Background and aim of the study: The results of tricuspid annuloplasty to treat functional tricuspid regurgitation (FTR) are sometimes suboptimal, and alternative techniques are needed. In the absence of reliable FTR models, and in an effort to minimize the need for animal experiments, a reproducible bench-model was developed of FTR, that allowed the simulation of the anatomic features of the condition.

Methods: A fresh porcine heart was mounted on a rigid support that was placed into a basin filled with saline; a closed circuit was then created with a centrifugal pump, equipped with connection tubes. The inflow tube of the pump conveyed saline from the basin to the pump; the outflow cannula was inserted through the pulmonary artery, across the pulmonary valve, into the right ventricle. The pump was activated to pressurize the right ventricle, thus inducing tricuspid valve regurgitation (TVR). The regurgitant flow through the valve was quantified using a flow-meter. Radiopaque markers were sutured to the head of each papillary muscle and to the tricuspid annulus, in order to trace the geometric changes of the tricuspid valve at increasing pump rates, using fluoroscopy. The efficacy of the bench-model was validated with 10 hearts.

Results: The TVR was increased proportionally with the right ventricular pressure (RVP) (TVR = 0.089xRVP - 1.515; R2 = 0.89). The increase in TVR was associated with increases in the annular-to-papillary muscles distance (APML) (TVR = 0.059xAPML - 2.94; R2 = 0.96), of the inter-papillary muscles distance (PMD) (TVR = 0.058xPMD - 8.58; R2 = 0.94), and of the triscuspid annular dilatation (TAD) (TVR = 0.05xTAD - 1.85; R2 = 0.89). Of these parameters, APML was the strongest predictor of TVR.

Conclusion: The porcine heart bench model represents a reproducible system to simulate the physiopathology of FTR, and has the potential to serve as a complementary method for the evaluation of new 'in vitro' technologies and therapies for FTR.

Background and aim of the study: Mini-sternotomy aortic valve replacement (MSAVR) has been increasingly performed at the authors' institution since October 2003. The study aim was to compare results obtained with MSAVR to those following AVR with conventional sternotomy (SAVR).

Methods: Between 1998 and 2008, a total of 143 consecutive patients (mean age: 67 +/- 12.5 years) underwent AVR at the authors' institution. Of these patients, 82 underwent SAVR, and 61 underwent MSAVR performed through a reversed-L-shaped median sternotomy with a transverse limb at the right fourth intercostal space. Ascending aortic and right atrial cannulation through the mini-sternotomy were employed for cardiopulmonary bypass (CPB).

Results: Typically, the MSAVR patients were slightly younger than SAVR patients (mean age: 67 +/- 16 years and 70 +/- 15 years, respectively; p = 0.037), had a lower incidence of diabetes (3% versus 18%, p = 0.008), and a slightly higher left ventricular ejection fraction (74.5 +/- 12% versus 71 +/- 12%, p = 0.019). There were no other inter-group preoperative differences. As expected, MSAVR required a slightly longer aortic cross-clamp time (49 +/- 19 min) compared to SAVR (44.5 +/- 16 min; p = 0.019), and longer CPB times (77 +/- 31 min versus 60 +/- 26 min; p <0.0001), though the overall operating times were similar (p = 0.38). Postoperatively, MSAVR patients were extubated at 3 +/- 5 h, similar to SAVR patients (4 +/- 5 h) (p = 0.13). The median intensive therapy unit stay was 1 +/- 1 days in both groups. The median hospital stay was comparable between groups (MSAVR, 7 +/- 5 days; SAVR, 8 +/- 4 days; p = 0.48). The MSAVR patients had a higher incidence of delayed pericardial effusions requiring pericardiocentesis (n = 4; p = 0.031), but this did not affect survival. The 30-day mortality was similar in both groups (MSAVR group, n = 1 (1.6%); SAVR group, n = 3 (3.7%); p = 0.64). At five years after surgery, freedom from cardiac-related death was 96 +/- 2.6% in MSAVR patients, and 89 +/- 4.9% in SAVR patients (p = 0.32).

Conclusion: Mini-sternotomy AVR is technically challenging with longer CPB and aortic cross-clamp times. However, with increasing surgical experience, it offers results comparable to those achieved with conventional AVR, and with acceptable cosmetic results.

Background and aim of the study: The study aim was to conduct an annual evaluation of plasma levels of C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and antibodies against Chlamydia pneumoniae during a 12-month period following the natural course of aortic valve stenosis (AVS).

Methods: A total of 60 patients with AVS and 14 control subjects underwent echocardiographic examinations at the start of the study period, and again after a 12-month follow up period. Subsequently, the AVS patients were allocated retrospectively to two groups (n = 30 in each) according to their echocardiographic parameters: patients who showed a progressive deterioration of valvular function (PAVS group); and those who showed a lack of such progression (LPAVS group). Plasma concentrations of CRP, TNF-alpha, IL-6, and antichlamydial IgA, IgG, and IgM antibodies were evaluated at the start of the study, and again during the 12th month.

Results: During the study, CRP levels were increased only in the AVS group. TNF-alpha and IgM levels were higher in the AVS group compared to controls, at both the initial visit and the final observation. During the 12-month observation period the TNF-alpha level was increased in the PAVS group, whereas CRP levels in the LPAVS group were decreased. TNF-alpha levels were higher in the PAVS group than the LPAVS group, at both the initial visit and after 12 months; CRP levels did not differ between these groups. In the PAVS group, the IL-6 level was higher after 12 months, but the IgM level was higher at the initial visit. The results of a factorial analysis identified the main factors responsible for the decrease in aortic valve area to be TNF-alpha and CRP.

Conclusion: TNF-alpha, CRP, and IgM antichlamydial antibodies should be further investigated as potential predictive factors for the progression of AVS.

Background and aim of the study: Although the EuroSCORE was developed for predicting operative mortality after cardiac surgery, it has also been shown to predict long-term mortality. It has been reported that postoperative heart failure (PHF) in association with surgery, albeit comparatively benign in the short term, has a profound impact on five-year survival after surgery for aortic stenosis (AS). The study aim was to determine the combined impact of EuroSCORE and PHF on long-term survival after isolated aortic valve replacement (AVR) for AS.

Methods: A total of 397 patients (48% females; average age 70 +/- 10 years) who underwent AVR for AS at the authors' institution between 1995 and 2000 was studied. The cohort was subdivided according to the additive EuroSCORE into a high-risk group (EuroSCORE >7) and a low-risk group (EuroSCORE < or = 7), and further analyzed in relation to PHF.

Results: The average follow up was 8.1 years (range: 5.2-11.2 years). Forty-five patients (11%) were treated for procedure-associated PHF. Patients with or without PHF and a high-risk EuroSCORE had crude five-year survivals of 57% and 64%, respectively (p = 0.6), whereas those with or without PHF but with a low-risk EuroSCORE had crude five-year survivals of 58% and 89%, respectively (p = 0.0003).

Conclusion: Both PHF and a high EuroSCORE were associated with poor long-term survival. The role of PHF per se for the long-term prognosis was illustrated by the fact that the negative impact on long-term survival was almost as profound in patients of the low-risk group as of the high-risk group.

Background and aim of the study: In patients with mitral stenosis (MS), previous studies have shown discordant results with regards to improvements in right ventricular (RV) function immediately after percutaneous mitral commissurotomy (PMC). Hence, the study aim was to evaluate the impact of PMC on RV function, by using Doppler-echocardiography.

Methods: A total of 41 patients with severe symptomatic MS, in sinus rhythm, who had been referred to the authors' institution for PMC, was prospectively enrolled. A group of 25 healthy age- and gender-matched subjects served as controls. Transthoracic echocardiography (TTE) was performed on the day before and at 24/48 h after PMC. The RV function was evaluated using the Tricuspid Annular Plane Excursion (TAPSE), the RV Tei index, and systolic myocardial velocities by Doppler tissue imaging peak isovolumic contraction (DTI(IVC)) and peak systolic (DTI(S)) at the lateral tricuspid annulus).

Results: All patients but three underwent a successful PMC. The mitral valve area (MVA) was significantly increased (1.8 +/- 0.3 versus 1.1 +/- 0.2 cm2, p <0.0001), while the mean gradient (5 +/- 2 versus 10 +/- 7 mmHg, p <0.0001) and systolic pulmonary artery pressure (40 +/- 10 versus 54 +/- 21 mmHg, p = 0.0002) were decreased. Compared to healthy controls, the RV dysfunction in MS patients was authenticated by the DTI(IVC) and the Tei index (8.4 +/- 3.0 versus 11.1 +/- 2.1 cm/s, p = 0.0002 and 0.33 +/- 0.10 versus 0.18 +/- 0.10 respectively, p <0.0001), but not by DTI(S) (12.9 +/- 3 versus 12.3 +/- 1.5 cm/s, p = 0.35) or TAPSE (24 +/- 5 versus 23 +/- 3 mm, p = 0.50). After PMC, no significant change regarding RV function was observed (TAPSE: 24 +/- 5 versus 24 +/- 5 mm, p = 0.54; Tei Index: 0.33 +/- 0.10 versus 0.36 +/- 0.12, p = 0.20; DTI(IVC): 8.4 +/- 3.0 versus 9.2 +/- 3.4 cm/s, p = 0.08 and DTI(S): 12.9 +/- 3.0 versus 13.0 +/- 3.4 cm/s, p = 0.54).

Conclusion: The DTI(IVC) and Tei index appear to serve as the more sensitive indices of RV dysfunction in patients with MS. Immediately after a successful PMC, no significant change in Doppler echocardiographic parameters of RV function was observed. Whether late improvement in RV function can be observed, and the prognostic value of these parameters realized, deserve further investigation.

During recent years there has been an increase in the referral pattern for surgery for non-rheumatic calcific mitral stenosis (CMS). Valve replacement for this condition presents some unique challenges, yet the management of CMS remains inadequately described. Herein are discussed the techniques and outcomes of surgery for CMS.

Background and aim of the study: Interatrial block (IAB), a frequently overlooked conduction delay between the atria, is defined as prolonged P-wave on the electrocardiogram (ECG). Previously, IAB has been shown to be an indicator of dilated and impaired left atrial function, and a predictor of both atrial fibrillation and embolic stroke. The study aim was to test the hypothesis that, on ECG, IAB with P-terminal force can reflect the echocardiographic severity of mitral stenosis (MS).

Methods: Patients with rheumatic MS who were referred to a single cardiac center for echocardiography between July and October 2009, and who met the study entry criteria (echocardiographically documented rheumatic MS), were invited to participate. Consequently, 116 such patients were studied prospectively, while a group of age- and gender-matched subjects without echocardiographic signs of rheumatic valve involvement served as controls. Transthoracic echocardiography was performed in all subjects.

Results: A positive correlation was observed between IAB (> or = 120 ms) and the mean mitral valve gradient (R = 0.3, p <0.001). A strong negative correlation was also present between the mitral valve area (MVA) and the presence of IAB (R = -0.3, p <0.001). The presence of pulmonary hypertension and a poor NYHA functional class were associated with a high incidence of significant IAB (R = 0.4, p <0.001; R = 0.3, p <0.001, respectively), and there was a strong correlation between IAB and the P-terminal force (p <0.001). Both, the presence of significant IAB and P-terminal force were correlated with a calcific mitral valve (p <0.001). Only the MVA (beta = 0.3; p = 0.008) was a predictor of IAB in multivariate analysis.

Conclusion: A severe mitral gradient, a decreased MVA, an increased pulmonary artery pressure, and a poor NYHA class were shown to correlate with IAB duration and P-terminal force. Significant IAB (> or = 120 ms) and P-terminal force might be considered as a novel indicator of echocardiographic severity and associated complications during the follow up of MS. However, these interrelations must be clarified in further studies.

Background and aim of the study: During the normal opening and closing of the mitral valve there is a finely tuned interaction between the changing ventricular dimensions and fluid pressures, the movement of papillary muscles apically, posteriorly and apart during diastole and in the opposite direction during systole, interactions between leaflets and their controlling cords, and the fluid dynamic forces being exerted on them. The main rough zone cords and the smooth zone of the anterior leaflet are under maximum tension in systole, but retain some tension throughout the cycle. The free edge cords and the rough zone of the leaflets can have no or minimal tension during diastole, and much less tension than the main rough zone cords and the smooth zone in systole. The variability of the form and distribution of rough zone cords influences the flexibility of the rough zone. The net effect of this interaction is a valve that opens rapidly for unobstructed forward flow, and closes at the end of the cycle with minimal leakage. The apical displacement of, usually, the right inferior papillary muscle as a result of ischemic ventricular disease pulls the leaflets into separation because the origins of cords supporting the anterior and posterior leaflets arise specifically from the anterior and posterior sides of each papillary muscle. Myocardial ischemia producing apical papillary displacement can be associated with heart failure and mitral insufficiency. Annuloplasty reducing the annulus to less than the normal systolic dimension can be effective in eliminating both insufficiency and heart failure when the papillary displacement is dominantly apical. In more severe cases of heart failure and mitral insufficiency, the mid-ventricular dimensions increase to a more severe degree, and both papillary muscles are displaced outwards and posteriorly.

Methods and results: Static in vitro experiments performed on three human and nine pig hearts showed that the outward papillary displacements increased the tension on first-order cords, rendering the anterior leaflet and the central scallop of the posterior leaflet stiff. The addition of posterior displacement caused the anterior leaflet to become directed at an angle to the displaced papillary muscles, and the scallops of the posterior leaflet to be perpendicularly splayed around the posterior left ventricular wall, such that the valve no longer opened or closed correctly.

Conclusion: The valve no longer opens or closes properly, and annuloplasty is no longer of use in restoring valve function.