Jolana Lipoldová

Autopsy and clinical context in deceased patients with implanted pacemakers and defibrillators: intracardiac findings near their leads and electrodes

AIMS To evaluate intracardiac findings near leads and causes of death in pacemaker/defibrillator patients. METHODS AND RESULTS Special autopsy was performed on 78 patients deceased in a hospital. Age at death was 77.9 +/- 10.0, implantation-death interval 4.0 +/- 3.3 years, ventricular leads n = 78, and atrial leads n = 21. Thrombi along leads in brachiocephalic vein/upper caval vein (BV/UCV) were found in 22 (7), in right atrium (RA) in 11 (8), and in right ventricle (RV) in 11 cases. Bipolar lead rings were fixed by fibrous tissue in 43 (4) cases. Connective tissue bridges and tunnels were found in BV/UCV in 44 (13), in RA in 17 (15), and in RV in 68 cases, with a length of 0.2-12.0 cm. Right ventricular leads in tricuspidal orifice were fixed by fibrous tissue in 11 and penetrating chordae in 25 cases. Main causes of death were: heart failure in 35, pulmonary embolism in 9, and myocardial infarction in 11 cases. CONCLUSION We have found (i) thrombi on ventricular/atrial leads in 33/48%, (ii) bipolar lead rings fixed by fibrous tissue in 68/22%, (iii) connective tissue bridges or tunnels in ventricle/atrium in 87/71%, and (iv) ventricular leads fixed to valve or penetrating chordae in 46% of patients. We do recommend caution when extracting leads.

Short-term Effects of Cardiac Resynchronization Therapy on Sleep-Disordered Breathing in Patients With Systolic Heart Failure

OBJECTIVES We evaluated the short-term effect of cardiac resynchronization therapy (CRT) on sleep apnea in patients with systolic heart failure. BACKGROUND Sleep-disordered breathing is common in patients with left ventricular systolic dysfunction. METHODS Twelve patients (mean [+/-SE] age, 59.6+/-7.8 years; mean left ventricular ejection fraction, 28.0+/-2.8%) with an implanted atrial-synchronized biventricular pacemaker for the treatment of left ventricular systolic dysfunction were selected and studied. Each subject underwent polysomnography on 3 consecutive nights with CRT on the first night, CRT off the second night, and CRT on the third night. Echocardiography was performed prior to each polysomnogram. RESULTS The central sleep event index (ie, the number of central sleep apneas [CSAs] and hypopneas per hour of sleep) score was lower with CRT compared to that without CRT (mean central sleep event index score with CRT on, 6.9+/-1.7 events per hour of sleep; mean central sleep event index score with CRT off, 14.3+/-2.9 events per hour of sleep; mean central sleep event index score with CRT on, 8.1+/-1.5 events per hour of sleep; p<0.001). Similarly, the cumulative duration of central sleep events (the number of minutes per hour of sleep during CRT) was one half that observed without CRT (CRT on, 2.8+/-0.7 min per hour of sleep; CRT OFF 6.2+/-1.2 min per hour of sleep; CRT ON 3.1+/-0.7 min per hour of sleep; p<0.001). There was a significant correlation between mitral regurgitant volume and central sleep event index on all three nights (r>or=0.77; p<0.01). CONCLUSIONS CRT reduces CSA severity in the short term. This reduction correlated significantly with the CRT-mediated reduction of mitral regurgitation.

Histological findings around electrodes in pacemaker and implantable cardioverter-defibrillator patients: comparison of steroid-eluting and non-steroid-eluting electrodes

AIMS To analyse histological findings surrounding the electrodes in pacemaker/implantable cardioverter-defibrillator (PM/ICD) patients. To compare histology around steroid-eluting and non-steroid ventricular pacing electrodes. METHODS AND RESULTS In autopsied PM/ICD patients histopathological findings around the electrodes were determined. Seventy patients were studied, PM(58), ICD(12), mean age 75.1 ± 9.3 years. The implantation-death interval was 4.0 ± 3.3 years. Most causes of death were cardiac (PM 52%, ICD 58%). The majority of atrial electrodes were attached to the endocardium and most ventricular electrodes were found in the myocardium (P ≤ 0.001). The maximum thickness of the fibrous electrode sheath was greatest for the ICD ventricular electrodes. Some electrodes were covered with fibrin thrombi and granulation tissue, most frequently in the ICD ventricular electrodes. The fibrous sheath usually contained chronic inflammatory cells and in some cases particles of foreign material, foreign body giant cells, and haematogenous pigment. The tissue around steroid-eluting ventricle PM electrodes was compared with the tissue around the non-steroid-eluting ventricle PM electrodes; granulation tissue, foreign material, giant cells being found more frequently around the steroid-eluting electrodes. The fibrous sheath was slightly thinner in the steroid-eluting electrodes. The histology around four coronary sinus electrodes was described. CONCLUSIONS Atrial electrodes were attached more superficially to the endocardium while PM and ICD ventricular electrodes were more frequently embedded in the myocardium. The electrodes were covered by a connective tissue sheath as a result of thrombus organization. This process persisted most frequently around ICD ventricular electrodes. Only borderline differences were found between the histological findings around steroid-eluting and non-steroid-eluting PM ventricular electrodes.

Home monitoring of implantable cardioverter-defibrillators: interpretation reliability of the second-generation "IEGM Online" system

Aims Intracardiac electrograms (IEGMs) are essential for the assessment of implantable cardioverter-defibrillator (ICD) function. The Biotronik Home Monitoring systems transmit an ‘IEGM Online’ that is shorter than the full-length programmer IEGM due to technical constrains. The aim of this study was to evaluate the accuracy of the physicians classification of the underlying rhythm based on the second-generation IEGM Online. Methods and results In total, 1533 patients treated with single- and dual-chamber ICDs and cardiac resynchronization therapy defibrillators were enrolled at 67 investigational sites and followed for 15 months. The investigators classified the rhythm shown in IEGM Online as ventricular tachycardia, ventricular fibrillation, atrial fibrillation, other supraventricular tachyarrhythmia, oversensing due to lead failure, T-wave oversensing, or other rhythm. At the next in-office follow-up, the investigators classified independently the rhythm seen in the corresponding programmer IEGM. The two rhythm classifications were compared thereafter. Both IEGM Online and programmer IEGM were available in 2099 arrhythmic or oversensing events, of which 146 (7.0%) were classified as other rhythm or artefacts and were excluded as inconclusive or atypical. The remaining 1953 events, affecting 352 patients (23.0%), were classified correctly in 1803 cases (92.3%). The accuracy of rough rhythm classification as ventricular, supraventricular, or oversensing was 97.2%. Conclusion The Lumax and IEGM Online HD Evaluation study demonstrates that remote IEGM analysis is reasonably accurate in a remote monitoring system that transmits shorter IEGM than the full-length programmer IEGM for the sake of frequent, fully automatic data transmission.

Heart rate variability analysed by Poincaré plot in patients with metabolic syndrome

INTRODUCTION The SD1 and SD2 indexes (standard deviations in two orthogonal directions of the Poincaré plot) carry similar information to the spectral density power of the high and low frequency bands but have the advantage of easier calculation and lesser stationarity dependence. METHODS ECG signals from metabolic syndrome (MetS) and control group patients during tilt table test under controlled breathing (20 breaths/minute) were obtained. SD1, SD2, SDRR (standard deviation of RR intervals) and RMSSD (root mean square of successive differences of RR intervals) were evaluated for 31 control group and 33 MetS subjects. RESULTS Statistically significant lower values were observed in MetS patients in supine position (SD1: p=0.03, SD2: p=0.002, SDRR: p=0.006, RMSSD: p=0.01) and during tilt (SD2: p=0.004, SDRR: p=0.007). CONCLUSION SD1 and SD2 combining the advantages of time and frequency domain methods, distinguish successfully between MetS and control subjects.

An additional marker of ventricular dyssynchrony

Patients suffering from heart failure with left bundle branch block (LBBB) can be effectively treated by resynchronization therapy (CRT). The ejection fraction, QRS duration (QRSd) and QRS morphology are the main selection criteria. Unfortunately, approximately one-third of CRT recipients are non-responders. Here we introduce an additional marker capable of distinguishing ventricular dyssynchrony more accurately. Methods: Ultra-high-frequency (UHF, sampling 25 kHz) 12-lead ECG, resting supine position, was measured. We analyzed 21 LBBB patients selected for CRT; the QRSd min/mean/max was 130/163/190 ms. Amplitude envelopes in the 500-1,000 Hz passband were computed and averaged with an R-wave trigger for each patient in the V1 and V6 leads. V1-V6 dyssynchrony (DYS) was computed as the time difference between UHF amplitude maximums in the V1 and V6 QRS complex region. Results: The DYS parameter min/mean/max was 1/68/115 ms. Patients with a small value of the DYS parameter, in spite of the fact that their QRS duration meets CRT criteria (> 120 ms), are not expected CRT responders. The DYS parameter indicates ventricular dyssynchrony and can potentially increase the percentage of CRT responders.

Usefulness of left ventricle dyssynchrony assessment before cardiac resynchronization implantation.

BACKGROUND A number of trials have demonstrated the effect of cardiac resynchronization therapy (CRT) on functional improvement and reversed left ventricle remodeling. Meeting contemporary guidelines approximately 30- 40% of patients do not respond to CRT (non-responders). AIM To quantify the predictive ability of basal QRS width and basal echocardiographic parameters of left ventricle contraction dyssynchrony in our group of CRT patients. To compare effectiveness of these parameters assessment in patients with ischemic (iCMP) and non-ischemic cardiomyopathy (niCMP) and with sinus rhythm (SR) and atrial fibrillation (AF). PATIENTS AND METHODS 194 patients after successful introduction of CRT device were evaluated. Evaluation of NYHA function class, QRS width and echocardiographic parameters including parameters of left ventricle contraction dyssynchrony (SPWMD: septal-to-posterior wall motion delay, Ts-sep-lat: time interval between maximum of systolic movement of septum and lateral wall using tissue Doppler imaging, IVMD: interventricular mechanical delay) performed before implantation and 3 months after implantation of CRT device. RESULTS Responder (improved in NYHA class after CRT) rate was 61%. SR patients showed higher benefit compared to AF patients (responder rate 63% vs. 52%, p<0.05). Narrowing of QRS width after CRT was observed only in responders. SPWMD and Ts-sep-lat decreased after CRT in all subgroups. SPWMD dyssynchrony (SPMWD > or = 130 ms) reduction after CRT was more expressed in niCMP population. Ts-sep-lat dyssynchrony (Ts-sep-lat > or = 65 ms) reduction after CRT was more expressed in SR patients. IVMD (IVMD > or = 60 ms) remained unchanged in average, but significant decrease was observed in responders and significant increase in non-responders. QRS width, SPWMD and Ts-sep-lat showed moderate sensitivity but poor specificity to predict CRT benefit. QRS width > or = 150 ms in niCMP patients showed higher sensitivity to predict CRT effect compared to iCMP patients (91%, 65% respectively). IVMD showed poor sensitivity but good specificity to predict CRT benefit. IVMD in SR patients (compared to AF patients) showed higher specificity to predict CRT effect (90%, 63% respectively). CONCLUSION None of tested left ventricle contraction dyssynchrony parameters showed good sensitivity and specificity to predict CRT benefit. QRS width as a predictor factor was more beneficial in non-ischemic patients and IVMD in sinus rhythm patients.

Cardiac resynchronization efficiency estimation by new ultra-high-frequency ECG dyssynchrony descriptor

The biventricular implantable pacemaker (BiV) is usually recommended for heart failure patients with LVEF ≤ 35% and QRS duration > 120ms. We introduce promising marker evaluating suitability and efficiency of the Cardiac Resynchronization Therapy (CRT) recipients. Data: 12-lead UHF-ECG, 25 kHz sampling, 10 minute resting measurement, 28 CRT subjects, each before BiV and with BiV on, VV delay o. Methods: A new parameter D YS was computed as the time diference between two maxima of UHF envelopes computed from VI and V6 leads in QRS complex in 500-1000Hz frequency band. The values of DYS and QRS width before and after BiV implantation are analysed. The assumption for being responder for BiV is high value of DYS before CRT and significant DYS decrease during biventricular pacing. Subjects with no response on BiV stimulation are under the borderline of DYS = 30ms before stimulation. Thus the D YS parameter can serve as a new marker for the prediction of Bi V pacemaker efficiency. This information cannot be derived from standard QRS width values prior BiV implantation.