The strength-duration curves for left bundle branch area pacing.

BACKGROUND: Despite growing clinical use of left bundle branch pacing (LBBP) there is scarcity of data regarding fundamentals of this pacing modality including chronaxie and rheobase. OBJECTIVE: The aims of this study were to calculate strength-duration curves with chronaxie, rheobase values for LBBP and left ventricular septal myocardial pacing (LVSP), to analyse battery current drain and presence of selective LBBP at very short pulse duration (PD). METHODS: The group of 141 patients with permanent LBBP were studied. The LBBP and LVSP capture thresholds were assessed at 6 different PDs to calculate the strength-duration curves. Battery current drain at these PDs and presence of selective LBBP were determined. For comparison of strength-duration curves between His bundle pacing (HBP) and LBBP, source data from our previous work based on 127 patients with HBP were obtained. RESULTS: The chronaxies for LBBP and LVSP were very similar (0.38 ms vs. 0.39 ms) and the rheobases were identical (0.27V). The chronaxie for LBBP was lower than for HBP (0.38ms vs. 0.53 ms, p < 0.001), whereas rheobases were similar (0.27V vs. 0.26V). A narrow zone of selective capture was present in 19% and 41% of patients at PD of 0.06 ms and 0.03 ms, respectively. When pacing with the safety margin of +1 V, the lowest battery current drain was achieved with PD of 0.2 ms. CONCLUSION: The obtained strength-duration curves for LBBP and LVSP provide insights for optimal programming of LBBAP devices with regard to pulse duration, voltage amplitude, battery longevity and selective capture.

Left bundle branch area pacing improves right ventricle function and synchrony.

BACKGROUND: The impact of left bundle branch area pacing (LBBAP) on right ventricular (RV) function and tricuspid regurgitation (TR) remains unclear. OBJECTIVE: We aimed to assess the long-term effects of LBBAP on RV performance and on TR. METHODS: RV function was evaluated using RV free wall strain (FWS), tricuspid annular plane systolic excursion (TAPSE), fractional area changing (FAC), and systolic (S`) velocity of the lateral tricuspid annulus. The presence of reverse septal flash (RSF) and basal bulge (BB) was used to assess RV motion pattern. The distance between the lead entry site on the interventricular septum and the septal leaflet of the tricuspid annulus was measured (lead-TV distance). RESULTS: The analysis included 122 subjects (62 males, age 76.5±11.4 years) with a median follow-up of 21 months. During follow-up, RV FWS improved significantly (15.2±5.8 vs 16.4±5.5, p < 0.001), while TAPSE, S`, and FAC remained unchanged. Left ventricular ejection fraction was an independent predictor for improved RV function (B: 3.51, CI 1.39 - 8.9, p = 0.01). With LBBAP, RSF disappeared in 22/23 (96%) patients, and BB in 15/22 (68%) patients in whom RSF and BB were present at baseline, respectively. RV function improvement was significantly higher when RSF was present at baseline (14 vs 11 patients, p = 0.02). At follow-up, no significant deterioration in TR occurred for the overall group. However, a lead-TV distance of < 24.5 mm was associated with TR progression. CONCLUSION: LBBAP has a favorable impact on RV function. A basal LBBAP position is associated with worsening TR.

Left bundle branch area pacing prevents pacing induced cardiomyopathy in long-term observation.

BACKGROUND: Left bundle branch area pacing (LBBAP) is one of the methods to deliver conduction system pacing which potentially avoids the negative impact of conventional right ventricular pacing. OBJECTIVE: To assess echocardiographic outcomes in a long-term observation in patients with LBBAP implemented for bradyarrhythmia indications. METHODS AND RESULTS: A total of 151 patients with symptomatic bradycardia and LBBAP pacemaker implanted, were prospectively included in the study. Subjects with left bundle branch block and CRT indications (n = 29), ventricular pacing burden <40% (n = 11), and loss of LBBAP (n = 10) were excluded from further analysis. At baseline and the last follow-up visit, echocardiography with global longitudinal strain (GLS) assessment, 12-lead ECG, pacemaker interrogation, and blood level of NT-proBNP were performed. The median follow-up period was 23 months (15.5-28). None of the analyzed patients fulfilled the criteria for pacing induced cardiomyopathy (PICM). Improvement in left ventricular ejection fraction (LVEF) and GLS was observed in patients with LVEF <50% at baseline (n = 39): 41.4 ± 9.2% versus 45.6 ± 9.9%, and 12.9 ± 3.6% versus 15.5 ± 3.7%, respectively. In the subgroup with preserved EF (n = 62), LVEF and GLS remained stable at follow-up: 59.3 ± 5.5% versus 60 ± 5.5%, and 19 ± 3.9% versus 19.4 ± 3.8%, respectively. CONCLUSION: LBBAP prevents PICM in patients with preserved LVEF and improves left ventricle function in subjects with depressed LVEF. LBBAP might be the preferred pacing modality for bradyarrhythmia indications.

Comparison of six risk scores for the prediction of atrial fibrillation recurrence after cryoballoon-based ablation and development of a simplified method, the 0-1-2 PL score.

INTRODUCTION: There are several prognostic scores for the assessment of risk of atrial fibrillation (AF) recurrence post ablation procedure. However, the use of these complex scores is difficult and the validation on different populations brought divergent results. Our goal was to compare the performance of these risk scores as the basis for the development of a new, simplified score based only on few universally predictive variables. METHODS: All cryoballoon-based AF ablations performed in a single-center over a 10-year period were prospectively analyzed with regard to AF recurrence. This served to analyze the performance of APPLE, CAAP-AF, SCALE-CryoAF, MB-LATER, CHADS2, and CHA2DS2-VASc risk scores. RESULTS: A total of 597 patients, mostly (78.1%) with paroxysmal AF were studied. Analyzed risk scores performed poorer than in the original publications because some risk factors were not predictive of AF recurrence. A simplified score named 0-1-2 PL, composed of just two universally predictive variables, AF type (1 point for Persistent AF) and LA dimension (1 point for LA size >45 mm) was developed. The 0-1-2 PL score stratified patients into low risk (0 points), intermediate risk (1 point), and high risk categories (2 points) which were related to a 2-year risk of AF recurrence of 21%, 37%, and 55%, respectively. This score had C-statistics (0.620) higher/comparable to other investigated much more complex scores. CONCLUSION: The assessment of risk of AF recurrence at the pre-ablation stage can be simplified without compromising accuracy. This could help to popularize risk assessment and standardization of AF management.

Patent foramen ovale and left atrial appendage flow velocity predict atrial fibrillation recurrence post cryoballoon ablation.

BACKGROUND: Transesophageal echocardiography (TEE) allows detailed characterization of atrial fibrillation (AF) substrate and could be valuable for predicting pulmonary vein isolation (PVI) procedure outcomes. AIMS: We aimed at assessing the value of TEE-derived left atrial (LA) and LA appendage (LAA) features as prognostic markers for AF recurrence after cryoballoon-based ablation. METHODS: Patients were enrolled using a prospective database of consecutive PVI procedures performed over a 7-year period. The following TEE-derived parameters were investigated: LAA emptying flow velocity (LAA-FV), the presence of patent foramen ovale (PFO), LA spontaneous echo contrast, and mitral regurgitation. Diagnosis of AF recurrence was based on scheduled and symptoms triggered ECG monitoring. The Cox's regression model and Kaplan-Meier survival curves were applied for statistical analysis. RESULTS: A total of 417 consecutive patients who underwent their first PVI using cryoballoon were analyzed (mean age: 59 years). AF recurrence was noted in 25.7% of patients (median follow-up of 24 months). Four TEE-derived variables had predictive values for AF recurrence: LAA-FV <45 cm/s, presence of PFO at resting state, LA spontaneous echo contrast, and mitral regurgitation. In the multivariable model, apart from the transthoracic echocardiography-derived LA size, two TEE-derived features (LAA-FV <45 cm/s and the presence of PFO) remained as independent predictors. CONCLUSIONS: This study proposed a novel TEE-derived AF recurrence risk factor - the presence of PFO - and confirmed the prognostic value of LAA flow velocity in patients undergoing cryoballoon-based AF ablation. These risk factors could be useful in the global assessment of AF recurrence risk and potentially helpful in planning the ablation strategy.

Fixation beats: A novel marker for reaching the left bundle branch area during deep septal lead implantation.

BACKGROUND: One of the challenges of left bundle branch (LBB) pacing is placing the pacing lead deep enough in the septum to reach the LBB area, yet not too deep to avoid perforation. OBJECTIVE: The purpose of this study was to investigate whether the occurrence of the ectopic beats with qR/rsR' morphology in lead V1 (fixation beats) during lead fixation would predict whether the desired intraseptal lead depth had been reached, whereas the lack of fixation beats would indicate a too-shallow position and the need for more lead rotations. METHODS: Consecutive patients during LBB pacing device implantation were analyzed retrospectively and then prospectively with respect to the occurrence of fixation beats during each episode of lead rotation. We compared the presence of fixation beats during the lead rotation event directly before the LBB area depth was reached vs during the events before intermediate/unsuccessful positions. RESULTS: A total of 339 patients and 1278 lead rotation events were analyzed. In the retrospective phase, fixation beats were observed in 327 of 339 final lead positions and in 9 of 939 intermediate lead positions (P <.001). Sensitivity, specificity, and positive and negative predictive values of the fixation beats as a marker for reaching the LBB area were 96.4%, 97.3%, 97.3%, and 96.5%, respectively. In the prospective, fixation beats-guided implantation phase, fixation beats were observed in all patients and only at the LBB capture depth. CONCLUSION: Monitoring fixation beats during deep septal lead deployment can facilitate the procedure and possibly increase the safety of lead implantation.

Programmed deep septal stimulation: A novel maneuver for the diagnosis of left bundle branch capture during permanent pacing.

INTRODUCTION: Permanent deep septal stimulation with capture of the left bundle branch (LBB) enables maintenance/restoration of the physiological activation of the left ventricle. However, it is almost always accompanied by the simultaneous engagement of the local septal myocardium, resulting in a fused (nonselective) QRS complex, therefore, confirmation of LBB capture remains difficult. METHODS: We hypothesized that programmed extrastimulus technique can differentiate nonselective LBB capture from myocardial-only capture as the effective refractory period (ERP) of the myocardium is different from the ERP of the LBB. Consecutive patients undergoing pacemaker implantation underwent programmed stimulation delivered from the lead implanted in a deep septal position. Responses to programmed stimulation were categorized on the basis of sudden change in the QRS morphology of the extrastimuli, observed when ERP of LBB or myocardium was encroached upon, as: "myocardial," "selective LBB," or nondiagnostic (unequivocal change of QRS morphology). RESULTS: Programmed deep septal stimulation was performed 269 times in 143 patients; in every patient with the use of a basic drive train of 600 milliseconds and in 126 patients also during intrinsic rhythm. The average septal-myocardial refractory period was shorter than the LBB refractory period: 263.0 ± 34.4 vs 318.0 ± 37.4 milliseconds. Responses diagnostic for LBB capture ("myocardial" or "selective LBB") were observed in 114 (79.7%) of patients. CONCLUSIONS: A novel maneuver for the confirmation of LBB capture during deep septal stimulation was developed and found to enable definitive diagnosis by visualization of both components of the paced QRS complex: selective paced LBB QRS and myocardial-only paced QRS.

Outcomes of atrial fibrillation ablation program based on single-shot techniques.

INTRODUCTION: Single-shot techniques such as cryoballoon and multipolar phased pulmonary vein ablation catheter (PVAC) are an alternative to the point-by-point radiofrequency method for atrial fibrillation (AF) ablation. However, there is a lack of data concerning sequential use of single-shot techniques, that is, for both the index and redo ablation. AIM: To assess long-term outcomes of the 'single-shot techniques only' AF ablation strategy. MATERIAL AND METHODS: We analyzed all consecutive AF ablations performed over a 10-year period (2009-2019) in a center where a 'single-shot technique only' principle was followed from the start of the AF ablation program. Kaplan-Meier AF-free survival curves were calculated and complications were assessed on the basis of our prospectively maintained database. RESULTS: A total of 597 patients (62.4 ±12.5 years) with paroxysmal (78.1%) or persistent (21.9%) AF entered the study and 655 AF ablation procedures were performed. In 96.5% of redos (n = 58) a different technique (mostly PVAC) was used than for the index ablation (mostly cryoballoon). The Kaplan-Meier estimates of 1, 2 and 5 years freedom from AF were 78.2%, 69.2%, and 56.0%, for the index ablation, and 80.3%, 76.1% and 68.3%, for the redo, respectively. The minor and major complication rates were 8.1%, and 4.0%, respectively. CONCLUSIONS: An AF ablation program based solely on sequential use of two different single-shot techniques for both index and redo procedures is safe and effective. These observations might have important practical implications for new operators/centers starting AF ablation programs and for use of single-shot techniques for redo procedures.

Cardiac resynchronization therapy-induced acute shortening of QRS duration predicts long-term mortality only in patients with left bundle branch block.

AIMS: QRS narrowing with initiation of biventricular pacing might be an acute electrocardiographic indicator of correction of left bundle branch block (LBBB)-induced depolarization delay and asynchrony. However, its impact on prognosis remains controversial, especially in non-LBBB patients. Our goal was to evaluate the impact of QRS narrowing on long-term mortality and morbidity in a large cohort of patients undergoing cardiac resynchronization therapy (CRT) with different pre-implantation QRS types: LBBB, non-LBBB, and permanent right ventricular pacing. METHODS AND RESULTS: This study included consecutive patients who underwent CRT device implantation. Study endpoints: death from any cause or urgent heart transplantation and death from any cause/urgent heart transplantation or hospital admission for heart failure. All pre- and post-implantation electrocardiograms were analysed using digital callipers, high-amplitude augmentation, 100 mm/s paper speed, and global QRS duration measurement method. A total of 552 CRT patients entered the survival analysis. During the 9 years observation period, 232 (42.0%) and 292 (52.9%) patients met primary and secondary endpoints, respectively. QRS narrowing predicted survival in the Kaplan-Meier analysis only in patients with LBBB. Multivariate Cox regression model showed that QRS narrowing was the major determinant of both study endpoints, with hazard ratios of 0.46 and 0.43, respectively. There was a strong relationship between mortality risk and shortening/widening of the QRS, albeit only in the LBBB group. Patients with non-LBBB morphologies had unfavourable prognosis similar to that in LBBB patients without QRS narrowing. CONCLUSION: Acute QRS narrowing in patients with LBBB might be a desirable endpoint of CRT device implantation.

Risk stratification in patients with cardiac resynchronisation therapy: the AL-FINE CRT risk score.

BACKGROUND: Mortality and morbidity in patients with cardiac resynchronisation therapy (CRT) remain very high. Prognostic evaluation of CRT candidates might be useful for the assessment of CRT indications, directing further therapy, counselling, etc. AIM: Our goal was to assess the prognostic value of various parameters in order to construct a risk score that could predict long-term mortality and morbidity during the initial evaluation of CRT candidates. METHODS: This was a retrospective, single-centre, large cohort study involving consecutive heart failure patients who underwent CRT device implantation. In order to build a prediction model, 28 parameters were analysed using uni- and multivariate Cox models and Kaplan-Meier survival curves. RESULTS: Data from 552 patients were used for the long-term outcome assessment. During nine years of follow-up, 232 patients met the primary endpoint of death and 128 patients were hospitalised for heart failure. The strongest and clinically most relevant predictors were selected as the final model. AL-FINE is the acronym for these six predictors: Age ( > 75 years), non-Left bundle branch block morphology (according to Strauss criteria), Furosemide dose ( > 80 mg), Ischaemic aetiology, New York Heart Association class ( > III), and left ventricular Ejection fraction ( < 20%). Depending on the number of AL-FINE score points, overall mortality at seven years was in the range of 28% (0-1 points) to 74% (3-6 points). CONCLUSIONS: A novel, multiparametric CRT risk score was constructed on the basis of simple and recognised clinical, electrocardiographic, and echocardiographic parameters that show a significant add-on effect on mortality in this specific population.

New ECG markers for predicting long-term mortality and morbidity in patients receiving cardiac resynchronization therapy.

We investigated prognostic value of four recently proposed ECG markers in patients with cardiac resynchronization therapy (CRT): 1./ pathological preimplantation QRS axis, 2./ increase in QRS amplitude in V3 during biventricular pacing, 3./ negative QRS in V1/V2 during left ventricular (LV)-only pacing, 4./ longer QRS duration during LV-only pacing. A longitudinal cohort study was performed (n = 552). RESULTS: During the 9-year observation period the primary endpoint (death from any cause or urgent heart transplantation) was met in 232 patients. The secondary endpoint of survival free of heart failure hospitalization was met in 292 patients. Long LV-paced QRS and pathological axis predicted unfavorable prognosis in Kaplan-Meier analysis. In multivariable Cox model (functional class, LV ejection fraction, LV end-diastolic dimension, permanent atrial fibrillation, age, gender, heart failure etiology, creatinine level, diabetes mellitus), LV-paced QRS duration remained a significant determinant of both endpoints. The other studied ECG markers lacked independent prognostic value.

Echocardiographic assessment of right ventricular function in responders and non-responders to cardiac resynchronization therapy.

INTRODUCTION: The aim of this study was to determine whether baseline right ventricular (RV) function assessed by standard echocardiography may indicate patients who will respond to cardiac resynchronization therapy (CRT). MATERIAL AND METHODS: The data of 57 patients (54 men, 95%), aged 66.4 ±8.7 years with heart failure (HF) having a CRT device implanted were collected. All patients had left ventricular ejection fraction (LVEF) ≤ 35% and QRS complex duration ≥ 120 ms. Echocardiographic examination with tissue Doppler imaging techniques and complex RV evaluation were performed at baseline and three months after CRT onset. RESULTS: Three months after CRT implantation, patients responding to CRT, defined as a reduction of left ventricle end-systolic volume (LVESV) of at least 10% (n = 34), compared to patients with a reduction of LVESV of less than 10% (n = 23), had at baseline a smaller right atrium diameter (47.85 ±11.33 mm vs. 52.65 ±8.69 mm; p = 0.028), higher TAPSE (14.56 ±2.57 mm vs. 13.04 ±2.93 mm; p = 0.030) and lower grade of tricuspid valve regurgitation (1.82 ±0.97 vs. 2.3 ±0.88; p = 0.033). CONCLUSIONS: This study showed that there are differences in baseline right ventricular function between responders and non-responders to CRT. Yet in our study, none of the baseline RV parameters provided any value in identifying patients who would respond to CRT.

Heart rate variability in the course of ST--segment elevation myocardial infarction treated with primary percutaneous transluminal coronary angioplasty in elderly and younger patients.

BACKGROUND: The aim of the study was to appraise time domain heart rate variability (HRV) parameters in patients with ST-segment elevation myocardial infarction (STEMI) in different age groups. MATERIAL AND METHODS: Retrospective analysis included 357 consecutive patients in sinus rhythm without diabetes, aged 27-87 years (mean age--63.0 +/- 11.8 years, 243 men) treated with primary percutaneous transluminal coronary angioplasty (PTCA) due to first in their life STEMI. Each patient had an echocardiographic examination and 24-hour ECG monitoring results interpreted. Participants were divided in the analysis applying the WHO old age criterion into two groups: group A < 65 years old (n = 188) and B aged > or = 65 years (n = 169). RESULTS: In the whole study group age negatively correlated with SDNN, SDANNI, SDNNI and EF, whereas positive correlation between EF and SDANN, and EF and SDNNI was observed. Elderly patients as compared to the younger individuals had significantly diminished SDNN, SDANN, SDNNI and more often SDNN < 70 ms (33.7% vs 20.7%, p < 0.0001). When the circumflex artery lesion was the cause of myocardial infarction SDNN and SDANN were significantly lower in the group B, whereas in case of PTCA of RCA, apart from decreased SDNN and SDANN, EF was also compromised in this group. CONCLUSIONS: Elderly patients with myocardial infarction with ST-segment elevation treated with primary PTCA, compared to the younger age group, are characterized by increased sympathetic activation assessed by heart rate variability and heart rate in 24-hour ECG monitoring.

[Concealed His bundle extrasystoles causing atrioventricular block]. / Utajona ekstrasystolia z peczka Hisa przyczyna bloku przedsionkowo-komorowego.

We present electrocardiograms of a 37 year-old male with frequent extrasystoles and second-degree atrioventricular block. Electrophysiological study confirmed the initial diagnosis of manifest and concealed His bundle ectopy as the cause of his brady- and tachyarrhythmia.

Mortality and morbidity in cardiac resynchronization patients: impact of lead position, paced left ventricular QRS morphology and other characteristics on long-term outcome.

AIMS: To investigate the effect of implantation-related characteristics, especially lead position and left ventricular (LV)-paced QRS morphology, on long-term mortality and morbidity in cardiac resynchronization therapy (CRT) patients. METHODS AND RESULTS: The study retrospectively analysed 362 consecutive patients who underwent CRT device implantation over a 6 year period. Pre-implantation, LV-only paced, and biventricularly paced 12-lead electrocardiograms were obtained. Left ventricular and right ventricular (RV) lead positions were determined using biplane fluoroscopy and roentgenograms. The Kaplan-Meier method was used to estimate the survival function for all-cause death/hospitalization and cardiovascular death/hospitalization. Univariate and multivariate Cox proportional hazards models were also applied. The mean follow-up time was 24.7 ± 16.9 months. There were 79 deaths (62 cardiovascular) and 99 unplanned hospitalizations (72 cardiovascular). One year and 2 year all-cause mortality rates were 8.5 and 18.0%, respectively. Electrocardiographic and fluoroscopic descriptors of the LV lead position were found to be predictors of mortality/morbidity (as were functional class, heart failure aetiology, hyponatremia, and chronic atrial fibrillation). In particular, the antero-apical pattern of LV-only paced QRS showed a hazard ratio (HR) of 1.8 in univariate and 1.7 in multivariate analysis for predicting all-cause death/hospitalization (P = 0.006). The apical/paraseptal LV lead position showed an HR of 2.1 in univariate and 1.9 in multivariate analysis for predicting cardiovascular death/hospitalization (P = 0.018). CONCLUSION: To achieve better long-term outcomes in CRT patients the antero-apical pattern of LV QRS complexes and apical or paraseptal LV lead position should be avoided.

Effects of biventricular pacing on right ventricular function assessed by standard echocardiography.

BACKGROUND AND AIM: The aim of this study was to evaluate the short term effect of cardiac resynchronisation therapy (CRT) on right ventricular (RV) function assessed by standard echocardiography. METHODS: Data from 57 patients (54 men, 95%; three women, 5%), aged 66.4 ± 8.7 years with heart failure (HF) was analysed. All patients were in NYHA III-IV functional classes, despite optimal pharmacological treatment according to the current guidelines, had left ventricular ejection fraction ≤ 35% and QRS complex ≥ 120 ms in a standard electrocardiogram. At baseline and three months after CRT implantation the patients' histories were taken, an anthropometrical examination was made, laboratory tests including the level of NT-proBNP and electrocardiogram were performed, and echocardiographic examination was extended by tissue Doppler imaging techniques and complex RV evaluation. RESULTS: Three months after CRT implantation in the whole study group, the average NYHA functional class had decreased from 3.11 ± 0.28 to 2.25 ± 0.68 (p < 0.001), and the six-minute walk test distance had increased from 298.04 ± 107.42 m to 373.12 ± 127.15 m (p < 0.001). CRT improved RV systolic function in the whole study group. Tricuspid annular plane systolic excursion had increased from 13.95 ± 2.80 to 15.79 ± 2.33 mm (p < 0.001), and so likewise had systolic excursion velocity (S'), which rose from 8.84 ± 3.45 to 11.00 ± 3.43 cm/s (p < 0.001). Tricuspid regurgitation grade decreased from 2.02 ± 0.95 to 1.86 ± 0.91 (p = 0.013). RV systolic pressure decreased from 31.07 ± 20.43 to 27.75 ± 17.35 mm Hg (p < 0.001). RV fractional area change rose from 31.35 ± 10.30% to 35.40 ± 10.51% (p < 0.001). CONCLUSIONS: This study showed that CRT improved RV systolic function evaluated with parameters assessed in standard echocardiographic examination three months after therapy initiation. The observed improvement was consistent among all applied echocardiographic parameters reflecting RV systolic function.

Electrocardiographic diagnosis of biventricular pacing in patients with nonapical right ventricular leads.

BACKGROUND: Assessment of left ventricular (LV) capture is of paramount importance in patients with biventricular (BiV) pacing. Our goal was to identify electrocardiographic features that differentiate between BiV and right ventricular (RV)-only pacing in patients with nonapical RV leads. METHODS: The study enrolled 300 consecutive patients with BiV devices and nonapical RV leads, and obtained from them 558 electrocardiograms with either BiV pacing (n = 300) or RV-only pacing (n = 258). RV pacing served as a surrogate for loss of LV capture. Electrocardiograms from the first 150 patients were used to identify BiV-specific features, and to construct an algorithm to differentiate between BiV and RV-only pacing. Electrocardiograms from the second 150 patients were used to validate the algorithm. RESULTS: The following electrocardiographic features typical of BiV pacing were identified: QS in lead V6 (specificity = 98.7%, sensitivity = 54.7%), dominant R in lead V1 (specificity = 100%, sensitivity = 23.3%), q in lead V6 (specificity = 96%, sensitivity = 22.7%), and a QRS < 160 ms (specificity = 100%, sensitivity = 66.0%). The algorithm based on those features was found to have an overall diagnostic accuracy of 95.0%, a specificity of 96.0%, and a sensitivity of 93.5%. CONCLUSIONS: The study identified QRS features that were very specific for BiV pacing in patients with nonapical RV leads. Sequential arrangement of those features resulted in an algorithm that was very accurate for differentiating between BiV pacing and loss of LV capture.

The influence of cardiac resynchronization therapy on selected inflammatory markers and aldosterone levels in patients with chronic heart failure.

The aim of the study was to assess the influence of cardiac resynchronization therapy(CRT) on a series of humoral parameters crucial for the pathophysiology of chronic heart failure such as aldosterone or the inflammatory markers. Thirty eight consecutive patients (aged 66.3 +/- 9.6 years, 31 men - 82% ) with chronic heart failure (57.9% with ischaemic background and 42.1% of non-ischaemic etiology) in stable for at least 3 months, NYHA class III - IV despite optimized pharmacotherapy, with left ventricular ejection fraction (LVEF) < or = 35% and wide QRS complex (> or = 120 ms) had the blood serum tested for the concentrations of interleukin-6 (IL-6), interleukin-18 (IL-18), C-reactive protein (CRP) and aldosterone before and 12-16 weeks after CRT introduction. In the study group aldosterone concentrations were significantly reduced. Among the inflammatory markers the level of IL-6 decreased, IL-18 concentrations showed a falling trend (445.1 +/- 225.7 pg/ml vs 418.4 +/- 229.6 pg/ml, p = 0.052), whereas no change of CRP serum contain was noted. It was showed that cardiac resynchronization therapy had an impact on systemic inflammation and hormonal status in patients with chronic heart failure during short-term observation.

Clinical and classic echocardiographic features of patients with, and without, left ventricle reverse remodeling following the introduction of cardiac resynchronization therapy.

BACKGROUND: The aim of the study was to assess clinical and classic echocardiographic data in patients with different cardiac resynchronization therapy (CRT) outcomes. METHODS: Sixty consecutive patients (aged 66.3 ± 8.7 years, 57 men) with chronic heart failure (CHF) in New York Heart Association (NYHA) classes III-IV despite optimized pharmacotherapy, with left ventricular end-diastolic diameter (LVEDD) > 55 mm, left ventricular ejection fraction £ 35% and wide QRS complex (≥ 120 ms), including individuals with permanent atrial fibrillation (AF) and single- and dual-chamber pacing, were assessed firstly before, and secondly three months after, biventricular heart stimulator implantation (excluding three patients who died during the follow-up). Patients developing ≥ 10% reduction of left ventricular end-systolic volume (LVESV) were classified as responders to CRT. RESULTS: The group of responders (n = 34, 59.7%) and the group of non-responders (n = 23, 40.3%) did not differ regarding baseline echocardiographic parameters or in terms of clinical data of age, gender, concomitant diseases, smoking or pharmacological treatment. The differences involved higher rates of ischemic CHF background, prevalence of hypertension and permanent AF, and a higher concentration of N-terminal pro-B-type natriuretic peptide (NT-proBNP) among the non-responders. In the multivariate logistic regression analysis, NT-proBNP, body mass index (BMI) and the presence of permanent AF correlated negatively with the magnitude of LVESV reduction following CRT introduction. CONCLUSIONS: Classic echocardiographic data did not predict left ventricle reverse remodeling. Higher rates of ischemic CHF aetiology, hypertension, permanent AF and higher NT-proBNP concentration were found in the group without at least 10% LVESV reduction at the three month follow-up. NT-proBNP, BMI and the presence of permanent AF had negative effects on the magnitude of LVESV.

Baseline tissue Doppler imaging-derived echocardiographic parameters and left ventricle reverse remodelling following cardiac resynchronization therapy introduction.

INTRODUCTION: The aim of the study was to assess the relation of baseline mechanical dyssynchrony with the left ventricular end-systolic volume (LVESV) decrease following cardiac resynchronization (CRT) therapy introduction. MATERIAL AND METHODS: Sixty consecutive patients (aged 66.3 ± 8.7 years; 57 men) with chronic heart failure (71.7% of ischaemic and 28.3% of non-ischaemic origin) and current indications for CRT were assessed before and 3 months after biventricular heart stimulator implantation. Longitudinal movements of twelve segments of the left ventricle (LV) (6 basal and 6 midlevel) and two segments of the right ventricle (RV) were analysed using tissue Doppler imaging (TDI) techniques with time from onset of Q wave in ECG to peak systolic velocity in colour-coded TDI (T(TDI)), time to peak strain (T(strain)) and time to peak strain rate (T(strain) (rate)). Minimal and maximal time differences within LV and between LV and RV walls were calculated. RESULTS: In the study group LVEF and 6-min walk test distance increased, while NYHA class, NT-proBNP level, left ventricular end-diastolic volume and LVESV decreased. Significant correlations between the magnitude of LVESV reduction with maximal time differences between T(strain) of 12 LV segments (r=0.34, p = 0.017) and time differences between T(TDI) basal LV-RV segments (r = -0.29, p=0.041) were found. CONCLUSIONS: Only a few TDI-derived parameters such as maximal time differences between T(strain) of 12 LV segments and T(TDI) difference of LV-RV basal segments can be useful to predict the magnitude of left ventricle reverse remodelling after CRT introduction.