Clinical anatomy of the spatial structure of the right ventricular outflow tract.

BACKGROUND: The right ventricular outflow tract (RVOT) is located above the supraventricular crest and reaches the level of the pulmonary valve. Detailed knowledge of the RVOT spatial structure and its morphology is extremely important for cardiac invasive therapeutic procedures. OBJECTIVES: To examine the spatial structure of the RVOT using virtual models of the right ventricle (RV) interior obtained post mortem. MATERIAL AND METHODS: The study was carried out using 40 adult hearts from both sexes fixed in formalin. Donors had a negative history of cardiovascular diseases. Silicone models of the interior of the RV were made and then subjected to a digital modelling procedure using the photogrammetry technique. For each 3D model of the RV, the RVOT was extracted and measurements were performed. RESULTS: Statistical analysis demonstrated that the dimensions of the transverse (p < 0.001) and sagittal (p = 0.002) axis at the level of the upper and lower border of the RVOT differed significantly. There was also a significant difference between the right and left height of the RVOT (p = 0.009). A clear correlation was found between the volume of the RVOT and the volume of the entire RV (r = 0.718, p < 0.001). CONCLUSIONS: The obtained 3D models of the RVOT can help standardize the data related to RVOT architecture. Furthermore, they can extend knowledge about the RVOT in the field of cardiology and improve the procedures in cardiac surgery.

Transferrin isoform analysis from dried blood spots and serum samples by gel isoelectric focusing for screening congenital disorders of glycosylation.

Congenital disorders of glycosylation (CDG) are a growing, heterogeneous group of genetic disorders caused by a defect in the glycoprotein synthesis. The first and still widely used method for routine CDG screening was isoelectric focusing (IEF) of serum transferrin. Dried blood spot (DBS) testing is commonly used in newborn screening procedures to detect inborn errors of metabolism. The aim of this study was to demonstrate the reliability of the IEF method in DBS testing. Dried blood spot testing can help in the postmortem diagnosis of CDG disorders when other material is unavailable. The patterns and concentrations of transferrin isoforms in serum and DBS are comparable, and slight differences do not affect interpretation of results.

Ventricular fibrillation induced by radiofrequency energy delivery for premature ventricular contractions arising from the right ventricular outflow tract: is implantablecardioverterdefibrillator indicated?

INTRODUCTION    Inadvertently induced ventricular fibrillation (VF) by radiofrequency (RF) energy delivery for premature ventricular complexes (PVCs) is a rare phenomenon; nevertheless, it is crucial to assess long­term risk of sudden cardiac death in these patients. OBJECTIVES    The aim of our study was to define the long­term prognosis in patients with normal ejection fraction (EF), in whom VF was inadvertently induced by RF energy application during ablation of symptomatic idiopathic PVCs originating from the right ventricular outflow tract (RVOT). PATIENTS AND METHODS    Among over 20 000 RF catheter ablations performed at 5 tertiary centers (2008-2016), 6 patients (5 men) had VF induced by RF application to the RVOT. The mean (SD) age of patients was 35.2 (16.8) years. All patients had normal EF (≥60%). We analyzed the risk of malignant ventricular arrhythmias and assessed heart function during follow­up. RESULTS    After ablation, baseline contrast­enhanced magnetic resonance imaging was performed in 4 of the 6 patients; no area of late gadolinium enhancement was observed. One patient received an implantable cardioverter­defibrillator (ICD). Exercise tests revealed only rare PVCs. All patients completedthe follow­up (mean [SD] duration of follow­up, 64.0 [34.9] months). All patients were alive, with no cases of syncope, documented ventricular tachycardia, or VF. The patient with an ICD received 2 inappropriate high­voltage therapies. CONCLUSIONS    Patients with inadvertently induced VF via RF energy application during ablation of PVCs from the RVOT, who have normal left ventricular function and no electrocardiography abnormalities have good prognosis and low VF risk during long­term follow­up. Therefore, ICD placement seems to be not indicated for these patients.

Radiofrequency ablation without the use of fluoroscopy - in what kind of patients is it feasible?

INTRODUCTION: The aim of the study was to describe the experience in performing ablation without fluoroscopy. MATERIAL AND METHODS: From 575 ablation procedures with CARTO performed in the period 2003-2008, 108 (42 M; age 40 ±16 years) were done without fluoroscopy. One patient had ablation using the Localisa system. There was one man with thrombocytopenia and two pregnant women. RESULTS: Right ventricular (RV) outflow tract arrhythmias and other RV arrhythmias were noted in 38 patients (35%) and 17 patients (15%), respectively. There were 5 (4.6%) left ventricular (LV) outflow tract arrhythmias and 19 (17.5%) other LV tachycardias; right accessory pathways in 17 patients (20%), in the middle cardiac vein in 1, Mahaim fibres in 1, and 3 cases of permanent junctional reciprocating tachycardias. One patient with CRT had AV node ablation (Localisa). In 3 patients there were also other arrhythmias treated: slow AV nodal pathway, typical flutter isthmus and right atrial tachycardia. In 2004, 1/96 CARTO procedures was done without fluoroscopy, in 2006 2/97, in 2007 19 (2 in LV) of 93, in 2008 87 (22 in LV) of 204. The percentage of ablations without fluoroscopy in every hundred CARTO procedures was: 1%, 1%, 8%, 23%, 46%, 28% (mean 18%). There were no procedure-related complications. CONCLUSIONS: It is feasible to perform ablations within both right and left sides of the heart without fluoroscopy. The number and type of non-fluoroscopic procedures depends on the operator's experience. Pregnant patients, with malignant history or with hematologic diseases should be ablated without fluoroscopy in centres that specialise in these kinds of procedures.

The choice of surgical specialization by medical students and their syncopal history.

BACKGROUND: The aim of the study was to assess whether medical students' fainting outside the university or while witnessing surgical procedures and/or autopsies influenced their choice of a specialization. MATERIALS AND METHODS: The study group consisted of 605 medical students (from fourth to sixth year of study) from five medical universities in Poland (325 women, 212 men and 8 responders of an unspecified gender). The median age of subjects studied was 23 years, and the interquartile range was 23-24 years. The students at each university were chosen randomly by the author who worked there and had contact with them. An anonymous questionnaire was developed to gather information regarding demographics, the specialization which each student wanted to choose, the syncope occurrence in the medical history, the syncope and presyncope occurrence during surgery and autopsy as well as the syncopal events' characteristics. RESULTS: The group of 15% of women and 30% of men declared to have pursued the surgical specialization (P<0.001), 29% of women and 56% of men declared the intention to pursue an invasive specialization (P<0.001). As many as 36.0% of women studied and 13.1% of men studied reported syncopal spells outside university (P<0.001). Only 41 students (6.8%) reported that syncope or presyncope in any studied circumstances had an impact on their specialization choice. The multivariate analysis showed that the choice of surgical specialization is related to the male gender and the absence of syncopal spells outside the university. CONCLUSIONS: Syncopal and presyncopal spells may affect the professional choices of the medical students. The male gender and a lack of syncope occurrence outside operating room are related to the choice of surgical specialization.

Mastocytosis in children and adults: clinical disease heterogeneity.

Mastocytosis is a clonal disease of the hematopoietic stem cell. The condition consists of a heterogeneous group of disorders characterized by a pathological accumulation of mast cells in tissues including the skin, bone marrow, liver, spleen and the lymph nodes. Mastocytosis is a rare disease which occurs both in children and adults. Childhood onset mastocytosis is usually cutaneous and transient while in adults the condition commonly progresses to a systemic form. The heterogeneity of clinical presentation of mastocytosis is typically related to the tissue mast cell burden, symptoms due to the release of mast cell mediators, the type of skin lesions, the patient's age at the onset and associated haematological disorders. Therefore, a multidisciplinary approach is recommended. The present article provides an overview of clinical symptoms, diagnostic criteria and treatment of mastocytosis to facilitate the diagnosis and management of mastocytosis patients in clinical practice.

Morphological remarks regarding the structure of conduction system in the right ventricle.

BACKGROUND: The knowledge of conduction system morphology has a vital significance in cardiology and cardiac surgery - it enables to interpret pathologies and choose treatment. This has been confirmed by numerous accounts, both in the context of e.g. atrial fibrillation ablations as well as treating septum defects. Due to diversity and changeability of conduction system structure and their clinical implications, its thorough analyses seem to bear special importance. AIM: To examine the structure of selected elements of conduction system present in the right ventricle (RV). METHODS: Elements of conduction system present in RV of 6 foetuses (from 12 to 32 weeks of foetus age), 6 children (from 1 day to 7-year-old) and 10 adults (from 37 to 79-year-old) were histologically examined. Cross sections of 10 moderator bands and 10 anterior papillary muscles of adult human hearts were made. Specimens including membranous and muscular parts of the septum along with diverging moderator band were taken from a group of foetus, child and adult hearts. Cuttings of 10 micron width were stained with Masson's method in Goldner's modification. On the basis of the sections of membranous and muscular parts of the septum, the continuities of the elements of the conduction system were analysed. RESULTS: It was observed that in most cases the right branch of His' bundle locates itself deep in the muscular tissue of the septum irrespective of age; it is clearly separate along its whole run and gradually penetrates the muscular tissue with its fibers. Hardly ever does the right branch of His' bundle locate itself on the surface, subendocardially, with a minimum penetration into the muscular tissue. Moreover, in most cases, elements of conduction system are present in moderator band. The main tissue constituting its stroma is above all muscular tissue and to a lesser extent, connective tissue. In addition to this, fat tissue in variable proportion was also observed. In cross sections of the moderator band a distinctively circumscribed stripe of fibers of the conduction system was found. However, one could also observe samples in which its identification was not possible. CONCLUSIONS: The right branch of His bundle within the muscular part of the septum in most cases is located intramuscularly irrespective of age. The results of analyses prove a relatively constant character of the presence of the conduction system within the moderator band.

The LocaLisa system as the key to shortening the procedure duration and fluoroscopy time during ablation of atrial fibrillation.

BACKGROUND: Ablation of atrial fibrillation (AF) can be difficult and time-consuming. Systems facilitating catheter navigation may be helpful. AIM: To compare the efficacy of the LocaLisa system with the conventional mapping/ablation approach to radiofrequency (RF) ablation of AF. METHODS: Group 1, consisting of 64 patients (48 male; aged 51.5+/-10.6 years), underwent segmental isolation of the pulmonary veins with the Lasso catheter and the LocaLisa system. Group 2, consisting of 64 patients (44 male, aged 51.4+/-11.0 years), had RF ablation guided by means of a conventional fluoroscopy-based approach. Clinical and procedural data were analysed. RESULTS: Nine patients from group 1 and three patients from group 2 had persistent AF. In group 1 the mean number of isolated veins was 3.98+/-0.96, while in group 2 - 4.0+/-0.95 (NS). In group 1 cavotricuspid isthmus lines were created in four patients and lines in the roof of the left atrium in two patients. One patient needed slow pathway ablation. In group 2 six patients had ablation of the cavotricuspid isthmus and a line was created at the roof of the left atrium in one patient. Two patients had ectopic activity ablated in the crista terminalis. Procedure times were 131.6+/-40.3 and 170.0+/-56.5 min (p <0.0001) and fluoroscopy times were 16.93+/-9.7 and 35.66+/-12.7 min (p <0.0001) for groups 1 and 2, respectively. Long-term efficacy of RF ablation was similar in both groups (for example, complete success was achieved in 59% of patients using LocaLisa and 50% without using this system, NS). CONCLUSIONS: The LocaLisa navigation system makes it possible to shorten both the duration of the procedure and the total fluoroscopy time during ablation of AF.

Left ventricle systolic volume in vasovagal syncope patients.

One of the hypotheses put forward concerning the mechanism of vasovagal syncope is that the vagal afferent fibres are activated during vigorous contractions against a partly empty left ventricle. The aim of the study was to confirm this hypothesis by using 2D echocardiography during a head-up tilt test. The study was carried out on 39 patients (17 male, 22 female, age range 21-64 years), all with a history of recurrent syncope. The patients were examined using a 2D echo to measure the end-diastolic and end-systolic volume before the head-up tilt test after the Westminster protocol (45 min/60 grade) and every five minutes after tilting. T patients during head-up tilt test had a positive response and 32 proved negative. A reduction of both the end-diastolic and end-systolic volumes of the left ventricle was noticed. There was no significant difference in the degree of ejection fraction reduction. The difference in ejection fraction reduction between the two groups was similarly non-significant. It was also noticed that the patients with a positive response had more vigorous contractions than those with a negative test. The decision was therefore taken to use a different parameter for the left ventricle contraction, namely the LV posterior wall slope. As this parameter is partly dependent on time, its use in confirming the extremely vigorous nature of the contractions was considered appropriate. Only 6 patients were tested using this parameter. A tendency towards greater left ventricle posterior wall slope values, both before and during tilting was noticed in the group of patients with vasovagal reaction. Our data shows that vigorous contraction is probably less responsible for vasovagal syncope release than left ventricle volume reduction.

Value of propranolol-induced heart rate and blood pressure changes in predicting results of tilt testing.

BACKGROUND: A degree of reduction of heart rate (HR) and blood pressure (BP) values following beta-blocker administration has been shown to indicate beta-blockade effectiveness. Whether this parameter is also useful in the identification of patients with vaso-vagal syncope (VVS) who could benefit from beta-blocker therapy, has not yet been established. AIM: To analyse the usefulness of propranolol-induced acute changes in HR and BP in the prediction of the results of tilt testing (TT) in patients with VVS. METHODS: The study group consisted of 37 patients with a history of at least two syncopal episodes in the past 6 months, in whom syncope was reproduced during TT. After positive baseline TT the patients were returned to supine position and were given intravenous propranolol. After 15 min supine rest the patients were tilted again using the same protocol as during the baseline test. Propranolol was considered effective when the result of the second (on drug) TT was negative or the time to syncope occurrence was longer than during baseline TT. During the whole procedure systolic BP (SBP), mean BP (MBP), diastolic BP (DBP) and HR were measured. These parameters were analysed in four different time-intervals: period I - between 13th and 15th minute of supine rest preceding the passive phase of TT, period II - between first and third minute of the passive TT, period III - following propranolol injection, between 13th and 15th minute of supine rest preceding second TT, and period IV - between first and third minute of second TT, either passive (if positive) or after NTG administration. Both, mean values and differences (Delta) in analysed parameters between various time-intervals (II-I, III-I, IV-II and IV-III) were taken into account. RESULTS: Intravenous propranolol occurred effective in preventing syncope during second TT in 29/37 (78%) patients. The DeltaSBP, DeltaMBP and DeltaDBP values calculated from periods III and IV were significantly different between patients with or without protective effects of propranolol. The cut-off values which were computed to obtain the highest value of total predictive accuracy (the highest value of the sum of sensitivity and specificity) were -5 mmHg for DeltaSBP, -4 mmHg for DeltaMBP and -2 mmHg for DeltaDBP. A stepwise logistic regression analysis revealed that DeltaSBP of -5 mmHg or less had the highest value in the prediction of a positive response to propranolol, reaching a sensitivity of 72%, specificity of 88%, positive predictive value of 95% and negative predictive value of 48%. CONCLUSIONS: Propranolol-induced changes in blood pressure values may predict the effectiveness of beta-blockade in preventing syncope during second TT performed after intravenous infusion of propranolol. A drug-induced reduction in systolic blood pressure of less than 5 mmHg may identify those who will benefit from beta-blocker therapy.