Changes in the cardiac hemodynamics and coronary blood flow in acute myocardial infarction due to perftoran

One hundred and twenty patients with acute myocardium infarction, who were receiving perftoran, were analyzed within the case study. The microcirculation condition was determined by biomicroscopy of the eye conjunctiva capillaries. Changes in capillaries were evaluated by the Ditzel classification. Hemostasis was evaluated by coalugram. The condition of the myocardium was examined by electrocardiography and Echo-cardiography. The contractive ability of the myocardium was assessed by a shortening degree of the anterior-posterior size and by the ejection fraction. According to the study results, the administration of perftoran increased the number of functioning capillaries, decreased the venous congestion and reduced the diameter of arterioles and venules. Hypercoagulation was significantly decreasing. The general evaluation of the contractive ability of myocardium was satisfactory in all patients.     

Hemodynamics, coronary blood flow, and myocardial metabolism in coronary shock; response to l-norepinephrine and isoproterenol

Hemodynamics and myocardial metabolism were evaluated in 18 patients in cardiogenic shock following acute myocardial infarction. The response to l-norepinephrine was studied in seven cases and the response to isoproterenol in four cases. Cardiac index (CI) was markedly reduced, averaging 1.35 liters/min per m(2). Mean arterial pressure ranged from 40 to 65 mm Hg while systemic vascular resistance varied widely, averaging 1575 dyne-sec-cm(-5). Coronary blood flow (CBF) was decreased in all but three patients (range 60-95, mean 71 ml/100 g per min). Myocardial oxygen consumption (MV(O2)) was normal or increased ranging from 5.96 to 11.37 ml/100 g per min. Myocardial oxygen extraction was above 70% and coronary sinus oxygen tension was below 22 mm Hg in most of the patients. The detection of the abnormal oxygen pattern in spite of sampling of mixed coronary venous blood indicates the severity of myocardial hypoxia. In 15 studies myocardial lactate production was demonstrated; in the remaining three lactate extraction was below 10%. Excess lactate was present in 12 patients. During l-norepinephrine infusion CI increased insignificantly. Increased arterial pressure was associated in all patients by increases in CBF, averaging 28% (P < 0.01). Myocardial metabolism improved. Increases in MV(O2) mainly paralled increases in CBF. Myocardial lactate production shifted to extraction in three patients and extraction improved in three. During isoproterenol infusion CI increased uniformly, averaging 61%. Mean arterial pressure remained unchanged but diastolic arterial pressure fell. CBF increased in three patients, secondary to decrease in CVR. Myocardial lactate metabolism deteriorated uniformly; lactate production increased or extraction shifted to production. In the acute state of coronary shock the primary therapeutic concern should be directed towards the myocardium and not towards peripheral circulation. Since forward and collateral flow through the severely diseased coronary bed depends mainly on perfusion pressure, l-norepinephrine appears to be superior to isoproterenol; phase-shift balloon pumping may be considered early when pharmacologic therapy is unsuccessful.     

Acute gastric ulceration in rats with obstructive jaundice with special reference to gastric mucosal blood flow

The mechanism of acute gastric ulceration in rats with obstructive jaundice was investigated in terms of the changes in the gastric mucosal blood flow, and the effect of vagotomy on ulceration was examined. 188 Sprague-Dawley rats weighing about 250 g were prepared and divided into 4 groups as follows; control group (sham operation), jaundiced group (ligation of the bile duct), vagotomized group (vagotomy with pyloroplasty), jaundiced and vagotomized group (simultaneous ligation of the bile duct and vagotomy with pyloroplasty). Two weeks after the operation, water immersion and restraint stress procedures were performed in these 4 groups. The gravity of acute gastric ulcerations was calculated by ulcer index. The gastric mucosal blood flow was measured by hydrogen clearance technique. The following results were obtained: In control group, ulcer index was increased and gastric mucosal blood flow was decreased after the stress procedures. The jaundiced group showed significantly higher ulcer index and early significant decrease of gastric mucosal blood flow after the stress procedures compared to the control group. The vagotomized group showed significantly decreased ulcer index after the stress procedures compared to the control group, however, the gastric mucosal blood flow showed almost the same values as the control group. The jaundiced and vagotomized group showed significant decrease of ulcer index and improvement of decrease of gastric mucosal blood flow compared to the jaundiced group. These results indicated that the gastric mucosal blood flow plays an important role in the occurrence of acute gastric ulceration in rats with obstructive jaundice, and vagotomy might be useful to prevent them by maintaining gastric blood flow in obstructive jaundice.     

Results of local thrombolysis with special reference to diabetic metabolism

The influence of diabetes on the primary and long-term success rate after 145 local thrombolyses in peripheral arterial disease stages III and IV was evaluated. 75 patients suffered from thrombotic, 62 patients from embolic occlusions, with eight patients suffering from thrombangitis obliterans. Regarding the localisation of vascular occlusion 0.6% suffered under an occlusion of the iliacal artery, 21% of the femoral artery, 16% of the popliteal artery, 7% of the vessel of the lower limb and 55.4% showed a combined occlusion of the femoral- and popliteal artery and the artery of the lower limb. In cases of embolic occlusions only marginal differences could be observed, while the primary success-rate of thrombotic occlusions showed greater differences between both groups (75% vs. 91%). During the follow-up, no differences between both groups could be established (patency-rate of 79% for both groups). The same applies to the prognostic factors: peripheral run off, length, duration of occlusion and the clinical stage (Fontaine IIb to IV). The remarkable differences between diabetic and non-diabetic patients in cases of occlusions of more than 16 cm (66% vs. 88% in primary and 55% vs. 77% in long-term success) can be explained by the high percentage of diabetic patients with poor run-off and microangiopathy. Regarding the above parameters, primary and long-term results seemed to be less in diabetic patients, even though a long-term patency could be observed in 2/3 of diabetic patients in stages IIb and IV with primary success.     

Prostacyclin and regional coronary blood flow in experimental myocardial infarction

Infusion of prostacyclin (PGI₂) has been reported to affect infarct size and myocardial blood flow favourably in various animal models of myocardial ischaemia. Recent data suggest that a similar effect of PGI₂ may occur also in humans with acute myocardial infarction. We addressed the hypothesis that PGI₂ redistributes myocardial blood flow following coronary ligation, and that this effect favours perfusion of myocardium at risk and thereby limits infarct size. Following ligation of a distal branch of the left coronary artery in anaesthetized dogs, PGI₂ (2–4 ng/kg/min) was infused for 72 h. Regional myocardial blood flow was assessed immediately after the coronary ligation and at the end of the drug infusion, by injection of ⁵⁷Co- and ¹¹³Sn-labelled microspheres, respectively. Coronary ligation reduced regional coronary blood flow by 40–70%. During the subsequent 72 h the blood flow increased, being at the end of the period 50–70% of the flow in the non-ischaemic myocardium. PGI₂ did not affect the spontaneous improvement of regional myocardial blood flow, as assessed at the end of the infusion. PGI₂ also failed to affect infarct size, either when expressed in relation to total left ventricular mass, or in relation to area at risk. We conclude that PGI₂, when infused immediately after coronary ligation in dogs in a clinically relevant dose, neither affects regional myocardial blood flow in the ischaemic regions, nor the size of the myocardial infarction.     

Perioperative cerebral hemodynamics and oxygen metabolism in neonates with single-ventricle physiology

Congenital heart disease (CHD) patients are at risk for neurodevelopmental delay. The etiology of these delays is unclear, but abnormal prenatal cerebral maturation and postoperative hemodynamic instability likely play a role. A better understanding of these factors is needed to improve neurodevelopmental outcome. In this study, we used bedside frequency-domain near infrared spectroscopy (FDNIRS) and diffuse correlation spectroscopy (DCS) to assess cerebral hemodynamics and oxygen metabolism in neonates with single-ventricle (SV) CHD undergoing surgery and compared them to controls. Our goals were 1) to compare cerebral hemodynamics between unanesthetized SV and healthy neonates, and 2) to determine if FDNIRS-DCS could detect alterations in cerebral hemodynamics beyond cerebral hemoglobin oxygen saturation (SO₂). Eleven SV neonates were recruited and compared to 13 controls. Preoperatively, SV patients showed decreased cerebral blood flow (CBF_i), cerebral oxygen metabolism (CMRO_2i) and SO₂; and increased oxygen extraction fraction (OEF) compared to controls. Compared to preoperative values, unstable postoperative SV patients had decreased CMRO_2i and CBF_i, which returned to baseline when stable. However, SO₂ showed no difference between unstable and stable states. Preoperative SV neonates are flow-limited and show signs of impaired cerebral development compared to controls. FDNIRS-DCS shows potential to improve assessment of cerebral development and postoperative hemodynamics compared to SO₂ alone.OCIS codes: (170.0170) Medical optics and biotechnology, (170.5380) Physiology, (170.3880) Medical and biological imaging     

Regional cerebral blood flow and oxygen metabolism during migraine with and without aura

Eleven cases of migraine with and without aura were investigated with positron emission tomography (PET). Regional cerebral blood flow (rCBF), oxygen metabolism (rCMRO₂) and oxygen extraction (rOER) were measured during baseline ( n =11), aura ( n = 6), headache ( n = 10) and after treatment with sumatriptan ( n = 4). Data were analysed using and ROI-based approach from 26 different anatomically defined regions, and also an exploratory approach whereby all subjects were normalized to a stereotactic brain atlas; t -maps were constructed by depicting significant changes between states. The exploratory approach revealed a region corresponding to the primary visual cortex with significant reductions in rCBF (23.1%) and rCMRO₂ (22.5%), but no change in rOER during the headache phase compared to baseline. These data suggest that cerebral ischemia was not the primary cause of the attacks in these cases.