalence of maternal tachycardia during late pregnancy and its association with anaemia, major cardiac diseases and/or complications and adverse maternal and perinatal outcomes. A case-control retrospective study design within a prospective study was employed with a quantitative approach. A total sample size of 204 participants, constituting 14.3% of the study population (N=1431) was purposefully selected from the Monica AN24™ recordings of the Safe Passage Study at Tygerberg Hospital to collect the data. Ethical approval was obtained from the Health Research Ethics Committee of the Faculty of Medicine and Health Sciences, Stellenbosch University and a waiver of consent had been granted. A group of 16 participants, who met the inclusion criteria, constituting 7.8% of the total sample, was selected for the pilot study. Reliability and validity was ensured by the pilot study and pre-testing the data collection instrument as it was tested under the exact circumstances as the actual study experts in the field of nursing and medical research and statistics were used. The data was analyzed by the use of the STATISTICA version 9 programme. The results show a 7.1% (n=102) prevalence of maternal tachycardia in late pregnancy. There were no pre-existing cardiac conditions in any of the groups and no maternal cardiac complications during pregnancy and delivery. The case group had a higher incidence (55.0%) of haemoglobin values lower than 11.0 g/dL than the control group (47.0%), however the Mann-Whitney U test revealed no statistically significant difference of the Hb values at 28 to 38 weeks between the case and the control groups. The participants presenting with anaemia (Hb < 11.0 g/dL) were classified as mild anaemia (Hb value of 7.0 – 10.9 g/dL). There were no participants that presented with severe anaemia (Hb value of < 7.0g/dL). There was an increased prevalence (9.1%) of infection in the participants presenting with maternal tachycardia, although this difference was not significant between the two groups. The infant outcome revealed an increased mean birth weight of 194g for the case group that presented with maternal tachycardia. Several recommendations were identified that were grounded in the study findings. The findings reveal that the current antenatal care practice in terms of not recording the maternal heart rate is sufficient. / AFRIKAANSE OPSOMMING: Die belangrikheid van die handhawing van moederlike welsyn gedurende die voorgeboorte tydperk is noodsaaklik vir die moeder en die baba. Alhoewel asimptomatiese moederlike tagikardie gesien kan word as deel van die fisiologiese veranderinge tydens swangerskap, kan dit ook 'n teken wees van 'n ernstige onderliggende toestand. Vorige studies het aangetoon dat moederlike sterftes kan voorkom in vroue met voorafgaande harttoestande (Naidoo, Desai & Moodley, 2002:17). Die kommer dat verskeie toestande wat verband hou met moederlike tagikardie, deur die gesondheidsorg stelsel kan deurglip sonder om opgemerk te word, het die navorser gemotiveer om hierdie studie te onderneem. Die studie is daarop gemik om die voorkoms van moederlike tagikardie tydens laat swangerskap en sy verbintenis met anemie, ernstige hartsiektes en/of komplikasies en ongunstige moederlike en perinatale uitkoms te bepaal. 'n Gevalkontrole retrospektiewe studie-ontwerp binne 'n voornemende studie is gebruik met 'n kwantitatiewe benadering. 'n Totale steekproefgrootte van 204 deelnemers, wat 14.3% van die populasie (N=1431) uitmaak is op ‘n doelgerigte manier uitgekies uit die Monica AN24™ opnames van die Veilige Geboorte Studie by Tygerberg Hospitaal om die data in te samel. Etiese goedkeuring is verkry van die Mensnavorsing Etiese komitee komitee van Fakulteit van Geneeskunde en Gesondheidswetenskappe van die Universiteit Stellenbosch en 'n kwytskelding van toestemming is verleen. 'n Groep van 16 deelnemers, wat voldoen aan die insluitingskriteria, wat 7,8% van die totale steekproef bestaan, is geselekteer vir die loodsstudie. Betroubaarheid en geldigheid is verseker deur die loodsstudie en die voorafgaande toets van die data-insamelingsinstrument onder presies dieselfde omstandighede as die werklike studie sowel as die gebruik van kenners in die gebied van verpleging en mediese navorsing en statistiek. Die data is ontleed deur die gebruik van die Statistica weergawe 9 program. Die resultate toon 'n 7,1% (n=102) voorkoms van moederlike tagikardie in laat swangerskap. Daar was geen onderliggende harttoestande in enige van die groepe en geen moederlike hartkomplikasies tydens swangerskap en geboorte nie. Die gevalgroep het 'n hoër voorkoms (55,0%) van Hb waardes laer as 11.0 g/dl as die kontrole groep (47.0%) gehad, maar die Mann-Whitney U-toets toon geen statisties beduidende verskil in die Hb waardes by 28-38 weke tussen die geval en die kontrolegroepe nie. Die deelnemers met anemie (Hb < 11.0 g/dl) is geklassifiseer met ligte bloedarmoede (Hb waarde van 7.0-10.9 g/dl). Daar was geen deelnemers wat erge bloedarmoede (Hb waarde van < 7.0g/dL) getoon het nie. Daar was verhoogde voorkoms (9,1%) van infeksie in die deelnemers met moederlike tagikardie, hoewel die verskil nie beduidend tussen die twee groepe was nie. Die baba uitkoms toon 'n toename in gemiddelde geboortegewig van 194g vir die gevalgroep wat met moederlike tagikardie gediagnoseer is. Verskeie aanbevelings is geïdentifiseer wat in die studie se bevindinge gegrond is. Die bevindinge dui daarop dat die huidige voorgeboortelike sorgpraktyk in terme van nie rekordering van die moederlike hartspoed voldoende is.

The accurate differentiation of a ventricular from a supraventricular origin of a wide QRS tachycardia (QRS > 120 milliseconds) is an important clinical problem. Misdiagnosis of this arrhythmia can lead to institution of inappropriate drug therapy acutely with potentially catastrophic consequences. Various diagnostic aids have been used to obtain electrocardiographic potentials to aid in the differentiation. This report assesses the clinical usefulness of oesophageal electrocardiography in the differentiation of wide complex tachycardias and describes a simple, safe technique to obtain oesophageal electrocardiograms. Eighteen consecutive patients between the ages of 27 and 71 years who were haemodynamically stable were selected for this study. The technique was performed in the following manner: A temporary pacing catheter was lubricated and passed nasally and advanced with the patient being instructed to swallow. Adjustments in catheter depth were made as necessary to obtain an optimal recording on a standard electrocardiograph recorder. Satisfactory placement with minimal patient discomfort was achieved within 6.5 minutes (average 4.5 minutes) in all cases. High quality tracings were obtained in every instance. In the 18 patients with tachyarrhythmia, AV dissociation consistent with ventricular tachycardia was demonstrated in 11 instances; in the remainder the diagnosis was supraventricular tachycardia. Of the 11 patients diagnosed as ventricular tachycardia, 9 were initially misdiagnosed as supraventricular tachycardia, whilst only 1 of 7 patients with supraventricular tachycardia was misdiagnosed. This study has demonstrated that oesophageal electrocardiography is useful in the differentiation of wide complex tachycardias. The technique outlined in this report is simple and offers the following advantages: the temporary pacing catheter is associated with minimal discomfort; the catheter allows easy manoeuverability within the oesophagus which allows proper depth to be easily obtained; the equipment used is routinely available. Therefore the technique offers a rapid, safe and simple method of obtaining an oesophageal electrocardiogram which is invaluable in the electrocardiographic differentiation of a wide complex tachycardia. / Thesis (M.Med.)-University of Natal, Durban, 1990.

Diss. (sammanfattning) Umeå : Univ., 2005. / Härtill 4 uppsatser.

Introdução: O diagnóstico diferencial entre as taquicardias de complexo QRS largo é de grande importância, pois o diagnóstico incorreto pode acarretar terapias inadequadas e potencialmente fatais. Critérios eletrocardiográficos têm sido utilizados para diferenciar a taquicardia ventricular da supraventricular com aberrância de condução, usando-se medidas dos intervalos das ondas do QRS em milissegundos e padrões eletrocardiográficos peculiares, mas sua consequência direta é a dificuldade na memorização e em sua aplicabilidade clínica. Objetivo: O objetivo deste estudo foi avaliar a acurácia diagnóstica de um novo critério eletrocardiográfico baseado no reconhecimento da negatividade do complexo QRS nas derivações DI, DII, V1 e V6, para o diagnóstico diferencial das taquicardias com QRS largo. Métodos: Foram avaliados 120 eletrocardiogramas de taquicardia ventricular ou taquicardia supraventricular com aberrância de condução por meio de dois métodos de avaliação: algoritmo de Brugada, que é composto por quatro passos, e um critério novo, composto por três passos para o diagnóstico. Os diagnósticos foram realizados com e sem conhecimento do dado clínico. As avaliações foram feitas por seis examinadores, sendo dois experientes na área (Grupo I), dois cardiologistas clínicos (Grupo II) e dois residentes de cardiologia na emergência (Grupo III). O padrão-ouro para o diagnóstico final foi o estudo eletrofisiológico. Resultados: Dos 120 pacientes, 68% apresentavam taquicardia ventricular e 32% taquicardia supraventricular com aberrância de condução. A idade dos pacientes variou de 17 a 85 anos, com média de 49,1 anos. A sensibilidade global foi maior (87,2%) quando o algoritmo de Brugada foi utilizado. A especificidade global foi maior (85,1%) com o critério novo. O valor preditivo positivo para taquicardia ventricular foi alto em ambos os métodos (90,9% no critério novo e 85,8% no algoritmo de Brugada). Os dois métodos tiveram boa acurácia (73,8% utilizando o critério novo e 81,4% o algoritmo de Brugada). O conhecimento do dado clínico não aumentou a acurácia diagnóstica. Entre os avaliadores mais experientes (Grupos I e II), a acurácia diagnóstica foi superior utilizando o algoritmo de Brugada em relação ao critério novo (84,6 e 85,8% vs. 74,2 e 74,6%). Para os avaliadores menos experientes (Grupo III), os dois métodos foram bastante semelhantes em termos de acurácia diagnóstica (73,7% no algoritmo de Brugada e 72,9% no critério novo), mas, para esses avaliadores, o critério novo apresentou maior especificidade que o algoritmo de Brugada (85,5% vs. 65,8%). Esses valores não mostraram alterações significativas com o conhecimento do dado clínico. O percentual de discordância entre os avaliadores foi maior utilizando o algoritmo de Brugada em relação ao critério novo (60,8% vs. 30%), e essa diferença persistiu com o conhecimento do dado clínico. Conclusão: O novo critério eletrocardiográfico apresentou boa acurácia no diagnóstico diferencial das taquicardias com QRS largo, podendo ser utilizado por médicos não especialista como alternativa ao algoritmo de Brugada. O conhecimento do dado clínico (presença ou não de cardiopatia) não aumentou a acurácia diagnóstica nos dois métodos / Introduction: The differential diagnosis of wide QRS complex tachycardia is of great importance because an incorrect diagnosis can lead to inappropriate and potentially deadly therapies. Electrocardiographic criteria have been used in an attempt to differentiate ventricular tachycardia from supraventricular tachycardia with aberrant conduction, measuring the QRS interval in milliseconds and peculiar electrocardiographic patterns, but its direct consequence is the difficulty in memorizing and its clinical applicability. Objective: The objective of this study was to evaluate the diagnostic accuracy of a new electrocardiographic criteria based on recognition of QRS complex negativity in leads DI, DII, V1 and V6 for the differential diagnosis of wide QRS tachycardias. Methods: We evaluated 120 ventricular tachycardia or supraventricular tachycardia with aberrant conduction electrocardiograms using two assessment methods: the Brugada algorithm, which consists of four steps, and a new proposed criterion, consisting of three steps to diagnosis. The diagnoses were performed with and without knowledge of the clinical data. Evaluations were made by six examiners, two experts in the area (Group I), two clinical cardiologists (Group II) and two in emergency cardiology residents (Group III). The gold standard for final diagnosis was the electrophysiological study. Results: Of the 120 patients, 68% presented with ventricular tachycardia and 32% presented with supraventricular tachycardia with aberrant conduction. The patients\' ages ranged from 17 to 85 years, with a mean age of 49.1 years. Global sensitivity was higher (87.2%) when Brugada algorithm was used. Global specificity was higher (85.1%) if the new criterion was used. Both methods presented a high positive predictive value for ventricular tachycardia (90.9% for the new criterion and 85.8% for the Brugada algorithm). Also, both methods had good accuracy (73.8% with the new criterion and 81.4% with the Brugada algorithm). Knowledge of clinical data did not increase diagnostic accuracy. Among the most experienced evaluators (Groups I and II), the diagnostic accuracy was superior using the Brugada algorithm compared with the new criterion (84.6 and 85.8% vs. 74.2 and 74.6%). For the less experienced evaluators (Group III), the two methods had very similar diagnostic accuracy (73.7% for the Brugada algorithm and 72.9% for the new criterion), but for those evaluators, the new criteria showed greater specificity than Brugada algorithm (85.5% vs. 65.8 %%). These values did not change significantly with knowledge of the clinical data. The percentage of disagreement among reviewers was higher for the Brugada algorithm than for the new criterion (60.8% and 30%, respectively), and this difference persisted with knowledge of the clinical data. Conclusion: The new electrocardiographic criteria showed good accuracy in the differential diagnosis of wide QRS tachycardias, and can be used by physicians not expert as an alternative to Brugada algorithm. Knowledge of clinical data (presence or absence of heart disease) did not increase the diagnostic accuracy for both methods

Introdução: O diagnóstico diferencial entre as taquicardias de complexo QRS largo é de grande importância, pois o diagnóstico incorreto pode acarretar terapias inadequadas e potencialmente fatais. Critérios eletrocardiográficos têm sido utilizados para diferenciar a taquicardia ventricular da supraventricular com aberrância de condução, usando-se medidas dos intervalos das ondas do QRS em milissegundos e padrões eletrocardiográficos peculiares, mas sua consequência direta é a dificuldade na memorização e em sua aplicabilidade clínica. Objetivo: O objetivo deste estudo foi avaliar a acurácia diagnóstica de um novo critério eletrocardiográfico baseado no reconhecimento da negatividade do complexo QRS nas derivações DI, DII, V1 e V6, para o diagnóstico diferencial das taquicardias com QRS largo. Métodos: Foram avaliados 120 eletrocardiogramas de taquicardia ventricular ou taquicardia supraventricular com aberrância de condução por meio de dois métodos de avaliação: algoritmo de Brugada, que é composto por quatro passos, e um critério novo, composto por três passos para o diagnóstico. Os diagnósticos foram realizados com e sem conhecimento do dado clínico. As avaliações foram feitas por seis examinadores, sendo dois experientes na área (Grupo I), dois cardiologistas clínicos (Grupo II) e dois residentes de cardiologia na emergência (Grupo III). O padrão-ouro para o diagnóstico final foi o estudo eletrofisiológico. Resultados: Dos 120 pacientes, 68% apresentavam taquicardia ventricular e 32% taquicardia supraventricular com aberrância de condução. A idade dos pacientes variou de 17 a 85 anos, com média de 49,1 anos. A sensibilidade global foi maior (87,2%) quando o algoritmo de Brugada foi utilizado. A especificidade global foi maior (85,1%) com o critério novo. O valor preditivo positivo para taquicardia ventricular foi alto em ambos os métodos (90,9% no critério novo e 85,8% no algoritmo de Brugada). Os dois métodos tiveram boa acurácia (73,8% utilizando o critério novo e 81,4% o algoritmo de Brugada). O conhecimento do dado clínico não aumentou a acurácia diagnóstica. Entre os avaliadores mais experientes (Grupos I e II), a acurácia diagnóstica foi superior utilizando o algoritmo de Brugada em relação ao critério novo (84,6 e 85,8% vs. 74,2 e 74,6%). Para os avaliadores menos experientes (Grupo III), os dois métodos foram bastante semelhantes em termos de acurácia diagnóstica (73,7% no algoritmo de Brugada e 72,9% no critério novo), mas, para esses avaliadores, o critério novo apresentou maior especificidade que o algoritmo de Brugada (85,5% vs. 65,8%). Esses valores não mostraram alterações significativas com o conhecimento do dado clínico. O percentual de discordância entre os avaliadores foi maior utilizando o algoritmo de Brugada em relação ao critério novo (60,8% vs. 30%), e essa diferença persistiu com o conhecimento do dado clínico. Conclusão: O novo critério eletrocardiográfico apresentou boa acurácia no diagnóstico diferencial das taquicardias com QRS largo, podendo ser utilizado por médicos não especialista como alternativa ao algoritmo de Brugada. O conhecimento do dado clínico (presença ou não de cardiopatia) não aumentou a acurácia diagnóstica nos dois métodos / Introduction: The differential diagnosis of wide QRS complex tachycardia is of great importance because an incorrect diagnosis can lead to inappropriate and potentially deadly therapies. Electrocardiographic criteria have been used in an attempt to differentiate ventricular tachycardia from supraventricular tachycardia with aberrant conduction, measuring the QRS interval in milliseconds and peculiar electrocardiographic patterns, but its direct consequence is the difficulty in memorizing and its clinical applicability. Objective: The objective of this study was to evaluate the diagnostic accuracy of a new electrocardiographic criteria based on recognition of QRS complex negativity in leads DI, DII, V1 and V6 for the differential diagnosis of wide QRS tachycardias. Methods: We evaluated 120 ventricular tachycardia or supraventricular tachycardia with aberrant conduction electrocardiograms using two assessment methods: the Brugada algorithm, which consists of four steps, and a new proposed criterion, consisting of three steps to diagnosis. The diagnoses were performed with and without knowledge of the clinical data. Evaluations were made by six examiners, two experts in the area (Group I), two clinical cardiologists (Group II) and two in emergency cardiology residents (Group III). The gold standard for final diagnosis was the electrophysiological study. Results: Of the 120 patients, 68% presented with ventricular tachycardia and 32% presented with supraventricular tachycardia with aberrant conduction. The patients\' ages ranged from 17 to 85 years, with a mean age of 49.1 years. Global sensitivity was higher (87.2%) when Brugada algorithm was used. Global specificity was higher (85.1%) if the new criterion was used. Both methods presented a high positive predictive value for ventricular tachycardia (90.9% for the new criterion and 85.8% for the Brugada algorithm). Also, both methods had good accuracy (73.8% with the new criterion and 81.4% with the Brugada algorithm). Knowledge of clinical data did not increase diagnostic accuracy. Among the most experienced evaluators (Groups I and II), the diagnostic accuracy was superior using the Brugada algorithm compared with the new criterion (84.6 and 85.8% vs. 74.2 and 74.6%). For the less experienced evaluators (Group III), the two methods had very similar diagnostic accuracy (73.7% for the Brugada algorithm and 72.9% for the new criterion), but for those evaluators, the new criteria showed greater specificity than Brugada algorithm (85.5% vs. 65.8 %%). These values did not change significantly with knowledge of the clinical data. The percentage of disagreement among reviewers was higher for the Brugada algorithm than for the new criterion (60.8% and 30%, respectively), and this difference persisted with knowledge of the clinical data. Conclusion: The new electrocardiographic criteria showed good accuracy in the differential diagnosis of wide QRS tachycardias, and can be used by physicians not expert as an alternative to Brugada algorithm. Knowledge of clinical data (presence or absence of heart disease) did not increase the diagnostic accuracy for both methods

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 113-118). Available also in a digital version from Dissertation Abstracts.

Thesis (M.S.)--University of Alabama at Birmingham, 2007. / Description based on contents viewed Oct. 5, 2007; title from title screen. Includes bibliographical references (p. 19-20).

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 192-211).

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