Comparative Electrocardiography of the Squamata

Mullen, Robert K.

doi:10.1086/physzool.40.2.30152446

Cited by 47 publications

(38 citation statements)

References 21 publications

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“…Thus, the sinus venosus is much bigger than commonly perceived, namely the area where the three caval veins are confluent, and in fact includes the caval veins [5], [12], [14], [57]. Consistently, the ‘caval veins’ all contract prior to the atria (Movies S4-6) as also shown with electrocardiography [58], [59]. Also, in amphibians, the sinus venosus is an expanded cavity [60]–[64].…”

Section: Discussionmentioning

confidence: 72%

Development of the Hearts of Lizards and Snakes and Perspectives to Cardiac Evolution

et al. 2013

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Birds and mammals both developed high performance hearts from a heart that must have been reptile-like and the hearts of extant reptiles have an unmatched variability in design. Yet, studies on cardiac development in reptiles are largely old and further studies are much needed as reptiles are starting to become used in molecular studies. We studied the growth of cardiac compartments and changes in morphology principally in the model organism corn snake (Pantherophis guttatus), but also in the genotyped anole (Anolis carolinenis and A. sagrei) and the Philippine sailfin lizard (Hydrosaurus pustulatus). Structures and chambers of the formed heart were traced back in development and annotated in interactive 3D pdfs. In the corn snake, we found that the ventricle and atria grow exponentially, whereas the myocardial volumes of the atrioventricular canal and the muscular outflow tract are stable. Ventricular development occurs, as in other amniotes, by an early growth at the outer curvature and later, and in parallel, by incorporation of the muscular outflow tract. With the exception of the late completion of the atrial septum, the adult design of the squamate heart is essentially reached halfway through development. This design strongly resembles the developing hearts of human, mouse and chicken around the time of initial ventricular septation. Subsequent to this stage, and in contrast to the squamates, hearts of endothermic vertebrates completely septate their ventricles, develop an insulating atrioventricular plane, shift and expand their atrioventricular canal toward the right and incorporate the systemic and pulmonary venous myocardium into the atria.

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Section: Discussionmentioning

confidence: 72%

Development of the Hearts of Lizards and Snakes and Perspectives to Cardiac Evolution

et al. 2013

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“…Although some ECG recordings were performed in Sauropsida in general (Kaplan and Schwartz, 1963;McDonald and Heath, 1971;Blanco, 1993;Heaton-Jones and King, 1994;Anderson et al, 1999;Espino et al, 2001;Martinez-Silvestre et al, 2003;Tan et al, 2013), the information available is restricted to a few species and there are almost no comparative studies among Squamate reptiles (Mullen, 1967;Bogan Jr., 2017) to fully understand the electrophysiological function of the heart in these terrestrial ectotherms. However, with respect to ECG methodology (Einthoven, 1903), there are also some limitations of this approach for poikilotherms and ectotherms.…”

Section: Discussionmentioning

confidence: 99%

HNK‐1 in Morphological Study of Development of the Cardiac Conduction System in Selected Groups of Sauropsida

Kvasilová

Gregorovičová

Kundrát

et al. 2018

The Anatomical Record

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Human natural killer (HNK)‐1 antibody is an established marker of developing cardiac conduction system (CCS) in birds and mammals. In our search for the evolutionary origin of the CCS, we tested this antibody in a variety of sauropsid species (Crocodylus niloticus, Varanus indicus, Pogona vitticeps, Pantherophis guttatus, Eublepharis macularius, Gallus gallus, and Coturnix japonica). Hearts of different species were collected at various stages of embryonic development and studied to map immunoreactivity in cardiac tissues. We performed detection on alternating serial paraffin sections using immunohistochemistry for smooth muscle actin or sarcomeric actin as myocardial markers, and HNK‐1 to visualize overall staining pattern and then positivity in specific myocyte populations. We observed HNK‐1 expression of various intensity distributed in the extracellular matrix and mesenchymal cell surface of cardiac cushions in most of the examined hearts. Strong staining was found in the cardiac nerve fibers and ganglia in all species. The myocardium of the sinus venosus and the atrioventricular canal exhibited transitory patterns of expression. In the Pogona and Crocodylus hearts, as well as in the Gallus and Coturnix ones, additional expression was detected in a subset of myocytes of the (inter)ventricular septum. These results support the use of HNK‐1 as a conserved marker of the CCS and suggest that there is a rudimentary CCS present in developing reptilian hearts. Anat Rec, 302:69–82, 2019. © 2018 Wiley Periodicals, Inc.

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“…Os parâmetros eletrocardiográficos para o ser humano e para os animais domésticos já estão bem determinados, porém, infelizmente ainda são escassos em répteis (Davies et al, 1951;Kaplan e Schwartz, 1963;Jayasinghe e Fernando, 1964;Valentinuzi et al, 1969a,b;Cook e Westron, 1979;Heaton et al, 1994) sendo ainda mais raros em serpentes (Mullen, 1967).…”

Section: Introductionunclassified

“…A presença de ondas SV parece ser muito mais notória em leituras pré-cordiais (Terrel et al, 1994), porém, por não terem sido realizadas neste trabalho tais leituras, a ausência de onda SV no padrão eletrocardiográfico de Crotalus durissus deve ser vista com cautela Os intervalos P-R e complexos QRS determinados por Mullen (1967) diferem um pouco de nossos achados, principalmente quanto às médias, o que pode ser explicado pelo uso de um pool de espécies, diferentemente de nosso trabalho que utilizou uma determinação espécie-específica e sob condições térmicas controladas. Vale à pena ressaltar que no trabalho de Mullen (1967) foram também utilizadas espécies de Crotalus (C. cerastes, C. scutulatus e C. viridis) que normalmente possuem um tamanho inferior às C. durissus (Campbell e Lamar 2004), todavia, por não constar a massa destes animais no trabalho, uma análise mais precisa para os achados fica restrita.…”

Section: Introductionunclassified

“…O segmento S-T e a onda T obtiveram moderada representatividade na leitura DII, concordando plenamente com os resultados de Mullen (1967) no tocante à dificuldade de se calcular a amplitude de T, apesar disso, a duração das ondas T em ambos os trabalhos é virtualmente igual, e a relação ST/RR foi muito próxima às detectadas anteriormente para a espécie (Hagensen et al, 2008), confirmando a independência deste intervalo da frequência.…”

Section: Introductionunclassified

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PARÂMETROS ELETROCARDIOGRÁFICOS DE CASCAVÉIS (Crotalus durissus, Linnaeus, 1758) EM CATIVEIRO.

Stuginski¹,

Fernandes²,

Grego³

2011

AVS

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Endereço para correspondência: Daniel Rodrigues Stuginski: dstuginski@yahoo.com.br RESUMO: Apesar de a eletrocardiografia ser vastamente empregada na clínica veterinária, esta ferramenta ainda é pouco utilizada no diagnóstico de patologias em serpentes. Este trabalho teve como objetivo a caracterização dos parâmetros eletrocardiográficos da cascavel Crotalus durissus em cativeiro, sob condições controladas. Para isto, 23 serpentes foram submetidas ao exame eletrocardiográfico, aonde os seguintes parâmetros foram analisados: a frequência cardíaca, ritmo, eixo cardíaco, ondas P e T, complexo QRS, assim como os intervalos P-R e segmento S-T nas derivações cardíacas DI, DII, DIII, aVF aVL e aVR. Os resultados obtidos demonstraram que a técnica foi eficiente nas mensurações das deflexões cardíacas, porém a análise da frequência e ritmo geralmente foram prejudicados devido a um viés estresse-induzido e sua interpretação deve ser cautelosa. Os parâmetros eletrocardiográficos de Crotalus durissus determinados neste trabalho foram bastante consistentes e com mínimas variações, o que parece possibilitar sua utilização no diagnóstico das doenças cardíacas em serpentes. A escassez de padrões eletrocardiográficos em serpentes torna muito difícil a comparação e a interpretação de como as variáveis morfológicas, fisiológicas e ecológicas podem influenciar os parâmetros eletrocardiográficos, por este motivo, novas pesquisas que determinem os padrões eletrocardiográficos de diferentes espécies serão absolutamente necessárias para o uso do eletrocardiograma como ferramenta diagnóstica na rotina clínica.Palavras-chave: répteis; serpentes; eletrocardiograma. ELECTROCARDIGRAPHIC PARAMETERS OF RATTLESNAKES (CROTALUS DURISSUS, LINNAEUS, 1758 ) IN CAPTIVITYABSTRACT: Although electrocardiography is widely used in veterinary practice, this tool still has little application in diagnosing diseases of snakes. This study aimed to characterize the electrocardiographic parameters of Crotalus durissus in captivity, under controlled conditions. For this, 23 snakes were subjected to ECG examination, where the following parameters were analyzed: heart rate, rhythm, cardiac axis, P and T waves, QRS complex, as well as the P-R and S-T intervals in the heart leads DI, DII, DIII, aVF , aVL and aVR The results showed that the technique used was effective to the measurements of cardiac deflections, but the analysis of heart rate and rhythm is generally impaired by a bias-induced stress and its interpretation should be cautious. The electrocardiographic parameters of Crotalus durissus determined in this study were fairly consistent, with minor variations, which seem to allow its use for cardiac disease diagnosis in snakes. The scarcity of electrocardiographic patterns for snakes makes difficult a comparison and interpretation of how the morphological, physiological and ecological data can influence the electrocardiogram, therefore, further research to determine the electrocardiographic pattern of different species will be absolutely necessary to the use ...

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Comparative Electrocardiography of the Squamata

Cited by 47 publications

References 21 publications

Development of the Hearts of Lizards and Snakes and Perspectives to Cardiac Evolution

Development of the Hearts of Lizards and Snakes and Perspectives to Cardiac Evolution

HNK‐1 in Morphological Study of Development of the Cardiac Conduction System in Selected Groups of Sauropsida

PARÂMETROS ELETROCARDIOGRÁFICOS DE CASCAVÉIS (Crotalus durissus, Linnaeus, 1758) EM CATIVEIRO.

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