Background: We hypothesized that altered myocardial perfusion distribution patterns could be seen with coronary distal emboli of different particle sizes using myocardial contrast echocardiography.
Methods: In 16 open-chest anesthetized dogs, microsphere suspensions of 9 or 500 microm in diameter were injected into the left anterior descending coronary artery until the mean left anterior descending coronary artery flow rate was reduced to less than 30% of baseline flow. During baseline conditions and after maximal embolization, real-time myocardial contrast echocardiography was performed by intravenous infusion of an echocontrast agent.
Results: In animals infused with 9-microm microspheres, a transmural perfusion defect was seen at the time of maximal embolization. In contrast, in animals infused with 500-microm microspheres, a subendocardial perfusion defect was observed.
Conclusions: The particle size of coronary distal emboli affects myocardial perfusion distribution.
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http://dx.doi.org/10.1016/j.echo.2005.08.007 | DOI Listing |
Am J Physiol Regul Integr Comp Physiol
December 2024
Curtin University, Curtin Medical Research Institute (Bentley, WA, AUSTRALIA).
Physical activity improves myocardial structure, function and resilience via complex, incompletely defined mechanisms. We explored effects of 1-2 wks swim training on cardiac and systemic phenotype in young male C57Bl/6 mice. Two wks forced swimming (90 min twice daily) resulted in cardiac hypertrophy (22% increase in heart:body weight, P<0.
View Article and Find Full Text PDFEur Heart J
January 2025
Department of Cardiology, Copenhagen University Hospital Rigshospitalet, Blegdamsvej 9, Copenhagen DK-2100, Denmark.
Cardiogenic shock represents a critical condition in which the heart is unable to maintain adequate circulation leading to insufficient tissue perfusion and end-organ failure. Temporary mechanical circulatory support offers the potential to stabilize patients, provide a bridge-to-recovery, provide a bridge-to-decision, or facilitate definitive heart replacement therapies. Although randomized controlled trials have been performed in infarct-related cardiogenic shock and refractory cardiac arrest, the optimal timing, appropriate patient selection, and optimal implementation of these devices remain complex and predominantly based on observational data and expert consensus, especially in non-ischaemic shock.
View Article and Find Full Text PDFIndian J Nucl Med
November 2024
Department of Cardiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Adenosine is extensively utilized in myocardial stress perfusion imaging for the detection and risk stratification of coronary artery disease. It has a well-established safety profile. The majority of the undesirable effects experienced during adenosine infusion are transient (owing to its brief half-life of ~10 s) and arise from the stimulation of receptors in the atrio-ventricular (AV) node (AV block) and bronchial smooth muscles (bronchospasm).
View Article and Find Full Text PDFRadiol Adv
October 2024
Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.
Purposes: The objective was to evaluate the accuracy of a novel CT dynamic angiographic imaging (CT-DAI) algorithm for rapid fractional flow reserve (FFR) measurement in patients with coronary artery disease (CAD).
Materials And Methods: This retrospective study included 14 patients (age 58.5 ± 10.
Cardiovasc Diagn Ther
December 2024
Operational Research Center in Healthcare, Near East University, Nicosia, Turkey.
Background: Cardiovascular diseases (CVDs) continue to be the world's greatest cause of death. To evaluate heart function and diagnose coronary artery disease (CAD), myocardial perfusion imaging (MPI) has become essential. Artificial intelligence (AI) methods have been incorporated into diagnostic methods such as MPI to improve patient outcomes in recent years.
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