Efficacy of cryoablation in idiopathic and non-idiopathic atrial fibrillation patients.

OBJECTIVES AND BACKGROUND: Studies assessing the unicentric and prospective comparison of efficacy of cryoballoon pulmonary vein isolation in idiopathic and non-idiopathic atrial fibrillation (AF) patients are missing. The aim of this study was to compare a single procedural outcome in these subgroups of AF patients. METHODS: A total of 208 patients with drug resistant AF were included in this study. Among them, 36 patients had idiopathic AF and 172 patients had non-idiopathic AF. The efficacy endpoint was freedom from any atrial arrhythmia lasting >30 s after a 3-months blanking period. RESULTS: The freedom from atrial arrhythmias without antiarrhythmic drugs after 1 and 3 years of follow-up, respectively, was 85.2 % and 70.4 % in patients with idiopathic AF; and 64.6 % and 39.9 % in patients with non-idiopathic AF (p=0.021). Moreover, the success rate when analysing only paroxysmal AF patients after 1 and 3 years of follow-up, respectively, was 95.7 % and 82 % in patients with idiopathic AF; and 72.6 % and 47 % in patients with non-idiopathic AF (p=0.022). CONCLUSIONS: A single cryoballoon pulmonary vein isolation was more effective in preventing atrial arrhythmias relapses in idiopathic AF patients compared to non-idiopathic AF patients. The best efficacy outcomes were observed in patients with paroxysmal idiopathic AF (Tab. 5, Fig. 2, Ref. 25).

Severity of nocturnal cardiac arrhythmias correlates with intensity of sleep apnea in men.

Various cardiac arrhythmias frequently occur in patients with sleep apnea, but complex analysis of the relationship between their severity and the probable arrhythmogenic risk factors is conflicting. The question is what cardiovascular risk factors and how strongly they are associated with the severity of cardiac arrhythmias in sleep apnea. Adult males (33 with and 16 without sleep apnea), matched for cardiovascular co-morbidity were studied by polysomnography with simultaneous ECG monitoring. Arrhythmia severity was evaluated for each subject by a special 7-degree scoring system. Laboratory, clinical, echocardiographic, carotid ultrasonographic, ambulatory blood pressure, and baroreflex sensitivity values were also assessed. Moderate sleep apnea patients had benign, but more exaggerated cardiac arrhythmias than control subjects (2.53 ± 2.49 vs. 1.13 ± 1.64 degrees of cumulative severity, p < 0.05). We confirmed strong correlations between the arrhythmia severity and known arrhythmogenic risk factors (left ventricular ejection fraction and dimensions, right ventricular diameter, baroreflex sensitivity, carotid intima-media thickness, age, previous myocardial infarction, and also apnea-hypopnea index). In multivariate modelling only the apnea-hypopnea index indicating the sleep apnea intensity remained highly significantly correlated with the cumulative arrhythmia severity (beta = 0.548, p < 0.005). In conclusion, sleep apnea modifying cardiovascular risk factors and structures or functions provoked various nocturnal arrhythmias. The proposed scoring system allowed a complex analysis of the contribution of various triggers to arrhythmogenesis and confirmed the apnea-hypopnea index as an independent risk for nocturnal cardiac arrhythmia severity in sleep apnea.

[Is there a relationship between inflammatory markers, oxidative stress and postoperative atrial fibrillation?]. / Existuje vztah medzi zápalovými markermi, oxidacným stresom a pooperacnou fibriláciou predsiení?

INTRODUCTION: Atrial fibrillation (AF) is one of the most common complications following heart surgery. The aim of this work was to verify the relationship between inflammatory markers, oxidative stress and postoperative arrhythmia. METHODS: 45 patients with ischemic heart disease (12 women and 33 men, mean age 62.3 ± 9.4 years) underwent surgical myocardial revascularization. The extracorporeal circulation (ECC) was used in 30 patients, without ECC was 15 patients. During the first 3 postoperative days was determining the incidence and duration of the AF, laboratory markers of inflammation (CRP, leukocytes, TNFα), malondialdehyde (MDA). RESULTS: Demographic data and associated disease were in this patients similar. The incidence of AF we documented in 30 patients (66.7%). In patients with postoperative AF were significantly higher levels of inflammatory markers (leukocytes 13.6 ± 3.6 vs 11.3 ± 3.6; 14.7 ± 3.9 vs 12.5 ± 2.9; 13.7 ± 4.1 vs 11.4 ± 13.7; p 0.05; CRP 138.1 ± 41.1 vs 69.9 ± 25.8; p 0.001; TNFα 11.3 ± 14.3 vs 8.7 ± 3.6; 12.1 ± 14.5 vs 8.7 ± 3.1; p 0.05) compared with patients who were free from AF. Values of MDA were not significantly different. CONCLUSION: Patients with post-operative atrial fibrillation were higher levels of inflammatory markers compared with patients with sinus rhythm but no significant differences in the levels of oxidative stress.

[Recurrent prosthetic endocarditis in a 21-year old patient with renal transplantation treated with allogeneic homograft]. / Recidivujúca protetická endokarditída u 21-rocného pacienta s transplantovanou oblickou riesená alogénnym homograftom.

Prosthetic infective endocarditis is a possible complication of implantation of a prosthetic cardiac valve. Without early and effective treatment, it can have fatal consequences. One treatment option is use of an allogeneic cryopreserved homograft. This case report presents a 21-year old patient after kidney transplantation due to hereditary nephrotic syndrome and aortic valve replacement with aortic conduits. After fever was noted in the patient, prosthetic infective endocarditis was diagnosed by echocardiography and also confirmed by CT-3D examination. The cryopreserved aortic homograft was implanted at the Department of Cardiac Surgery. This along with additional conservative management effectively treated the infection. Based on literature data and our own experience, we believe that the treatment of prosthetic endocarditis after aortic valve replacement with cryopreserved homograft can be a method of choice.

Catheter ablations of supraventricular tachycardias.

BACKGROUND: Supraventricular tachycardias (SVT) occur at all ages. Their spectrum as well as tolerance change with increasing age. OBJECTIVES: The aim of our study was to assess the course of SVT catheter ablations in elderly patients when compared to younger population. METHODS: The course of the SVT radiofrequency catheter ablation (RFCA) in the group of 288 patients, who underwent catheter ablation at our department during 24 months was retrospectively evaluated. Patients were divided into two subgroups according to age. In the first group 142 patients younger than 65 years were included and 146 patients aged 65 years or more in the second group. In both groups, the occurrence of heart rhythm disorders, fluoroscopy time and the incidence of complications with varying severity were observed. RESULTS: Life-threatening complications were observed only in three patients from the first group (one pulmonary embolism and two unintended complete atrioventricular blocks). Serious complications included a haemopericardium requiring a pericardial drainage in two cases and an arterial-venous fistula in one patient in the first group, and one retroperitoneal heamatoma in the second group. Minor complications represented by one heamatoma larger than 5x5cm occurred in one patient from each group. The occurrence of complications as well as average fluoroscopy time were not correlated between the groups. CONCLUSION: Based on our experience, radiofrequency catheter ablation of SVT in elderly patients is a safe procedure when indicated correctly. Taking into account the physical status of patients in this age group it is advisable to simplify and thus shorten the procedure (Tab. 1, Ref. 13). Full Text in PDF www.elis.sk.

[Clinical implications of enlargement of left atrium]. / Klinické dôsledky zväcsenia lavej predsiene.

Enlargement of left atrium (LA) has been shown to be a barometer of diastolic burden and a predictor of common cardiovascular outcomes such as atrial fibrillation, stroke, congestive heart failure, and cardiovascular death. Different methods exist for the assessment of LA size. The American Society of Echocardiography recommended LA volume and its indexed value assessed by 2-dimensional echocardiography, to measure LA size. Current findings suggest that echocardiographically determined LA size may become an important clinical risk identifier in preclinical cardiovascular disease and should be assessed as a part of routine echocardiographic evaluation.

[The importance of contractile reserve in patients with resynchronization therapy]. / Význam globálnej kontraktilnej rezervy u pacientov s resynchronizacnou liecbou.

INTRODUCTION: Contractile reserve of the myocardium is a strong prognostic factor in patients with heart failure. The presence of a significant amount of myocardial fibrosis might lead to insufficient response to resynchronization therapy We assumed that pre-implantation examination of global contractile reserve will allow prediction of the response to resynchronization treatment. METHODS: 25 symptomatic patients (NYHA III) with severe systolic dysfunction [ejection fraction (EF) 28.9 ± 6.9%] with signs of electric asynchrony (QRS 120 ms) went through dobutamine echocardiography prior to resynchronization treatment. The global contractile reserve was determined from the change to EF at rest and at the peak of pharmacological burden (40 µg/kg/min). Patients with a rise in EF of more than 5% and/or endsystolic volume reduction of more than 15% after three months of resynchronization treatment were considered responders. RESULTS: Compared to non-responders, responders had higher increase in EF during dobutamine stress echocardiography (Δ 12.8 ± 7.4 % vs. Δ 3.4 ± 7.1 %, p = 0.0042). Three months from the initiation of resynchronization therapy, the global myocardial contractile reserve also significantly correlated with EF increase (r = 0.67, p = 0.007). The 6% increase in EF during dobutamin stress echocardiography predicted responders to resynchronization therapy with 83% sensitivity and 75% specificity. CONCLUSION: The global contractile reserve may play an important role in prediction of a response to resynchronization therapy.

[Septic shock due to infective endocarditis of stimulation system of implantable cardioverter-defibrillator]. / Septický sok v dôsledku infekcnej endokarditídy stimulacného systému implantabilného kardioverter defibrilátora.

We present a case of a 60-year old patient hospitalized at the Department of Infectious Diseases and Travel Medicine, Medical faculty of UPJS and L. Pasteurs University Hospital in Kosice with suspected gastroenteritis. The patient was admitted to an intensive care unit because of the signs of septic shock. Within one hour from admission, the patient was administered early goal directed therapy for septic shock. Subsequently, infectious endocarditis of stimulation electrodes and tricuspid valve was identified as the origin of the infection. The stimulation system was then explanted from a stabilized and afebrile patient at the Department of cardiac Surgery of Eastern Slovak Institute of Cardiac and Vascular Diseases in Kosice. This case should emphasise frequently atypical course of this serious disease and the need for early identification of severe sepsis to enable timely management to affect mortality.

[Resynchronization therapy for heart failure--still many question marks]. / Resynchronizacná liecba srdcového zlyhávania-- stále vel'a otáznikov.

At present, the potential benefit of resynchronization therapy, i.e. an improved quality of life and prolonged survival in patients with heart failure, is not achieved in every patient. The 30% non-response has prompted a search for new criteria predicting patient response to resynchronization treatment. An absence of mechanical dyssynchrony, viability of the myocardium and an inadequate positioning of the intracardiac left ventricular lead probably limit the response to resynchronization therapy. ECG remains essential for the selection of suitable patients.

[Why there is atrial fibrillation after cardiac operations?]. / Preco vzniká fibrilácia predsiení po kardiochirurgických operáciách?

Atrial fibrillation (AF) is the most frequent arrhythmias after cardiac operations. Its incidence ranges from 10-65%. Often there is a patient discomfort, prolongs hospitalization, increases costs of operation and may be permanent or recurrent course. The cause of postoperative AF is multifactorial. The prevention of non-pharmacological and pharmacological interventions. The conventional treatment strategies include monitoring ventricular rate, restoration of sinus rhythm and prevention of thromboembolic events. The development of effective therapies designed to decrease the high incidence of postoperative AF may be important in the future.

Cryothermal ablation of typical atrial flutter.

OBJECTIVES: To evaluate the efficacy and safety of cryoablation compared with the radiofrequency (RF) method in the treatment of typical atrial flutter (AFL). METHODS: 12 patients with typical counterclockwise AFL underwent cryoablation of the cavotricuspid isthmus. Cryoablation was performed with a 9F catheter with an 8 mm tip electrode. Applications were delivered by point-by-point technique to create the ablation line. The end point of the procedure was achievement of bidirectional isthmus conduction block. Control group consisted of 12 consecutive patients who underwent the ablation by means of RF method. RESULTS: We found no differences in the duration of transisthmic conduction after ablation in both groups and in the fluoroscopy time. We found significant differences in the procedural time (187 +/- 81 vs 110 +/- 35 minutes, p<0.01) and in the analgesic use (0/12 vs 12/12, p<0.01). After a 3 month follow-up all patients in both groups were free from the recurrence of AFL, 1 pacient in cryoablation group had paroxysm of atrial fibrillation. CONCLUSIONS: Efficacy and safety profile of cryoablation are similiar with RF ablation. Procedural time in the cryoablation group is significantly longer but the use of analgesics can be completely avoided (Tab. 2, Ref. 20). Full Text (Free, PDF) www.bmj.sk.

The effect of myocardial revascularization on malignant ventricular arrhythmias in coronary artery disease.

BACKGROUND: Malignant ventricular arrhythmia in coronary artery disease (CAD) is a severe life-threatening disease and a risk factor for sudden cardiac death. Myocardial revascularization influences the arrhythmogenic substrate of the malignant ventricular arrhythmia in the secondary prevention of sudden cardiac death. Its effectivity remains controversial. OBJECTIVES: The aim of this study is to assess the inducibility of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF) in patients after myocardial revascularization and to compare the effectivity of complete and incomplete revascularization. PATIENTS: Fifty patients with documented sustained VT or VF and CAD were examined in our department. RESULTS: Conservatively treated patients were significantly older than revascularized patients (68 +/- 8 versus 62 +/- 9 years, p<0.05). We registered a trend towards a lower inducibility of malignant ventricular arrhythmias in the revascularized group and completely revascularized subgroup, but without statistical significance. Incompletely revascularized patients comprised only of men (100% versus 66.6%, p<0.05). Fewer ICDs were implanted in the completely revascularized group (55.6% versus 92.3%, p<0.05). CONCLUSION: Myocardial revascularization has little effect on the inducibility of malignant ventricular arrhythmias after myocardial revascularization. Complete revascularization significantly decreases the need of ICD implantation when compared to incomplete one (Tab. 3, Fig. 4, Ref. 24). Full Text (Free, PDF) www.bmj.sk.

[Early haemodynamic changes after radiofrequency ablation of the atrioventricular junction]. / Vcasné hemodynamické zmeny po rádiofrekvencnej ablácii predsienovokomorového spojenia.

INTRODUCTION: The effect of radiofrequency ablation of the atrioventricular junction may be accompanied by undesired effect of right ventricular stimulation. The objective of the study was to evaluate early haemodynamic effects of catheter ablation in patients with permanent atrial fibrillation resistant to pharmacotherapy. METHOD: The study included 19 patients aged 66.9 +/- 12.4 years on an average. Depending on the basal ejection fraction (EF), we divided the patients in to two groups (the 1 st group patients had EF less than 50 %, the 2nd group patients had EF equal to 50 % or higher). The patients were underwent radiofrequency ablation of the atrioventricularjunction and a pacemaker implantation. Haemodynamic changes were evaluated by measuring the ejection volume (EV) and the minute volume (MV) using echocardiography basally prior to and after the intervention, at different stimulation frequencies. For a more precise evaluation of the patients' condition, we defined the EVi am MVi indices as the ratio between the above values at different stimulation frequencies and the basal value. OUTCOME: EV in patients with a low EF increases at all stimulation frequencies with the maximum effect observed in the frequency band from 60-100/min. At stimulation frequency of 60/min, the volume increased from 26.4 ml before ablation to 39.5 ml after ablation. MV grows or remains unchanged at all frequencies except for 60/min, at which the growth in EV cannot compensate the drop in MV due to a fall in frequency. Patients in the 2nd group had a high EV value (52.3 ml) before ablation. After the intervention, their EV increased only at stimulation frequency of 60 and 80/min (64.0 and 55.1 ml, respectively). Also these patients' MV was high before ablation (6,097 ml). After the intervention, their MV decreased for all stimulation frequencies, but showed a growing tendency. Statistical evaluation showed negative correlation between EVi and MVi on the one hand, and between EF and the average of the left ventricle in systole on the other. CONCLUSION: Our results have shown that radiofrequency transcatheter ablation of the atrioventricular node (RFCA AVN) is beneficial for certain patients in both the groups, even though the mechanisms of improving their clinical condition are different.

[Non-fluoroscopic mapping techniques in contemporary catheter ablation therapy of dysrhythmias]. / Nefluoroskopické mapovacie techniky v súcasnei katétrovei ablacnei liecbe dysrytmií.

Rapid development and clinical introduction of 3D techniques of intracardial mapping significantly extended the possibilities of catheter ablation therapy of dysrhythmias. Contemporary imaging techniques allow precise determination of the source and the way of propagation of dysrhythmia in myocardium, which is an evitable condition of a successful ablation therapy. Although the fluoroscopic image during electrophysiologic examination allows continuous check of the position of catheters in the heart, due to its low resolution it remains just rough estimation of their real position. The objective of the authors of this lucid work was to give a brief characteristic of the basic principles of the activity of 3D mapping systems used nowadays and to approximate their significance and advantages for ablation therapy of individual dysrhythmias in clinical practice.

Acute toxicity of propafenone in a case of suicidal attempt.

We describe a successful treatment of 28-year old man who ingested in a suicidal attempt up to 30 pills each containing 150 mg (4500 mg) of propafenone. Results of clinical toxicology were obtained with high performance liquid chromatography from the urine sample. Semiquantitative analysis has shown a high peak for propafenone hydrochloride. The main clinical findings were coma, hypotension, acidosis, sinoatrial block, junctional tachycardia and ventricular arrhythmias necessitating defibrillation. Maximum occurence of arrhythmias was observed 2.5 hours after hospital admission, while the cessation of toxic signs started 4.5 hours later. Gastric lavage, arteficial ventilation, administration of alkalinization solutions and management of rhythm disorders were the most important therapeutic measures in this case. (Fig. 2, Ref. 18.)

[Electrophysiologic mechanisms of atrial rhythm disorders. I. Atrial fibrillation]. / Elektrofyziologické mechanizmy predsienových porúch rytmu. I. Predsienová fibrilácia.

Atrial fibrillation (AF) is a frequent finding in clinical practice. In advanced age its incidence is rising and according to the literature the prevalence is as high as 3.2-11%. AF doubles the mortality and brings a fivefold risk of the most frequent embolic complication--a cerebrovascular attack. The typical electrophysiological feature are intra-atrial defects of the conduction and the absence of refractory period adaptation with regard to the cycle length. In 1962 Moe, based on experimental work, postulated the hypothesis on multiple independent wavelets which move in a random fashion through the myocardium round several islets or strips of refractory tissue. Modern mapping studies confirmed the reentry concept as the mechanism of atrial fibrillation. Two forms of reentry were observed: the leading circle reentry and the random reentry. The main factors which facilitate the development of AF are dilatation of the atria, reduced rate of conduction of the impulse and shortening of the refractory. A combination of these factors leads to a reduction of the size of the wave which is a multiple of the refractory period and rate of the impulse. This leads to the formation of smaller waves which may co-exist in greater number in the dilated atria. Persistence of AF depends on the number of waves present. A small number of waves can disappear at a certain moment or change into one wave and this leads to the development of sinus rhythm or atrial flutter.

[Serum noradrenaline and ventricular tachycardia]. / Sérový noradrenalín a komorová tachykardia.

Sudden cardiac death is in the majority of cases due to ventricular tachycardia (VT) developing into ventricular flutter or ventricular fibrillation. It is therefore very important to detect patients with the risk of sudden cardiac death because their mortality depends on the treatment selected. The authors tried to shift the problem of sudden cardiac death into the sphere of cardioendocrinology. They examined the serum levels of norepinephrine (NE) in 17 patients. They collected simultaneously blood samples from the left cubital vein and right atrium after 5 minutes stimulation of the apex of the right ventricle, the frequency of stimulation being 100/min. In ten patients during electrophysiological examination VT was induced (four patients had persisting VT). The authors found a declining NE serum value in the periphery and rising intracardial NE serum level after ventricular stimulation. These differences were statistically significant in patients with VT but not in patients without VT.

[Pathophysiologic mechanisms of atrial rhythm disorders. II. Atrial flutter]. / Patofyziologické mechanizmy predsienových porúch rytmu. II. Predsienový flutter.

Atrial flutter is a common cardiac dysrhythmia which responds for half of the supraventricular tachycardias with exception of atrial fibrillation. Activation and entrainment mapping studies in man and in animals confirmed the reentry mechanism of atrial flutter and demonstrated that the reentry circuit is located in the right atrium. The most important anatomical structures which enable the occurrence of atrial flutter are crista terminalis, Eustachian valve/ridge and tricuspid annulus. In typical atrial flutter the impulse rotates "counterclockwise". According to the present knowledge the reentry circuit surrounds a central obstacle made by the orifices of the superior and inferior vena cava linked by a line of functional block in the region of crista terminalis. The anterior barrier is created by tricuspid annulus. The anterolateral wall of the right atrium is activated craniocaudally. Crista terminalis and tricuspid annulus form a funnel which leads the impulse into the isthmus with slow conduction located between the vena cava orifice and tricuspid annulus. Septal activation is ascending and the activation wave considerably widens and becomes irregular. The upper link of the circuit is located above and anteriorly to the superior vena cava. The left atrium is activated passively and does not play an important role in the reentrant circuit. Reverse flutter has the same substrate as typical flutter but rotates in an opposite "clockwise" manner.

[Proarrhythmia--a paradox in clinical cardiology]. / Proarytmia--paradox klinickej kardiológie.

On the basis of both literature data and our own experience, the review analyzes the problem of proarrhythmia. The origin of proarrhythmia is determined by: left ventricular function, coronary bloodflow, autonomous nervous system tonus, the presence of hidden lesions of the conductive system of the heart or the presence of accessory tracts, antiarrhythmic therapy or other therapy with cardiotropic preparations and the state of the internal environment. Each antiarrhythmic drug can evoke proarrhythmia. Regarding the therapy of current proarrhythmia, the competitive preference is ascribed to those antiarrhythmic drugs which are quickly eliminated. Regarding both the antiarrhythmic therapy and the possible occurrence of proarrhythmia in patients with ichaemic heart disease, the administration of Beta-blockers seems to be mostly prospective. (Fig. 3, Ref. 11).

[Subacute morphologic changes in the heart after radiofrequency ablation in the area of the atrioventricular junction]. / Subakútne morfologické zmeny na srdci po rádiofrekvencnej ablácii v oblasti átrioventrikulárnej junkcie.

Catheter ablation of the atrioventricular (AV) junction for due to refractory supraventricular tachycardias by means of the radiofrequency (RF) current is at present an accepted and widespread mode of therapy. Although pathomorphological findings of the early postablative period are well documented in animals, only few data are available on pathological postablative changes in humans. In this paper we present the necropsy findings in a woman who suddenly died 25 days after RF ablation of AV junction. In this case the ablative procedure has caused subendocardial necrosis revealing signs of advanced organisation with deposits of lipofuscin and haemosiderin. We have also found the necrosis of fat tissue in the vicinity of the tricuspid anulus in the stage of advanced resorption. The recent complication was the thrombotic occlusion of a small branch of coronary artery in the right atrial posterior wall causing a nonextensive acute infarction. We conclude that our findings are in agreement with the literature data on morphologic similarity of ablative lesions and reparative processes in experimental models and clinical practice. (Fig. 4, Ref. 8.)