Conditions Of Circulatory Arrest Research Articles

Chronic thromboembolic pulmonary hypertension in a patient with myxoma of the heart and thrombophilia of mixed genesis

Objective. To describe the clinical case of a young patient with chronic thromboembolic pulmonary hypertension (CTEPH) with heart myxoma and thrombophilia of mixed origin, who underwent surgical treatment.Materials and methods. Patient Z., 24 years old, was admitted to the cardiology department with cough with sputum production that occurs during physical activity, including streaks of blood, shortness of breath with slight physical exertion, legs and feets edema, weakness and dizziness. The examination was carried out: electrocardiography; multislice computed tomography pulmonary angiography; echocardiography (EchoCG); transesophageal EchoCG; magnetic resonance imaging of the heart with contrast; screening for coagulopathy.Results. Based on clinical data, medical history, laboratory, instrumental diagnostic, we have put the diagnosis: Myxoma of the right atrium. Patent foramen ovale. Thrombophilia of mixed origin: hereditary – heterozygous mutation of the prothrombin gene (factor 2), acquired – hyperhomocysteinemia. Postthrombotic deep vein disease of the left lower limb. Recurrent pulmonary embolism (last relapse dated October 19, 2022). CTEPH functional class III (World Health Organization), moderate risk. Congestive heart failure with reduced right ventricular ejection fraction, functional class III (by the New York Heart Association). Relative tricuspid valve regurgitation grade 3. The patient underwent surgery: thromboendarterectomy from the right pulmonary artery under conditions of circulatory arrest and deep hypothermia, removal of a right atrium myxoma under conditions of artificial circulation and blood cold cardioplegia: tricuspid valve plasty according to De Vega. After surgery patient’s condition was significantly improved.Conclusion. The features of diagnosis and treatment of a patient suffering from CTEPH and cardiac myxoma are outlined. Surgery: Pulmonary thrombectomy and cardiac myxoma removal may improve the patient’s condition with CTEPH and left atrial myxoma.

Clinical aspects of the blood lactate dynamics during operations on the heart and the aorta in conditions of cardiopulmonary bypass

The frequency and the causes for the development of hyperlactatemia during operations on the heart and aorta in conditions of cardiopulmonary bypass (CB) is not adequately described in the literature. To study the clinical significance of the lactate dynamics in arterial blood depending on the source ofpathology, stages of operation, basic parameters of cardiopulmonary bypass, the characteristics of the post-perfusion period, and to identify ways to prevent the development of intraoperative hyperlactatemia in surgical interventions on the heart and aorta. 420 adult cardiac surgery patients operated on the heart and ascending aorta were examined. All patients were operated on under balanced General anesthesia, CB in hypothermic or normothermic mode. Lactate level in arterial blood and the frequency of hyperlactatemia were analyzed at the following stages of operation: after induction of anesthesia, prebypass period, during CB, in the postbypass period and at the time of admission of the patient in the ICU. During CB we analyzed the duration of the CB, the degree of hemodilution, calculated value of oxygen delivery. Oxygen consumption was recorded in the current mode, the monitor CDI-500. Hyperlactatemia was considered the concentration of lactate above 3 mmol/L. Preperfusion period in all groups of cardiac surgery patients was characterized by a normal level of blood lactate in the absolute majority ofpatients, the frequency of hyperlactatemia did not exceed 1%. Hemodynamic stability was achieved without the use of catecholamines by optimizing volemia and heart rate. While CB showed a trend of increasing lactate on average in comparison with the previous period in patients operated on the heart. Duration CB less than 3 hours was not a factor in the development of hyperlactatemia, provided that oxygen delivery in all patients during perfusion exceeded 300 ml/min/m2, hematocrit ofperfusate at the end of CB was at 25-27% in most patients. To maintain it at a large hemodilution the ultrafiltration hemoconcentration was used. The frequency of hyperlactatemia was 3%. A significant increase in lactate concentration at the end of the CB to 3.39k1,3 mmol/l (range of 2.1-7.2 mmol/l) on the background of metabolic acidosis found only in patients with circulatory arrest due to receipt of blood products of anaerobic glycolysis after the resumption of the CB. They have frequency of hyperlactatemia risen to 29%. The lac- tate average value at admission ofpatients in the ICU with application of 50-60% ofpatients in dopamine/dobutrex at a dose of 5 mcg/kg/min and reaching the targets of transfusion therapy was slightly higher in the baseline period and corresponded to the upper level of normal values. Only during operations on the aortic arch under conditions of circulatory arrest, the concentration of lactate at the end of the operation was 3,4+1,1 mmol/l with a tendency to decrease in comparison with the period of the CB. From 88 to 93% patients during operations on the heart and ascending aorta without circulatory arrest and 64% ofpatients after operations on the aortic arch with circulatory arrest were admitted to the ICU with a normal lactate level in arterial blood Conclusion. The duration ofperfusion less than 3 hours in the conditions of these indicators preservation is not a risk factor for the development of hyperlactatemia. In postbypass period during operations on the heart and aorta without circulatory arrest about 90% ofpatients transferred to the intensive care unit (ICU) with normal values of lactate. During operations on the aortic arch with circulatory arrest about 60% ofpatients have normal levels of lactate at admission from the operating room to the ICU.

Mediastinitis and pseudoaneurysm of brachiocephalic artery long after the resection of invasive thymoma and postoperative irradiation

Mediastinitis is a complication after median sternotomy. We report a rare case of mediastinitis and mycotic pseudoaneurysm of the brachiocephalic artery that occurred long after the resection of invasive thymoma and postoperative irradiation and was treated with extensive procedures. Clinical Summary A 68-year-old woman was seen with skin ulceration and suppuration from the wound in the anterior chest wall. She had undergone resection of invasive thymoma through median sternotomy 65 months previously. This operative treatment included combined resection of pericardium, right lung, and superior vena cava, along with interposition of an artificial polytetrafluoroethylene graft between the brachiocephalic vein and the right atrium. The patient received adjuvant radiation therapy of 50 Gy to the mediastinum for pathologically diagnosed Masaoka stage III thymoma. Computed tomography of the chest showed a dilated branch of the aortic arch compressing the sternum posteriorly, an occluded artificial graft between the brachiocephalic vein and the right atrium, an dlow-densit yarea si nth emediastinu m(Figur e1) .A cultur eof the suppuration grew Pseudomonas aeruginosa. Arteriography showe da sacra laneurys mo fth ebrachiocephali carter y(Figur e2). The patient underwent excision of the aneurysm through median resternotomy and extended right collar incision for the diagnosis of mediastinitis and mycotic aneurysm of brachiocephalic artery. The implanted polytetrafluoroethylene graft was found to be filled with pus and was removed. After the sternum had been released from the aneurysm, the wall of which was found to be extremely thin, the aneurysm ruptured suddenly. Cardiopulmonary bypass was quickly instituted through the previously exposed cannulations of the femoral artery and vein, with the ruptured aneurysm compressed by the surgeon’s finger. Selective cerebral perfusion was established with additional cannulations of the right axillary artery and the right atrium. The aneurysm of the brachiocephalic artery was excised under conditions of circulatory arrest with profound hypothermia. A Dacron polyester fabric graft was anastomosed with the tailored aortic arch at the origin of the brachiocephalic artery proximally. The distal anastomosis was at the bifurcation of common carotid artery and subclavian artery, with cardiopulmonary bypass restarted without axillary artery perfusion. Circulatory arrest time was 22 minutes, and the duration of cardiopulmonary bypass was 224 minutes. After the patient was weaned from cardiopulmonary bypass, necrotic sternum was resected and the infected mediastinum was irrigated with povidone iodine. Pedicled

A sutureless technique for the relief of pulmonary vein stenosis with the use of in situ pericardium

Pulmonary vein (PV) stenosis develops as a progressive and usually lethal complication after surgical repair of total anomalous PV connection. Conventional surgical repair for the management of recurrent PV stenosis has been generally unsuccessful because of proliferative neointimal hyperplasia resulting in recurrent PV obstruction. The factors that result in recurrent stenosis after the usual types of patch venoplasty are unknown. We speculated that direct suturing of PVs and patch material may be the substrate for turbulent blood flow triggering intimal hyperplasia and eventual narrowing of the vein. On the basis of these considerations, we developed a sutureless technique for repairing PV stenosis with in situ pericardium. We present here its early but promising results. Patients PATIENT 1. Patient 1 was born in January 1995 with infradiaphragmatic total anomalous PV connection and severe obstruction of the descending vertical vein. On day 1, the infradiaphragmatic anomalous vein was ligated and the confluence was anastomosed to the left atrium under conditions of hypothermic circulatory arrest. At 6 months, the child had conspicuous tachypnea. Echocardiography revealed obstructed left PVs with a mean gradient of 7 mm Hg (peak 16 mm Hg) and suprasystemic right ventricular pressure. Angiocardiography demonstrated variable obstruction of all four PVs, with a mean pulmonary artery pressure of 38 mm Hg (systolic 92 mm Hg). At reoperation, obstruction of all PVs was confirmed. Under conditions of circulatory arrest, a pedicled flap of free right atrial wall–superior vena cava junction based at the inferior vena cava was used to patch the right-sided veins and carried behind the aorta to patch the left upper PV. The left lower vein was repaired with a flap created from the left atrial appendage. After that operation, the child had repeated admissions with respiratory tract infections, complicated at 1 year by hemoptysis. Echocardiography revealed recurrence of obstruction. At the second reoperation, atretic left-sided veins and severe stenosis of right-sided veins were noted. The PVs were opened, and an in situ pericardial sutureless patch was used for reconstruction. Echocardiography a year later showed patent veins, with mean gradients of 4 mm Hg on the right side and 5 mm Hg on the left. The estimated mean pulmonary artery pressure was 10 mm Hg. Perfusion lung scan showed 67% perfusion on the right side and 33% on the left. The child currently has no symptoms. PATIENT 2. Patient 2, a female infant, was born on January 1995 with total anomalous PV connection to coronary sinus with echocardiographic evidence of partial obstruction. At 2 weeks, she underwent repair consisting of unroofing of the coronary sinus, as described by Van Praagh and Harken. On completion of the procedure, the patient could not be weaned from cardiopulmonary bypass. At this time the right ventricular pressure was suprasystemic. The child was placed on extracorporeal membrane oxygenator and subsequently weaned after 3 days, with delayed sternal closure in 10 days as a result of persistent hemodynamic instability. Echocardiographic findings before discharge revealed unobstructed PV confluence–left atrium connection. However, echocardiography 4 months later revealed an obstructed right upper PV with a mean right ventricular pressure of 25 mm Hg. Perfusion scan showed 87% perfusion to the left lung and 13% to the right. Eleven months after the operation, echocardiography and cardiac catheterization revealed pulmonary hypertension, with a mean pulmonary artery pressure of 34 mm Hg and anatomically right PV stenosis. At reoperation, the presence of severe bilateral PV stenosis extending from left atrium a variable distance into the intraparenchymal PVs was confirmed. An in situ pericardial baffle was used for repair, as described here. Cardiac catheterization 6 months later revealed normal venous drainage on the left side and mild obstruction on the right side. The mean pulmonary artery pressure was 16 mm Hg. Perfusion lung scan showed 42% to left lung and 58% to right. The child has no symptoms at 15 months of postoperative follow-up. Technique. Standard cardiopulmonary bypass technique is used. The incision is made into the left atrium and extended into both upper and lower PV ostia separately (Fig. 1, A). This incision can be carried into the secondary, and if necessary, the tertiary branches of both the upper and lower lobe veins to a level at which the intima appears grossly normal. The pericardium overlying the entrance of the PVs is used to create an enlarged communication between the opened PVs and the left atrium. The neoatrium is created by suturing the pericardium to the epicardium of the left atrium, completely circumscribing the opening in the left atrium and PVs so that the PV effluent is contained by pericardium. The reconstruction is From the Division of Cardiovascular Surgery, Department of Surgery, Hospital of Sick Children, and University of Toronto Faculty of Medicine, Toronto, Ontario, Canada.

Hypoxia potentiates exercise-induced sympathetic neural activation in humans

Our purpose was to test the hypothesis that hypoxia potentiates exercise-induced sympathetic neural activation in humans. In 15 young (20-30 yr) healthy subjects, lower leg muscle sympathetic nerve activity (MSNA, peroneal nerve; microneurography), venous plasma norepinephrine (PNE) concentrations, heart rate, and arterial blood pressure were measured at rest and in response to rhythmic handgrip exercise performed during normoxia or isocapnic hypoxia (inspired O2 concn of 10%). Study I (n = 7): Brief (3-4 min) hypoxia at rest did not alter MSNA, PNE, or arterial pressure but did induce tachycardia [17 +/- 3 (SE) beats/min; P less than 0.05]. During exercise at 50% of maximum, the increases in MSNA (346 +/- 81 vs. 207 +/- 14% of control), PNE (175 +/- 25 vs. 120 +/- 11% of control), and heart rate (36 +/- 2 vs. 20 +/- 2 beats/min) were greater during hypoxia than during normoxia (P less than 0.05), whereas the arterial pressure response was not different (26 +/- 4 vs. 25 +/- 4 mmHg). The increase in MSNA during hypoxic exercise also was greater than the simple sum of the separate responses to hypoxia and normoxic exercise (P less than 0.05). Study II (n = 8): In contrast to study I, during 2 min of exercise (30% max) performed under conditions of circulatory arrest and 2 min of postexercise circulatory arrest (local ischemia), the MSNA and PNE responses were similar during systemic hypoxia and normoxia. Arm ischemia without exercise had no influence on any variable during hypoxia or normoxia.(ABSTRACT TRUNCATED AT 250 WORDS)