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.

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.

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.

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.

Cardiac allograft vasculopathy in adult human recipients: a case series of seven patients and review of literature.

BACKGROUND: Chronic rejection (CR) also called cardiac allograft vasculopathy (CAV) is, besides infections and malignant tumors, the leading cause of death during the late period of post-heart transplant. PATIENTS AND METHODS: In this paper, we present a series of seven cases with chronic post-transplant cardiac rejection in the light of our experience related to histopathological aspects, difficulties in diagnosing and survival time. RESULTS: Our study comprises patients whose ages ranked at the time of transplant between 33 and 58 years, with a mean age of 47.71 years, the ratio between men and women being 6:1. Chronic rejection - cardiac allograft vasculopathy occurred in all seven patients comprised in this study, the earliest in the second year post-transplant (three patients), followed by the third year (one patient), the seventh and eighth year (one patient) and the latest survival period being over 11 years (one patient). Four out of the seven patients with chronic rejection events were preceded by episodes of acute cellular rejection. The most convincing indirect evidence of chronic rejection in endomyocardial biopsies were: ischemic events of the myocardiocytes and impaired microvascular network because of perivascular and interstitial fibrosis. CONCLUSIONS: Our study shows that the most important morphological factors correlated with the manifestation of chronic rejection were the episodes of acute cellular rejection or perivascular and interstitial fibrosis, these injuries also being indirect signs mainly detectable at the level of endomyocardial biopsies.

Patchy myocardial pattern of virus sequence persistence in heart transplant recipients--possible role of sampling error in the etiology.

BACKGROUND: The pathway from viral myocarditis to end-stage heart failure is commonly accepted, but diagnosis of virus-mediated myocardial injury remains challenging. Virus persistency in the myocardium may accelerate ventricular failure; thus, a precise diagnosis of virus persistency may prevent the development of end-stage heart failure. METHODS: We performed a systematic investigation on the sampling error of viral diagnostics in heart transplant recipients: Transmural samples from 5 regions of the explanted hearts from recipients during heart transplantation were amplified using entero-, adeno-, and herpesvirus sequences and histologic examinations performed. RESULTS: We examined 175 myocardial samples from dilated cardiomyopathy and 100 samples from 20 forensic medicine patients. Seven patients were positive for the examined viruses: 10 positive regions for adenovirus, and 1 positive region for herpes virus DNA, but none for enterovirus. A focal myocardial pattern was detected for adenovirus. CONCLUSION: Our results with the patchy myocardial viral persistence may explain possible false-negative results related to virus-mediated etiology among end-stage dilated cardiomyopathy patients. Therefore, repeated endomyocardal biopsies, and multiple cardiac samples are recommended to be obtained to evaluate the etiology of heart failure, thus reducing the occurrence of end-stage heart failure and decreasing the number of patients requiring heart transplantation.

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.

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.

Long-term restenosis rate of eversion endarterectomy on the internal carotid artery.

OBJECTIVES: The eversion endarterectomy of the internal carotid artery was introduced in Hungary in 1991. The aim of this study was to define the long-term restenosis rate of this procedure. PATIENTS AND METHODS: Between 1991 and 1993, 171 operations, on 151 patients, were performed by single surgeon: with long-term follow up of 109 patients, which included annual physical and ultrasound examinations. Restenosis rate and plaque morphology were defined. Survival and patency rate were analysed by life-tables. RESULTS: The combined perioperative stroke morbidity and mortality rate was 0.8%. The 5-year patient survival rate was 85%, the recurrent stenosis free rate was 88% at 5 years. Only 9% of the patients had carotid restenosis of more than 70% during this period. Ultrasound plaque morphology showed calcification in one case. Two patients had re-operations, with plaque histology showed myointimal hyperplasia in each case. CONCLUSIONS: Our results for restenosis are compare favourably with the 2-34% restenosis rate reported in the literature. Ultrasound and histological findings suggest that atherosclerosis does not play a significant role in the development of restenosis after the eversion carotid endarterectomy.

[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.

Shortening the second phase duration of biphasic shocks: effects of class III antiarrhythmic drugs on defibrillation efficacy in humans.

INTRODUCTION: The specific waveform providing optimal defibrillation threshold (DFT) is unknown. We compared the defibrillation efficacy of biphasic pulses with second phases (P2) of 2 and 5 msec in a randomized prospective clinical study. METHODS AND RESULTS: Intraoperative DFTs of 62 patients (age 54 +/- 13 years; ejection fraction 43% +/- 17%; amiodarone 47%, d,l-sotalol 13%) were determined in random order using a binary search protocol. Anodal shocks of 60% tilt first phases (P1) and P2 of 2 msec/5 msec were delivered from two 100-microF capacitors between the right ventricular electrode and the test housing of a Phylax 06/XM device. Mean DFT was significantly lower using the shorter P2 (9.5 +/- 4.5 J vs 11.3 +/- 5.2 J; P < 0.0001). According to subgroup analysis, the effect of changing P2 duration was only influenced by antiarrhythmic treatment. DFT decreased markedly using the shorter P2 in patients treated with amiodarone (10.7 +/- 4.9 J vs 13.4 +/- 5.6 J; P < 0.00001) or d,l-sotalol (6.1 +/- 3.3 J vs 9.1 +/- 4.6 J; P < 0.05). The difference in patients not treated with Class III drugs was found to be insignificant. Chronic amiodarone treatment increased DFT only when the longer P2 was used. CONCLUSION: Biphasic shocks with shorter P2 should be used in patients undergoing Class III antiarrhythmic treatment.

[Simultaneous carotid and coronary operations: experience and results of 11 years (1990-2000)]. / Szimultán végzett carotis-coronaria mútétek: 11 év tapasztalatai és eredményei (1990-2000).

Between 1990-2000 163 coronary + carotid procedures were performed. The mean age was 4 years higher than it was at patients underwent isolated CABG (63.4 y vs 59.8 y). Clinically proven obliterative artery diseases in other anatomical regions were also present in more than 60% of patients. The half of the procedures were performed under emergency and urgent circumstances. The cardiac status and the coronary morphology were found to be unstable in half of the patients. The "Euroscore" risk evaluation model was used for risk scoring. The mean score value was as high as 6.26. According to this the estimated surgical lethality could have been as high as 11.2%. The real surgical lethality value was far under this estimated level (7.36%). The 1, 5, 10 year survival rate were as high as 89%, 82%, 68% (Kaplan-Meier). The majority of the patients was in NYHA I-II at the end of the follow-up period. The majority of the early and late deaths were found to be myocardial in origin. The estimated surgical risk of the simultaneous procedures could be reduce by accepting of the severe surgical indications existing at this surgical field and with the availability of an experienced operating team.

[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.

[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.

[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.

[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.

[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.

[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.

Characteristics of long QT with permanent bradycardia.

The study was aimed to investigate the electrophysiological properties of long QT syndrome associated with permanent bradycardia. The investigations were performed in 26 patients suffering from long QT duration (QTC-frequency adapted QT-:484 +/- 34 ms) with permanent, marked bradycardia (heart rate: 42 +/- 7 min-1). Adams Stokes syncopal attack appeared in 12 patients, while in 14 cases ventricular tachycardia attack with syncope could be observed (study group). As control served the data of 30 patients suffering from long lasting marked bradycardia (heart rate: 44 +/- 7 min-1) with normal QT (QTC:420 +/- 28 ms). Each patient was candidate for pacemaker implantation. The following questions were studied: 1. The effect of heart rate on QT duration. The experiments were performed by electrical ventricular stimulation. 2. The effect of sympathetic and parasympathetic-pharmacologic-blockade on QT time. The study was performed under electrical ventricular stimulation by administration of propranolol and atropine. 3. The dispersion of QT time was studied by using electrical heart stimulation and 12 lead ECG recording. Electrophysiological investigations were performed in 14 patients with long QT and permanent bradycardia. On augmentation of the cycle length (bradycardia) the increase in the QT duration was more-out of all proportion-expressed in long QT. On pharmacologic sympathetic blockade in long QT syndrome the QT duration significantly diminished. The QT dispersion was more expressed in patients with prolonged QT interval and on bradycardia the QT dispersion further increased significantly. The irritability of the ventricle was markedly augmented in patients with long QT and bradycardia. Appearance of polymorphous ventricular tachycardia could frequently be observed and could be regularly induced by early ventricular extrastimuli and bradycardia.(ABSTRACT TRUNCATED AT 250 WORDS)