Atrial activity during thePR segment of the MCG

Leifer, Mark C.; Capos, N.; Griffin, Jerry C.; Wikswo, John P.

doi:10.1007/bf02455930

Cited by 4 publications

(2 citation statements)

References 7 publications

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“…Although a preliminary magnetic measurement of the PR interval's MF had been reported in 1978 (116), high-resolution (HR) MCG recordings of the PR segment were carried out independently both with unshielded MCG and in MSR since the early 1980s (27,33,117,118). The physiological interpretation of HR MCG waveforms of the PR interval was controversial (34,(119)(120)(121)(122) until the nature of the so-called "ramp-like" pattern recorded during the PR interval (Figure 3A) was definitely clarified within the development of software for automatic MF mapping and interactive subtraction. In fact, by subtracting the atrial repolarization field component from the whole PR interval's MF, a weaker remaining MF generated by sources moving from the AV junction downward along the interventricular septum was identified, consistent with the activation of the His-Purkinje System (123), coherently with the output of a more advanced mathematical model of the normal AV conduction pathways (124)(125)(126) and later by simultaneous MCG and invasive His bundle electrogram recording (127) and by direct comparison of atrial magnetic repolarization field distribution and simultaneous atrial monophasic action potential recording (128) (Figure 3B).…”

Section: Unshielded Mcg: the Pastmentioning

confidence: 99%

Clinical magnetocardiography: the unshielded bet—past, present, and future

Brisinda,

Fenici,

Fenici

2023

Front. Cardiovasc. Med.

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Magnetocardiography (MCG), which is nowadays 60 years old, has not yet been fully accepted as a clinical tool. Nevertheless, a large body of research and several clinical trials have demonstrated its reliability in providing additional diagnostic electrophysiological information if compared with conventional non-invasive electrocardiographic methods. Since the beginning, one major objective difficulty has been the need to clean the weak cardiac magnetic signals from the much higher environmental noise, especially that of urban and hospital environments. The obvious solution to record the magnetocardiogram in highly performant magnetically shielded rooms has provided the ideal setup for decades of research demonstrating the diagnostic potential of this technology. However, only a few clinical institutions have had the resources to install and run routinely such highly expensive and technically demanding systems. Therefore, increasing attempts have been made to develop cheaper alternatives to improve the magnetic signal-to-noise ratio allowing MCG in unshielded hospital environments. In this article, the most relevant milestones in the MCG's journey are reviewed, addressing the possible reasons beyond the currently long-lasting difficulty to reach a clinical breakthrough and leveraging the authors’ personal experience since the early 1980s attempting to finally bring MCG to the patient's bedside for many years thus far. Their nearly four decades of foundational experimental and clinical research between shielded and unshielded solutions are summarized and referenced, following the original vision that MCG had to be intended as an unrivaled method for contactless assessment of the cardiac electrophysiology and as an advanced method for non-invasive electroanatomical imaging, through multimodal integration with other non-fluoroscopic imaging techniques. Whereas all the above accounts for the past, with the available innovative sensors and more affordable active shielding technologies, the present demonstrates that several novel systems have been developed and tested in multicenter clinical trials adopting both shielded and unshielded MCG built-in hospital environments. The future of MCG will mostly be dependent on the results from the ongoing progress in novel sensor technology, which is relatively soon foreseen to provide multiple alternatives for the construction of more compact, affordable, portable, and even wearable devices for unshielded MCG inside hospital environments and perhaps also for ambulatory patients.

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Section: Unshielded Mcg: the Pastmentioning

confidence: 99%

Clinical magnetocardiography: the unshielded bet—past, present, and future

Brisinda,

Fenici,

Fenici

2023

Front. Cardiovasc. Med.

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“…Os últimos anos proporcionaram mais progressos em investigação clínica [45-48] e também em pesquisa básica [49][50][51][52][53][54] A figura 1.1 mostra esquematicamente o sistema criogênico contido em um dewar de fibra de vidro com superisolamento [67]. O reservatório de hélio líquido, necessário para manter o circuito supercondutor a uma temperatura de 4.20 Kelvin, usualmente mantém o sistema frio por alguns dias.…”

Section: Prefaciounclassified

Gradiômetros supercondutores acoplados a SQUIDs e sua aplicação em biomagnetismo.

Bruno¹

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Aos meus pais. AGRADECIMENTOS Gostaria de agradecer em primeiro lugar ao Prof. Sergio Mascarenhas que desde a minha infância me estimulou e me incentivou com seu exemplo, a adentrar nas lides científicas. Como ele gost~de dizer, eu acabei tentando conjugar o verbo ser. Também foi ele que em meados de 1979 me apresentou ao Prof. Paulo Costa Ribeiro que me orientou neste trabalho. Ao Paulo meu orientador e amigo, agradeço por estes mais de dez anos de convívio com um otimismo diário, com a crítica sempre construtiva e por ter acre-ditad~em mim e neste projeto. Desejo agradecer também a Profa. Yvonne Mascarenhas e ao Prof. Jan Slaets por todo empenho, interesse e hospitalidade sem o que esta tese não teria se concretizado.

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