Recently developed stimulation techniques are capable of eliminating polarization afterpotentials caused by the emitted stimulus. A well-controlled study method was developed to initiate various degrees of fusion and to monitor changes in the morphology of the endocardial signal. The study was performed on two dogs. The zone during which fusion could be provoked was less than 30 ms in both dogs. In addition, the results show a significant decrease in the endocardial T-wave amplitude as soon as fusion was noticed, while the QT interval then slightly lengthened. Furthermore, the evoked R-wave duration shortened during fusion, while the stimulus to R-wave interval lengthened. These results have consequences for pacemakers that use evoked endocardial signal characteristics for driving a pacemaker function.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1111/j.1540-8159.1988.tb06297.x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Manipulating Mechanical Forces in the Developing Zebrafish Heart Using Magnetic Beads.
J Vis Exp
January 2025
Department of Bioengineering, Imperial College London; The Francis Crick Institute;
Mechanical forces continuously provide feedback to heart valve morphogenetic programs. In zebrafish, cardiac valve development relies on heart contraction and physical stimuli generated by the beating heart. Intracardiac hemodynamics, driven by blood flow, emerge as fundamental information shaping the development of the embryonic heart.
View Article and Find Full Text PDFClinical Application of the Fetal HQ Technique in the Evaluation of Normal Fetal Cardiac Function at Different Gestational Weeks.
Echocardiography
January 2025
Department of Ultrasound Diagnosis, Gansu Provincial Maternity and Child-Care Hospital (Gansu Provincial Central Hospital), Lanzhou, Gansu, P.R. China.
Objectives: To investigate the clinical value of fetal heart quantification (fetal HQ) in the evaluation of normal fetal heart size, morphology, and cardiac function at different gestational weeks.
Materials And Methods: A total of 101 pregnant women diagnosed with a healthy fetus by fetal echocardiography from September 2021 to December 2023 were selected and classified into four different periods of gestational weeks: 20-28 weeks (25 cases), 29-32 weeks (26 cases), 33-36 weeks (26 cases), and 37-40 weeks (24 cases). Quantitative analyses were performed by automatically tracking the endocardium using fetal HQ software that comes with the Voluson E10 from GE.
Unmasking the Hidden Threat: The Role of Left Ventricular Subendocardial Involvement in Autoimmune Rheumatic Disease.
Clin Cardiol
January 2025
Department of Cardiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
Background: Late gadolinium enhancement (LGE) has been found in patients with autoimmune rheumatic disease (ARD). However, the prognostic implications of some specific LGE patterns in ARD patients remain unclear.
Purpose: To investigate the prevalence and prognostic significance of left ventricular (LV) subendocardium-involved LGE (LGEse) in a cohort of ARD patients.
Multimodality Imaging Supports Cardiac Lesion Diagnosis in Patient With Liver Carcinoma: A Case Report.
Cancer Rep (Hoboken)
December 2024
Vietnam National Heart Institute, Bach Mai Hospital, Hanoi, Vietnam.
Introduction: Nonbacterial thrombotic endocarditis (NBTE) is a rare cardiac manifestation in patients with advanced malignancies of the lungs, pancreas, gynecological system, and gastrointestinal tract. It is often confirmed postmortem by histopathological evidence of sterile platelet-fibrin deposits attached to the endocardium, most often on heart valves. To the best of our knowledge, our case is the first to report multiple heart lesions caused by the systemic effect of cholangiocarcinoma.
View Article and Find Full Text PDF[Cardiac myxoma: biological features, morphology, differential diagnosis].
Arkh Patol
December 2024
Cancer Research Institute, branch of Tomsk National Research Medical Center, Tomsk, Russia.
Cardiac myxoma in its morphology is a typical benign tumor, meanwhile, the fact of its localization in the heart chamber, directly in the constant blood flow, largely determines the clinical behavior of this neoplasm, which is often manifested by the development of characteristics that formally determine the aggressive and even malignant nature of the course. Accordingly, the malignancy of cardiac myxoma is determined more by its clinical behavior (recurrence, multifocality of the lesion, the presence of mechanisms of spread similar to metastasis) rather than by its histological picture. In the structure of primary benign tumors of the heart, myxoma occupies a dominant position and its incidence is up to 85%.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!