Evaluation of a new algorithm for tracking activation during atrial fibrillation using multipolar catheters in humans.

BACKGROUND: Conventional mapping techniques during atrial fibrillation (AF) are difficult to apply because of cycle length irregularity. Mapping studies are usually restricted to short durations of AF in limited regions because of the laborious manual annotation of local activation time (LAT). The purpose of this study was to test an automated algorithm to map activation during AF, with comparable accuracy to manual annotation. METHODS: Left atrial (LA) mapping was performed using a 20-pole double loop catheter (AFocusII) in 30-second data segments from 16 patients. The new algorithm (RETRO-Mapping) was designed to detect wavefront propagation between electrodes, and display activating wavefronts on a two-dimensional representation of the catheter. Activation patterns were validated against their bipolar electrograms and with isochronal maps. The mapping protocol was approved by the research ethics committee (13/LO1169 and 14/LO1367). RESULTS: During AF, uniform wavefront activation direction (mean ± SD, degrees) from manually constructed isochronal maps was comparable to RETRO-Propagation Map (RETRO-PM) and RETRO-Automated Direction (RETRO-AD): 1 ± 6.9 for RETRO-PM; and 2 ± 6.6 for RETRO-AD. There was no significant difference in activation direction assigned to 1373 uniform wavefronts during AF when comparing RETRO-PM with RETRO-AD (Bland-Altman mean difference: -0.1 degrees; limits of agreement: -8.0 to 8.3; 95% CI -0.4 to 0.2; (r = 0.01) R2 = < 0.005; P = .77). CONCLUSION: We have developed and validated a new technique to map activation during AF. This technique shows comparable accuracy to that of conventional isochronal mapping with careful manual adjustment of LAT.

Cycle Length Evaluation in Persistent Atrial Fibrillation Using Kernel Density Estimation to Identify Transient and Stable Rapid Atrial Activity.

PURPOSE: Left atrial (LA) rapid AF activity has been shown to co-localise with areas of successful atrial fibrillation termination by catheter ablation. We describe a technique that identifies rapid and regular activity. METHODS: Eight-second AF electrograms were recorded from LA regions during ablation for psAF. Local activation was annotated manually on bipolar signals and where these were of poor quality, we inspected unipolar signals. Dominant cycle length (DCL) was calculated from annotation pairs representing a single activation interval, using a probability density function (PDF) with kernel density estimation. Cumulative annotation duration compared to total segment length defined electrogram quality. DCL results were compared to dominant frequency (DF) and averaging. RESULTS: In total 507 8 s AF segments were analysed from 7 patients. Spearman's correlation coefficient was 0.758 between independent annotators (P < 0.001), 0.837-0.94 between 8 s and ≥ 4 s segments (P < 0.001), 0.541 between DCL and DF (P < 0.001), and 0.79 between DCL and averaging (P < 0.001). Poorer segment organization gave greater errors between DCL and DF. CONCLUSION: DCL identifies rapid atrial activity that may represent psAF drivers. This study uses DCL as a tool to evaluate the dynamic, patient specific properties of psAF by identifying rapid and regular activity. If automated, this technique could rapidly identify areas for ablation in psAF.

Airway obstruction can be better predicted using Global Lung Function Initiative spirometry reference equations in Marfan syndrome.

Marfan syndrome is a genetic disorder of the connective tissue, including involvement of the lungs.Pulmonary function test was performed in 32 asymptomatic adult Marfan patients using European Community for Coal and Steel (ECCS) and Global Lung Function Initiative (GLI) reference values.Using GLI equations for reference, significantly lower lung function values were noted for forced vital capacity (FVC) (87.0 ± 16.6% vs. 97.1 ± 16.9%; P < 0.01) and forced expiratory volume in the first second (FEV1) (79.6 ± 18.9% vs. 88.0 ± 19.1%; P < 0.01) predicted compared to ECCS. Obstructive ventilatory pattern was present in 25% of the cases when calculating with GLI lower limit of normal (LLN), and it was significantly more common in men as compared to women (n = 6, 50% vs. n = 2, 10%; P = 0.03).GLI is more suitable to detect early ventilatory changes including airway obstruction in young patients with special anatomic features, and should be used as a standard way of evaluation in asymptomatic Marfan population.

Efficacy of the non-adenosine analogue A1 adenosine receptor agonist (BR-4935) on cardiovascular function after cardiopulmonary bypass.

BACKGROUND: We tested the hypothesis that pharmacological preconditioning with a newly developed, potent non-adenosine analogue A1AdoR agonist (BR-4935) improves biventricular cardiac and endothelial function after cardiopulmonary bypass. METHODS: Twelve anesthetized dogs underwent cardiopulmonary bypass. Dogs were divided into two groups: group 1 (n = 6) received saline vehicle, group 2 (n = 6) received BR-4935 before cardiopulmonary bypass. Biventricular hemodynamic variables were measured using a combined pressure-volume conductance catheter. Coronary blood flow, ATP content, malondialdehyde and myeloperoxidase levels and vasodilatative responses to acetylcholine and sodium nitroprusside were also determined. RESULTS: Administration of the A1AdoR agonist led to a significantly better recovery of left and right ventricular systolic function after 60 minutes of reperfusion. Although the vasodilatative response to sodium nitroprusside was similar in both groups, acetylcholine resulted in a significantly greater increase in coronary blood flow in the BR-4935 group. In addition, the ATP content was significantly higher in the same group. Furthermore, malondialdehyde and myeloperoxidase levels significantly decreased in the A1AdoR group. CONCLUSION: Pharmacological preconditioning with a new, potent non-adenosine analogue A1AdoR agonist improves biventricular function recovery and endothelial function after hypothermic cardiac arrest.

Note: Performance of a novel electrostatic quadrupole doublet for nuclear microprobe application.

The newly designed and constructed electrostatic quadrupole doublet (EQD) at the University of North Texas (UNT) has achieved mass independent focusing of MeV particles to a spot size of 3.3 × 3.5 µm. The EQD is compared to the Louisiana magnetic doublet which is also in use at UNT. Characteristics such as demagnification and sensitivity to aberrations are simulated by the matrix raytracing software, propagation of rays and aberrations by matrices and compared for each focusing system. Particle induced x-ray emission (PIXE) maps of a 2000 mesh Cu grid are compared and show that both doublets produce suitable spot sizes for microprobe analysis. A coarser, 200 mesh grid and incident beams of 2 MeV H+ and O+ show the EQD to be stigmatic given common aperture sizes and lens potentials.

Aprotinin and perioperative complications in cardiac surgery.

AIM: Recently, the clinical significance of aprotinin-induced renal dysfunction and other end-organ complications in patients undergoing cardiac surgery has engendered substantial controversy. Therefore, we assessed the effect of aprotinin on end-organ complications in patients undergoing cardiac surgery. METHODS: Data of 674 patients (mean age 65.4 +/- 11.0 years, 457 males) undergoing cardiac surgery between January 1 and December 31, 2005 at Semmelweis University were used for the analyses. Preoperative, intraoperative and postoperative clinical and surgical variables were recorded. Patients administered aprotinin received the drug either as a low-dose regimen, a loading dose of 1 million kallikrein-inhibitor units (KIU), 1 million KIU in pump, and 1 million KIU post pump (or continuous infusion of 0.25 million KIU per hour); or a high-dose regimen, a loading dose of 2 million KIU, 2 million KIU in pump, and 2 million KIU post pump (or continuous infusion of 0.5 million KIU per hour). The outcomes were renal complications defined as a 25% reduction in postoperative calculated creatinine clearance compared to the preoperative baseline or renal failure requiring dialysis; and the composite of renal, cardiovascular and cerebrovascular complications and all-cause mortality. RESULTS: Patients underwent coronary artery bypass surgery (63%), valvular (27%) or a combination (5%) and surgery on the ascending aorta (5%). There were 550 patients (81.6%) who received aprotinin treatment. In multivariate regression analyses when the relation between high or low dose aprotinin compared to no aprotinin was evaluated, the likelihood of renal complications [high dose: odds ratio (OR)=1.4, 95% confidence interval (CI), 0.6-3.0, P=0.4; low dose: OR=1.2, 95%CI, 0.7-2.3, p=0.5], and the composite outcome variable (high dose: OR=1.6, 95%CI, 0.8-3.4, P=0.2; low dose: OR=1.3, 95%CI, 0.7-2.3, P=0.4) were not significantly increased. CONCLUSION: Our analysis suggests that aprotinin use in either a high or low dose regimen was not associated with an increase in adverse end-organ complications.

Breakthrough in the Transplantation of Thoracic Organs in Hungary.

In 2016 the focus was, by all means, on the transplantation on thoracic organs. More than 50 heart transplantations were performed in this year. With this achievement, the Hungarian Heart Transplantation Program became one of the leading programs in the world. In the Thoracic Surgery Unit of the National Institute of Oncology and the Thoracic Surgery Department of Semmelweis University the first successful lung transplantation was carried out on December 12, 2015 when the Hungarian Lung Transplantation Program was launched.

[Incidence of stenosis of the internal carotid artery among patients waiting for coronary surgery]. / Arteria carotis interna szükületek gyakorisága coronaria mütétre váró betegek között.

1273 patients awaiting for coronary surgery were screened towards coexisting internal carotid artery stenoses. Non-significant carotid stenosis was revealed in 7.3% of these patients. In 48 patients (3.8%) the revealed stenoses were found to be hemodynamically significant. The coexistence of significant carotid stenoses with coronary artery disease was especially high at elderly patients. Among male patients over 70 years of age the occurrence of high grade carotid stenosis was as high as 10%. The 75% of significant stenoses was found to be asymptomatic. These would not been revealed without the carotid screening. The goal of this study is drawing attention to the frequent coexistence of coronary artery disease with carotid artery stenoses.

[Percutaneous transluminal angioplasty in atypical aortic coarctation in an adult patient]. / Felnöttkori atípusos coarctatio aortae percutan transzluminális angioplasztikája.

In the reported case, coarctation of the aortic arch (Coa) was the cause of hypertonia. Coa diminishes the expected lifetime, and operative treatment is required. PTA is contradictory in the treatment of coarctation. In the reported case coarctation was located on the aortic arch, and because of the risk of the operation PTA was performed. The dilatation was successful, hypertension resolved, and there was no significant difference in the blood pressure on the extremities. 16 months after the dilatation the patient is symptomless. The result of this case indicates that PTA of the Coa of the aorta is feasible. More experience is needed to establish its role.

[Traumatic rupture of the descending aorta]. / Az aorta descendens traumás eredetü rupturája.

During a ten-year period 16 patients were seen with aortic rupture and false aneurysm secondary to blunt trauma. One patient underwent an acute operation, 4 patients had operative therapy elective delayed and 11 patients were operated on for chronic traumatic false aneurysm. Operative delay was done in case of simultaneous multisystem injury (e.g. shock caused by abdominal injuries, cerebral contusion or pulmonary contusion on the right side). The shunt bypass method of repair was used in the case of 3 patients, cardiopulmonary bypass in 6 cases and simple aortic cross-clamping in 6 patients. One operation was performed without aortic cross-clamping. Primary repair was achieved in three patient, in 3 more cases a patch was inserted and in 9 cases interposition Dacron grafting was accomplished. One "wrapping" operation was performed. In 2 cases, reoperation was necessary because of postoperative bleeding. One patient died in the perioperative period. Right sided hemiparesis occurred in one patient postoperatively. Rupture does not affect the whole aortic wall, especially in young people because of the natural elasticity of vessel. The appearing shock and hypotension might protect the mediastinal pleura against bursting. This could provide a chance to survive. Our experience indicate: Elective delay of operation in patients with multiple system injuries can be achieved with antihypertensive therapy.

[Total proximal reconstruction of chronic aortic dissection in patients with Marfan syndrome]. / Marfan-kóros betegeknél észlelt krónikus aorta dissectio teljes proximalis korrekciója.

Authors present two patients suffering from Marfan syndrome. Asymptomatically developed serious cardiovascular complications being characteristic of the syndrome itself were revealed at both cases. Type "A" aortic dissection was found at the first, and type "B" aortic dissection involving even the arch as well revealed at the other patient. They were operated on an elective base. Total proximal aortic reconstructions (aortic root-ascending aorta-arch) were performed under deep hypothermia using total circulatory arrest (35 and 87 min). Both patients are doing well without complaints 3-4 months following the surgical interventions. Control angiographic imagination has found normal anatomic conditions at one of the patients. Anastomosis stenosis at the borderline of the arch and descending aorta was revealed at the other case which should be necessary to operate at an later occasion.

[Experience with the surgical management of constrictive pericarditis]. / Tapasztalataink a constrictiv pericarditis sebészi kezelésében.

61 patients were operated on for constrictive pericarditis at the Cardiovascular Surgical Clinic of Semmelweis Medical University in the last 33 years. The average hospital mortality of the surgical pericardiectomy was 4.9%. The final conclusions of this retrospective and follow up study are as follows: pericardiectomy is the method of choice in the treatment of constrictive pericarditis, since it does not has any therapeutic alternative, its hospital mortality is low and it results excellent early and late postoperative functional effects.

[Distribution of lipoprotein fractions in men with arteriosclerosis obliterans]. / A lipoprotein frakciók megoszlása arteriosclerosis obliteransban szenvedö férfiakban.

The fasting serum total cholesterol, triglyceride, LDL-cholesterol, VLDL-cholesterol and HDL-cholesterol were determined in fifty male patients with arteriosclerosis obliterans (ASO) confirmed by angiography. Twenty five of the patients were hyperlipidemic and significantly elevated concentration of atherogenic lipoproteins could be demonstrated compared to age matched control group of healthy subjects (n = 20). The HDL-cholesterol level in the patient group was significantly decreased even if comparing normolipemic patients to controls. In the postprandial phase of cholesterol loading (600 mg) the serum total cholesterol, LDL-cholesterol and HDL-cholesterol levels did not change in both groups. A marked increase in serum total triglyceride, VLDL-cholesterol and VLDL/HDL-cholesterol ratio was detected and the differences between the two groups regarding these lipoprotein fractions were increased. The importance of cholesterol-rich VLDL in ASO and its relationship to familial dysbetalipoproteinemia are discussed.

[New method for the intraoperative biochemical monitoring of cerebrospinal fluid in surgery of thoracoabdominal aortic aneurysms]. / Uj módszer a cerebrospinalis fluidum (CSF) intraoperatív biokémiai monitorozásában thoracoabdominalis aortaaneurysma-mútétek során.

Paraplegia remains to be one of the most dangerous complications following thoracoabdominal aortic surgery with an incidence of 0.5 to 40%. Therefore, intraoperative monitoring of spinal cord function is very important when choosing the appropriate surgical technique. Early detection of spinal cord injury continues to be a crucial problem, moreover, the currently applied electrophysiological methods appear to be inaccurate. The aim of the study was to detect prospective spinal cord injury intraoperatively by monitoring the biochemical parameters of the cerebrospinal fluid (CSF). The authors studied the reversible aerobic/anaerobic metabolic changes by monitoring CSF lactate levels, moreover S-100 protein and neuron-specific enolase (NSE) concentrations--specific for neuroglia and neuronal injury, respectively. One of the important methods to prevent paraplegia is the intraoperative CSF drainage, which may improve spinal cord perfusion. Between 1996-1998 51 patients underwent reconstructive thoracic or thoracoabdominal aortic aneurysm operation. The continuously drained CSF was collected in 10 ml fractions during the preparation, whereas during aortic cross-clamping and de-clamping 10 minute fractions were used. All CSF samples were immediately analysed intraoperatively for pH, pCO2, HCO3, potassium and lactate levels, S-100 protein and NSE were analysed by immunoluminescence. CSF lactate levels increased slightly during aortic clamping and a moderate, but non-significant increase was found in the hyperemic phase (reperfusion) in patients without spinal cord ischemia. Spinal cord injury was detected in 7 cases. These patients exhibited a significant CSF-lactate increase (control vs aortic cross-clamping: 1.9 vs 5.3 mmol/l), moreover CSF-lactate remained elevated throughout the whole operation. Paraplegia did not occur, Tarlov 2 paraparesis developed in four cases and three patients displayed cerebral damage. Intraoperative CSF--especially CSF-lactate--monitoring may help the operating team to detect early anaerobic changes of the metabolism the spinal cord.

[Importance of carotid artery studies prior to coronary surgery]. / Carotis vizsgálat jelentösége coronaria mütétek kapcsán.

The incidence of cerebral complications following extracorporal cardiac operations is reported to be approximately 2%. One of the possible reasons behind these complications is the presence of significant carotid stenosis as coexistent disease to the cardiac illness requiring surgery. Because of the common etiology carotid stenosis coexists mainly with a coronary artery disease. The authors make known their own screening methods based on the correct exploration of medical history and on the proper physical examinations. Coexistent significant carotid stenosis was revealed in 3.6% of 1056 patients who underwent coronary surgery within the period of 41 months. In all of these cases prophylactic carotid endarterectomy was performed. In twenty cases within this group the carotid reconstructions were performed simultaneously with myocardium revascularization. Staged endprocedures were performed in the other 18 cases. There was no surgical mortality and only one patient suffered major stroke. The authors emphasize the importance of carotid screening among patients awaiting coronary surgery especially in patients who previously sustained cerebral ischemic attacks, the presence of carotid bruits or any other known localization of obliterate arterial disease and finally in all patients over 60 years of age.

[Atrial fibrillation after open-heart surgery--incidence, prevention and treatment]. / Posztoperatív pitvarfibrillàció okai, gyakorisága, megelözése és kezelése szívsebészeti betegeknél.

Atrial fibrillation is a common problem in the postoperative period following open-heart surgery. The pathogenesis of postoperative atrial fibrillation is likely to be multifactorial, however increased sympathetic activation may play a significant role. The aim of the study was to detect the incidence and possible reasons of atrial fibrillation in the first three postoperative days after open-heart surgery. Atrial fibrillation was detected in a total of 48 patients (mean age 64.8 +/- 8.8 years) of the 302 consecutive patients included in the study. The incidence of atrial fibrillation was 15.9%. In the history of patients with atrial fibrillation paroxysmal or persistent atrial fibrillation occurred in 18 cases. Acute ischaemia, hypopotassemia, high dose catecholamines contributed to the development of arrhythmias in 6, 4 and 4 cases, respectively. Lack of perioperative beta-blocker treatment was seen in 35 cases. Postoperative bleeding and reoperation occurred prior to the onset of atrial fibrillation in 9 instances. The applied antiarrhythmic therapy was metoprolol, amiodarone, propafenon and electrical cardioversion in 33, 21, 4 and 2 cases, respectively. Incidence of atrial fibrillation was found significantly lower in patients receiving beta-blocker premedication (13/181 [7.18%] versus 35/121 [28.9%]). There was no correlation between the incidence of atrial fibrillation and the length of the surgery, aortic-cross clamp time and the number of bypass grafts. Absence of preoperative beta-blocker treatment, previous atrial fibrillation and combined surgery were found to be strong predictors of atrial fibrillation. There was weaker association with increased age. On the basis of the outcome of our study beta-blocker premedication is suggested in most patients undergoing open-heart surgery.

[Development and results of valve replacement surgery at the Városmajor Clinic 1976-1990 (retorospective clinical analysis)]. / A szívbillentyü-sebészet fejlödése és eredményei a Városmajori Klinikán 1976-1990 (retrospektív klinikai analízis).

In Hungary valve replacement is still a major indication for heart surgery in adults. In the Cardiovascular Surgical Clinic of Semmelweis Medical University of Budapest from 1976 to 1990 2435 patients were operated for valve disease. Majority of the cases had single (aortic n = 856, mitral n = 912) or double (aortic + mitral n = 513) valve replacement. Over this 15 years period there have been many alterations in patients characteristics and surgical technique as well. In spite of the increasing mean age of patients the operative mortality has decreased (in the last 5 years period it was 2.7%, 5.5% and 7.9% in the three groups respectively). At the same time the number of patients requiring valve re-replacement or combined valve + coronary procedure has increased. The use of bioprosthetic valves has fallen below 10 percent from the 60--80 percent observed between 1976--1980. The analysis showes excellent surgical results in the field of valve replacement in Hungary.

[Coronary surgery at the Cardiovascular Surgical Clinic (1976-1990)]. / Coronariasebészet az Er- és Szívsebészeti Klinikán (1976-1990).

In the Cardiovascular Surgical Clinic of the Semmelweis Medical University of Budapest the first coronary artery bypass grafting (CABG) procedure was performed in 1975. Since that time coronary artery surgery has become a routine everyday practice representing more than half of the total workload of adult cardiac surgery. The analysis of 1347 operations performed between 1976-1990 on patients with coronary heart disease showed the followings: the first few years--so called learning curve of CABG operations is characterised by high mortality. With passing time the number of cases performed each year increased rapidly and the surgical technique has improved too. At the same time the operative mortality figures showed decreasing tendency--it was 2.1% for the last 609 cases. All observed parameters showed some progress: in 1990 the average number of grafts per patient was 3.09, internal mammary artery usage 15 percent and the mean aortic cross clamp time per anastomosis 24.5 minutes. Complete myocardial revascularisation is the key point of coronary artery surgery. In order to achieve this target in all operated cases further technical improvement is necessary.

[Experience with surgical treatment of prosthetic valve endocarditis]. / Múbillentyú-endocarditis sebészi kezelésével szerzett tapasztalataink.

Prosthetic valve endocarditis (PVE) is a rare but dangerous complication that may occur after the implantation. The authors retrospectively summarize their 11-year experience in treating PVE. 2357 prosthetic valve (PV) implantations were performed over 11 years at the Department of Cardiovascular Surgery, Semmelweis University, Budapest, PVE was found to be the indication for operation in 1.8% of the cases (43/2357). 43 surgical interventions were carried out on 38 patients (mean age: 52.5 yrs, male/female ratio: 25/13). Blood cultures were positive in 86% and negative in 14% of the cases. The infected PV-s were replaced emergently (14%), urgently (79%) or electively (7%). The explanted valves were aortic in 55% and mitral 45% of the cases, 63% were mechanical and 37% biological. PVE followed the primary PV implantation in less than a year in 39.5%. Infected environment during the primary PV implantation was found to be a predisposing factor for the late endocarditis episodes. The mean age of the infected and explanted aortic bioprosthetic valves was significantly higher than that of explanted mechanical valves (p < 0.05). No such difference could be found at the mitral valves. The explanted valves were replaced by mechanical (75.5%) or biological (22.5%) devices. Homograft was implanted once. Early postoperative mortality of the primary PV replacements was 10.5%) devices. Homograft was implanted once. Early postoperative mortality of the primary PV replacements was 10.5%. Endocarditis reoccurred in 20% of the cases. Means follow-up duration was 45.5 months. Two-, five- an 10-year survival were 75%, 64% and 51% respectively. In conclusion in the surgical treatment of PVE, bioprosthetic and mechanical valves are suitable alternatives as opposed to homografts and freestyle stentless valves.

[Coronary artery bypass grafting without extracorporeal circulation]. / Koszorúérmútétek extrakorporális keringés alkalmazása nélkül.

At the Department of Cardiovascular Surgery of Semmelweis University, Budapest we have performed 57 coronary bypass operations without using cardiopulmonary bypass between 1996 and September 2001. Due to the learning phase we preferred cases of 1-2 wessel diseases, and revascularisation necessary on the anterior surface of the heart. In the beginning the stabilization of the operative field was ensured by manual methods, then by applying mechanical stabilization devices (Octopus 2, Genzyme). As to the type of operative indication overwhelmingly elective operations were performed. REDO procedure, i.e. repeated coronary bypass operation was carried out in 2 cases. Forty-eight patients recovered without complication. Two patients died, one of them suffered perioperative infarction, the other died due to cerebral complication. Total mortality was 3.5%. As a consequence of cardiac ischaemia in the direct postoperative period, we performed emergent coronary ballon dilatation (PTCA) in two cases. In three cases we experienced perioperative infarction. We followed up our patients by way of interview and telephone interview. The follow-up is 95%, the average follow-up time is 15 months. Significant cardiac event (infarction, PTCA or REDO coronary operation) took place in the case of 7 patients. In the majority of our patients the operation resulted in an improvement of condition, 43 patients are free from angina.