1,720,984 research outputs found
The office-ambulatory blood pressure differnce is associated to the prognostic arterial thickness and stiffness indices
No full textValutazione incruenta del flusso coronarico mediante ultrasonografia Doppler dell'arteria mammaria interna anastomizzata coronaria sinistra durante sforzo isometrico
No full textIsometric contraction of small group of muscles is believed to increase heart rate and contractility and arterial pressure without significant changes in systemic arterial resistance. Such a manoeuvre has been employed in this work to study dynamic changes induced in blood flow into coronary bed, in subjects in which an anastomosis of the internal mammary artery to anterior descending coronary artery was performed. Ten patients with no clinical signs of myocardial ischaemia at rest and during exercise, were requested to perform an endurance left handgrip manoeuvre, at 50% of maximal voluntary contraction. Doppler blood velocity curve in the anastomosed mammary artery; non-invasive blood pressure curve at a finger of the right hand by Finapres; the electrocardiogram, were recorded. A significative increase in heart rate and mean and diastolic blood pressure was found. Blood flow significantly increased, approximately in the same percentage as double product was increased. A calculated index of coronary resistance did not show significant changes. In this group of patients, the handgrip manoeuvre may display the ability of the cardiac pump to match its metabolic needs due to increased pressure load, by employing the same developed pressure load as an adequate coronary perfusion pressure. It is suggested to employ this simple test in the routine monitoring of patients with internal mammary artery bypass grafts
Usefulness of Doppler color ultrasonography for the non-invasive diagnosis of the atherosclerotic plaque
No full textNoninvasive Estimation of the Internal Mammary Artery Bypass Graft Patency: A Six-Year Follow-up
No full textEcho Doppler of the internal mammary artery (IMA) can be considered a good clinical and diagnostic tool in detecting the flow in the IMA bypass graft. The aim of the present study was to evaluate the reliability of transcutaneous echo-Doppler ultrasonography in the detection of early and long-term pathologies of the IMA bypass graft. The study was carried out on 161 consecutive patients (127 men and 34 women, mean age fifty-two +/- ten years) who had undergone surgical myocardial revascularization by anastomosis of the left IMA pedicle to the left anterior descending coronary artery. All patients underwent echo-Doppler examination in resting conditions, during forced hyperventilation and Valsalva maneuver four times per year. Supine exercise test was performed annually for five years, and selective angiography of the IMA graft (IMAg) was done when symptoms and/or conventional stress test and/or echo-Doppler examination required it. The results showed that, for anatomic reasons only, in 87% (140 patients), it was possible to study the IMAg. In these patients, 16 stenoses greater-than-or-equal-to 40%-99%, 5 occlusions, and 3 intercostal steals were detected. These results, compared with selective angiography, showed high sensitivity, specificity, and accuracy of echo-Doppler of the IMAg
Tachycardia and coronary blood flow: non-invasive estimation during Valsalva manoeuvre and exercise
No full textSimultaneous changes in cycle length and coronary blood flow were studied during Valsalva manoeuvre and supine cycloergometer exercise test in 10 male patients (mean age 48+/-12 years) who had successfully undergone myocardial revascularization by surgical anastomosis of the left internal mammary artery on the left anterior descending coronary artery. Blood velocity curves in the left internal mammary artery were obtained by a non-invasive continuous-wave Doppler probe at rest, in the last phase of the expiratory effort of the Valsalva manoeuvre and at the maximum load attained during the exercise test. Mean arterial pressure by sphygmomanometer, and cardiac cycle length on the basis of Doppler recording were measured. Mean blood velocity, the length of the blood column entering the coronary bed at each cycle (cardiac cycle times mean velocity), an index of blood cell acceleration (the ratio of mean velocity to cardiac cycle), and an index of coronary resistance (the ratio of mean pressure to mean velocity), were calculated
Geometry of the carotid arteries and tilt-up hypotension in subjects with essential arterial hypertension
No full textAccuratezza dell'eco-color Doppler nella valutazione quantitativa delle dolicoarteriopatie delle arterie carotidi
No full textThe noninvasive assessment of coronary flow during isometric exercise by Doppler ultrasonography of the internal mammary artery anastomosed to the left coronary]
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