| 26. |
- Meurling, Carl, et al.
(author)
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Attenuation of electrical remodelling in chronic atrial fibrillation following oral treatment with verapamil
- 1999
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In: Europace. - : Oxford University Press (OUP). - 1532-2092 .- 1099-5129. ; 1:4, s. 234-241
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Journal article (peer-reviewed)abstract
- AIMS: Electrical remodelling with shortening of the atrial refractory period and increased fibrillatory rate occurs after onset of atrial fibrillation and can be attenuated by pre-treatment with intravenous verapamil. The aim of the present study was to investigate whether already established fibrillatory-induced shortening of atrial fibrillatory cycle length could be reversed with oral verapamil. METHODS AND RESULTS: Thirteen patients (nine men; mean age 67 years) with chronic atrial fibrillation (CAF) were studied. The dominant atrial cycle length (DACL) was estimated non-invasively using the frequency analysis of fibrillatory ECG (FAF-ECG) method. Measurements were repeated following treatment with slow release oral verapamil. DACL increased from 147 +/- 13 ms to 156 +/- 21 ms after 1 day (P=0.02), to 164 +/- 18 ms after 5 days (P=0.005) and finally to 160 +/- 16 ms after 6 weeks (P=0.008). CONCLUSION: Long-term oral treatment with verapamil increases the DACL significantly in patients with CAF. The prolongation is evident after 1 day and is further developed during the first 5 days of treatment. Since DACL is believed to be an index of refractoriness, the findings of the present study suggest that this treatment increases the atrial refractory period in patients with CAF.
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| 27. |
- Mokhtari, Arash, et al.
(author)
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Sternal stability at different negative pressures during vacuum-assisted closure therapy
- 2006
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In: Annals of Thoracic Surgery. - : Elsevier BV. - 1552-6259 .- 0003-4975. ; 82:3, s. 1063-1067
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Journal article (peer-reviewed)abstract
- Background. Vacuum-assisted closure (VAC) is a widely used therapy in patients with poststernotomy mediastinitis. The aim of this study was to evaluate sternal stability during VAC application at seven negative pressures (-50 to -200 mm Hg) in a porcine wound model. Methods. Six pigs underwent median sternotomy and 2 steel wires were fixed at each sternal side and connected to a traction device. The device was connected to a force transducer linked to a force recorder. VAC therapy was applied to the wound. At each negative pressure, the length and width of the wound were measured before and after traction was started. Traction was increased stepwise up to 400 N. Results. The diastasis induced by a certain lateral force was similar in wounds treated with -75, -125, and -175 mm Hg. At -75 mm Hg, a significant improvement (p < 0.01) in sternal stability was seen compared with the open-chest setting. This was not further improved at -125 or -175 mm Hg. High negative pressures (-150 to -200 mm Hg) in combination with a high lateral force (> 200 N) increased the risk of separation of the foam from the wound edges, with air leakage or organ rupture as a result. Conclusions. Our results suggest that low negative pressures (-50 to -100 mm Hg) stabilize the sternum as efficiently as high negative pressures (-150 to -200 mm Hg). Low negative pressures (-50 to -100 mm Hg) were more beneficial, however, because no air leakage or organ rupture was observed at these pressures.
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| 28. |
- Olsson, Bertil, et al.
(author)
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Förmaksflimmer - ny kunskap ger nya behandlingsmöjligheter
- 1999
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In: Läkartidningen. - 0023-7205. ; 96:36, s. 3796-3803
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Journal article (peer-reviewed)abstract
- Atrial fibrillation (AF) is the most common cardiac arrhythmia prompting treatment. Advances in our knowledge of the pathophysiology of AF provide the basis for new and improved treatment modalities. Thus, focal excitation and localised impulse conduction defects are possible trigger factors which can be counteracted by focal ablation and pacing synchronisation, respectively. Perpetuation of AF, caused by continuous multisite re-entry, is promoted by successive shortening of repolarisation. Internal defibrillation and anatomical limitation of re-entry are treatments that counteract perpetuation of the arrhythmia. Current knowledge of AF and the application of new treatments are discussed by the Lund AF research group.
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| 29. |
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| 30. |
- Petzina, Rainer, et al.
(author)
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Hemodynamic effects of vacuum-assisted closure therapy in cardiac surgery: assessment using magnetic resonance imaging.
- 2007
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In: Journal of Thoracic and Cardiovascular Surgery. - : Elsevier BV. - 1097-685X .- 0022-5223. ; 133:5, s. 1154-1162
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Journal article (peer-reviewed)abstract
- Objective: The hemodynamic effects of vacuum-assisted closure therapy in cardiac surgery are debated. The aim of the present study was to quantify cardiac output and left ventricular chamber volumes after vacuum-assisted closure using magnetic resonance imaging, which is known to be the most accurate method for quantifying these measures. Methods: Six pigs had median sternotomy followed by vacuum-assisted closure treatment in the presence and absence of a paraffin gauze interface dressing. Cardiac output and stroke volume were examined using magnetic resonance imaging flow quantification (breath-hold and real-time). Chamber volumes were assessed using cine magnetic resonance imaging. Results: Cardiac output and stroke volume decreased immediately after application of negative pressures of 75, 125, and 175 mm Hg (13% +/- 1% decrease in cardiac output). Interposition of 4 layers of paraffin gauze dressing over the heart during vacuum-assisted closure therapy resulted in a smaller decrease in cardiac output (8% +/- 1%). Conclusions: Vacuum-assisted closure therapy results in an immediate decrease in cardiac output, although to a lesser extent than shown previously. Covering the heart with a wound interface dressing lessens the hemodynamic effects of vacuum-assisted closure.
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| 31. |
- Sjögren, Johan, et al.
(author)
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Effects of vacuum-assisted closure on central hemodynamics in a sternotomy wound model
- 2004
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In: Interactive Cardiovascular and Thoracic Surgery. - : Oxford University Press (OUP). - 1569-9285 .- 1569-9293. ; 3:4, s. 666-671
-
Journal article (peer-reviewed)abstract
- Several authors have reported promising results with vacuum-assisted closure therapy in poststernotomy mediastinitis. The aim of this study was to investigate the hemodynamic outcome following the application of six negative pressures on an open sternotomy wound. Six 70-kg pigs underwent median sternotomy followed by vacuum-assisted closure therapy. Six negative pressures (-50, -75, -100, -125, -150, and -175mmHg) were applied to each pig for 30min each while hemodynamic parameters were measured. An increase in cardiac output was observed at -75mmHg when compared to the other five pressures: -50mmHg (P<0.05; CI 0.12-1.13l/min), -100mmHg (P<0.001; CI 0.34-1.32l/min), -125mmHg (P<0.001; CI 0.51-1.52l/min), -150mmHg (P<0.001; CI 0.50-1.47l/min), and -175mmHg (P<0.05; CI 0.13-1.17l/min). A decrease in systemic vascular resistance was observed at -75mmHg when compared to -125mmHg (P<0.01; CI 108-552dyn.s/cm(5)) and -150mmHg (P<0.01; CI 90-543dyn.s/cm(5)), but not compared to the other pressures. No change (P=ns) was observed in heart frequency, mean arterial pressure or central venous pressure. Our data demonstrates that vacuum-assisted closure therapy of -50 to -175mmHg does not impair the central hemodynamics in a porcine sternotomy model.
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| 32. |
- Sjögren, Johan, et al.
(author)
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Poststernotomy mediastinitis: a review of conventional surgical treatments, vacuum-assisted closure therapy and presentation of the Lund University Hospital mediastinitis algorithm.
- 2006
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In: European Journal of Cardio-Thoracic Surgery. - : Oxford University Press (OUP). - 1010-7940. ; 30:6, s. 898-905
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Research review (peer-reviewed)abstract
- Poststernotomy mediastinitis, also commonly called deep sternal wound infection, is one of the most feared complications in patients undergoing cardiac surgery. The overall incidence of poststernotomy mediastinitis is relatively low, between 1% and 3%, however, this complication is associated with a significant mortality, usually reported to vary between 10% and 25%. At the present time, there is no general consensus regarding the appropriate surgical approach to mediastinitis following open-heart surgery and a wide range of wound-heating strategies have been established for the treatment of poststernotomy mediastinitis during the era of modern cardiac surgery. Conventional forms of treatment usually involve surgical revision with open dressings or closed irrigation, or reconstruction with vascularized soft tissue flaps such as omentum or pectoral muscle. Unfortunately, procedure-related morbidity is relatively frequent when using conventional treatments and the tong-term clinical outcome has been unsatisfying. Vacuum-assisted closure is a novel treatment with an ingenious mechanism. This wound-heating technique is based on the application of local negative pressure to a wound. During the application of negative pressure to a sternal wound several advantageous features from conventional surgical treatment are combined. Recent publications have demonstrated encouraging clinical results, however, observations are still rather limited and the underlying mechanisms are largely unknown. This review provides an overview of the etiology and common risk factors for deep sternal wound infections and presents the historical development of conventional therapies. We also discuss the current experiences with VAC therapy in poststernotomy mediastinitis and summarize the current knowledge on the mechanisms by which VAC therapy promotes wound heating. Finally, we suggest a structured algorithm for using VAC therapy for treatment of poststernotomy mediastinitis in clinical practice. (c) 2006 Elsevier B.V. All rights reserved.
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| 33. |
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| 34. |
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| 35. |
- Steingrímsson, Steinn, et al.
(author)
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Sternocutaneous fistulas after cardiac surgery: incidence and late outcome during a ten-year follow-up.
- 2009
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In: Annals of Thoracic Surgery. - : Elsevier BV. - 1552-6259 .- 0003-4975. ; 88:6, s. 1910-1915
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Journal article (peer-reviewed)abstract
- BACKGROUND: Sternocutaneous fistulas (SCFs) after cardiac surgery represent a complex surgical problem involving multiple hospital admissions, prolonged antibiotic treatment, and repeated debridements. Our objective was to identify the incidence of and risk factors for SCF, and to evaluate long-term survival. METHODS: A total of 12,297 patients underwent sternotomy for cardiac surgery between January 1999 and December 2008, and 32 patients were diagnosed as having SCF during follow-up. Risk factors were identified with multivariate analysis and survival was compared using the log-rank test. RESULTS: The cumulative incidence of SCF at one year was 0.23%. There was no significant difference in mean time from sternal closure after cardiac surgery to intervention for SCF with (n = 9) or without (n = 23) preceding sternal wound infection (SWI); 6.1 +/- 4.2 versus 6.9 +/- 4.6 months, (p = ns). Risk factors for developing SCF were previous SWI (odds ratio [OR] = 15.7), renal failure (OR = 12.5), smoking (OR = 4.7), and use of bone wax during cardiac surgery (OR = 4.2). Negative-pressure wound therapy was applied in 20 cases of extensive SCFs. Five-year survival of SCF patients was 58% +/- 1% as compared with 85% +/- 4% in the control group (p = 0.003). CONCLUSIONS: Sternocutaneous fistula is a devastating diagnosis with significant morbidity and mortality. Previous SWI, renal failure, smoking, and use of bone wax are major risk factors. However, in a majority of patients SCF is not preceded by SWI and our results indicate that SCF may be a foreign body infection that develops in susceptible patients with risk factors for poor wound healing. Negative-pressure wound therapy may be a valuable adjunct in the treatment of extensive SCF.
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| 36. |
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| 37. |
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| 38. |
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| 39. |
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| 40. |
- Zindovic, Igor, et al.
(author)
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Predictors and impact of massive bleeding in acute type A aortic dissection.
- 2017
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In: Interactive Cardiovascular and Thoracic Surgery. - : Oxford University Press (OUP). - 1569-9293 .- 1569-9285. ; 24:4, s. 498-505
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Journal article (peer-reviewed)abstract
- Objectives: Bleeding complications associated with acute type A aortic dissection (aTAAD) are a well-known clinical problem. Here, we evaluated predictors of massive bleeding related to aTAAD and associated surgery and assessed the impact of massive bleeding on complications and survival.Methods: This retrospective study of 256 patients used Blood Conservation Using Antifibrinolytics in a Randomized Trial (BART) criteria to define massive bleeding, which was met by 66 individuals (Group I) who were compared to the remaining patients (Group II). Multivariable logistic regression was used to identify independent predictors of massive bleeding and in-hospital mortality, Kaplan-Meier estimates for analysis of late survival, and Cox regression analysis to evaluate independent predictors of late mortality.Results: Independent predictors of massive bleeding included symptom duration (odds ratio [OR], 0.974 per hour increment; 95% confidence interval [CI], 0.950-0.999; P = 0.041) and DeBakey type 1 dissection (OR, 2.652; 95% CI, 1.004-7.008; P = 0.049). In-hospital mortality was higher in Group I (30.3% vs 8.0%, P <0.001). Kaplan-Meier estimates of survival indicated poorer survival for Group I at 1, 3 and 5 years (68.8 ± 5.9% vs 92.8 ± 1.9%; 65.2 ± 6.2% vs 85.3 ± 2.7%; 53.9 ± 6.9% vs 82.1 ± 3.3 %, respectively; log rank P < 0.001). Re-exploration for bleeding was an independent predictor of in-hospital (OR, 3.109; 95% CI, 1.044-9.256; P = 0.042) and late mortalities (hazard ratio, 3.039; 95% CI, 1.605-5.757; P = 0.001).Conclusions: Massive bleeding in patients with aTAAD is prompted by shorter symptom duration and longer extent of dissection and has deleterious effects on outcomes of postoperative complications as well as in-hospital and late mortalities.
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| 41. |
- Zindovic, Igor, et al.
(author)
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Recombinant factor VIIa use in acute type A aortic dissection repair : A multicenter propensity-score-matched report from the Nordic Consortium for Acute Type A Aortic Dissection
- 2017
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In: Journal of Thoracic and Cardiovascular Surgery. - : Elsevier BV. - 0022-5223 .- 1097-685X. ; 154:6, s. 2-1859
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Journal article (peer-reviewed)abstract
- Background: Surgery for acute type A aortic dissection (ATAAD) is often complicated by excessive bleeding. Recombinant factor VIIa (rFVIIa) effectively treats refractory bleeding associated with ATAAD surgery; however, adverse effects of rFVIIa in these patients have not been fully assessed. Here we evaluated rFVIIa treatment in ATAAD surgery using the Nordic Consortium for Acute Type A Aortic Dissection (NORCAAD) database. Methods: This was a multicenter, propensity score-matched, retrospective study. Information about rFVIIa use was available for 761 patients, of whom 171 were treated with rFVIIa. We successfully matched 120 patients treated with rFVIIa with 120 controls. Primary endpoints were in-hospital mortality, postoperative stroke, and renal replacement therapy (RRT). Survival data were presented using Kaplan-Meier estimates. Results: Compared with controls, patients treated with rFVIIa received more transfusions of packed red blood cells (median, 9.0 U [4.0-17.0 U] vs 5.0 U [2.0-11.0 U]; P = .008), platelets (4.0 U [2.0-8.0 U] vs 2.0 U [1.0-4.4 U]; P <.001), and fresh frozen plasma (8.0 U [4.0-18.0 U] vs 5.5 U [2.0-10.3 U]; P = .01) underwent reexploration for bleeding more often (31.0% vs 16.8%; P = .014); and had greater 24-hour chest tube output (1500 L [835-2500 mL] vs 990 mL [520-1720 mL]). Treatment with rFVIIa was not associated with significantly increased rates of in-hospital mortality (odds ratio [OR], 0.74; 95% confidence interval [CI], 0.34-1.55; P = .487), postoperative stroke (OR, 1.75; 95% CI, 0.82-3.91; P = .163), or RRT (OR, 1.18; 95% CI, 0.48-2.92; P = .839). Conclusions: In this propensity-matched cohort study of patients undergoing ATAAD surgery, treatment with rFVIIa for major bleeding was not associated with a significantly increased risk of stroke, RRT, or mortality.
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| 42. |
- Zindovic, Igor, et al.
(author)
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The Coagulopathy of Acute Type A Aortic Dissection : A Prospective, Observational Study
- 2019
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In: Journal of Cardiothoracic and Vascular Anesthesia. - : Elsevier BV. - 1053-0770. ; 33:10, s. 2746-2754
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Journal article (peer-reviewed)abstract
- Objective: To evaluate the hemostatic system in patients undergoing surgery for acute type A aortic dissection (ATAAD) compared with those undergoing elective aortic procedures. Design: This was a prospective, observational study. Setting: The study was performed at a single university hospital. Participants: Twenty-five patients with ATAAD were compared with 20 control patients undergoing elective surgery of the ascending aorta or the aortic root. Interventions: No interventions were performed. Measurements and Main Results: Platelet count and levels of fibrinogen, D-dimer, prothrombin time/international normalized ratio, activated partial thromboplastin time, and antithrombin were analyzed perioperatively and compared between the 2 groups. Patients with ATAAD had lower preoperative levels of platelets (188 [156-217] × 10 9 /L v 221 [196-240] × 10 9 /L; p = 0.018), fibrinogen (1.9 [1.6-2.4] g/L v 2.8 [2.2-3.0] g/L; p = 0.003), and antithrombin (0.81 [0.73-0.94] kIU/L v 0.96 [0.92-1.00] kIU/L; p = 0.003) and significantly higher levels of D-dimer (2.9 [1.7-9.7] mg/L v 0.1 [0.1-0.2] mg/L; p < 0.001) and prothrombin time/international normalized ratio (1.15 [1.1-1.2] v 1.0 [0.93-1.0]; p = 0.001). Surgery caused significant changes of the coagulation system in both groups. Intraoperative bleeding volumes were larger in the ATAAD group (2,407 [1,804-3,209] mL v 1,212 [917-1,920] mL; p < 0.001), and patients undergoing ATAAD surgery received significantly more transfusions of red blood cells (2.5 [0.25-4.75] U v 0 [0-2.75] U; p = 0.022), platelets (4 [3.25-6] U v 2 [2-4] U; p = 0.002), and plasma (2 [0-4] U v 0 [0-0] U; p = 0.004) compared with the elective group. Conclusions: This study demonstrates that ATAAD is associated with a coagulopathic state. Surgery causes additional damage to the hemostatic system in ATAAD patients, but also in patients undergoing elective surgery of the ascending aorta or the aortic root.
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| 43. |
- Zindovic, Igor, et al.
(author)
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The role of von Willebrand factor in acute type A aortic dissection and aortic surgery
- 2019
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In: Thrombosis Research. - : Elsevier BV. - 0049-3848. ; 178, s. 139-144
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Journal article (peer-reviewed)abstract
- Introduction: Massive bleeding is a serious complication associated with impaired survival after surgery for acute type A aortic dissection (ATAAD). There are no previous reports evaluating the effect of ATAAD and associated surgery on von Willebrand factor (VWF). The aim of the present study was to analyze VWF activity (VWF:GPIbM) and thus the potential of Factor (F) VIII/VWF concentrate as a treatment for refractory bleeding in surgery for acute type A aortic dissection. Material and methods: We prospectively compared serial measurements of VWF:GPIbM in 25 patients with ATAAD to 20 control patients undergoing elective surgery of the ascending aorta or the aortic root. In 10 of the ATAAD patients, high molecular weight multimer distribution was measured. Results: Preoperatively, ATAAD patients demonstrated significantly higher VWF:GPIbM (1.58 (1.40–2.05) kIU/L vs 1.25 (1.02–1.42) kIU/L, p = 0.003). In the ATAAD group, VWF:GPIbM significantly decreased to 1.24 (0.98–1.44) kIU/L at lowest core temperature (T0 vs T1 p < 0.001), but remained unchanged in the elective group (1.25 (1.04–1.43) kIU/L, T0 vs T1 p < 0.625). Neither aortic dissection nor hypothermia caused any changes to the proportion of high molecular weight multimers when compared to control patients. Both groups demonstrated supernormal VWF:GPIbM on the first and fifth day after surgery. Conclusions: This report showed that patients with acute aortic dissection had increased levels of VWF:GPIbM before surgery that decreased slightly during surgery. Our study could not provide evidence that would encourage administration of FVIII/VWF concentrate for major bleeding in patients undergoing surgery for ATAAD as well as elective aortic procedures.
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