Anna Lewczuk

Myocardial perfusion assessed by contrast echocardiography correlates with angiographic perfusion parameters in patients with a first acute myocardial infarction successfully treated with angioplasty

BACKGROUND Angiographic flow in an epicardial artery does not define perfusion at the microvascular level. AIM To compare myocardial contrast echocardiography (MCE) with angiographic methods of assessing microvascular reperfusion in patients with acute myocardial infarction (AMI). METHODS One hundred consecutive patients with a first ST segment elevation myocardial infarction and single-vessel disease were successfully treated with primary percutaneous coronary intervention. Regional contrast score index (RCSI), corrected Thrombolysis In Myocardial Infarction (TIMI) frame count (cTFC), TIMI myocardial perfusion grade (TMPG) and myocardial blush grade were evaluated. RESULTS Among 717 asynergic segments on MCE, 168 revealed a lack of perfusion. TMPG and cTFC correlated significantly with RCSI (P=0.031 and P=0.027, respectively). Myocardial blush grade did not correlate with RCSI (P=0.067). Patients with anterior AMI had significantly more segments with a perfusion defect on MCE than patients with inferior AMI (P=0.0001). CONCLUSIONS MCE results correlate with angiographic methods of perfusion assessment such as TMPG and cTFC. Anterior AMI is associated with a greater extent of perfusion defect. MCE results correlate also with recovery of systolic left ventricular function and clinical outcome at six month follow-up.

Thrombocytopenia and perioperative complications after stentless Freedom Solo valve implantation.

BACKGROUND Freedom Solo (FS) stentless bioprostheses have superior haemodynamic performance compared to stented valves; however, the data of thrombocytopenia after FS implantations is disturbing. AIM To compare platelet count and perioperative complications between stentless and stented biological valves in patients undergoing aortic valve replacement. METHODS In 29 patients, FS bovine valves (Sorin Group, Saluggia, Italy) were implanted. Platelet counts were analysed before surgery, on the day of operation, on four consecutive postoperative days (POD) as well as at discharge, and compared to 29 control patients with biological stented porcine valves (Labcor Laboratorios TLBP-A Supra). The analysis of the perioperative variables extracorporeal circulation (ECC), aortic cross clamping (XC) and mechanical ventilation times, as well as blood supply, was performed. RESULTS Initial platelet counts were comparable in both groups. In the FS group, platelet levels on the four consecutive POD were significantly lower. The lowest platelet value (13 × 10³/μL), related to fatal thrombotic thrombocytopenic purpura, was found in one patient from the FS group. ECC as well as XC and mechanical ventilation times, were significantly longer in the FS group, and more blood transfusions in these patients were required. In multiple regression analysis, ECC and XC times did not correlate with platelet count. CONCLUSIONS Implantations of FS stentless bioprostheses are related to significantly lower platelet counts. Severe perioperative complications and their relation to thrombocytopenia need further evaluation.

Perfusion assessed by real-time contrast echocardiography correlates with clinical and echocardiographic parameters in patients with first STEMI treated with PCI - 6-month follow-up.

Introduction Angiographic flow in an epicardial artery does not define perfusion at a microvascular level in patients with acute myocardial infarction (AMI). The aim of the study was assessing microvascular reperfusion by myocardial contrast echocardiography (MCE) and left ventricular (LV) functional recovery by echocardiographic methods in patients treated with primary PTCA. Material and methods 100 consecutive patients with first ST-elevation AMI with single vessel disease treated successfully with primary PCI were enrolled. Regional contrast score index (RCSI), ejection fraction (EF), wall motion score index (WMSI), and end-systolic and end-diastolic volume (ESV, EDV) were evaluated during hospitalization and at 6-month follow-up. The patients were divided into 2 groups according to the absence (Group 1) or presence (Group 2) of perfusion defects on MCE. Results Group 1 had lower WMSI (p = 0.0009), higher EF than Group 2 (44.7 and 55.9% respectively, p = 0.000067), and lower ESV (66.0 and 52.6 ml respectively, p = 0.003185). In Group 1 LVEF increased significantly on 6-month follow-up (p = 0.026), while in Group 2 it decreased (p = 0.0175). Both EDV and ESV were significantly lower in Group 1 (p = 0.0106 and p = 0.002882, respectively). There was a correlation between the presence of perfusion defects in the initial contrast echo and unfavourable change in ejection fraction during the follow-up (ANOVA for repeated measures, F[1.91] = 5.85, p = 0.0175). The combined clinical end-point (death and reinfarction) was significantly lower in patients without perfusion defect (p = 0.039). Conclusions Myocardial contrast echocardiography results correlated with clinical outcome and recovery of systolic left ventricular function at 6-month follow-up.

Effect of on-pump versus off-pump coronary bypass surgery on cardiac function assessed by intraoperative transesophageal echocardiography.

PURPOSE To compare cardiac function assessed by intraoperative transesophageal echocardiography in patients undergoing cardiac revascularization with or without cardiopulmonary bypass. MATERIAL AND METHODS Forty-one patients scheduled for elective, isolated cardiac revascularization (21 on-pump and 20 off-pump) were prospectively analyzed. Patients were matched for demographic (age and gender), anthropometric (BMI), clinical (co-morbidities, EuroScore) and laboratory variables (blood counts, renal function, left ventricular function). Transesophageal echocardiography was performed after induction of anesthesia, protamine sulfate administration, and chest closure. Left ventricular wall motion score index, end-diastolic area, fractional area change, right ventricular area change and end-diastolic area were assessed. Troponin I and C-reactive protein concentrations were measured. RESULTS Regarding echocardiographic parameters of left and right ventricular function no significant differences between on-pump and off-pump groups at any point-of-time measurements were found. Troponin I and C-reactive protein were higher in on-pump as compared to off-pump group (p=0.001 and p=0.002; p=0.003 and p=0.001, respectively). CONCLUSIONS In elective patients scheduled for cardiac revascularization there were no difference in cardiac performance assessed by intraoperative echocardiography regardless of surgical method used.

Silent pulmonary embolism in a patient with acute myocardial infarction and type B acute aortic dissection - a case report

A 69-year-old man while being treated for type B aortic dissection was also found to have acute myocardial infarction. The patient initially was treated conservatively. Prophylactic anticoagulant treatment of potential thrombosis was not given because of aortic dissection. Stent-graft implantation to the thoracic aorta was considered at the time. Unexpectedly, elective computer tomography (CT), revealed 2 large thrombi at the bifurcation of the pulmonary trunk. The patient did not show any symptoms of pulmonary embolism. Heparin therapy was initiated immediately. The patient responded well to the therapy and on transesophageal echocardiography and subsequent CT no embolic material was found. Since that time, the patient is receiving oral anticoagulation. The case we present raises the question of anticoagulation prophylaxis in the presence of aortic dissection in bedridden patients. Failure to use such therapy in our patient could have resulted in an unfavorable clinical outcome.

Blood flow velocity in the middle cerebral artery during transnasal endoscopic skull base surgery performed in controlled hypotension.

BACKGROUND AND PURPOSE To assess blood flow velocity in the middle cerebral artery (MCA) during transnasal endoscopic procedures performed with decreased hemodynamic parameters. MATERIALS AND METHODS In 40 patients who underwent endoscopic skull base surgery in controlled hypotension (studied group) and in 13 patients operated without reduction of hemodynamic parameters (control group), blood flow velocity in MCA was assessed with transcranial color Doppler sonography. RESULTS Blood flow velocity in MCA remained within the range of age-specific reference values in all patients before operation. It decreased significantly in both groups after induction of anesthesia and then dropped even further in studied group of patients when hemodynamic parameters were reduced; the systolic velocity fell below the normal reference values in 25% of patients, the mean velocity in 50% and the diastolic velocity in 57% of patients. The diastolic velocity was much more heavily influenced by diminished hemodynamic parameters than systolic velocity in the studied group as opposed to the control group where reduction of blood flow velocity pertained equally systolic and diastolic velocity. CONCLUSION During transnasal endoscopic procedures performed in moderate hypotension, in addition to significant drop of blood flow velocity to values well below the normal reference range, a divergent reduction of systolic and diastolic velocity was detected. Since divergent systolic and diastolic velocity may indicate an early phase of cerebral autoregulation compromise, and the decrease of mean blood flow velocity in MCA corresponds with a decrease of cerebral blood flow, further investigations in this field seem warranted.

Is it safe to decrease hemodynamic parameters to achieve bloodless surgical field during transnasal endoscopic procedures? Our experience in fifteen patients

Dear Editor, During transnasal endoscopic operations, precision of surgical treatment is possible only if the intraoperative bleeding is reduced to a minimum. Poor visualisation contributes to elongation of the procedure and may lead to complications. Manoeuvres like putting the patient in the reverse Trandelenburg position and/or local application of vasoconstrictors prove insufficient for longer or more extensive procedures. In this situation, on surgeon’s request, reduction in the patient’s hemodynamic parameters is performed by anaesthesiologist. Mean arterial blood pressure values between 50 and 150 mmHg are traditionally considered as corresponding to the physiological cerebral autoregulatory plateau. To support thisnotion, a classic studybyLassen canbequoted,who found only insignificant change in cerebral perfusion within this range of pressure in 376 human individuals using inert gas method. What is more, even with further reduction in mean arterial pressure to values of 35–40 mmHg, still sufficient oxygen supply to the brain (as calculated from arteriovenous oxygen difference) can be maintained in normotensive persons, thanks to the mechanism of increased oxygen absorption from circulating blood. Also several clinical series were reported in which heart rate was reduced to 60 bits/min inorder toachievebloodless operativefieldduring endoscopic transnasal procedures. Suchmanoeuvre was proved to be safe because no patient developed any neurological deficit postoperatively. From data like the cited above, one can conclude that reduction in mean arterial pressure in normotensive subjects to 60 mmHgandheart rate to 60 beats/min is generally safe. Nevertheless, with advances in anaesthetic methods,more andmore elderly patientswith different health problems are operated on endoscopically. Apparently, these patients are not likely to tolerate decreased hemodynamic parameters as well as young healthy persons do. Thevelocityof bloodflow in themajor cerebral arteriesmay be assessed with transcranial colour-coded Doppler sonography and has been proved to correlate with cerebral perfusion. In this study, we aimed at assessing changes in blood flow parameters in the middle cerebral artery when bloodless surgical field was achieved by reduction in hemodynamic parameters during transnasal endoscopic procedures.