Multicentre experience with valve-sparing aortic root replacement by means of combined remodelling and external aortic ring annuloplasty in patients with Marfan syndrome.

OBJECTIVES: The most recent valve-sparing root replacement technique combines the advantages of the reimplantation (David) and remodelling (Yacoub) techniques. The aortic root is reconstructed according to the remodelling technique, the aortic valve is repaired according to the principle of effective height, and an external ring provides annular support. The purpose of this study was to evaluate operative and mid-term outcomes using this technique in patients with Marfan syndrome. METHODS: Adult patients with Marfan syndrome who had an indication for aortic root surgery according to European Society of Cardiology guidelines and were operated on using this new root replacement technique were retrospectively evaluated. Follow-up was obtained from standard outpatient visits and included echocardiography. RESULTS: The study group comprised 22 patients (mean age 36 years, 68% males). Mean follow-up was 7.5 years. There were no mortalities. Two patients required aortic valve replacement because of aortic regurgitation. In both patients, the aortic root was severely dilated (≥65 mm) preoperatively, with grade III aortic valve regurgitation and aortic valve cusps that were very fragile. Aortic regurgitation was grade ≤I on follow-up in 18 of the remaining 20 patients. CONCLUSIONS: Valve-sparing root replacement using remodelling combined with aortic-ring annuloplasty is safe in patients with Marfan syndrome. The mid-term outcome is promising in patients undergoing elective valve-sparing root replacement at recommended root diameters. However, in patients with extremely dilated aortic roots and already severe aortic regurgitation, the technique should be used cautiously as aortic cusps are fragile and might not be suitable for durable repair. CLINICAL REGISTRATION NUMBER: UMCG Research registry #11208.

A chart review on surgical myocardial debridging in symptomatic patients: a safe procedure with good long-term clinical outcome and coronary computed tomographic angiography results.

OBJECTIVES: Myocardial bridging is mostly diagnosed as an incidental imaging finding but can result in severe vessel compression and significant clinical adverse complications. Since there is still an ongoing debate when to propose surgical unroofing, we studied a group of patients where this was performed as an isolated procedure. METHODS: In 16 patients (38.9 ± 15.7 years, 75% men) who had surgical unroofing for symptomatic isolated myocardial bridges of the left anterior descending artery, we retrospectively analysed symptomatology, medication, imaging modalities used, operative techniques, complications and long-term outcome. Computed tomographic fractional flow reserve was calculated to understand its potential value for decision-making. RESULTS: Most procedures were performed on-pump (75%, mean cardiopulmonary bypass 56.5 ± 27.9 min, mean aortic cross-clamping 36.4 ± 19.7 min). Three patients needed a left internal mammary artery bypass since the artery dived inside the ventricle. There were no major complications or deaths. The mean follow-up was 5.5 years. Although there was a dramatic improvement in symptoms, still 31% experienced atypical chest pain at various moments during follow-up. Postoperative radiological control was performed in 88%, showing no residual compression or recurrent myocardial bridge and patent bypass if performed. All postoperative computed tomographic flow calculations (7) showed a normalization of coronary flow. CONCLUSIONS: Surgical unroofing for symptomatic isolated myocardial bridging is a safe procedure. Patient selection remains difficult but introducing standard coronary computed tomographic angiography with flow calculations could be helpful in preoperative decision-making and during follow-up.

Patient Satisfaction After Inguinal Hernia Surgery: Literature Review of an Overlooked Patient-Reported Outcome Measure.

INTRODUCTION: Patient satisfaction after inguinal hernia surgery is currently underappreciated and not as well studied as other patient-reported outcome measures (PROMs) on this topic. This study aims to review the literature and summarize available data. MATERIALS AND METHODS: A literature review was conducted using Medline with focus on patient-reported satisfaction after elective, inguinal hernia surgery in adults. All inguinal hernia repair techniques were considered. Small sample sizes and short follow-up periods were excluded. The methodology and results of the remaining articles were reviewed. Due to heterogeneity of reporting between articles, only a descriptive analysis was performed. RESULTS: The available data from patient-reported outcome measures regarding satisfaction yields considerable heterogeneity and lacks validation. We found that 53% of all included studies used an asymmetrical response questionnaire. Although there is an overwhelming positive patient satisfaction, wide ranges of satisfaction were seen (78-100% more than averagely satisfied, compared to 0-15% less than averagely satisfied). The number of patients not willing to undergo inguinal hernia repair again ranges from 1-16%. CONCLUSION: Our study demonstrates that patient-reported satisfaction after inguinal hernia surgery is not uniformly surveyed and remains unvalidated. Further research on patient-reported satisfaction would benefit from the reported raw data of a standardised, validated, and symmetrical five-point Likert or 11-point NRS scale on regular intervals pre- and postoperatively.

Endomysial fibrosis, rather than overall connective tissue content, is the main determinant of conduction disturbances in human atrial fibrillation.

AIMS: Although in persistent atrial fibrillation (AF) a complex AF substrate characterized by a high incidence of conduction block has been reported, relatively little is known about AF complexity in paroxysmal AF (pAF). Also, the relative contribution of various aspects of structural alterations to conduction disturbances is not clear. In particular, the contribution of endomysial fibrosis to conduction disturbances during progression of AF has not been studied yet. METHODS AND RESULTS: During cardiac surgery, epicardial high-density mapping was performed in patients with acutely induced (aAF, n = 11), pAF (n = 12), and longstanding persistent AF (persAF, n = 9) on the right atrial (RA) wall, the posterior left atrial wall (pLA) and the LA appendage (LAA). In RA appendages, overall and endomysial (myocyte-to-myocyte distances) fibrosis and connexin 43 (Cx43) distribution were quantified. Unipolar AF electrogram analysis showed a more complex pattern with a larger number of narrower waves, more breakthroughs and a higher fractionation index (FI) in persAF compared with aAF and pAF, with no differences between aAF and pAF. The FI was consistently higher at the pLA compared with the RA. Structurally, Cx43 lateralization increased with AF progression (aAF = 7.5 ± 8.9%, pAF = 24.7 ± 11.1%, persAF = 35.1 ± 11.4%, P < 0.001). Endomysial but not overall fibrosis correlated with AF complexity (r = 0.57, P = 0.001; r = 0.23, P = 0.20; respectively). CONCLUSIONS: Atrial fibrillation complexity is highly variable in patients with pAF, but not significantly higher than in patients with acutely induced AF, while in patients with persistent AF complexity is higher. Among the structural alterations studied, endomysial fibrosis, but not overall fibrosis, is the strongest determinant of AF complexity.

Long term effects of surgical and transcatheter aortic valve replacement on FFRCT in patients with severe aortic valve stenosis.

The long-term variations of fractional flow reserve derived from coronary computed tomography (FFRCT) after surgical (SAVR) or transcatheter (TAVR) aortic valve replacement in patients with severe aortic valve stenosis (AS) have not been investigated. A total of 25 patients with isolated, severe AS underwent coronary computed tomography with 3-vessel FFRCT analysis (Heartflow Inc.-Redwood City, California, USA) and measurement of total coronary volume (V), left ventricular mass (M) and their ratio (V/M) before and 6 months after SAVR or TAVR. A significant increase in V/M due to a decrease in left ventricular mass 6 months after intervention was observed, whereas total coronary volume did not change (coronary volume pre: 2924.5 ± 867.9 mm3, coronary volume post: 2844.2 ± 792.8 mm3, P = 0.158; LV mass pre: 151.7 ± 40.7 g, LV mass post: 127.3 ± 34.7 g, P < 0.001; V/M pre: 19.5 ± 4.1 mm3/g, V/M post: 22.7 ± 4.28 mm3/g, P = 0.002). FFRCT (expressed as area under the virtual pullback curve) remained constant. This proof-of-concept study showed that FFRCT was not subject to the confounding effect of left ventricular mass regression after SAVR or TAVR. Despite significant left ventricular remodeling at 6 months after AS treatment, FFRCT values remained constant. Further studies are needed comparing the performance of the different invasive and non-invasive coronary physiological indices in this patient cohort.

Let us ask the patient: Psychological well-being from a patients'-perspective due to postponed care of cardiac surgery during the COVID-19 lockdown.

Introduction: The onset of the COVID-19 pandemic has forced a rapid and extensive change in the need of intensive care beds. Therefore, we decided early in the pandemic to suspend all elective cases of cardiac surgery and closed the ambulatory clinic. The effect of this strategy on the mental well-being of the non-COVID-19 patients is unknown. The aim of this study is to assess whether planned or operated patients suffered from either anxiety or depression by their altered medical care trajectory and if their score influenced decision-making. The findings intend to anticipate individual needs during subsequent waves of the COVID-19 pandemic.Methods: The patient population consisted of two groups. The first group included planned patients whose operation date was delayed; in the second group, the postoperative control visit was postponed. Both groups received a twofold questionnaire. Part one was the Hospital Anxiety and Depression scale, part two a series of questions on the influence of the COVID-19 pandemic on cardiac surgical care from a patient's perspective.Results: The study population was composed of 46 patients (63% men). Most of them (82,6%) would like the surgery to be performed as fast as possible, even before the end of the first wave of COVID-19-related hospitalizations. Of all patients 30,4% have avoided to consult a physician because of fear and 34,8% consulted a physician by phone call. When they physically consulted a physician, there was a prominent role for the general practitioner (41,3% went to the GP vs 19,6% to the specialist). Most (58,7%) of the patients would have liked a (tele)consultation with the cardiac surgeon.Conclusions: Regardless of the HADS, one can state that a closer follow-up using telemedicine during the pandemic is expected by all patients. All patients prefer their surgery to take place even during a pandemic.

Incidence, prevalence, and trajectories of repetitive conduction patterns in human atrial fibrillation.

AIMS: Repetitive conduction patterns in atrial fibrillation (AF) may reflect anatomical structures harbouring preferential conduction paths and indicate the presence of stationary sources for AF. Recently, we demonstrated a novel technique to detect repetitive patterns in high-density contact mapping of AF. As a first step towards repetitive pattern mapping to guide AF ablation, we determined the incidence, prevalence, and trajectories of repetitive conduction patterns in epicardial contact mapping of paroxysmal and persistent AF patients. METHODS AND RESULTS: A 256-channel mapping array was used to record epicardial left and right AF electrograms in persistent AF (persAF, n = 9) and paroxysmal AF (pAF, n = 11) patients. Intervals containing repetitive conduction patterns were detected using recurrence plots. Activation movies, preferential conduction direction, and average activation sequence were used to characterize and classify conduction patterns. Repetitive patterns were identified in 33/40 recordings. Repetitive patterns were more prevalent in pAF compared with persAF [pAF: median 59%, inter-quartile range (41-72) vs. persAF: 39% (0-51), P < 0.01], larger [pAF: = 1.54 (1.15-1.96) vs. persAF: 1.16 (0.74-1.56) cm2, P < 0.001), and more stable [normalized preferentiality (0-1) pAF: 0.38 (0.25-0.50) vs. persAF: 0.23 (0-0.33), P < 0.01]. Most repetitive patterns were peripheral waves (87%), often with conduction block (69%), while breakthroughs (9%) and re-entries (2%) occurred less frequently. CONCLUSION: High-density epicardial contact mapping in AF patients reveals frequent repetitive conduction patterns. In persistent AF patients, repetitive patterns were less frequent, smaller, and more variable than in paroxysmal AF patients. Future research should elucidate whether these patterns can help in finding AF ablation targets.

Geometric characteristics of bicuspid aortic valves.

OBJECTIVE: We studied the coaptation angles α and ß in bicuspid aortic valve geometry from computed tomography scan images. METHODS: In 45 patients, we calculated the coaptation angle α (the angle between the nonfused commissures crossing the center of coaptation), angle ß (between the nonfused commissures crossing the center of the reference circle), angles γ1 and γ2 and ε1 and ε2 (angle between the nonfused commissures and the coaptation point at the raphe or the perfect midpoint, respectively), the length of the raphe, the absolute and relative sinuses' surfaces (relative to the perfect circle and the percentage exceeding the ideal circle). Spearman correlation was employed to investigate the associations among all parameters. RESULTS: The coaptation angles α and ß were significantly different (P < .001). We found a significant correlation of α with the length of the raphe (P = .008), whereas ß was dependent on the position of the commissures. Both γ1 and γ2 (P = .04), or ε1 and ε2 (P < .001) significantly differed from each other and ε2 was the most constant angle, although its size geometrically depends on ß. The noncoronary was the largest sinus, and ß was the primary determinant of its increased size in bicuspid aortic valves with righ/left fusion pattern. CONCLUSIONS: The coaptation angle α is influenced by the length of the raphe, whereas angle ß is dependent on the position of the commissures. The position of the raphe can vary and is not always situated in the middle of the free edge. The position of the right/non commissure is variable, whereas the right/left commissure is more fixed.

Percutaneous tracheostomy for long-term ventilated COVID-19-patients: rationale and first clinical-safe for all-experience.

INTRODUCTION: COVID-19 infection has resulted in thousands of critically ill patients admitted to ICUs and treated with mechanical ventilation. Percutaneous tracheostomy is a well-known technique utilised as a strategy to wean critically ill patients from mechanical ventilation. Worldwide differences exist in terms of methods, operators, and settings, and questions remain regarding timing and indications. If tracheostomy is to be performed in COVID-19 patients, a safe environment is needed for optimal care. MATERIAL AND METHODS: We present a guidewire dilating forceps tracheostomy procedure in COVID-19 patients that was optimised including apnoea-moments, protective clothing, checklists, and clear protocols. We performed a retrospective analysis of the outcome after tracheostomy in COVID-19 patients between March 2020 and May 2020. RESULTS: The follow-up of the first 16 patients, median age 62 years, revealed a median intubation time until tracheostomy of 18 days and median cannulation time of 20 days. The overall perioperative complication rate and complication rate while cannulated was 19%, mainly superficial bleeding. None of the healthcare providers involved in performing the procedure developed any symptoms of the disease. CONCLUSIONS: This COVID-19-centred strategy based on flexibility, preparation, and cooperation between healthcare providers with different backgrounds facilitated percutaneous tracheostomy in COVID-19 patients without an increase in the overall complication rate or evidence of risk to healthcare providers. Our findings provide initial evidence that tracheostomy can be performed safely as a standard of care for COVID-19 patients requiring prolonged mechanical ventilation as was standard practice in ICU patients prior to the COVID-19 pandemic to promote ventilator weaning and patient recovery.

Electrocardiographic and clinical predictors of permanent pacemaker insertion following Perceval sutureless aortic valve implantation.

BACKGROUND: Sutureless aortic valve replacement surgery (AVR) is a reasonable alternative surgical approach in those patients with aortic stenosis who would benefit from reduced cross clamp time, such as elderly and high-risk patients. We sought to evaluate the incidence of pacemaker (PM) implantation following sutureless AVR and to analyse possible pre-operative electrocardiographic and clinical predictors of PM implantation. METHODS AND RESULTS: Between November 2013 and March 2015, 58 patients (male 43%, age 77.9 ±â€¯4.9 years) having undergone sutureless AVR with a Perceval prosthesis (Sorin Biomedica Cardio Srl, Saluggia, Italy) were taken into consideration for our analysis. During a mean follow up of 13.8 ±â€¯5.0 months (median 13 months), 14 patients (24.1%) underwent pacemaker (PM) implantation following sutureless AVR procedure. Among these patients, 12 (86%) presented III degree atrioventricular (AV) block, 1 (7%) presented II degree AV block, and remaining one (7%) severe symptomatic bradycardia. The comparison of pre-operative characteristics between PM group and no PM group highlighted that QRS duration, EuroSCORE II index and chronic renal dysfunction were significantly associated with the development of AV conduction abnormalities/symptomatic bradycardia requiring PM implantation (respectively, p = 0.01, p = 0.02 and p = 0.03). CONCLUSIONS: The incidence of PM implantation after sutureless AVR was 24.1% in the present study. The EuroSCORE II, QRS duration and renal dysfunction were significantly associated with higher risk of AV conduction abnormalities/symptomatic bradycardia requiring PM placement.

Long-Term Follow-Up of Probands With Brugada Syndrome.

This study analyzes the natural history of a large cohort of probands with Brugada syndrome (BrS) to assess the predictive value of different clinical and electrocardiographic parameters for the development of ventricular fibrillation (VF) or sudden cardiac death (SCD) during a long-term follow-up. Baseline characteristics of 289 consecutive probands (203 men; mean age 45 ± 16 years) with a Brugada type 1 electrocardiogram were analyzed. After a mean follow-up of 10.1 ± 4.6 years, 29 malignant arrhythmias occurred. On multivariate analysis, a history of VF and syncopal episodes, fragmented QRS (f-QRS), spontaneous type 1 electrocardiogram, and early repolarization pattern were significantly associated with later occurrence of VF/SCD. In patients with drug-induced BrS, the accentuation or de novo appearance of f-QRS in other leads was always associated with VF/SCD. Cerebrovascular events occurred in 8 patients with atrial fibrillation (15.1%), most of them (75%) presenting as the first clinical manifestation. The time-to-diagnosis was found to be significantly shorter in those patients who directly came to our center than in those who referred to our center for a second opinion. In conclusion, systematic use of the pharmacologic challenge in patients with unexplained cardiovascular symptoms and/or atrial fibrillation might significantly improve the identification of BrS with a shortening of the time-to-diagnosis. The CHA2DS2VASc score might be inappropriate for predicting transient ischemic attack or stroke in BrS. This study confirms the independent predictive value of previous VF and syncopal episodes, f-QRS, type 1 electrocardiogram, and early repolarization pattern. In BrS a sufficiently long follow-up is necessary before conclusions on prognosis are apparent.

Implantable cardioverter defibrillator therapy in young individuals: comparison of conventional and subcostal approaches-a single-centre experience.

AIM: The aim of our study is to compare two approaches of implantable cardiac defibrillator (ICD) implantation, conventional (supra/subpectoral) and subcostal in young adults in terms of procedural complications and adverse events encountered during follow-up. METHODS AND RESULTS: From January 2007 to December 2013, all patients under the age of 50 years who received an ICD in our centre were included in this study. Patient's hospital records were analysed for procedural complications and adverse events during follow-up until December 2014. Data from device on first interrogation after implantation and on follow-up were also noted. A total of 106 patients of which 40.6% had Brugada's syndrome (65.1% male, age 33.6 ± 10.97 years) were included in analysis; 71 (61%) had ICD placed in (sub/supra) pectoral and 35 (33%) in subcostal position. Only seven patients received an epicardial lead system. During the follow-up period of 2.1 ± 1.8 years, 84.90% of the patients had no adverse events. Most of the complications, procedural and during follow-up, occur in conventionally placed, pectoral ICD. Lead follow-up data in both groups, conventional and subcostal, showed no difference in right ventricular (RV) shock impedance and R wave sensing, P-value = 0.56 and 0.77, respectively. Lead survival was 95 and 97%, respectively, in conventional and subcostal groups over a mean follow-up of 2.1 ± 1.8 years. Log-rank test for lead survival was not significant in terms of site of implantation. CONCLUSION: To the best our knowledge, this is the first study demonstrating subcostal ICD placement in young adults and resulting in equivalent to better outcomes when compared with conventionally placed pectoral ICD. Subcostal ICD placement might be considered an alternative option in young adults as it results in better procedural outcomes and also comparable rate of adverse events during follow-up, but bigger studies with a larger number of patients are needed for a definitive conclusion.

Midterm clinical outcomes of concomitant thoracoscopic epicardial and transcatheter endocardial ablation for persistent and long-standing persistent atrial fibrillation: a single-centre experience.

AIMS: The purpose of this study was to analyse the efficacy and complication rates of the simultaneous hybrid procedure in a series of patients with persistent and long-standing persistent atrial fibrillation (AF) in a midterm follow-up. METHODS AND RESULTS: Sixty-four consecutive patients (56 males, 59.7 ± 8.7 years) having undergone isolation of pulmonary veins (PVs) and posterior wall of left atrium (LA) by means of hybrid thoracoscopic ablation for symptomatic persistent (n = 21, 33%) and long-standing persistent AF (n = 43, 67%) were analysed. At a mean follow-up of 23.1 ± 14.1 months (median 21; range 6-57), the success rate without antiarrhythmic therapy was achieved in 67.2% of patients. Procedure-related complications were observed in 13 patients (20.3%) including 2 LA perforations (3.1%) requiring, respectively, conversion to sternotomy and small left-sided thoracotomy. The success rate did not significantly differ between persistent and long-standing persistent AF (respectively, 71.4 and 65.1%; P = 0.4). Patients with AF relapse during the blanking period were 4.60 times more likely to have AF recurrence after 3 months from the ablation procedure. CONCLUSION: The hybrid procedure yields promising results in the setting of both persistent and long-standing persistent AF after midterm follow-up, at the expense of a non-negligible rate of adverse events. Our findings need to be confirmed by further larger and prospective studies.

Does sinus rhythm conversion after cardiac surgery affect postoperative health- related quality of life?

BACKGROUND: We investigated the impact and the predictive value of sinus rhythm at 12 months (SR12) on subscales of three different HrQoL questionnaires: SF-36., EuroQoL and MFI 20. METHODS: Data of 125 cardiac surgery patients with pre-operative AF from our previous randomized trial were used. Based on their rhythm outcome patients were divided in two groups: SR12 or AF at 12 months follow up (non-SR12). All questionnaires were self-administered pre-operatively and at 3 months, 6 months and 12 months after surgery. RESULTS: Synus rhytm at 12 months was predictive of improvement of SF36- mental score (MS, p = 0.021), Euro-QoL-MS (p = 0.009), VAS (p = 0.006), and MFI 20-MS (p = 0.009). We failed to find any significant interactions between SR12 and any of the other significant risk factors: age <65 years, paroxysmal type of AF and preoperative AF duration <12 months. In contrast, SR12 was not significant in predicting physical score (PS) subscales of any of the questionnaires (all, p > 0.05) which were predicted by age <65 years (SF36-PS, p = 0.029) by paroxysmal type of AF and age <65 years (Euro-QoL-PS, p = 0.017 and p = 0.04, respectively) and by AF duration <12 months, paroxysmal type of AF and age < 65 years (MFI 20-PS, p = 0.019, p = 0.020 and p = 0.015, respectively). CONCLUSIONS: Specific mental-related HrQoL scales are much more sensitive to sinus rhythm conversion. Sinus rithm mantainance shows significant effects on mental scores independently of other cofactors. Successful conversion to sinus rhythm after surgical ablation during cardiac surgery does not significantly affect phisical health related quality of life during 1 year follow up.

Contact forces during hybrid atrial fibrillation ablation: an in vitro evaluation.

PURPOSE: Data on epicardial contact force efficacy in dual epicardial-endocardial atrial fibrillation ablation procedures are lacking. We present an in vitro study on the importance of epicardial and endocardial contact forces during this procedure. METHODS: The in vitro setup consists of two separate chambers, mimicking the endocardial and epicardial sides of the heart. A circuit, including a pump and a heat exchanger, circulates porcine blood through the endocardial chamber. A septum, with a cut out, allows the placement of a magnetically fixed tissue holder, securing porcine atrial tissue, in the middle of both chambers. Two trocars provide access to the epicardium and endocardium. Force transducers mounted on both catheter holders allow real-time contact force monitoring, while a railing system allows controlled contact force adjustment. We histologically assessed different combinations of epi-endocardial radiofrequency ablation contact forces using porcine atria, evaluating the ablation's diameters, area, and volume. RESULTS: An epicardial ablation with forces of 100 or 300 g, followed by an endocardial ablation with a force of 20 g did not achieve transmurality. Increasing endocardial forces to 30 and 40 g combined with an epicardial force ranging from 100 to 300 and 500 g led to transmurality with significant increases in lesion's diameters, area, and volumes. CONCLUSIONS: Increased endocardial contact forces led to larger ablation lesions regardless of standard epicardial pressure forces. In order to gain transmurality in a model of a combined epicardial-endocardial procedure, a minimal endocardial force of 30 g combined with an epicardial force of 100 g is necessary.

Assessment of mechanical properties of porcine aortas under physiological loading conditions using vascular elastography.

Non-invasive assessment of the elastic properties of the arterial wall is often performed with ultrasound (US) imaging. The purpose of this study is to estimate mechanical properties of the vascular wall using in vitro inflation testing on biological tissue and two-dimensional (2-D) US elastography, and investigate the performance of the proposed methodology for physiological conditions. An inflation experiment was performed on 12 porcine aortas for (a) a large pressure range (0-140mmHg); and (b) physiological pressures (70-130mmHg) to mimic in vivo hemodynamic conditions. Two-dimensional radiofrequency (RF) data were acquired for one longitudinal and two transverse cross-sections for both experiments, and were analyzed to obtain the geometry and diameter-time behavior. The shear modulus (G) was estimated from these data for each pressure range applied. In addition, an incremental study based on the static data was performed to (1) investigate the changes in G for increasing mean arterial pressure (MAP) for a certain pressure difference (30, 40, 50 and 60mmHg); (2) compare the results with those from the dynamic experiment, for the same pressure range. The resulting stress-strain curves and shear moduli G (94±16kPa) for the static experimentare in agreement with literature and previous work. A linear dependency on MAP was found for G, yet the effect of the pulse pressure difference was negligible. The dynamic data revealed a G of 250±20kPa, whereas the incremental shear modulus (Ginc) was 240±39kPa. For all experiments, no significant differences in the values of G were found between different image planes. This study shows that 2-D US elastography of aortas during inflation testing is feasible and reproducible under controlled and physiological circumstances. In future studies, the in vivo, dynamic experiment should be repeated for a range of MAPs, and pathological vessels should be examined.

Repeat Procedures After Hybrid Thoracoscopic Ablation in the Setting of Longstanding Persistent Atrial Fibrillation: Electrophysiological Findings and 2-Year Clinical Outcome.

INTRODUCTION: In order to increase success rates of invasive treatment of persistent atrial fibrillation, the hybrid approach was developed, combining video-assisted thoracoscopic epicardial procedure with conventional endocardial catheter ablation. Currently, there are no reports of electrophysiological findings and clinical outcomes of repeat procedures after the hybrid approach. METHODS AND RESULTS: Out of 64 patients who were treated by hybrid ablation for persistent atrial fibrillation (AF), 14 underwent the repeat catheter ablation and were selected for this study. All 14 patients initially presented with longstanding persistent atrial fibrillation and markedly dilated atria. The hybrid procedure was performed in a single act and the mean time to redo procedure was 346 ± 227 days. In 57% of patients indication for redo procedure was regular atrial tachycardia, and the rest presented with recurrent atrial fibrillation. In 36% of patients, recovered conduction was found along the previous ablation lesions. Only 9% of pulmonary veins were reconnected (0.36 veins per patient) and 7% of box lesions were not complete. The overall success rate at 2 years follow-up after the repeat procedure, including second repeat procedure and patients taking antiarrhythmic drugs, was 64% (57% without drugs and further ablation). One case of moderate pulmonary vein stenosis was detected as a consequence of hybrid procedure. CONCLUSION: Hybrid atrial fibrillation ablation results in durable lesions and high rates of chronic pulmonary vein isolation even after long-term follow-up. Most of the repeat procedures after the hybrid approach are related to left atrial flutters that could be successfully treated by catheter ablation.

Indices of bipolar complex fractionated atrial electrograms correlate poorly with each other and atrial fibrillation substrate complexity.

BACKGROUND: The pathophysiological relevance of complex fractionated atrial electrograms (CFAE) in atrial fibrillation (AF) remains poorly understood. OBJECTIVE: The aim of this study was to comprehensively investigate how bipolar CFAE correlates with unipolar electrogram fractionation and the underlying electrophysiological substrate of AF. METHODS: Ten-second unipolar AF electrograms were recorded using a high-density electrode from the left atrium of 20 patients with AF (10 with persistent AF and 10 with paroxysmal AF) undergoing cardiac surgery. Semiautomated bipolar CFAE algorithms: complex fractionated electrogram-mean, interval confidence interval, continuous electrical activity, average complex interval, and shortest complex interval were evaluated against AF substrate complexity measures following fibrillation wave reconstruction derived from local unipolar activation time. The effect of interelectrode spacing and electrode orientation on bipolar CFAE was also examined. RESULTS: All 5 semiautomated bipolar CFAE algorithms showed poor correlation with each other and AF substrate complexity measures (conduction velocity, number of waves or breakthroughs per AF cycle, and electrical dissociation). Bipolar CFAE also correlated poorly with fractionation index derived from unipolar electrograms. Increased interelectrode spacing resulted in an increase in bipolar CFAE detected except for the interval confidence interval algorithm. CFAE appears unaffected by bipolar electrode orientation (vertical vs horizontal). By contrast, unipolar fractionation index correlated well with AF substrate complexity measures and can be regarded as a marker for conduction block. CONCLUSION: The lack of pathophysiological relevance of bipolar CFAE analysis may in part contribute to the divergent and limited success rates of catheter ablation strategies targeting CFAE.