Issues - Journal of arrhythmology №80, 15/05/2015

Quality of contact of ablation electrode with tissue during catheter ablation of atrial fibrillation based on experience of operating electrophysiologist

S.E. Mamchur, E.A. Khomenko, E.V. Gorbunova, N.S. Bokhan, M.P. Romanova, M.Yu. Kurilin, D.A. Shcherbinina, S.A. Tumanova

To study the quality of contact (QoC) of the ablation electrode with tissue during the catheter ablation of atrial fibrillation (AF) based on the experience of operating electrophysiologist, 52 patients aged 53.1±4.6 years (20 men and 32 women) with paroxysmal (n=18) or persistent AF (n=34) were examined. In Group I (n=27), the procedure was carried out by two electrophysiologists who previously conducted 184 and 203 pulmonary vein isolations (PVI), respectively; in Group II (n=25), by two electrophysiologists who previously conducted 11 and 12 PVI. Irrigated catheters SmartTouch (Biosense Webster, USA) were used in all cases. To assess the QoC of the electrode with the myocardium, 34 procedures were performed in the patients with persistent AF with capturing the QoC data on 3D maps. After completion of the planned design of the ablative procedure, the information on the mean QoC was captured on the map, its value was subsequently recorded. In 18 cases of PVI in patients with paroxysmal AF, the operator performed PVI on one side without having information about QoC and on the contralateral side upon receiving the digital and graphic information about QoC.

The criteria of the procedure success were achieved in all cases because, upon unblinding of the data on QoC, there was no need to make additional radiofrequency applications. Both groups showed high correlation of areas with a poor contact with areas where, after the first series of application, additional applications were required because electrophysiological criteria of the ablation success were not met. The worst contact was achieved in the area of the lateral crest and carinas between the upper and lower pulmonary veins. When non-experienced operators (electrophysiologists) performed PVI, a possibility of assessment of QoC in a real-time mode improved achievement of the target parameters of QoC contacts with the myocardium. Thus, when performing the AF ablation, the worst contact of the catheter was achieved in the area of the lateral crest and carinas between the upper and lower pulmonary veins. In more than 60% of cases, the areas with a poor contact have the same location as the area where additional applications are indicated due to the lack of electrophysiological criteria of the successful ablation. When carrying out PVI, the experienced electrophysiologists reach in a majority of cases an optimal pressure on the myocardium irrespective of availability of the information on QoC.

To study the quality of tissue contact of the ablation electrode during the catheter ablation of atrial fibrillation based on the experience of operating electrophysiologist, 52 patients aged 53.1±4.6 years (20 men and 32 women) with paroxysmal (n=18) or persistent AF (n=34) were examined and treated.

Key words: atrial fibrillation, pulmonary veins, left atrium, radiofrequency catheter ablation, transmural injury, ablation electrode, strength of contact.

Effect of optimization of cardiac resynchronization therapy on electrophysiological cardiac remodeling

V.K. Lebedeva, T.A. Lyubimtseva, M.A. Trukshina, E.A. Lyasnikova, D.S. Lebedev

To assess the dynamics of an impact of optimization of QRS-complex-width based interventricular delay (VVD) on the hemodynamics of patients receiving cardiac resynchronization therapy (CRT), 120 patients with the sinus rhythm and implanted CRT systems due to the indications by the national guidelines were examined. The study subjects were randomized into two following groups: Group I (n=60) with optimization of VVD and Group II (n=60) receiving only conventional treatment without VVD optimization (with AVD [atrioventricular delay optimization] only). QRS width was measured before implantation (QRS_BL) and thereafter every 6 months in the temporary device suppression mode (QRS_NO-ST) and when measuring the biventricular stimulated QRS complex width (QRS_ST) throughout the VVD optimization period. The VVD optimization was carried out by a gradual change in the stimulation delay time of the right/left ventricle pre-activation (from 0 ms to 40 ms) and simultaneous measurement of QRS_ST width on ECG. The final VVD was considered as that corresponding to the narrowest QRS. AVD was selected in both study groups based on the sensed/paced P wave duration; the final atrioventricular interval was considered as that corresponding to the symmetric complete P wave availability. Echocardiography was performed in all study subjects before the CRT implantation and every 6 months thereafter, with assessment of hemodynamic parameters.

During a 24‑month follow-up, there was a significant QRS_ST reduction in Group I (p=0.041), the final QRS_ST was lower in Group I than in Group II (p=0.016; no difference between the study groups were reported at baseline for the etiology of cardiomyopathy, age, and QRS_ST), and the final QRS_NO-ST was lower in Group I than in Group II (p=0.044). The end systolic volume (ESV) and end diastolic volume (EDV) of the left ventricle (LV) significantly decreased in both groups; the final ESV LV was lower in Group I than in Group II (p=0.033). Ejection fraction (EF) of the LV increased in both groups; the rise was more pronounced in Group I (p=0.048). The heart failure functional class decreased in both study groups, to 2.12 in Group I and to 2.64 in Group II; the functional class in Group I was significantly lower (p=0.046). Thus, the AVD and VVD optimization can improve response to CRT; the narrowest biventricular QRS complex can reflect the optimal cardiac synchronization. ECG is a reproducible technique for the dynamic CRT optimization.

To assess the dynamics of an impact of optimization on interventricular delay based on the QRS complex width on the hemodynamics, 120 patients with the sinus rhythm and CRT systems implanted according to the indications by the national guidelines were examined.

Key words: chronic heart failure, cardiac resynchronization therapy, atrioventricular delay, interventricular delay, electrocardiography, echocardiography.

Effect of treatment strategy on quality of life of patients with paroxysmal and persistent atrial fibrillation

G.A. Petrova, M.Yu. Gilyarov, D.A. Andreev, D.V. Regushevskaya, O.I. Keyko, P.A. Alferova, A.L. Syrkin

To assess the quality of life (QoL) of patients with atrial fibrillation (AF) depending on the treatment strategy chosen and follow-up strategy in an out-patient setting, 146 patients were examined. The patients were treated using any of two following conventional strategies: sinus rhythm recovery and its subsequent maintenance (rhythm control strategy, n=86) or maintenance of AF with the heart rate control (rate control strategy, n=60). Factors influencing selection of the treatment strategy of patients admitted due to paroxysmal AF were assessed on the first stage of the study. Using special questionnaires and scales, assessed were tolerance of AF, the quality of life, the level of anxiety and depression, and the extent of chest pain at the background of AF. The second stage of the study consisted in the follow-up in an out-patient setting. The patients were randomized into two following groups: Group 1 received "active follow-up" and Group 2 received "standard follow-up" program. The active follow-up included monthly visits to the hospital, a possibility of phone contacts with the treating physician initiated by the patient, and hospitalization in good time, when indicated. Checkup of patients from the "standard follow-up" group was performed only at baseline and in 6 months.

Selection of treatment strategy of patients with AF was determined by the following factors: age, alcohol abuse, left atrium diameter, type of AF (paroxysmal /persistent), and the subject's willingness. During the direct questioning, the physicians reported duration of the AF paroxysm of more than 1 year and appropriately tolerated AF as the most valuable factors related to the treatment strategy selection. When making decision on the sinus rhythm recovery, the most valuable factors were the subject's willingness, lack of significantly dilated AF, rare (less than 4 times a year) paroxysms of AF, and a relatively young age. The QoL of patients with AF treated using the rate control strategy was considerably lower than in whom the rhythm control strategy was used (the sinus rhythm was recovered and maintained). In addition, the latter group of patients was characterized by a higher prevalence of depression. The QoL dynamics in patients with AF did not depend on the treatment strategy but depended on the subject sex, baseline QoL, type of out-patient follow-up program, and social factors (lonely unconnected persons). Patients with a better QoL (psychological component) were more compliant to the therapy and were less subjected to self-discontinuation of anticoagulants (after 6 and 24 months of follow-up) and Amiodarone (after 24 months of follow-up).

To assess the quality of life of patients with atrial fibrillation depending on the treatment strategy chosen and follow-up strategy in an out-patient setting, 146 patients were examined.

Key words: quality of life, depression, atrial fibrillation, sinus rhythm, out-patient follow-up, anticoagulant therapy, Amiodarone.

Post-operative atrial fibrillation in elderly subjects

O.A. Rubanenko

To assess prevalence of post-operative atrial fibrillation (AF) after aortocoronary bypass grafting surgery (ACBG) in elderly patients, 440 patients with coronary heart disease (CHD) were examined. Standard checkup (including laboratory and instrumental tests) was performed in the study subjects. The patients were distributed into two following age groups: Group 1 consisted of 177 middle-aged subjects aged 53.1±4.9 years (men: 97%); Group 2 consisted of 263 elderly subjects aged 66.1±4.7 years (men: 77%).

During the follow-up period, post-operative AF occurred in 75 patients (17%), including 9.6% of middle-aged patients and 22.0% of elderly patients. The history of stroke and thyroid disease was significantly more frequent in Group 2 (6.5% and 1.7%, p=0.01, and 3.8% and 0.6% p=0.02, respectively); pulmonary diseases were more prevalent in Group 1 (20.9% and 11.0%, p=0.004). The antero-posterior diameter of the left atrium (LA) and the interventricular septum thickness were more pronounced in the elderly patients than in the middle-aged subjects (39.4±4.9 mm and 37.5±4.0 mm, p=0.045, and 11.0±1.7 mm and 10.4±2.1 mm, p=0.01, respectively). ACBG without extracorporeal circulation (on a beating heart) was performed more frequently in Group 1 than in Group 2 (15.3% and 9.3%, p=0.047). The significant predictive value was found for the following factors: age >59 years (OR: 2.4; 95% CI: 1.3‑4.4; p=0.005), LA size >39 mm (OR: 3.7; 95% CI: 2.1‑6.6; p<0.0001); left ventricular ejection fraction <51% (OR: 1.9; 95% CI: 1.3‑3.3; p=0.04), aortic cross-clamping time >36 min (OR: 1.7; 95% CI: 1.1‑3.2; p=0.03), and time of ischemia >19 min (OR: 2.0; 95% CI: 1.1‑3.7; p=0.02). For the on-pump time >56 min, OR was 1.2 (95% CI: 0.56‑2.8; p=0.5).

Thus, post-operative AF in elderly patients is characterized by a high prevalence as compared with middle-aged subjects. Predictors of the arrhythmia were age, antero-posterior LA size, left ventricular ejection fraction, aortic cross-clamping time, and time of ischemia.

Key words: atrial fibrillation, aortocoronary bypass grafting, elderly patients

Surgical treatment of atrial fibrillation during the Ross procedure

A.M. Karaskov, A.V. Bogachev‑Prokofyev, I.I. Demin, R.M. Sharifulin, S.I. Zheleznev, A.B. Open, A.N. Pivlin

To assess the outcomes of the simultaneous the Ross procedure and surgical treatment of atrial fibrillation (AF), 16 patients aged 50.5 years [45-59 years] were examined and surgically treated. 10 patients had persistent AF; other study subjects, paroxysmal AF. The aortic valvular disease correction in all study subjects was performed using the Ross procedure. In a majority of cases (13 patients), radiofrequency ablation (RFA) was performed with the aid of a non-irrigated bipolar device; in one case, an irrigated device. In two patients, a cryoprobe was used for fragmentation of the left atrium (LA). The left atrial technique of ablation was used the most frequently; in 6 cases of paroxysmal AF, the pulmonary vein and left appendage isolation was carried out.

In the course of the left atrial RFA, the first stage of the procedure included ablation of the left and right pulmonary vein ostia, as well as the left atrial appendage. Then, after aortic occlusion and left atriotomy, the LA ablation was performed. The technique of left atrial cryoablation consisted in creating three endocardial lines: pulmonary veins were isolated as a single process by applying two lines from an edge of atriotomy access on the LA with their connection located near the left appendage; the third line was applied towards the mitral valve fibrous ring. The left appendage was occluded from inside either by double-row suture or by ligation.

No hospital mortality was detected. One patient experienced the significant aortic insufficiency on the second day after the surgery which required the aortic valve re-replacement with a mechanical valve. The sinus node dysfunction was observed in 5 patients; it required performing temporary cardiac pacing. A dual-chamber pacemaker was implanted to one patient due to the complete atrioventricular block. Paroxysms of AF in the early post-operative period occurred in 6 patients and required cardioversion. By discharge, 15 patients have had the sinus rhythm; recurrence of AF was documented in a study subject with a history of arrhythmia of more than 3 years. The study subjects were discharged receiving Amiodarone in a supporting daily dose of 200 mg.

After discharge, 14 patients had a checkup. The mean follow-up period was 24.7 months [4‑43 months]. The sinus rhythm was documented during the ECG Holter monitoring in 10 patients; the AF recurrence, in 3 patients. The data obtained permit one to conclude that simultaneous atrial ablation during the Ross procedure is a safe and effective procedure which can recover the sinus rhythm is a majority of patients.

To assess the outcomes of the simultaneous the Ross procedure and surgical treatment of atrial fibrillation, 16 patients aged 50.5 years [45-59 years] were examined and surgically treated.

Key words: aortic valve disease, Ross procedure, atrial fibrillation, left atrium, pulmonary veins, radiofrequency catheter ablation, cryoablation, anticoagulant therapy.

Biventricular pacing in patients with preserved left ventricular ejection fraction after radiofrequency ablation of atrioventricular node in a series of clinical cases

A.V. Kozlov, S.S. Durmanov, R.M. Babukov

To assess the clinical effect and dynamics of echocardiographic (echoCG) indices of diastolic and systolic left ventricular (LV) function after replacement of a pacemaker to a system for cardiac resynchronization therapy (CRT) in patients with preserved LV ejection fraction (EF) and symptoms of chronic heart failure (CHF) at the background of permanent right ventricular pacing after radiofrequency ablation (RFA) of atrioventricular (AV) node, three patients were examined 1-2 years after RFA of AV node. All patients received the optimal conventional medical treatment of CHF. At baseline, the total score of the quality of life questionnaire for patients with CHF, the results of 6‑minute walk test (6‑MWT), and echoCG indices of both systolic and diastolic LV function were assessed. The measurements were performed with the aid of the GE Vingmed Ultrasound Vivid 9 device according to the guidelines by ASE. In all patients, the left ventricular electrode was implanted into the target position on the LV lateral wall according to the conventional technique. No complications of the procedure were reported. To exclude the placebo effect, the right ventricular pacing with unchanged parameters was kept for 1 month after the procedure; then biventricular pacing started. The patients' checkup was performed 1, 3, and 6 months after the procedure. The effectiveness of the CRT system functioning was tested using a programmer and 6‑MWT, the total score of the quality of life questionnaire for patients with CHF was evaluated, and transthoracic echoCG was performed.

At baseline, in all patients, 100% right ventricular pacing was made; the paced QRS complex width was 180‑200 ms. Cardiac pacing was performed in the VVIR mode in 2 patients and in the VVI mode in one subject. All patients had symptoms of CHF III‑IV (NYHA). EchoCG signs of the LV diastolic dysfunction were detected in all subjects. At the background of CRT, the QRS complex width shrank by 60-70 ms and made up 130‑140 ms; all patients showed an increased 6‑MWT distance (increased by 81‑108 m). The quality of life improved; the changes were equal to 20‑40 points. EF increased by 6-8%, the heart size decreased by 10-20 ml in 2 patients and remained unchanged in one patient. The extent of mitral regurgitation decreased in 2 patients and remained unchanged in one patient.

Three case reports given cannot lead to far-reaching conclusions; the issue fosters further studies on a larger sample. At the same time, replacement of a pacemaker to a CRT system is a potential method of improvement of the subject's state and signs of the LV diastolic dysfunction in patients with symptoms of CHF and preserved LV EF after RFA of AV node.

To assess the clinical effect and dynamics of echocardiographic indices of diastolic and systolic left ventricular function after replacement of a pacemaker to a system for cardiac resynchronization therapy in patients with preserved left ventricular ejection fraction and symptoms of chronic heart failure at the background of permanent right ventricular pacing after radiofrequency ablation of atrioventricular node, three patients were examined.

Key words: chronic heart failure, permanent atrial fibrillation, radiofrequency ablation, atrioventricular node, cardiac pacemaker, cardiac resynchronization therapy, echocardiography, left ventricular ejection fraction.

Improving noninvasive methodology of surface epi- and endocardial mapping in patients with impaired intraventricular conduction

S.V. Zubarev, M.P. Chmelevsky, M.A. Budanova, M.A. Trukshina, A.V. Ryzhkov, A.V. Pakhomov, T.A. Lyubimtseva, V.K. Lebedeva, D.S. Lebedev

To analyze anatomical mapping techniques and explore potentialities of non-invasive surface epi- and endocardial mapping (NEEM) in the diagnosis of complete left ventricular myocardial dyssynchrony, 41 patients with complete left bundle branch block (LBBB) were examined. The study subjects were either candidates to cardiac resynchronization therapy (CRT) or the CRT system has been implanted to them earlier.

Magnetic resonance imaging (MRI) was performed before implantation of the CRT devices in 13 patients of Group I. Multispiral computed tomography (MSCT) was performed to 28 patients of Group II with already implanted devices. NEEM was performed in all study subjects using the Amicard 01C EP LAB system (Switzerland). Different maps (including isopotential, isochronous, and activation distribution maps constructed using the ADM technique) were built on segment-marked epi/endocardial ventricular models. With the aid of the maps, the late activation zone of the left ventricle (LV) in LBBB was assessed, interventricular (ventriculo-ventricular, VVD) delay and SD12 for LV were calculated; deviation of the early activation zones from the point of the right ventricle (RV) or LV pacing was assessed.

During the non-invasive mapping, both MRI and MSCT can be used. When using MSCT with non-contrasted cardiac series, epi/endocardial models were built similar to those made when using contrast media. An algorithm is suggested of selection of imaging techniques during NEEM based on the subject's clinical state. NEEM showed sufficiently high diagnostic accuracy on the LV free wall and the RV (right ventricle) apex.

The late activation zone in case of LBBB on the medial basal (mid-basal) level of LV was found in 32% of patients (n=13) in the posterior wall, in 32% of patients (n=13) in the lateral wall, in 34% of subjects (n=14) in the posterior and lateral walls, and in 2% of patients (n=1) in the left ventricular apex. The epicenter of late activation on the LV free wall in case of LBBB may be considered the optimal place for the LV electrode implantation. VVD was assessed with the aid of NEEM as 79±17.9 ms and using tissue Doppler echocardiography (TD ehcoCG) as 74.9±18.3 ms with the positive correlation (r=0.45, p=0.003). SD12 was assessed for LV as 24.2±6.1 s using the NEEM technique and as 36.7±14.2 s using TD echoCG, with the positive correlation: r=0.4, p=0.016. Mapping can be an alternative technique of evaluation of dyssynchrony in case of extremely poor visualization of echoCG images. Further scientific research and improvement of NEEM technique is required.

Review

Long QT interval and the syndrome of obstructive sleep apnea-hypopnea

N.V. Borodin, O.V. Lyshova

The data are considered on the long QT interval syndrome as a potential predictor of adverse outcome in patients with the syndrome of obstructive sleep apnea/hypopnea.

Key words: long QT interval, QT interval dispersion, ventricular depolarization, syndrome of obstructive sleep apnea/hypopnea, sudden cardiac death.

Clinical Case Report

A clinical case of combination of long QT interval, atrioventricular block, and polymorphic ventricular tachycardia as a manifestation of fatal orphan hereditary disease

T.V. Fedorova, N.V. Omelchenko, I.A. Urvantseva, N.D. Gunchenko

A case report is given of a neonate with a combination of congenital long QT interval syndrome, atrioventricular block, and polymorphic ventricular tachycardia.

Key words: long QT interval syndrome, Jerwell and Lange-Nielsen syndrome, Andersen-Tawil syndrome, Timothy syndrome, atrioventricular block, polymorphic ventricular tachycardia, sudden death.

Guide to authors

Automated calculation of statistical parameters of study samples

I.A. Dubrovsky

Guide to practitioners

Current potentialities of remote learning in cardiology and arrhythmology

M.M. Medvedev

Российский Научно-Практический
рецензируемый журнал
ISSN 1561-8641

Санкт-Петербургское общество кардиологов им Г. Ф. Ланга
НИИК: www.almazovcentre.ru
ИНКАРТ: www.incart.ru