Aortic valve leaflet and root dimensions in normal tricuspid aortic valves: A computed tomography study.

BACKGROUND AND AIM OF THE STUDY: The aim of this study was to use coronary computed tomography in patients with normal tricuspid aortic valves to perform detailed aortic root and aortic valve geometric analysis with a focus on the asymmetry of the three leaflets. METHODS: Retrospective analysis of anonymized coronary computed tomography angiograms was performed using dedicated software, where manual aortic root segmentation and marking of several points of interest were followed by automated measurements of aortic root and leaflets. Asymmetry of the three leaflets in individual patients was assessed by calculating absolute and relative differences between the largest and the smallest of the three leaflets. RESULTS: We analyzed 70 aortic valves, the mean patient age was 53 ± 11 years, and 50% (n = 35) of patients were female. All aortic valves were tricuspid, without calcifications and aortic roots were of normal dimensions. Some degree of asymmetry was present in all analyzed valves. Absolute and relative differences for free margin length were 3.2 ± 1.4 mm and 9.3 ± 3.8%, respectively. The largest relative difference was noted in the coaptation area (36.5 ± 16.5%) and the smallest in leaflet effective height (6.1 ± 4.8%). Using predefined cutoff criteria for absolute differences in leaflet dimensions, 86% of the valves were classified as asymmetric. CONCLUSIONS: Most normal tricuspid aortic valves show some degree of asymmetry. Equal free margin length of the three leaflets is not needed for normal tricuspid aortic valve function. Leaflet effective height showed the least amount of asymmetry confirming its importance in keeping the aortic valve competent.

Intra-cardiac ultrasound guided approach for catheter ablation of typical right free wall accessory pathways.

BACKGROUND: Right free wall accessory pathways (AP) are difficult to treat with catheter ablation as ablation catheter (AC) instability at the tricuspid annulus often precludes successful procedure. The aim of our study was to test a novel intra-cardiac echocardiography (ICE) guided technique for AC placement. Feasibility and success rates were observed. METHODS: Eight consecutive patients (aged 29 ± 21 years, 4 female) with Wolff-Parkinson-White syndrome and a right free wall AP were included in the study. ICE, three-dimensional (3D) electro-anatomic mapping (EAM) system, and a steerable long sheath were used together with either an irrigated or a non-irrigated tip radio-frequency AC to achieve a "loop" manoeuvre which provided AC tip stability at the ventricular aspect of the tricuspid annulus. X-ray fluoroscopy was not used. RESULTS: Three patients had an anterior and five had a lateral location of the right free wall AP. Procedures were successful in all patients, without recurrences during the mean follow-up of 397 ± 363 days. Average procedural duration was 90 ± 31 min. On average, 6.6 ± 5.7 ablations were needed. Average time to terminate AP conduction after the start of ablation was 4.8 ± 4.2 s. In five patients (62%) AP conduction was successfully terminated with the first ablation. There were no procedural complications. CONCLUSIONS: The novel ICE-guided approach with concomitant use of the steerable sheath and the 3D EAM system for zero-fluoroscopy mapping and ablation of the right free wall APs proved feasible and resulted in excellent acute and long-term outcomes.

Contemporary Valvular Mechanisms of Aortic Regurgitation in Tricuspid Aortic Valves: Importance in Repair Versus Replacement Strategy.

BACKGROUND: This study was performed to determine cusp causes of aortic regurgitation in patients with tricuspid aortic valves without significant aortic dilatation and define cusp pathologies amenable to surgical repair (aortic valve repair [AVr]) versus aortic valve replacement. METHODS AND RESULTS: We retrospectively reviewed surgical reports of consecutive adults with tricuspid aortic valves undergoing surgery for clinically significant aortic regurgitation within a prospective registry from January 2005 to September 2019. Valvular mechanisms were determined by systematic in vivo intraoperative quantification methods. Of 516 patients, 287 (56%) underwent repair (AVr; mean±SD age, 59.9±12.4 years; 81% men) and 229 (44%) underwent replacement (aortic valve replacement; mean±SD age, 62.8±13.8 years [P=0.01 compared to AVr]; 67% men). A single valvular mechanism was present in 454 patients (88%), with cusp prolapse (46%), retraction (24%), and perforation (18%) being the most common. Prolapse involved the right cusp in 86% of cases and was more frequent in men (P<0.001). Two-dimensional transesophageal echocardiography accuracy for predicting mechanisms was 73% to 82% for the right cusp, 55% to 61% for the noncoronary cusp, and 0% for the left-coronary cusp. Cusp prolapse, younger age, and larger patient size were associated with successful AVr (all P<0.03), whereas retraction, perforation, older age, and concomitant mitral repair were associated with aortic valve replacement (all P<0.03). CONCLUSIONS: Right cusp prolapse is the most frequent single valvular mechanism in patients with tricuspid aortic valve aortic regurgitation, followed by cusp retraction and perforation. The accuracy of 2-dimensional transesophageal echocardiography is limited for left and noncoronary cusp mechanistic assessment. Prolapse is associated with successful AVr, whereas retraction and perforation are associated with aortic valve replacement. With systematic intraoperative quantification methods and current surgical techniques, more than half of tricuspid aortic valve aortic regurgitation cases may be successfully repaired.

Segmental analysis of aortic basal ring dimensions in normal and dilated tricuspid aortic roots.

OBJECTIVES: In patients with aortic root aneurysm, the aortic basal ring is frequently dilated. It has been speculated that the muscular part of the basal ring dilates most. The purpose of this study was to analyse the segmental dilatation of the basal ring, comparing normal and dilated roots in patients with tricuspid aortic valves. METHODS: Retrospective analysis of computed tomography studies in patients with normal and dilated aortic roots was performed. Lengths of segments of the basal ring corresponding to each of the 3 sinuses, and to the muscular and fibrous parts were measured. Fractions of these segments relative to the total basal ring perimeter were calculated. RESULTS: We analysed 152 normal and 126 dilated aortic roots and 86 propensity-matched pairs. Basal ring dilatation was present in all segments of dilated aortic roots with subtle differences between the segments corresponding to the 3 sinuses. The muscular part of the basal ring dilated proportionately to its fibrous part, with no difference in fractions of measured muscular part in normal and dilated roots [42.2% (interquartile range 4.3%) vs 42.1% (interquartile range 6.3%)]. CONCLUSIONS: Basal ring dilatation was present in all segments corresponding to the 3 sinuses in dilated aortic roots. Both muscular and fibrous parts dilated equally, supporting the need to stabilize the entire basal ring when performing aortic valve repair surgery.

Thymic fat pad flap to cover the left internal thoracic artery graft.

With a skeletonized harvesting technique of the left internal thoracic artery (LITA), opening of the pleural space during dissection can usually be avoided. However, due to the bulging of the ventilated lungs, the LITA graft comes to lie immediately below the sternum at the end of the procedure, which makes it vulnerable to injury in case of a reoperation. The authors present a simple technique to move the skeletonized LITA graft away from the undersurface of the sternum, by using a thymic fat pad flap (TFP).

Influence of type of aortic valve prosthesis on coronary blood flow velocity.

BACKGROUND: Severe aortic valve stenosis is associated with high resting and reduced hyperemic coronary blood flow. Coronary blood flow increases after aortic valve replacement (AVR); however, the increase depends on the type of prosthesis used. The present study investigates the influence of type of aortic valve prosthesis on coronary blood flow velocity. METHODS: The blood flow velocity in the left anterior descending coronary artery (LAD) and the right coronary artery (RCA) was measured intraoperatively before and after AVR with a stentless bioprosthesis (Sorin Freedom Solo; n = 11) or a bileaflet mechanical prosthesis (St. Jude Medical Regent; n = 11). Measurements were made with an X-Plore epicardial Doppler probe (Medistim, Oslo, Norway) following induction of hyperemia with an adenosine infusion. Preoperative and postoperative echocardiography evaluations were used to assess valvular and ventricular function. Velocity time integrals (VTI) were measured from the Doppler signals and used to calculate the proportion of systolic VTI (SF), diastolic VTI (DF), and normalized systolic coronary blood flow velocities (NSF) and normalized diastolic coronary blood flow velocities (NDF). RESULTS: The systolic proportion of the LAD VTI increased after AVR with the St. Jude Medical Regent prosthesis, which produced higher LAD SF and NSF values than the Sorin Freedom Solo prosthesis (SF, 0.41 ± 0.09 versus 0.29 ± 0.13 [P = .04]; NSF, 0.88 ± 0.24 versus 0.55 ± 0.17 [P = .01]). No significant changes in the LAD velocity profile were noted after valve replacement with the Sorin Freedom Solo, despite a significant reduction in transvalvular gradient and an increase in the effective orifice area. AVR had no effect on the RCA flow velocity profile. CONCLUSION: The coronary flow velocity profile in the LAD was significantly influenced by the type of aortic valve prosthesis used. The differences in the LAD velocity profile probably reflect differences in valve design and the systolic transvalvular flow pattern.

Use of a totally artificial heart for a complex postinfarction ventricular septal defect.

The incidence of cardiac rupture complicating myocardial infarction has declined since the introduction of thrombolytic therapy. Despite the advances in the management of myocardial infarction, cardiac rupture remains an important cause of death among infarction-related fatalities. We discuss a patient who presented to our hospital with myocardial infarction and who subsequently developed a complex ventricular septal rupture, for which surgical repair was not feasible. Implantation of a CardioWest Total Artificial Heart (SynCardia Systems) allowed for immediate hemodynamic stabilization and served as a bridge to transplantation.

Minimally invasive surgical aortic valve replacement versus transfemoral transcatheter aortic valve implantation in low-risk octogenarians : Observational, retrospective and single-center study.

BACKGROUND: The aim of this study was to compare short-term and mid-term outcomes in low-risk octogenarian population treated with transfemoral transcatheter aortic valve implantation (tf-TAVI) or minimally invasive aortic valve replacement (mini-AVR) for severe aortic stenosis. METHODS: In this single-center, retrospective cohort study we gathered data on low-risk (Society of Thoracic Surgeons [STS] score < 4%) octogenarians before and after tf-TAVI and mini-AVR performed between January 2013 and May 2019; follow-up was completed in May 2022. Short-term outcomes were hospital length of stay, in-hospital all-cause mortality and other major postoperative outcomes. Mid-term clinical outcomes were 1­year and 3­year all-cause mortality. Propensity score-based matching was performed. RESULTS: In total 106 patients were matched, resulting in 53 pairs. In-hospital complications were similar between the matched groups of patients with the exception of mild and moderate paravalvular leak (mini-AVR vs. tf-TAVI: mild PVL: 3.8% vs. 45.3%, p < 0.001; moderate PVL: 0% vs. 3.8%, p = 0.4952) and of postprocedural acute kidney injury that was more frequent in mini-AVR group (mini-AVR vs. tf-TAVI: 22.6% vs. 5.7%; p = 0.023). Hospital length of stay (p = 0.239) and in-hospital mortality (p = 0.495) did not differ between groups. The 1-year and 3­year all-cause mortality Kaplan-Meier estimates were similar between mini-AVR and tf-TAVI. CONCLUSION: In the present study on low-risk octogenarians, transfemoral TAVI and minimally invasive AVR showed comparable short-term and mid-term results. Both procedures are deemed safe and effective. Larger RCTs will be required to determine which low-risk patients will benefit most from TAVI.

Left ventricular venting in veno-arterial extracorporeal membrane oxygenation: A computer simulation study.

INTRODUCTION: Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is the fastest way to restore circulation in refractory cardiogenic shock, however it cannot unload the failing left ventricle. There is a lack of consensus regarding optimal approach to left ventricular venting in V-A ECMO patients with severely depressed or absent left ventricular function. METHODS: A computer model was developed in Matlab Simulink R20016b (MathWorks, Inc., Natick, MA, USA) to analyze different venting options as well as atrial septostomy in the setting of cardiogenic shock and V-A ECMO. RESULTS: The model has shown an inverse linear relationship between left atrial pressure and either vent, Impella or atrial septum defect flow rate. The minimum vent flow required to prevent pulmonary edema in complete loss of left ventricular function needed to be higher than the bronchial blood flow. Atrial septostomy restored normal pulmonary blood flow with low left atrial pressure but induced stasis in the left ventricle. Venting the pulmonary artery induced stasis in the entire pulmonary circulation as well as left atrium and left ventricle. Venting the left ventricle directly with a cannula or Impella device avoided blood stasis. CONCLUSION: Our data suggest that reduction of left atrial pressure is linearly related to the vent, Impella or atrial septal defect flow rate. The preferred vent location is the left ventricle as it avoids stasis in the pulmonary circulation and cardiac chambers.

Cardiac myxoma: single tertiary centre experience.

BACKGROUND: Although cardiac myxoma (CM) are rare and benign, they can cause life-threatening complications, such as hemodynamic disturbances or embolization. Surgical excision of the tumour is the treatment of choice. The aim of the study was to evaluate the epidemiological characteristics, clinical presentation, imaging findings, and outcomes of surgical treatment of patients with CM treated in the largest tertiary care centre in Slovenia. PATIENTS AND METHODS: We retrospectively analysed the medical records of all patients referred to our institution between January 2005 and December 2020 and identified 39 consecutive adult patients with pathologically confirmed CM. RESULTS: The average annual incidence of CM in the study was 3 per 2 million population per year. Patients were more often female (n = 25, 64%). The mean age at diagnosis was 63.1 ± 13.6 years. Dyspnoea was the most common presenting symptom (31%). CM was an incidental finding in 11 patients (28%). Seven patients presented with thromboembolic event (18%). Transthoracic echocardiography (TTE) was performed in all patients, however additional imaging was required in 22 patients (56%). All patients in our series were successfully treated surgically without in-hospital mortality. During the follow-up period (6 months to 16 years) three patients (8%) died, and all deaths were unrelated to CM. There was no recurrence of CM during the follow-up. CONCLUSIONS: Our single-centre study confirms that CM is rare cardiac tumour with diverse clinical presentation. Our data shows data that CM might be more prevalent than considered before. Surgical resection of the tumour is safe with excellent short- and long-term outcomes.

Intracardiac echocardiography-guided transseptal puncture for fluoroless catheter ablation of left-sided tachycardias.

BACKGROUND: Integration of intracardiac echocardiography (ICE) and 3D electroanatomic mapping (EAM) system allows transseptal punctures (TSP) without the use of fluoroscopy. Compared with fluoroscopy, ICE provides better visualization of the anatomy relevant to TSP and early recognition of complications. The aim was to evaluate efficacy and safety of entirely ICE-guided TSPs in patients who underwent fluoroless catheter ablation of left-sided tachycardias. METHODS: Consecutive 524 adult and pediatric patients referred to our institution from July 2014 to December 2019 were analyzed. Patients with cardiac implantable electronic devices (CIEDs) were also included. All procedures were performed with ICE-guided TSP combined with 3D EAM. Adverse events following TSP and within 30 days of the procedure were analyzed. RESULTS: Altogether 949 TSPs (363 double punctures, 76.5%) were performed in 586 fluoroless ablation procedures: 451 (77%) were ablation of atrial fibrillation or atypical flutter, 75 (12.8%) of left-sided accessory pathway, 33 (5.6%) of ventricular tachycardia, and 27 (4.6%) of focal atrial tachycardia. Forty-six (7.8%) procedures were performed in pediatric population and 36 procedures (6.1%) in patients with CIED. Only 2 TSPs were unsuccessful (2/949, 0.2%). Overall procedural complication rate was 1.9% (11/586 procedures). There was only 1 TSP-related pericardial tamponade (2/949, 0.2%). In CIED patients, there was 1 lead dislocation following TSP. CONCLUSIONS: Entirely ICE-guided TSPs for different left-sided tachycardias can be safely and effectively performed in adult and pediatric population without the use of fluoroscopy. However, caution is advised in CIED patients due to possible lead dislocation risk.

Cerebral microemboli in mini-sternotomy compared to mini- thoracotomy for aortic valve replacement: a cross sectional cohort study.

BACKGROUND: Recently adopted mini-thoracotomy approach for surgical aortic valve replacement has shown benefits such as reduced pain and shorter recovery, compared to more conventional mini-sternotomy access. However, whether limited exposure of the heart and ascending aorta resulting from an incision in the second intercostal space may lead to increased intraoperative cerebral embolization and more prominent postoperative neurologic decline, remains inconclusive. The aim of our study was to assess potential neurological complications after two different minimal invasive surgical techniques for aortic valve replacement by measuring cerebral microembolic signal during surgery and by follow-up cognitive evaluation. METHODS: Trans-cranial Doppler was used for microembolic signal detection during aortic valve replacement performed via mini-sternotomy and mini-thoracotomy. Patients were evaluated using Addenbrooke's Cognitive Examination Revised Test before and 30 days after surgical procedure. RESULTS: A total of 60 patients were recruited in the study. In 52 patients, transcranial Doppler was feasible. Of those, 25 underwent mini-sternotomy and 27 had mini-thoracotomy. There were no differences between groups with respect to sex, NYHA class distribution, Euroscore II or aortic valve area. Patients in mini-sternotomy group were younger (60.8 ± 14.4 vs.72 ± 5.84, p = 0.003), heavier (85.2 ± 12.4 vs.72.5 ± 12.9, p = 0.002) and had higher body surface area (1.98 ± 0.167 vs. 1.83 ± 0.178, p = 0.006). Surgery duration was longer in mini-sternotomy group compared to mini-thoracotomy (158 ± 24 vs. 134 ± 30 min, p < 0.001, respectively). There were no differences between groups in microembolic load, length of ICU or total hospital stay. Total microembolic signals count was correlated with cardiopulmonary bypass duration (5.64, 95%CI 0.677-10.60, p = 0.027). Addenbrooke's Cognitive Examination Revised Test score decreased equivalently in both groups (p = 0.630) (MS: 85.2 ± 9.6 vs. 82.9 ± 11.4, p = 0.012; MT: 85.2 ± 9.6 vs. 81.3 ± 8.8, p = 0.001). CONCLUSION: There is no difference in microembolic load between the groups. Total intraoperative microembolic signals count was associated with cardiopulmonary bypass duration. Age, but not micorembolic signals load, was associated with postoperative neurologic decline. TRIAL REGISTRY NUMBER: clinicaltrials.gov , NCT02697786 14.

New graft sizing rings for aortic valve reimplantation procedures.

OBJECTIVES: The objective was to design sizing rings that would enable proper sizing of the graft in reimplantation procedures and to perform leaflet repair before graft implantation. METHODS: The rings were designed in Autodesk Fusion 360 (San Rafael, CA, USA) and 3D printed using a commercial online 3D printing service. We designed incomplete rings with a low profile and complete rings with a high profile. The complete rings are best suited for reimplantation procedures, whereas low profile C rings are intended for isolated aortic valve repair, where the ascending aorta is not transected. The rings come in sizes corresponding to Vascutek Gelweave graft sizes (Vascutek Terumo, Renfrewshire, Scotland). The ring internal diameters are 5% larger than the designated ring sizes and account for the 5% stretch of the grafts when pressurized. Blades of the rings are placed at 20° intervals. The slits between the blades are designed in such a way that the commissural U-sutures, when put in place and under tension, will lock the ring in position. RESULTS: The rings were successfully used in 10 of our latest reimplantation procedures. After dissection of the aortic root, the commissures were suspended with U-stitches and then the ring was seated onto them. Complete leaflet repair with plication to achieve adequate effective height was then performed, followed by graft implantation. No additional leaflet repair was needed. CONCLUSIONS: The newly designed sizing rings enable proper sizing of the graft in reimplantation procedures and enable complete leaflet repair before graft implantation.

Understanding coronary artery bypass transit time flow curves: role of bypass graft compliance.

OBJECTIVES: Low mean bypass graft flow (Q) and high pulsatility index (PI) measured by the transit time flow measurement method are not specific for anastomotic stenosis, but occur with competitive flow and poor coronary run-off. We hypothesized that graft compliance is responsible for these changes and that flow measured at the proximal end of the coronary bypass can be viewed as a sum of the graft capacitive flow and flow that passes through the distal anastomosis. METHODS: Transit time flow measurements (TTFMs) of 15 left internal thoracic artery (LITA) to LAD bypass grafts and 10 saphenous vein grafts (SVGs) to either the right coronary artery (RCA) or posterior descending artery (PDA) were analysed. The TTFM was performed on the proximal and distal end of the graft, and proximally with distal occlusion of the graft. Low mean bypass graft flow PI and diastolic filling (DF) measured distally and proximally were compared, and graft compliance was estimated. RESULTS: Diastolic filling was higher distally in every single case (LITA-LAD: distal DF 76 ± 12% vs proximal 66 ± 13%, P = 0.005; SVG-RCA/PDA: distal 72 ± 15% vs proximal 63 ± 12%, P = 0.018). There were no significant differences in Q and PI. Subtracting the distal from the proximal flow gave a result identical to the proximal TTFM in distally occluded grafts, confirming the presence of graft capacitive flow. Graft compliance estimated from the flow of distally occluded grafts was 0.99 ± 0.47 µl/mmHg for LITA grafts and 0.78 ± 0.42 µl/mmHg for SVG grafts. CONCLUSIONS: The study confirmed that the TTFM measured at the proximal end of the coronary bypass could be viewed as a sum of graft capacitive flow and the flow that passes through the distal anastomosis. Graft capacitive flow increases the systolic and decreases the diastolic TTFM when measured at the proximal end of the graft. It explains the higher DF when the TTFM is measured at the distal end of the graft and the increase in the PI at the proximal end when Q decreases. As the influence of graft capacitive flow on the PI in low Q can be eliminated by performing the TTFM at the distal end of the graft, we believe that the value of PI is clinically irrelevant.

Mitral regurgitation and axial flow left ventricular assist device: a computer simulation study.

Good right ventricular function is one of the major determinants of long-term outcomes in patients with implanted left ventricular assist devices (LVADs). In the present study, a computer model was developed to assess the impact of mitral regurgitation on right ventricular workload at different levels of LVAD support. Left ventricular assist device was simulated by a model of HeartMate II. The computer model has shown that the regurgitant volume of the mitral valve falls significantly only after the systolic pressure in the left ventricle decreases, which occurs at higher LVAD revolutions per minute (RPM) when there is no ejection through the aortic valve. However, at low LVAD RPM, the pressures in the left atrium and the pulmonary artery decrease significantly, despite a small decrease in regurgitant volume. According to the computer model, LVAD support decreases mitral regurgitation. Furthermore, regurgitant volume has a smaller impact on the right ventricular afterload when compared with a heart without LVAD support.

Intraoperative left subclavian artery occlusion with left hand ischaemia and steal syndrome in the left internal thoracic artery.

We present a case of a 62-year old man with a left main stenosis, left coronary artery dominance, normal ejection fraction and no valvular pathology, and status post right carotid artery stenting, who was scheduled for elective coronary revascularization. We performed off-pump coronary revascularization, anastomosing the left internal thoracic artery to the left anterior descending artery, and three separate saphenous vein grafts to the intermediate artery and the first and second obtuse marginals, respectively. Proximally, the right internal thoracic artery was used as the inflow for all three venous grafts due to a heavily calcified ascending aorta. During the construction of the distal anastomoses to the obtuse marginals, the arterial pressure in the left radial artery suddenly dropped. The left hand was found to be pale and pulseless. A femoral artery catheter was placed for pressure monitoring and the anastomoses were completed as planned. Intraoperative transit-time graft flow measurement showed a reversed flow in the left internal thoracic artery. Postoperatively, angiography was performed showing a subtotal stenosis of the proximal left subclavian artery. The artery was dilated and stented. The postoperative course was uneventful and the patient was discharged on the 12th postoperative day.