281 research outputs found
Doppler-echocardiographic findings in a patient with persisting right ventricular sinusoids
The Doppler-echocardiographic features of persisting right ventricular myocardial sinusoids are presented. An 18-year-old patient with persisting right ventricular sinusoids had undergone comissurotomy for critical pulmonary artery stenosis at the age of 12 months. Follow-up catheterization at the age of 17 years revealed no signs of residual pulmonary artery stenosis, outflow tract obstruction or pulmonary hypertension. No shunt could be documented. High systolic velocity jets within the myocardial sinusoids were recorded by means of continuous-wave Doppler. Pulmonary artery blood flow velocity was recorded mainly consequent to atrial contraction and was reduced during right ventricular ejection period, thus reflecting impaired systolic and diastolic right ventricular functio
Divided right atrium. Diagnosis by echocardiography, and considerations on the functional role of the Eustachian valve
A child presented at birth with severe cyanosis. Echocardiography showed hypoplasia of the right heart with a right-to-left shunt at atrial level. A conservative approach was adopted initially, and the situation improved over a few months, with reversal of the atrial shunt. Surgery was successfully performed at 4 years of age after further echocardiography revealed a congenitally large Eustachian valve and an atrial septal defec
Surgically induced unilateral pulmonary hypertension: time-related analysis of a new experimental model
Objective: Patients with irreversible pulmonary vascular obstructive disease caused by pulmonary hypertension due to congenital heart defects are considered either inoperable or only candidates to lung transplantation. This study evaluated an experimental model of surgically induced unilateral pulmonary hypertension. Methods: In eight pigs, 2-months-old, the left pulmonary artery was divided at the origin and end-to-side anastomosed to the descending thoracic aorta through a left thoracotomy. In this way, increased pulmonary blood flow in the right lung and systemic perfusion pressure and oxygenation in the left lung were obtained. After an interval of 6-12 weeks the animals underwent cardiac catheterization and were then sacrificed. Histological examination was done on both the lungs. Results: The mean left-to-right shunt through the left pulmonary artery diminished from 58.9±9.6% at the end of the procedure to 4.5±1.5% at the latest hemodynamic evaluation (P<0.01). Pressures and saturations remained identical in aorta and left pulmonary artery, without reduction (NS) with FiO2=1.0 ventilation; in the right pulmonary artery there was a mild elevation of the pressures, but still responsive (P<0.05) to FiO2=1.0 ventilation. Lung histology showed normal right pulmonary arteries, but irreversible vascular lesions like intimal fibrosis, medial hypertrophy, vascular occlusions, plexiform and dilatation lesions in all the left lungs. Conclusions: The lung exposed to systemic pressure and oxygenation develops irreversible vascular lesions typical of pulmonary vascular obstructive disease. The lung exposed to increased flow shows only mild elevation of the arterial pressure, remains responsive to oxygen vasodilatation, and displays normal histolog
Prevention and therapy of leg ischaemia in extracorporeal life support and extracorporeal membrane oxygenation with peripheral cannulation.
Extracorporeal membrane oxygenation (ECMO) and extracorporeal life support (ECLS) have been around for a long time, but it is only in recent years, with the advent of acute respiratory distress syndrome consecutive to influenza A (H1N1) infection, that these life-saving technologies have seen a broader application. Although the results of ECLS and ECMO are perceived as generally encouraging, there are still disturbing complications related to peripheral cannulation in general and, more specifically, to cannulation in the groin. The present review was designed to assess the magnitude of this latter problem, i.e. leg ischaemia related to ECLS and ECMO, in the literature and to identify strategies for possible therapies and, more importantly, prevention. The search strategy selected identified seven original articles with more than twenty patients, totalling 407 patients who underwent veno-arterial ECMO, and one large review dealing with all kinds of complications. For the original reports, the number of cases with veno-arterial support ranged from 21 to 143, with, as far as available, frequency of ischaemic complications between 11% and 52%, a reported range of surgical intervention between 9% and 22%, and a leg amputation rate from 2% to 10%. It appears that the number of reports dealing with lower extremity ischaemia during ECMO increases in parallel with the number of reports about ECMO. Strategies for early detection of peripheral ischaemia, interventions for efficient reperfusion, and measures for prevention including new concepts with smaller and eventually bidirectional arterial cannulas are discussed
Daily reoxygenation decreases myocardial injury and improves post-ischaemic recovery after chronic hypoxia
Objective: In contrast to the clinical evidence, experimental studies showed that chronic hypoxia (CH) confers a certain degree of protection against ischaemia-reperfusion damage. We studied the effects of daily reoxygenation during CH (CHReox) on hearts exposed to ischaemia-reperfusion. We also separated the intrinsic effects on the myocardium of CH and CHReox from those related to circulatory and nervous factors. Methods: Fifty-one Sprague-Dawley rats were maintained for 15 days under CH (10% O2) or CHReox (10% O2+1hday−1 exposure to air). Normoxic (N, 21% O2) rats were the control. The animals were randomly assigned to one of the three following protocols: (1) protocol A: hearts (n=7 per group) were subjected to 30-min occlusion of the left anterior descending (LAD) coronary artery followed by 3-h reperfusion, with measurement of the injury by tetrazolium staining; (2) protocol B: the end-diastolic pressure (EDP) and left ventricular developed pressure×heart rate (LVDP×HR) were measured in Langendorff-perfused isolated hearts (n=5 per group) during 30-min global ischaemia and 45-min reperfusion; and (3) protocol C: hearts (n=5 per group) were frozen for the determination of levels of endothelial nitric oxide synthase (eNOS) by Western blotting. Results: CHReox hearts displayed greater phosphorylation of the eNOS and enhanced plasma level of nitrates and nitrites in comparison to CH hearts (P≪0.0001, Bonferroni's post-test). The infarct size was greater in CH than in N hearts (P≪0.0001, Bonferroni's post-test) while it was reduced in CHReox in comparison to CH and N hearts (P≪0.0001). At the end of reperfusion, EDP was higher in CH than CHReox and N hearts (P=0.01, Bonferroni's post-test) while LVDP×HR was higher in CHReox and N than in CH hearts (P=0.03, Bonferroni's post-test). Conclusions: Exposure to CH results in impairment of myocardial tolerance to ischaemia-reperfusion, greater injury and reduced recovery of performance, in agreement with clinical evidence. Infarct size, diastolic contracture and myocardial performance have been reduced, respectively, by 63%, 64% and 151% with daily reoxygenation compared with chronic hypoxia by accelerating intrinsic adaptive change
Divided right atrium. Diagnosis by echocardiography, and considerations on the functional role of the Eustachian valve
A child presented at birth with severe cyanosis. Echocardiography showed hypoplasia of the right heart with a right-to-left shunt at atrial level. A conservative approach was adopted initially, and the situation improved over a few months, with reversal of the atrial shunt. Surgery was successfully performed at 4 years of age after further echocardiography revealed a congenitally large Eustachian valve and an atrial septal defect
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