In order to avoid the potential risk of a short refractory period and the inconvenience of the electronic blocking mechanism at the highest synchronous rate with the conventional atrial triggered pulse generator, two more functions have been added to the normal atrial triggered (VAT) pulse generator. First, it has been designed to be ventricular inhibited; second, a highest synchronous rate detector has been added. When the highest synchronous rate of about 140 is exceeded, the atrial signals are blocked and the frequency of the basic rate generator is increased to about 130. Two patients could hardly feel the change from atrial triggered pacing to ventricular inhibited stimulation, and both were able to work at higher loads with this type of pacing compared with the conventional atrial triggered pulse generator.
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http://dx.doi.org/10.1111/j.1540-8159.1979.tb04274.x | DOI Listing |
Am J Med
January 2025
Professor of Medicine, Department of Cardiology, Tufts Medical Center, (Tufts University School of Medicine), Boston, MA 02111, USA. Electronic address:
Cardiologists and gastroenterologists often encounter the coexistence of symptoms and functional abnormalities, but determining causation is more difficult. In 1962 Smith and Papp first coined the term "linked angina". Their statement was preceded by the experiment whereby increase in bile duct pressure elicited the typical chest pain in patients with ischemic heart disease.
View Article and Find Full Text PDFEchocardiography
February 2025
Department of Cardiology, Loyola University Medical Center, Maywood, Illinois, USA.
The left atrium (LA) is pivotal in cardiac hemodynamics, serving as a dynamic indicator of left ventricular (LV) compliance and diastolic function. The LA undergoes structural and functional adaptations in response to hemodynamic stress, infiltrative processes, myocardial injury, and arrhythmic triggers. Remodeling of the LA in response to these stressors directly impacts pulmonary circulation, eventually leading to pulmonary capillary involvement, pulmonary artery hypertension, and eventually right ventricular failure.
View Article and Find Full Text PDFEur Heart J Case Rep
January 2025
Cardiovascular Centre, Social Medical Corporation Steel Memorial Yawata Hospital, 1-1-1 Haruno-machi, Yahatahigashi-ku, Kitakyushu 805-8508, Japan.
Background: The superior vena cava (SVC) acts as a non-pulmonary vein (PV) trigger for atrial fibrillation (AF) in 2%-6% of patients and harbours 25%-40% of non-PV foci. Approximately 10% of patients with AF have epicardial connections (ECs) between the atrium and PV inside the PV isolation lines, which are associated with AF recurrence. However, the contribution of EC(s) between the SVC and right atrium (RA) to subsequent AF remains unknown.
View Article and Find Full Text PDFCureus
December 2024
Department of Obstetrics and Gynecology, Sakakibara Heart Institute, Fuchu, JPN.
Preterm birth remains a leading cause of neurodevelopmental disability in offspring, prompting various preventive measures. However, controversies persist surrounding these approaches, particularly regarding beta-mimetic drugs. In Japan, it remains a concerning reality that ritodrine infusion continues to be used for long-term tocolysis in preterm labor, despite the warning issued by the US Food and Drug Administration.
View Article and Find Full Text PDFHeart Rhythm
January 2025
Division of Cardiology, University of Ottawa Heart Institute, Canada. Electronic address:
Background: The assessment of left ventricular (LV) systolic function and quantification of LV ejection fraction (EF) in patients with atrial fibrillation (AF) can be difficult. We previously demonstrated that LV volume changes over the 100 ms of systole (LVEF) can be used as a measure of LV systolic function.
Objective: We sought to evaluate the applicability of LVEF in AF patients.
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