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1.
Eur Heart J Case Rep ; 6(3): ytac107, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35474681

ABSTRACT

Background: Complete embolization of a prosthetic heart valve is extremely rare and dangerous. This case reports a total embolization of a mechanical aortic valve and contributes to the literature regarding the diagnostic challenges related to infective endocarditis and follow-up after valvular surgery. Case summary: A 28-year-old male 11.5 years status-post a mechanical aortic valve replacement presented with acute onset of chest pain and dyspnoea while jogging. The patient lost consciousness and went into cardiopulmonary arrest with acute pulmonary oedema and circulatory shock. An echocardiogram revealed an empty aortic annulus, and a chest radiograph showed an embolized valve in the aortic arch. The patient underwent emergent removal of the embolized valve and replacement with a new mechanical aortic valve. The patient survived with minimal sequelae. At a 3-month follow-up, he had resumed work, and the only sequelae were mild left ventricular dysfunction and minor vision loss. Although he experienced no warning signs or symptoms, the most likely aetiology for embolization of the valvular prosthesis was infective endocarditis, which was revealed by re-evaluation of an echocardiogram recorded 1 month before the presentation which demonstrated a subtle motion abnormality of the valve. Conclusions: We present a case of a late complete embolization of a mechanical aortic valve most likely caused by asymptomatic infective endocarditis. The case illustrates the challenges in follow-up after valvular surgery and highlights the ultimate benefit of a well-functioning pre-hospital to hospital chain.

2.
BMJ Case Rep ; 14(11)2021 Nov 11.
Article in English | MEDLINE | ID: mdl-34764116

ABSTRACT

Infective endocarditis (IE) is associated with severe complications and a high mortality rate. Identification of the causative pathogen is crucial to optimise treatment. We present a case of prosthetic valve endocarditis caused by Corynebacterium freneyi, a very rare cause of human infection and not previously reported as a cause of IE. Despite proper antibiotic therapy, the patient eventually needed surgery after progression of the infection. After surgery, he quickly recovered without evidence of relapse during an 8-month follow-up period. This report highlights critical decision making in a complex and potentially life-threatening situation, where neither guidelines nor previous clinical or microbiological experience were able to give clear treatment recommendations.


Subject(s)
Endocarditis, Bacterial , Endocarditis , Heart Valve Prosthesis , Prosthesis-Related Infections , Corynebacterium , Endocarditis, Bacterial/diagnosis , Endocarditis, Bacterial/drug therapy , Heart Valve Prosthesis/adverse effects , Humans , Male , Prosthesis-Related Infections/diagnosis , Prosthesis-Related Infections/drug therapy
3.
Cardiol J ; 27(5): 518-523, 2020.
Article in English | MEDLINE | ID: mdl-30444258

ABSTRACT

BACKGROUND: Optical coherence tomography (OCT) is a high-resolution imaging modality able to provide near-histological images of vessel walls making it possible to distinguish intima and media layers of the vessel wall separately. The use of this imaging technique is increasing while data on the variability and reliability is lacking. The aim of this study was to investigate the reproducibility of frequency-domain OCT in vein grafts used for coronary revascularization. METHODS: Five pullbacks were analyzed by the same analyst with a 1-month delay (intraobserver) and by two different analysts (interobserver). Five pairs of pullbacks from the same catheters and vein graft were also analyzed (inter pullback). RESULTS: Optical coherence tomography showed low variability in intra- and interobserver analysis with relative differences of mean media and intima thicknesses and areas of less than 5% for most parameters. Relative differences of the same parameters in the inter pullback analysis were in the 5-15% range. Intra- and interobserver reliability was excellent (intraclass correlation coefficient [ICC] > 0.90) for intima thickness and intima, media and intima-media area measurements. Inter pullback reliability was good (ICC: 0.75-0.90) for intima and intima-media area measurements, and moderate to good for mean intima thickness measurements (ICC: 0.79; 0.7338-0.8284). CONCLUSIONS: Optical coherence tomography provides good reproducibility for the measurements of parameters relevant for the development of atherosclerosis in vein grafts. CLINICAL TRIAL REGISTRATION: ID NCT01834846.


Subject(s)
Tomography, Optical Coherence , Humans , Observer Variation , Reproducibility of Results
4.
Clin Respir J ; 12(1): 40-47, 2018 Jan.
Article in English | MEDLINE | ID: mdl-26954393

ABSTRACT

INTRODUCTION: Endobronchial ultrasound with transbronchial needle aspiration (EBUS-TBNA) has become an important diagnostic tool for the pulmonologist. Learning this procedure and maintaining technical skills requires continuous practice and evaluation. OBJECTIVES: The aims of the study were a retrospective evaluation of the diagnostic quality of the EBUS-technique and the learning profile of the endoscopy team during the first years (2007-2013) of experience in an unselected population. METHODS: EBUS-TBNA procedures were analysed for clinical data, including results from surgery or clinical/radiological follow-up for at least 6 months. Rapid on-site cytological evaluation (ROSE) was introduced on regular basis the forth year. RESULTS: A total of 711 EBUS-TBNA from 635 patients were included. The percentage of representative EBUS-TBNA initially decreased the first years (minimum 60,9%), before increased to a final result of 82,4%. There was a lower proportion of representative EBUS-TBNA in the benign group (76,8%) vs the malignant group (85,8%). A significant increase in the proportion of representative EBUS-TBNA was seen after ROSE had been introduced. The major indications were diagnosing/staging of lung cancer (54%) and mediastinal lymphadenopathy of unknown cause (25,7%). The sensitivity detecting malignancy was 94,9%, negative predictive value 81,2% and diagnostic accuracy 95,8%. During the study period the percentage of re-examinations with EBUS-TBNA declined from 18,0% to 8,2%. CONCLUSION: After an initial run-in period with declining results, the overall diagnostic yield of EBUS-TBNA increased and reached acceptable levels. These results underline the importance of continuously evaluation of our own results when new methods are implemented in clinical practice.


Subject(s)
Clinical Competence , Education, Medical, Graduate , Endoscopic Ultrasound-Guided Fine Needle Aspiration/methods , Learning , Lung Neoplasms/diagnosis , Pulmonary Medicine/education , Adolescent , Adult , Aged , Aged, 80 and over , Bronchi , Child , Female , Follow-Up Studies , Humans , Male , Middle Aged , Retrospective Studies , Time Factors , Young Adult
5.
Ann Thorac Surg ; 104(4): 1313-1317, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28648540

ABSTRACT

BACKGROUND: Less-than-optimal long-term patency of the saphenous vein is one of the main obstacles for the success of coronary artery bypass grafting (CABG). Results from the IMPROVE-CABG trial has shown that harvesting the saphenous vein with a pedicle of perivascular tissue less than 5 mm while using manual distention provides comparable occlusion rates but significantly less intimal hyperplasia at early follow-up. The impact of pedicled veins on duration of operations, leg wound infections, and postoperative bleeding is unknown. METHODS: One hundred patients undergoing first-time elective CABG were randomly assigned to conventional or pedicled vein harvesting. Perioperative and postoperative data were collected prospectively during the hospital stay and at follow-up. RESULTS: Duration of extracorporeal circulation was significantly longer in the pedicled vein group (mean: 76 min versus 65 min, p = 0.006); however, no significant difference was found in the cross-clamp time. No significant difference was found in intraoperative vein graft flow, postoperative bleeding, or leg wound infections (4% in each group). No reoperations were due to vein graft bleeding. CONCLUSIONS: Harvesting a pedicled vein provides comparable postoperative bleeding and leg wound infection rates in selected patients. The technique is associated with a slightly longer duration of extracorporeal circulation than harvesting conventional veins. Promising early results using the pedicled vein technique may contribute to a change in standard vein harvesting technique for CABG in selected patients.


Subject(s)
Coronary Artery Bypass/methods , Saphenous Vein/transplantation , Aged , Coronary Artery Bypass/adverse effects , Female , Humans , Length of Stay , Male , Middle Aged , Postoperative Hemorrhage/etiology , Surgical Wound Infection/etiology , Tissue and Organ Harvesting/methods , Transplantation, Autologous , Vascular Patency
6.
Physiol Rep ; 4(19)2016 10.
Article in English | MEDLINE | ID: mdl-27702881

ABSTRACT

Cardiac power, the product of aortic flow and blood pressure, appears to be a fundamental cardiovascular parameter. The simplified version named cardiac power output (CPO), calculated as the product of cardiac output (CO) in L/min and mean arterial pressure (MAP) in mmHg divided by 451, has shown great ability to predict outcome in a broad spectrum of cardiac disease. Beat-by-beat evaluation of cardiac power (PWR) therefore appears to be a possibly valuable addition when monitoring circulatory unstable patients, providing parameters of overall cardiovascular function. We have developed a minimally invasive system for cardiac power measurement, and aimed in this study to compare this system to an invasive method (ttPWR). Seven male anesthetized farm pigs were included. A laptop with in-house software gathered audio from Doppler signals of aortic flow and blood pressure from the patient monitor to continuously calculate and display a minimally invasive cardiac power trace (uPWR). The time integral per cardiac cycle (uPWR-integral) represents cardiac work, and was compared to the invasive counterpart (ttPWR-integral). Signals were obtained at baseline, during mechanically manipulated preload and afterload, before and after induced global ischemic left ventricular dysfunction. We found that the uPWR-integral overestimated compared to the ttPWR-integral by about 10% (P < 0.001) in both normal hearts and during ventricular dysfunction. Bland-Altman limits of agreement were at +0.060 and -0.054 J, without increasing spread over the range. In conclusion we find that the minimally invasive system follows its invasive counterpart, and is ready for clinical research of cardiac power parameters.


Subject(s)
Blood Pressure/physiology , Cardiac Output/physiology , Counterpulsation/methods , Monitoring, Intraoperative/instrumentation , Monitoring, Intraoperative/methods , Monitoring, Physiologic/methods , Ventricular Dysfunction/physiopathology , Acute Disease , Animals , Aorta/physiology , Arterial Pressure/physiology , Echocardiography, Doppler/methods , Heart Failure/physiopathology , Hemodynamics/physiology , Humans , Male , Predictive Value of Tests , Swine , Ultrasonography, Doppler/methods , Ventricular Function, Left/physiology
8.
J Cardiothorac Vasc Anesth ; 29(2): 367-73, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25529437

ABSTRACT

OBJECTIVE: To assess the effect of coronary artery bypass grafting with cardiopulmonary bypass on muscle perfusion, oxygen extraction, and lactate release during postoperative rest and exercise. DESIGN: Prospective observational study. SETTING: University hospital. PARTICIPANTS: Patients undergoing planned coronary artery bypass grafting. INTERVENTION: Knee-extensor exercise before and after coronary artery bypass grafting. MEASUREMENTS AND MAIN RESULTS: Femoral artery blood flow was measured with ultrasound. Femoral vein blood and arterial blood were sampled at rest and during light exercise and were analyzed for hemoglobin, lactate, oxygen saturation, and oxygen partial pressure. Fourteen patients were tested before and after surgery. The arterial lactate concentrations were increased after surgery, both at rest and during light exercise. Resting arterial lactate increased from 0.65 (0.5-0.8) to 1.0 (0.9-1.3) mmol/L (p=0.01) (median and interquartile range). Furthermore, lactate was released from the leg even during postoperative rest, and the release of lactate was increased during postoperative exercise. There were no significant differences between the preoperative and postoperative femoral artery blood flow. Femoral vein oxygen partial pressure was reduced significantly after surgery, indicating reduced muscle cell oxygen partial pressure. CONCLUSIONS: The patients had elevated anaerobic metabolism in skeletal muscle after surgery to compensate for anemia. Lactate was released from the leg into the general circulation during postoperative rest and exercise. The postoperatively reduced hemoglobin concentration of 11.4 mg/dL (10.6-12.3) resulted in increased anaerobic metabolism and release of lactate from skeletal muscle. The authors concluded that coronary artery bypass grafting patients are susceptible to anaerobic metabolism even with maintained peripheral blood flow.


Subject(s)
Anaerobic Threshold/physiology , Coronary Artery Bypass/trends , Femoral Artery/metabolism , Lactic Acid/blood , Muscle, Skeletal/metabolism , Aged , Biomarkers/blood , Female , Humans , Male , Middle Aged , Postoperative Period , Prospective Studies
9.
Physiol Rep ; 1(6): e00159, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24400160

ABSTRACT

Cardiac power (PWR) is the continuous product of flow and pressure in the proximal aorta. Our aim was to validate the PWR integral as a marker of left ventricular energy transfer to the aorta, by comparing it to stroke work (SW) under multiple different loading and contractility conditions in subjects without obstructions in the left ventricular outflow tract. Six pigs were under general anesthesia equipped with transit time flow probes on their proximal aortas and Millar micromanometer catheters in their descending aortas to measure PWR, and Leycom conductance catheters in their left ventricles to measure SW. The PWR integral was calculated as the time integral of PWR per cardiac cycle. SW was calculated as the area encompassed by the pressure-volume loop (PV loop). The relationship between the PWR integral and SW was tested during extensive mechanical and pharmacological interventions that affected the loading conditions and myocardial contractility. The PWR integral displayed a strong correlation with SW in all pigs (R (2) > 0.95, P < 0.05) under all conditions, using a linear model. Regression analysis and Bland Altman plots also demonstrated a stable relationship. A mixed linear analysis indicated that the slope of the SW-to-PWR-integral relationship was similar among all six animals, whereas loading and contractility conditions tended to affect the slope. The PWR integral followed SW and appeared to be a promising parameter for monitoring the energy transferred from the left ventricle to the aorta. This conclusion motivates further studies to determine whether the PWR integral can be evaluated using less invasive methods, such as echocardiography combined with a radial artery catheter.

10.
Eur J Cardiothorac Surg ; 41(6): 1377-83, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22219475

ABSTRACT

OBJECTIVES: Levosimendan is a novel inotropic agent claimed to improve myocardial contractility by a calcium-sensitizing effect. Our aim was to evaluate dose-dependent effects of levosimendan on left ventricular (LV) contractility and energetic properties in an acute, ischaemic heart failure porcine model. METHODS: Six pigs were used in an anaesthetized in vivo open-chest model. The time points of measurements were: baseline, after heart failure induction and after dose 1-4 (D1-D4). Heart failure was induced by microembolization of the left coronary artery before infusion of four different doses (D1: 2.5 µg/kg, D2: 10 µg/kg, D3: 40 µg/kg, D4: 80 µg/kg) of levosimendan. Haemodynamics were assessed by the pressure-conductance catheter technique. LV oxygen consumption was calculated from coronary flow measurements and coronary sinus blood gases. Mitochondrial respiration was studied in biopsies of the LV. RESULTS: Levosimendan had no significant, load-independent effect on contractile force (slope of preload recruitable stroke work was 34 mmHg immediately following failure and 39 (P = 0.406), 42 (P = 0.219), 46 (P = 0.067) and 41 (P = 0.267) at D1-D4), although the more load-dependent contractility indicator of dP/dt(max) was slightly increased at dose 4 (P < 0.05). LV energy conversion efficiency (PVA-MVO2 relationship) remained unaltered at all doses. Maximal mitochondrial respiration decreased after induction of failure and remained at an unaltered low level during levosimendan infusion. CONCLUSIONS: Surprisingly, levosimendan had no significant effect on contractility, energy efficiency and mitochondrial respiration of the LV, in a porcine model of acute heart failure. At high doses, levosimendan induced vasodilatation and increased heart rate and cardiac output.


Subject(s)
Cardiotonic Agents/administration & dosage , Heart Failure/physiopathology , Hydrazones/administration & dosage , Pyridazines/administration & dosage , Animals , Cardiotonic Agents/pharmacology , Disease Models, Animal , Dose-Response Relationship, Drug , Female , Heart Failure/etiology , Hemodynamics/drug effects , Hemodynamics/physiology , Hydrazones/pharmacology , Mitochondria, Heart/drug effects , Mitochondria, Heart/physiology , Myocardial Contraction/drug effects , Myocardial Contraction/physiology , Oxygen Consumption/drug effects , Oxygen Consumption/physiology , Pyridazines/pharmacology , Simendan , Sus scrofa , Ventricular Function, Left/drug effects , Ventricular Function, Left/physiology
11.
Scand Cardiovasc J ; 44(5): 301-6, 2010 Oct.
Article in English | MEDLINE | ID: mdl-21080848

ABSTRACT

OBJECTIVES: Freedom Solo is a stentless biological aortic valve which is implanted supra-annularly with a single suture line. An increased risk of postoperative thrombocytopenia in the early postoperative period has been reported in recent studies. In our study we evaluated postoperative haemodynamic performance and thrombocyte-levels. DESIGN: Thirty seven patients who underwent valve implantation of the Sorin Freedom Solo stentless valve were included. The haemodynamic performance of the valve was evaluated by transthoracic echocardiography postoperatively at the fourth day (mean) and after a median of 4.2 months. RESULTS: The mean gradient (mmHg) of Freedom Solo was 7.5 at four days and 8.6 at 4.2 months. Postoperatively no patient had more than grade 1 leakage. Seven percent of the patients had a reduction of thrombocytes to less than 20% of the preoperative level. Seventy six percent had a minimum postoperative thrombocyte level less than 100*10(9)/L. The 30 days mortality in our patient material was zero. CONCLUSIONS: Implantation of the Freedom Solo valve was uncomplicated in our experience. Favourable transvalvular gradients and no significant leaks were found. In accordance with the literature, we found a high percentage of patients having a postoperative level of thrombocytes less than 100*10(9)/L after implantation of Freedom Solo.


Subject(s)
Aortic Valve , Bioprosthesis , Heart Valve Prosthesis Implantation , Heart Valve Prosthesis , Aged , Bioprosthesis/adverse effects , Echocardiography , Female , Follow-Up Studies , Heart Valve Prosthesis/adverse effects , Heart Valve Prosthesis Implantation/adverse effects , Hemodynamics/physiology , Humans , Male , Prosthesis Design , Retrospective Studies , Thrombocytopenia/etiology , Treatment Outcome
12.
Cardiovasc Res ; 88(3): 512-9, 2010 Dec 01.
Article in English | MEDLINE | ID: mdl-20581004

ABSTRACT

AIMS: Competitive flow from native coronary vessels is considered a major factor in the failure of coronary bypass grafts. However, the pathophysiological effects are not fully understood. Low and oscillatory wall shear stress (WSS) is known to induce endothelial dysfunction and vascular disease, like atherosclerosis and intimal hyperplasia. The aim was to investigate the impact of competitive flow on WSS in mammary artery bypass grafts. METHODS AND RESULTS: Using computational fluid dynamics, WSS was calculated in a left internal mammary artery (LIMA) graft to the left anterior descending artery in a three-dimensional in vivo porcine coronary artery bypass graft model. The following conditions were investigated: high competitive flow (non-significant coronary lesion), partial competitive flow (significant coronary lesion), and no competitive flow (totally occluded coronary vessel). Time-averaged WSS of LIMA at high, partial, and no competitive flow were 0.3-0.6, 0.6-3.0, and 0.9-3.0 Pa, respectively. Further, oscillatory WSS quantified as the oscillatory shear index (OSI) ranged from (maximum OSI = 0.5 equals zero net WSS) 0.15 to 0.35, <0.05, and <0.05, respectively. Thus, high competitive flow resulted in substantial oscillatory and low WSS. Moderate competitive flow resulted in WSS and OSI similar to the no competitive flow condition. CONCLUSION: Graft flow is highly dependent on the degree of competitive flow. High competitive flow was found to produce unfavourable WSS consistent with endothelial dysfunction and subsequent graft narrowing and failure. Partial competitive flow, however, may be better tolerated as it was found to be similar to the ideal condition of no competitive flow.


Subject(s)
Coronary Artery Bypass , Coronary Vessels/physiology , Hydrodynamics , Mammary Arteries/physiology , Models, Cardiovascular , Regional Blood Flow/physiology , Stress, Mechanical , Anastomosis, Surgical , Animals , Blood Flow Velocity/physiology , Coronary Vessels/surgery , Endothelium, Vascular/physiopathology , Mammary Arteries/transplantation , Models, Animal , Shear Strength , Swine
13.
Eur J Cardiothorac Surg ; 36(6): 1024-30, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19592266

ABSTRACT

OBJECTIVE: Levosimendan is a calcium-sensitising inotropic agent and a vasodilator used in the treatment of heart failure. Post-cardiotomy cardiac failure is more common in patients with a low preoperative left ventricular ejection fraction (LVEF). We aim at investigating how prophylactic treatment with levosimendan before weaning from cardiopulmonary bypass (CPB) affects postoperative haemodynamics and outcome in patients with low preoperative LVEF. METHODS: Patients with a preoperative LVEF < or =30% treated with levosimendan before weaning from CPB were included in the study. Each patient was matched to a control patient with respect to the following criteria: surgical procedure, EuroSCORE, age, gender and the use of intra-aortic balloon pump. We investigated postoperative haemodynamics in the intensive care unit (ICU) at time points: 1, arrival; 2, approximately 7h after arrival; and 3, the first postoperative morning. In addition, mortality was evaluated. RESULTS: Thirty patients treated with levosimendan and 30 matched controls were enrolled in the study. No statistically significant differences in cardiac index (CI) (l min(-1)m(-2)), stroke volume index (SVI) (mlm(-2)), mixed venous O(2)-saturation (SvO(2)) (%) or heart rate (HR) (beats per minute) between the two groups measured at the three time points 1-3 were registered. Mean arterial blood pressure (MAP) (mmHg) was lower in the levosimendan group both at time points 2 (68, range: 65-71 vs 75, range: 72-78; p=0.009) and 3 (72, range: 69-74 vs 78, range: 74-82; p=0.01), despite a higher dose of norepinephrine in the treatment group (p=0.021). A significantly higher number of control patients were treated with classic adrenergic inotropes both in the operating room (p=0.013) and in the ICU (p<0.001). Thirty days mortality was the same in both groups (7%). CONCLUSIONS: Prophylactic infusion of levosimendan initiated before weaning from CPB did not lead to superior haemodynamic parameters (CI, SVI, SvO(2)) compared to controls. Levosimendan reduced MAP and increased the need for norepinephrine postoperatively.


Subject(s)
Cardiopulmonary Bypass/adverse effects , Heart Failure/prevention & control , Hydrazones/therapeutic use , Pyridazines/therapeutic use , Vasodilator Agents/therapeutic use , Ventricular Dysfunction, Left/drug therapy , Aged , Cardiotonic Agents/therapeutic use , Case-Control Studies , Drug Administration Schedule , Drug Evaluation/methods , Female , Heart Failure/etiology , Hemodynamics/drug effects , Humans , Hydrazones/administration & dosage , Male , Middle Aged , Norepinephrine/therapeutic use , Phosphodiesterase Inhibitors/administration & dosage , Phosphodiesterase Inhibitors/therapeutic use , Preanesthetic Medication , Pyridazines/administration & dosage , Retrospective Studies , Simendan , Stroke Volume/drug effects , Vasodilator Agents/administration & dosage , Ventricular Dysfunction, Left/physiopathology
14.
Eur J Cardiothorac Surg ; 36(1): 137-42; discussion 142, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19376731

ABSTRACT

OBJECTIVE: To assess whether coronary graft flow patterns are affected differently by native coronary competitive flow or by stenosis of the coronary anastomosis. METHODS: Nine pigs (65-70 kg) underwent off-pump grafting of the left internal mammary artery to the left anterior descending artery (LAD). Transit-time flow patterns in the mammary grafts were recorded under four different conditions: (1) baseline flow (proximal LAD occluded), (2) full competitive flow, (3) partial competitive flow and (4) after creation of a stenosis in the anastomosis. Competitive flow was achieved by an adjustable occluder on the left anterior descending artery. The mean luminal stenosis of the anastomosis was 75+/-11%, calculated by epicardial ultrasound. Mean flow, systolic and diastolic antegrade and retrograde flow during different flow conditions were calculated as ratios of baseline flow and compared. Different derived flow indexes were calculated and compared in the same manner. Friedman's test and post hoc analyses by Wilcoxon signed-ranks were performed without correction for multiple comparisons. RESULTS: Mean graft flow was more reduced by competitive flow than by a stenotic anastomosis of 75+/-11%. Competitive flow significantly decreased diastolic antegrade flow and both diastolic and systolic maximum peak flows, but increased retrograde flow, compared with baseline and stenosis. Furthermore, competitive flow and stenosis could be distinguished by analysis of several derived indexes. Pulsatility index (maximum-minimum flow/mean flow) and insufficiency percent (retrograde flow as fraction of total flow) was increased significantly more by competitive flow than by stenosis. Diastolic filling percent was significantly reduced at competitive flow compared with stenosis and baseline. CONCLUSIONS: The mammary graft flow was significantly reduced by native coronary competitive flow, but marginally decreased by a stenotic anastomosis of 75% mean luminal stenosis. Reduction of graft flow due to competition was particularly evident in diastole. A detailed flow pattern analysis may differentiate between competitive flow and stenosis of the anastomosis.


Subject(s)
Coronary Artery Bypass, Off-Pump , Coronary Circulation , Coronary Restenosis/physiopathology , Internal Mammary-Coronary Artery Anastomosis , Animals , Coronary Restenosis/diagnostic imaging , Disease Models, Animal , Mammary Arteries/physiopathology , Pulsatile Flow , Rheology/methods , Sus scrofa , Ultrasonography
15.
Tidsskr Nor Laegeforen ; 127(11): 1496-9, 2007 May 31.
Article in Norwegian | MEDLINE | ID: mdl-17551552

ABSTRACT

BACKGROUND: The purpose of this study was to establish patient characteristics and the severity and extent of thoracic injury for patients referred to a Norwegian regional trauma centre. MATERIAL AND METHODS: All patients (n = 436) treated for thoracic injuries at St. Olavs University Hospital between 01.01. 2003 and 31.12. 2004 were analysed retrospectively. The patients were identified from the hospital diagnosis registry by ICD-10 codes. RESULTS: Traffic accidents and falls accounted for 92% of all injuries. The most common thoracic injury was rib fracture (55%) and the most common internal thoracic injury was pneumothorax (24%). About half of the patients (221/446) had associated extra-thoracic injuries. Observation and pain relief was the only treatment in 290 patients. Chest tube was the most common treatment, and was used in 88 cases (20%). 50 patients (12%) received ventilator treatment. Nine patients underwent thoracic surgery, four of these died. In-hospital mortality was 5% (20/436 patients). Head injury and bleeding from internal organs were the most frequent causes of death. CONCLUSIONS: Thoracic injuries are a frequent challenge at St. Olavs University Hospital. Many patients have both thoracic and extra-thoracic injuries. Mortality is related to the severity of the injury, advanced age and comorbidity.


Subject(s)
Thoracic Injuries/epidemiology , Accidents, Traffic , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Hospital Mortality , Humans , Injury Severity Score , Male , Middle Aged , Pneumothorax/diagnosis , Pneumothorax/epidemiology , Pneumothorax/therapy , Retrospective Studies , Rib Fractures/diagnosis , Rib Fractures/epidemiology , Rib Fractures/therapy , Thoracic Injuries/diagnosis , Thoracic Injuries/therapy , Trauma Centers
16.
Eur J Cardiothorac Surg ; 31(4): 677-84, 2007 Apr.
Article in English | MEDLINE | ID: mdl-17303433

ABSTRACT

OBJECTIVE: The time constant of mechanical restitution (T((MRC))), proposed to reflect changes in calcium release and uptake, has been shown to increase in left ventricular (LV) failure, and might have a potential as an index of contractile function. However, in vivo studies of the effect on T((MRC)) of changing loading conditions in the normal and failing heart have not been reported. Consequently, in this study, we tested the hypothesis that the increase in T((MRC)) in vivo is independent of preload and afterload. METHODS: Left ventricular pressure-volume loops were assessed at baseline in eight open chest pigs using the combined pressure-volume conductance catheter technique during right atrial pacing at 120b/min. Mechanical restitution curves (MRC) were constructed during four different loading conditions in all eight animals: uninfluenced load, reduced preload (balloon catheter in v. cava inferior), increased afterload (balloon catheter in descending aorta), and increased preload combined with reduced afterload (aortocaval shunting). Acute LV failure was then induced by microembolization through the left main coronary artery, and the experimental protocol was repeated. Contractile response was defined as the maximal first derivative of pressure (dP/dt(max)), and T((MRC)) was calculated using a least square approximation algorithm. RESULTS: Hemodynamic data 30min after microembolization showed decreased mean arterial pressure (98+/-14-67+/-10mmHg, (mean+/-SD) P<0.0001) and dP/dt(max) (1482+/-193-1001+/-125mmHg/s, P=0.001). Stroke volume decreased from 30+/-5 to 20+/-5ml (P<0.0001) compared to baseline, and preload recruitable stroke work decreased from 52+/-7 to 31+/-10mmHg (P=0.002). T((MRC)) increased in all eight animals after induction of LV failure at all loading conditions. There was no difference between the different loading conditions at baseline, nor at LV heart failure, but T((MRC)) increased significantly after the induction of heart failure (ANOVA, two ways). CONCLUSIONS: We have shown that the left ventricular T((MRC)) increases after developed heart failure. The increase in T((MRC)) was independent on loading conditions and thus have a potential for a contractility index.


Subject(s)
Myocardial Contraction/physiology , Animals , Blood Pressure/physiology , Cardiac Output, Low/physiopathology , Cardiac Pacing, Artificial/methods , Coronary Circulation/physiology , Female , Heart Function Tests/methods , Male , Models, Biological , Myocardial Ischemia/physiopathology , Stress, Mechanical , Stroke Volume/physiology , Swine , Ventricular Dysfunction, Left/physiopathology
17.
Shock ; 25(4): 370-6, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16670639

ABSTRACT

UNLABELLED: Our previous studies indicate that left ventricular end-systolic pressure-volume relations (ESPVRs) or elastance (Ees) are not reduced in studies where expected reductions of contractility should be found (i.e., heart failure, stunning, and endotoxemia). The present study was done to assess whether this phenomenon is due to a particular load sensitivity of elastance, rendering this index inappropriate as a measurement of contractility in pathologic states in vivo. METHODS AND RESULTS: Analysis of previously generated data revealed an increased ESPVR in stunned hearts, in pigs made endotoxemic, and in hearts rapidly paced. After inducing acute heart failure by microembolization, the ESPVR was increased when assessed using linear relations but reduced when assessing ESPVR by a curvilinear algorithm. To further evaluate the effect of different load alterations on ESPVR, this relation was generated by (i) inferior vena caval occlusions (VCOs); (ii) gradually occluding the descending aorta (pressure interventions); and (iii) rapidly infusing blood (120 mL) into the left atrium (volume increments). The load protocol was applied in 5 pigs, before and after the left ventricle was stunned by 11 brief left main coronary artery occlusions/reperfusions (accumulated ischemia 20 min affecting 81% of the left ventricle). Correlation coefficients for left ventricular elastance ranged from 0.93 to 0.99 in all the 3 types of loading interventions. Despite significant reductions in stroke volume, stroke work, and dP/dtmax, VCO-calculated linear and curvilinear Ees increased 90 min after stunning (55% +/- 4% and 94% +/- 6%, respectively). Linear Ees during pressure interventions decreased 36% +/- 1%, whereas curvilinear Ees decreased 33% +/- 3%. During volume infusions, linear Ees decreased 27% +/- 2%. We achieved the same results after blocking the baroreceptor reflexes using hexamethonium. CONCLUSIONS: The Ees is particularly load dependent and will reflect load interventions more than the inotropic state of the cardiac muscle. A VCO-generated Ees increase could be an unmasking of a pronounced preload sensitivity in failing myocardium.


Subject(s)
Cardiac Output, Low/physiopathology , Cardiology/methods , Heart Failure/physiopathology , Myocardial Contraction/physiology , Animals , Cardiology/instrumentation , Data Interpretation, Statistical , Myocardial Stunning/physiopathology , Swine
18.
Interact Cardiovasc Thorac Surg ; 5(5): 608-10, 2006 Oct.
Article in English | MEDLINE | ID: mdl-17670659

ABSTRACT

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was what the long-term results of cardiac valve replacements are in left sided endocarditis with a history of i.v. drug abuse? A total of 286 publications were found using the reported search, of which nine presented the best evidence to answer the clinical question. The author, journal, date and country of publication, patients group studied, study type, relevant outcomes, results, and study weaknesses of these papers were tabulated. We conclude that cardiac valve replacement for left sided endocarditis in i.v. drug users carries a substantial mortality. Continued drug abuse is the commonest cause of death in this patient group. In contrast, the type of valve used to perform the replacement does not seem to influence mortality. Postoperative management should focus on treatment of the drug addiction.

19.
Scand Cardiovasc J ; 39(1-2): 107-14, 2005 Apr.
Article in English | MEDLINE | ID: mdl-16097424

ABSTRACT

OBJECTIVES: The time constant of mechanical restitution (T(MRC)), proposed to reflect changes in calcium release and uptake, has been shown to increase in left ventricular (LV) failure. In this study, we tested the hypothesis that T(MRC) also can identify post-ischemic, reversible LV dysfunction (stunning). DESIGN: Stunning was induced by a series of left main coronary artery occlusions in eight anesthetized open chest pigs. Left ventricular pressure-volume relations were assessed using a pressure-volume catheter during right atrial pacing. Mechanical restitution curves (MRCs) were constructed using two different measures of contractile response: maximal first derivative of pressure (CR(dP/dtmax)) and stroke work (CR(SW)). RESULTS: Mean arterial pressure, stroke volume and dP/dtmax were decreased 30 min after stunning. Slopes of end-systolic pressure volume relation and preload recruitable stroke work, however, showed no significant changes after stunning. For MRCs based on CR(dP/dtmax), T(MRC) increased in all eight animals. Using CR(SW), T(MRC) increased in seven out of eight pigs. CONCLUSIONS: Ischemia-reperfusion induce changes in MRCs based on CR(dP/dtmax), and CR(SW). The MRC concept may have potential as a clinical left ventricular performance index.


Subject(s)
Hemodynamics/physiology , Myocardial Ischemia/therapy , Myocardial Reperfusion/methods , Myocardial Stunning , Animals , Cardiac Catheterization , Disease Models, Animal , Female , Male , Myocardial Contraction/physiology , Myocardial Ischemia/physiopathology , Random Allocation , Sensitivity and Specificity , Stroke Volume/physiology , Swine
20.
Eur J Heart Fail ; 6(6): 705-13, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15542405

ABSTRACT

BACKGROUND AND AIMS: The effect of nitric oxide (NO) manipulation in acute heart failure has not been sufficiently investigated. Therefore, we assessed the impact of NO-synthase (NOS) inhibition on left ventricular (LV) function and energetics as well as overall hemodynamics, in a porcine model of acute ischemic LV failure. METHODS: Acute heart failure was induced by left coronary artery microembolization in fourteen anesthetized pigs. LV pressure-volume relationships and mechanical work (PVA) were assessed 30 min after stable heart failure, using pressure-conductance catheters. Myocardial oxygen consumption (MVO(2)) was determined from coronary flow and coronary arteriovenous oxygen difference. Microembolization led to a significant decrease in cardiac output, arterial pressure and LV systolic and diastolic performance. Animals were then randomized to a control group (n=7) or to receive 15 mg/kg N(omega)-Nitro-L-arginine-metyl ester (n=7), an inhibitor of NO synthase (NOS). RESULTS: Measurements 15 min later revealed that NOS inhibited animals had significantly reduced cardiac output (1.53+/-0.45 vs. 2.13+/-0.49 l/min, P=0.003) and stroke work (1054+/-461 vs. 1296+/-348 mmHg ml, P=0.03), and also displayed a significant increase in the slope of the MVO(2)-PVA relationship (2.57+/-0.53 vs. 1.92+/-0.15, P=0.008), i.e. an inefficient chemomechanical coupling. NOS inhibition did not alter contractility, diastolic function or arterial pressure, but afterload was significantly increased compared to controls (arterial elastance 6.03+/-1.48 vs. 2.74+/-0.34 mmHg/ml, P=0.009). CONCLUSION: Inhibition of NOS in experimental acute heart failure increased afterload without altering left ventricular systolic and diastolic function. Consequently, cardiac output was reduced. Furthermore, mechanoenergetic efficiency was severely impaired. NOS inhibition in acute heart failure and cardiogenic shock warrants further investigations.


Subject(s)
Myocardial Ischemia/physiopathology , Nitric Oxide Synthase/antagonists & inhibitors , Ventricular Function, Left/physiology , Animals , Blood Pressure , Cardiac Output , Energy Metabolism , Male , Oxygen Consumption , Random Allocation , Swine
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