Evaluation of atrial function after surgical ablation of atrial fibrillation: a Speckle tracking study.

AIM: AIM of our study was to assess atrial function in patients who underwent atrial fibrillation (AF) surgical ablation by a novel echocardiographic technique (speckle tracking). METHODS: From February 2006 to April 2008, in 11 consecutive pts with paroxysmal or persistent AF (6 males, mean age 69.6±9.7 years) undergoing cardiac surgery, concomitant AF surgical ablation was performed with bipolar radiofrequency clamp (Cobra_Bipolar® system). These pts, all in stable sinus rhythm (SR), were echoed after a mean follow-up of 14.6±9.3 months from surgery. Speckle tracking was used to estimate global LA strain, peak strain and the standard deviation of the time-to-peak (% of R-R' interval) of the deformation of 6 segments identified along the septum, the roof and the lateral wall of LA in a 4-chamber view. RESULTS: These patients showed a mild LA enlargement (mean volume 43.4±11.6 mL/sqm). In 5 of them (45.4%) no A waves were detected on MPWD and pulmonary venous flow, but speckle tracking showed preserved atrial function with a mean global strain of 5.5 ± 3.3 %, a mean peak strain of 10.4 ± 5.7 % and a TP-SD of 15.1±8.7 ms. CONCLUSION: Our study seems to show that surgical AF ablation has a lower impact on atrial function in comparison with data from literature about percutaneous catheter ablation. This is probably related to an higher sensitivity of this type of echocardiography evaluation, but this finding must be confirmed by other trials.

Twelve-year follow up with the Sorin Pericarbon bioprosthesis in the mitral position.

BACKGROUND AND AIMS OF THE STUDY: The aim of this study was to evaluate the long-term follow up of the Pericarbon pericardial bioprosthesis implanted in the mitral position. METHODS: Between January 1985 and January 1991, 78 patients (26 males, 52 females; mean age 56.9 +/- 7.8 years) underwent isolated mitral valve replacement with a Pericarbon valve. All bioprostheses were size 29 mm and implanted by the same surgeon. RESULTS: Total follow up was 663.2 pt-years and it was 97% complete. Early mortality was 1.3% (1/78); two minor cerebral embolisms were observed as early complications. At 12 years the overall survival rate was 85.0 +/- and valve-related survival 93.1 +/- 3.0%; freedom from embolic events was 83.0 +/- 4.5% and from endocarditis 98.7 +/- 1.3%. Freedom from primary tissue failure was 56.8 +/- 6.6%; it was 86.3 +/- 7.5% in patients aged > 60 years and 36.8 +/- 8.2% in younger patients. There were 27 reoperations, 26 for primary tissue failure, one for endocarditis. Comparison between basal and follow up echocardiographic studies showed a significant stenotic deterioration of the bioprosthesis and a negligible incidence of regurgitation. Morphological findings of explanted bioprostheses were characterized by stenotic and diffuse microcalcification, but no tissue tear was observed. CONCLUSIONS: These results confirm that the Pericarbon bioprosthesis is structurally safe and free from the fatigue problems which afflicted the first and second generation of pericardial valves. As with other tissue valves, the rate of calcification is age-dependent, suggesting preferential use of the Pericarbon prosthesis in elderly people.

Williams-Beuren syndrome. Long-term results of surgical treatments in six patients.

To settle long-term outcome after surgery for supravalvular aortic stenosis in the Williams-Beuren syndrome, we reviewed the records of 6 patients who had repair of the localized form (n = 5) or diffuse form (n = 1) at our Institution from 1965 to 1971. Four patients were females and 2 males, ages at operation ranged from 9 to 16 years (mean = 13 +/- 2.37 years). In all the patients was present the typical elfin facies with mental retardation and reduced I.Q. Preoperative omeral pressure was different between left and right arm (89 +/- 7/67 +/- 8 vs 105 +/- 8/77 +/- 4). Chest X-ray showed and enlargement of the cardia silhouette in all the patients. Cardiac catheterization, performed in all the patients, allowed diagnosis of supravalvular aortic stenosis and, in one case of subaortic stenosis associated. Intraoperatively a coronary tree enlargement was found in all cases with particular involvement of the right coronary in two patients. The mean diameter of the ascending aorta was 5.67 +/- 1.97 mm but the smallest (3 mm) was in the diffuse group. In group with localized stenosis the aortic root was enlarged with a teardrop patch in Dacron (n = 4) or a simple transverse suture after a longitudinal incision (n = 1). A pantaloon-shaped patch was necessary in the diffuse form case. There were no operative deaths and all the patients were discharged from the hospital after 2 weeks. A clinical follow-up was possible in all the patients (10%) extended from 25 to 30 years (mean = 27.7 +/- 2.19 years); there were no late deaths and at presents time the mean age of the patient is 40 +/- 3 years. All patients were in functional class I or II. There was no significant difference between patients with a teardrop-shaped or pantaloon-shaped patch in terms of late gradient, survival, or aortic insufficiency studied by Echocardiography and color-Doppler. Of six patients two are living with parents or relatives but four are in a farm-college for disable people working and having some responsibility. We conclude that surgery for the correction of supravalvular aortic stenosis in Williams-Beuren syndrome is mandatory and both the procedures with patch techniques provide excellent long-term results of gradients and aortic valve competence. Moreover the patients after the operation can have a normal activity with a satisfactory style and expectation of life.

Heart valve replacement with CarboMedics bileaflet prosthesis: surgical results and clinical evaluation. A medium term follow-up.

From March 1990 to July 1991, 110 patients (44 males, 66 females; mean age 54.44 +/- 8.8 years) underwent hearth valve replacement with a CarboMedics bileaflet prosthesis (CarboMedics Inc, Texas, USA). Preoperative pathophysiologic conditions were: aortic stenosis in 32 patients, aortic regurgitation in 22 patients; mitral stenosis in 27 patients and mitral regurgitation in 14 patients. Mitroaortic disease was present in 14 patients but 1 had triple valve disease. NYHA class was III or IV in 91 patients (83%). Operative mortality rate was 0.91% (1 patients). Actuarial survival rate is 95% at 58 months. Actuarial freedom from thromboembolic events in 95% at 58 months. Actuarial freedom from hemorrhage is 100%. Endocarditis befell in 2 patients; actuarial freedom from this complication at 58 months is 95%. Actuarial freedom from reoperation in 99%. We conclude that the low incidence of valve related events and the low mortality supports the use of the bileaflet valve CarboMedics.

[Transeptal access to the mitral valve. Long-term results]. / Accesso transettale alla valvola mitrale.

Optimal mitral valve repair or replacement requires an excellent exposure. We used a transeptal approach since 1975 at our Institution to obtain adequate exposure of mitral valve in 135 patients (48 males, 87 females, mean age 47.4 +/- 11.8, range 12-68). A mechanical valve (Bjork = 120; Sorin = 15) was implanted in mitral position. Associated procedures were performed in the 66% of the patients and most of them were tricuspid repair. About half of the patients were at the second or third cardiac operation after a previous closed heart mitral commissurotomy 15.15 +/- 5.6 years before. Exposure was excellent in the 95% of the cases. Hospital mortality was 12.6% and significantly major in patients at redo operation. Three patients with a concomitant aortic valve replacement required a definitive pace-marker implantation. A complete follow-up was possible in all patients who survived at operation. Actuarial survival rate at 10 years in 83% and at 20 years is 70%. Freedom from all events valve related at 10 years is 86% and at 20 years is 74%. None of the patients at echocardiographic follow-up revealed complications related to the transeptal approach to the mitral valve. In conclusion we suggest the use of transeptal approach to the mitral valve in case of redo-operations, concomitant tricuspid repair, small left atrium and in case of mitral valve repair because of the good exposure and the less inherent complications.

[Correlation between malfunction of a bioprosthesis and deformation of a valve stent. Comparison of three different vale models]. / Correlazione tra malfunzionamento di protesi biologiche e deformazione dello stent valvolare. Confronto tra diversi modelli di valvola.

BACKGROUND: Stent deformation seems to be effective in the long term performances of bioprostheses. METHODS: The Inward Banding Angle (IBA) of three different models of bioprostheses explanted during the period 1991-1992 at our Division of Cardiac Surgery in 45 different patients (26 males; 9 females; mean age 59.71 +/- 10.74, range 26-75) has been measured. Explanted valves were as follow: Hancock, (H = 13); Carpentier-Edwards (C = 14) e Xenomedica (X = 18). Primary tissue failure was the most common cause of re-operation (n = 30; 66.7%) but also endocarditis (n = 6; 13.3%) and paraprothetic leak (n = 10; 22.2%). A semi-quantitative score (0-4) was used to assess calcifications (1.51 +/- 1.56); tears (0.41 +/- 0.98); vegetation's (0.51 +/- 0.99) and fibrosis (2.7 +/- 1.27). The mean follow-up was 7.77 +/- 3.79 years (range 1.5 +/- 16 years). The mean IBA evaluated after explantation was 3.34 +/- 2.29 degrees. RESULTS: Statistical analysis showed a significance in term of IBA in the Hancock group vs Carpentier (P < 0.02); a less duration in the Xenomedica group vs H and C (p < 0.001) and an increased susceptibility to vegetation's and fibrosis in the Xvs C (p < 0.01) and H (p < 0.05) respectively. A suggestive correlation between IBA and time and between IBA and diameter was found but no statistical significance was observed. CONCLUSIONS: In conclusions, it is suggested that all materials tends to deform during time and a possible explanation of stent deformation can be the different material used in the stent fabrication. Moreover, mechanical stress and compression around the ring can be another mechanism of creep.

Bovine pericardial bioprosthesis in mitral position. A ten-year follow-up.

BACKGROUND: The pericardial bovine prosthesis Pericarbon should offer some advantages in comparison with the former generations, because its development is focused on solving previous problems and resulted in the variation of the pericardial fixation method, of valve structure and of stent coating. This hypothesis was evaluated through a retrospective follow-up. METHODS: Between 1985 and 1989, 78 Pericarbon prostheses O 29 were implanted in mitral position by the same surgeon. All patients received warfarin for the first three months to maintain an International Normalized Ratio between 2.5 and 3.5; after which they received antiaggregant therapy indefinitely. With an average follow-up period of 7.34 years for a total of 573 patient-years, we evaluated perioperative and late mortality, late morbidity (thromboembolic and haemorrhagic events, reoperations, primary tissue failures, endocarditic events) and patient clinical conditions. RESULTS: Perioperative mortality was 1.28% (1/78), late mortality was 11.6% (9/77) with 5 valve-related deaths. 5-year survival was 93% and 10-year survival 97%. Fifteen patients required reoperation for prosthetic replacement, fourteen for primary tissue failure. There were ten minor thromboembolic events, one major event, one haemorrhage and one prosthetic endocarditis (the last two with patient exitus). After 10 years (75% of patients were in New York Heart Association class I-II. CONCLUSIONS: Besides the known better haemodynamic performance, Pericarbon bioprosthesis seems to present a survival and redofreedom curve comparable to the best porcine prosthesis, with less incidence of endocarditis, thromboembolic events and prosthesis leakage.

Levosimendan induces NO production through p38 MAPK, ERK and Akt in porcine coronary endothelial cells: role for mitochondrial K(ATP) channel.

BACKGROUND AND PURPOSE: Levosimendan acts as a vasodilator through the opening of ATP-sensitive K(+) channels (K(ATP)) channels. Moreover, the coronary vasodilatation caused by levosimendan in anaesthetized pigs has recently been found to be abolished by the nitric oxide synthase (NOS) inhibitor N(omega)-nitro-L-arginine methyl ester, indicating that nitric oxide (NO) has a role in the vascular effects of levosimendan. However, the intracellular pathway leading to NO production caused by levosimendan has not yet been investigated. Thus, the purpose of the present study was to examine the effects of levosimendan on NO production and to evaluate the intracellular signalling pathway involved. EXPERIMENTAL APPROACH: In porcine coronary endothelial cells (CEC), the release of NO in response to levosimendan was examined in the presence and absence of N(omega)-nitro-L-arginine methyl ester, an adenylyl cyclase inhibitor, K(ATP) channel agonists and antagonists, and inhibitors of intracellular protein kinases. In addition, the role of Akt, ERK, p38 and eNOS was investigated through Western blot analysis. KEY RESULTS: Levosimendan caused a concentration-dependent and K(+)-related increase of NO production. This effect was amplified by the mitochondrial K(ATP) channel agonist, but not by the selective plasma membrane K(ATP) channel agonist. The response of CEC to levosimendan was prevented by the K(ATP) channel blockers, the adenylyl cyclase inhibitor and the Akt, ERK, p38 inhibitors. Western blot analysis showed that phosphorylation of the above kinases lead to eNOS activation. CONCLUSIONS AND IMPLICATIONS: In CEC levosimendan induced eNOS-dependent NO production through Akt, ERK and p38. This intracellular pathway is associated with the opening of mitochondrial K(ATP) channels and involves cAMP.

Hemodynamic effect of intracoronary administration of levosimendan in the anesthetized pig.

In this study the hemodynamic effects of intracoronary injection of levosimendan in anesthetized pigs and the mechanisms involved were examined. In 12 anesthetized pigs instrumented for measurement of heart rate (HR), aortic blood pressure (ABP), central venous pressure (CVP), left ventricular end-diastolic blood pressure, left ventricular contractility and relaxation, and mean coronary blood flow (CBF), levosimendan has been injected into the left anterior descending coronary artery at doses corresponding to the ones commonly used in clinics as bolus administration but adapted to the measured CBF. In a further 9 pigs levosimendan has been administered after the blockade of alpha and beta adrenoceptors, muscarinic receptors, and coronary nitric oxide synthase (NOS) to investigate the action mechanism of the drug. The intracoronary bolus administration of doses of levosimendan corresponding to 12 and 24 microg/kg in 10 minutes exerted, respectively, CBF increases of 26.3% and 41.3% of the control values in the absence of changes in the other hemodynamic variables. The blockade of the autonomic nervous system did not prevent the coronary vasodilation, which was, however, abolished by the NOS inhibition. The intracoronary administration of levosimendan exerts positive effects on myocardial blood supply without changes in ABP, HR, CVP, or in myocardial kinetics. The coronary effects of levosimendan are related to NO production.

Aortic arch aneurysms: surgical results and follow up in 56 patients.

From January 1989 to December 1994, 56 patients, 43 male and 13 female, mean age 61.21 +/- 10.05 years, underwent surgical procedures on the aortic arch at our institution. Forty-six patients underwent emergency or urgent operations, fourty-four of them presented acute aortic dissections involving the aortic arch. All operations were performed in cardiopulmonary by-pass, 39 operations in deep hypothermic circulatory arrest, 10 in deep hypothermic circulatory arrest and hypothermic retrograde cerebral perfusion. The overall hospital mortality was 17.9% (10 patients). The main causes of hospital mortality were: multiorgan failure (3 patients) and major neurological damage (2 patients). In the group of patients that underwent hypothermic retrograde cerebral perfusion there was no major neurological damage. In the follow up there were no deaths and 4 reoperations related to the aortic pathology. The cerebral protection represents the main problem in the aortic arch surgery. The deep hypothermic circulatory arrest is an effective method to reduce the cerebral and visceral ischemia, in particular in acute dissection; nevertheless this method leads to more bleeding complications and lengthening of the cardiopulmonary bypass in time. In our experience, the hypothermic retrograde cerebral perfusion associated with deep hypothermic circulatory arrest appears to be a useful method to prevent cerebral damage. However this procedure needs further investigation.

[Mitral valve bioprosthesis from bovine pericardium. Color Doppler echographic study and long-term follow up]. / Bioprotesi valvolari mitraliche di pericardio bovino. Studio ecocardiografico e color Doppler e follow-up a lungo termine.

Pericardial heart valve bioprostheses have been utilized for 20 years. In spite of encouraging initial results, long-term follow-up showed a higher incidence of structural failures and primary tissue failures than porcine bioprostheses. Pericarbon represents the newest generation of bovine pericardial bioprostheses. Aim of this study is the long-term evaluation with echocardiographic and color Doppler technique of an innovative bioprostheses, in particular, its morfological and functional characteristics. From 1985 to 1989, 78 consecutive patients (21 males, 57 females, mean age 56.5 +/- 8.16 years) underwent mitral valve replacement with Pericarbon 29, by the same operator, who preserved the mitral posterior leaflet. One month after operation, 21 of these patients underwent echo-color Doppler evaluation, in normalized hemodynamic conditions (normality ranges). In 1995, at the end of the followup, 30 of the remaining 54 patients underwent new echo-color Doppler evaluation and these data were compared with normality ranges values. Leaflets' thickness increased from 0.98 +/- 0.09 to 2.87 +/- 0.73 mm (anterior leaflet; p < 0.0001) and from 1.02 +/- 0.08 to 2.71 +/- 0.45 mm (posterior leaflet; p < 0.0001) 43.3% of anterior leaflet and 53.3% of posterior leaflet showed fibrocalcic lesions. Mean transvalvular gradient increased from 3.4 +/- 0.2 to 6.6 +/- 3.4 mmHg (p < 0.0001); also functional area decreased (p < 0.0001). We have found no paraprosthetic regurgitation and a very low number of central prosthetic regurgitation. Left ventricular function, evaluated by ejection fraction and regional kinesis, remained substantially preserved.