This study was undertaken to determine the relationships between myocardial mitochondrial function, regional myocardial blood flow (MBF), and tissue ATP content in acute ischemia. Fifty-one anesthetized dogs were used in the tests. MBF was measured by the H2 gas clearance method in order to define the ischemic area, during periods of coronary occlusion of 10, 20, 60, and 90 min. The correlation...

AIM To compare the interocular and intraocular differences of capillary perfusion, and the intraocular regional differences of retinal blood flow in the macular area of healthy volunteers. METHODS Tissue blood flow in the macula was examined in both eyes of 20 healthy volunteers with the Heidelberg retinal flowmeter. Blood flow measurements were made in a 10 degrees x 2.5 degrees area superio...

The controversy regarding the mechanism(s) of left ventricular (LV) dysfunction in chronic coronary artery disease is, in part, related to the lack of an appropriate animal model for this condition. We have developed such a model by placing Ameroid constrictors on proximal portions of coronary arteries in dogs who were euthanized (mean of 6 wk) after the development of severe global LV dysfunct...

Background Myocardial blood flow (MBF) can be quantified from arterial input function (AIF) and myocardial output function in perfusion MRI by using tracer kinetic modeling. Fermi function constrained deconvolution has been widely used to determine MBF and myocardial perfusion reserve (MPR). However, stress MBF and MPR in healthy subjects quantified by the Fermi deconvolution approach were repo...

AIMS We studied the interrelation between oxygen consumption and myocardial blood flow (MBF) during recovery. MBF is directly dependent on oxygen consumption. The latter is linearly related to the heart rate-blood pressure product (RPP, bpm × mmHg), an index reflecting external cardiac work. In the immediate post-exercise period, cardiac output decreases considerably. This is expected to be par...

BACKGROUND Myocardial arterial spin labeling (ASL) is a noninvasive MRI based technique that is capable of measuring myocardial blood flow (MBF) in humans. It suffers from poor sensitivity to MBF due to high physiological noise (PN). This study aims to determine if the sensitivity of myocardial ASL to MBF can be improved by reducing image acquisition time, via parallel imaging. METHODS Myocar...

BACKGROUND Recent evidence suggests that the diagnostic accuracy of myocardial perfusion imaging is improved by quantifying stress myocardial blood flow (MBF) in absolute terms. We evaluated a comprehensive quantitative (13)N-ammonia positron emission tomography ((13)NH3-PET) diagnostic panel, including stress MBF, coronary flow reserve (CFR), and relative flow reserve (RFR) in conjunction with...

BACKGROUND Microneurography and venous occlusion plethysmography can be considered methods of assessment of the sympathetic activity. OBJECTIVE To evaluate the intensity of the sympathetic activity through microneurography and venous occlusion plethysmography in patients with heart failure (HF) and correlate this intensity with prognosis. METHODS 52 patients with HF (ejection fraction < 45%...

BACKGROUND Elevated serum uric acid (SUA) levels have been independently associated with cardiovascular disease. Stress myocardial perfusion positron emission tomography (PET) allows for measurement of absolute myocardial blood flow (MBF) and quantification of global left ventricular coronary flow reserve (CFR). A CFR <2.0 is considered impaired coronary vascular function, and it is associated ...

We tested the hypothesis during the combined challenges of altered inspired O2 fraction (FIO2) and posture changes at lower power output regardless of body position that the vascular conductance (VC) recruitment to the exercising muscle would not limit muscle perfusion and estimated O2 delivery (DO2est ). However, in head-down tilt at the higher power output exercise in hypoxia, the recruitment...