Safety and acute efficacy of cryoballoon ablation for atrial fibrillation at community hospitals.

AIMS: Pulmonary vein isolation (PVI) using cryoballoon ablation (CBA) is an established procedure for treating symptomatic paroxysmal and persistent atrial fibrillation (AF). The safety and efficacy of PVI performed at community hospitals are unknown. We aimed to determine the safety and acute efficacy of PVI using CBA performed at community hospitals with limited annual case numbers. METHODS AND RESULTS: This registry study included 1004 consecutive patients who had PVI performed for symptomatic paroxysmal (n = 563) or persistent AF (n = 441) from January 2019 to September 2020 at 20 hospitals. Each hospital performed fewer than 100 CBA-PVI procedures/year according to local standards. Procedural data, efficacy, and complication rates were determined. The mean number of CBA procedures performed/year at each centre was 59 ± 25. The average procedure time was 90.1 ± 31.6 min and the average fluoroscopy time was 19.2 ± 11.4 min. Isolation of all pulmonary veins was documented in 97.9% of patients. The most frequent reason for not achieving complete isolation was development of phrenic nerve palsy. No hospital deaths were observed. Two patients (0.2%) suffered a clinical stroke. Pericardial effusion occurred in six patients (0.6%), two of whom (0.2%) required pericardial drainage. Vascular complications occurred in 24 patients (2.4%), two of whom (0.2%) required vascular surgery. Phrenic nerve palsy occurred in 48 patients (4.8%) and persisted up to hospital discharge in six patients (0.6%). CONCLUSION: Pulmonary vein isolation procedures for paroxysmal or persistent AF using CBA can be performed at community hospitals with high acute efficacy and low complication rates.

Outcome in patients undergoing upgrade to cardiac resynchronization therapy: predictors of outcome after upgrade to CRT.

The advantages of upgrade to cardiac resynchronisation therapy (CRT) have not been explored as carefully as the outcomes of de novo CRT implantations. Furthermore selection criteria for patients with the potential to benefit the most from this therapy are unknown. Therefore, we analyzed the long term outcome and its predictors in a real-world cohort receiving a CRT upgrade from previous pacemaker (PM) and defibrillator devices (ICD). We analyzed 86 patients (mean age 68 ± 9 years; 89% male) undergoing CRT upgrade procedures. Response to CRT as well as long term patient outcome was analyzed. NYHA class improved in majority of the patients during short term period (61%), and this trend remained constant during long term follow-up (54%). The observed all-cause mortality was 54% with mean survival of 49 ± 4 months. 11 patients underwent left ventricular assist device implantation or heart transplantation. In the multivariate analysis, only kidney function assessed by GFR (HR 0.97; 95% CI 0.95-0.99; p = 0.009) and LVEF (HR 0.92; 95% CI 0.87-0.97; p = 0.002) remain predictors for mortality. Patients who undergo an upgrade procedure to CRT demonstrate a significant response rate assessed by improvement in NYHA class, with initial baseline parameters such as LVEF and kidney function remaining significant predictors for mortality.

Individually tailored vs. standardized substrate modification during radiofrequency catheter ablation for atrial fibrillation: a randomized study.

Aims: This randomized single-centre study sought to compare the efficacy and safety of pulmonary vein isolation (PVI) plus voltage-guided ablation vs. PVI with or without linear ablation depending on the type of atrial fibrillation (AF). Methods and results: Overall, 124 ablation-naive patients with paroxysmal or persistent AF were randomized to PVI with (persistent AF) or without (paroxysmal AF) additional linear ablation (control group) vs. PVI plus ablation of low-voltage areas (LVAs) irrespective of AF type. Bipolar voltage mapping was performed during stable sinus rhythm. An LVA consisted of ≥ 3 adjacent mapping points that each had a peak-to-peak amplitude ≤0.5 mV. After a mean follow-up of 12 ± 3 months, significantly more patients in the LVA ablation group were free from atrial arrhythmia recurrence >30 s off antiarrhythmic drugs (AADs) after a single procedure (primary endpoint) compared with control group patients [40/59 (68%) vs. 25/59 (42%), log-rank P = 0.003]. Arrhythmia-free survival on or off AADs was found in 33/59 control group patients (56%) and in 41/59 LVA ablation group patients (70%) (adjusted log-rank P = 0.10). During the 7 day Holter monitoring period at 12 months, significantly more patients in the LVA ablation group were free from arrhythmia recurrence on or off AADs [45/50 (90%) vs. 33/46 (72%), P = 0.04]. No between-group differences were observed regarding procedure duration, fluoroscopy time, and major complications. Conclusion: In this single-centre study, individually tailored substrate modification guided by voltage mapping was associated with a significantly higher arrhythmia-free survival rate compared with a conventional approach applying linear ablation according to AF type.

Mapping-guided characterization of mechanical and electrical activation patterns in patients with normal systolic function using a sensor-based tracking technology.

AIMS: In times of evolving cardiac resynchronization therapy, intra-procedural characterization of left ventricular (LV) mechanical activation patterns is desired but technically challenging with currently available technologies. In patients with normal systolic function, we evaluated the feasibility of characterizing LV wall motion using a novel sensor-based, real-time tracking technology. METHODS AND RESULTS: Ten patients underwent simultaneous motion and electrical mapping of the LV endocardium during sinus rhythm using electroanatomical mapping and navigational systems (EnSite™ NavX™ and MediGuide™, SJM). Epicardial motion data were also collected simultaneously at corresponding locations from accessible coronary sinus branches. Displacements at each mapping point and times of electrical and mechanical activation were combined over each of the six standard LV wall segments. Mechanical activation timing was compared with that from electrical activation and preoperative 2D speckle tracking echocardiography (echo). MediGuide-based displacement data were further analysed to estimate LV chamber volumes that were compared with echo and magnetic resonance imaging (MRI). The lateral and septal walls exhibited the largest (12.5 [11.6-15.0] mm) and smallest (10.2 [9.0-11.3] mm) displacement, respectively. Radial displacement was significantly larger endocardially than epicardially (endo: 6.7 [5.0-9.1] mm; epi: 3.8 [2.4-5.6] mm), while longitudinal displacement was significantly larger epicardially (endo: 8.0 [5.0-10.6] mm; epi: 10.3 [7.4-13.8] mm). Most often, the anteroseptal/anterior and lateral walls showed the earliest and latest mechanical activations, respectively. 9/10 patients had concordant or adjacent wall segments of latest mechanical and electrical activation, and 6/10 patients had concordant or adjacent wall segments of latest mechanical activation as measured by MediGuide and echo. MediGuide's LV chamber volumes were significantly correlated with MRI (R2= 0.73, P < 0.01) and echo (R2= 0.75, P < 0.001). CONCLUSION: The feasibility of mapping-guided intra-procedural characterization of LV wall motion was established. CLINICAL TRIAL REGISTRATION: http://www.clinicaltrials.gov; Unique identifier: CT01629160.

Sensor-based electromagnetic navigation to facilitate implantation of left ventricular leads in cardiac resynchronization therapy.

INTRODUCTION: Implantation of cardiac resynchronization therapy (CRT) devices can be challenging, time consuming, and fluoroscopy intense. To facilitate placement of left ventricular (LV) leads, a novel electromagnetic navigation system (MediGuide™, St. Jude Medical, St. Paul, MN, USA) has been developed, displaying real-time 3-D location of sensor-embedded delivery tools superimposed on prerecorded X-ray cine-loops of coronary sinus venograms. We report our experience and advanced progress in the use of this new electromagnetic tracking system to guide LV lead implantation. METHODS AND RESULTS: Between January 2012 and December 2013, 71 consecutive patients (69 ± 9 years, 76% male) were implanted with a CRT device using the new electromagnetic tracking system. Demographics, procedural data, and periprocedural adverse events were gathered. The impact of the operator's experience, optimized workflow, and improved software technology on procedural data were analyzed. LV lead implantation was successfully achieved in all patients without severe adverse events. Total procedure time measured 87 ± 37 minutes and the median total fluoroscopy time (skin-to-skin) was 4.9 (2.5-7.8) minutes with a median dose-area-product of 476 (260-1056) cGy*cm(2) . An additional comparison with conventional CRT device implantations showed a significant reduction in fluoroscopy time from 8.0 (5.8; 11.5) to 4.5 (2.8; 7.3) minutes (P = 0.016) and radiation dose from 603 (330; 969) to 338 (176; 680) cGy*cm(2) , respectively (P = 0.044 ). CONCLUSION: Use of the new navigation system enables safe and successful LV lead placement with improved orientation and significantly reduced radiation exposure during CRT implantation.

Patient discomfort following catheter ablation and rhythm device surgery.

AIMS: Proper management of post-interventional pain relieves unwarranted patient distress and enhances patient satisfaction. There have been only a limited number of investigations into patient discomfort following electrophysiological interventions. This study aims to quantify pain after interventional procedures, including ablation of atrial fibrillation (AF) or ventricular tachycardia (VT), as well as implant or explant of pacemakers or implantable cardioverter defibrillators. METHODS AND RESULTS: One-hundred and two consecutive patients (mean age 66 years, 70 men) were asked to quantify post-interventional pain on a numeric rating scale (NRS 0-10) every 2 h during a period of 24 h after their intervention (49 ablations in deep propofol sedation, 53 device surgeries in local anaesthesia with mepivacaine 1%) and to specify the type of pain. Pain was classified as moderate to severe in case of NRS > 3. Post-operative pain medication included non-opioid and opioid analgesics as per the treating physicians' discretion. Sixty-one patients (60%) suffered from moderate-to-severe pain within the first 24 h after the procedure, despite the use of analgesics in 47 patients (46%). Pain was present in an early period (0-6 h) in 54% and in a late period (8-24 h) in 40% of patients. Patients complained of back pain (44%), pain at the site of the device pocket (39%), pain at the groin after puncture (7%), and pericarditic pain (5%). Multivariate analysis identified female gender (P = 0.046) associated with early post-interventional pain while age, diabetes mellitus, body mass index, type of intervention, and procedure time were not related to early or late post-interventional pain. CONCLUSION: The findings highlight the high prevalence and the poor predictability of moderate-to-severe post-interventional pain within the first 24 h after catheter ablation and cardiac device surgery procedures, despite the use of peri-interventional analgesics. These findings highlight the need for more careful pain assessment and management programmes.

Precordial QRS amplitude ratio predicts long-term outcome after catheter ablation of electrical storm due to ventricular tachycardias in patients with arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: Radiofrequency catheter ablation is currently considered as the therapeutic option of choice in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and recurrent ventricular tachycardia (VT). METHODS: This study intended to assess the long-term outcome of catheter ablation in patients with ARVC and electrical storm. The specific objective was to assess the relationship between precordial QRS amplitude ratio and outcome of catheter ablation in these patients. RESULTS: Twenty-eight patients (19 men, age 52.3±14.2years) underwent 48 catheter ablation procedures (range 1-6, six epicardial). During a mean follow-up of 18.7±15.1months, 13 patients (46.5%) experienced VT recurrence. Age >50years and ∑QRSmvV1-V3/∑QRSmvV1-V6≤0.48 but not right ventricular size and acute ablation outcome were associated with VT recurrence during the follow up. CONCLUSION: Age >50years and ∑QRSmvV1-V3/∑QRSmvV1-V6≤0.48 predict recurrence of VT after successful radiofrequency catheter ablation of VT in patients with ARVC and electrical storm.

Treatment with novel oral anticoagulants in a real-world cohort of patients undergoing cardiac rhythm device implantations.

AIMS: The safety and efficacy of novel oral anticoagulants in patients with atrial fibrillation undergoing pacemaker or implantable cardioverter-defibrillator interventions have not been clearly defined. Therefore, we compared the incidence of bleeding and thrombo-embolic complications following cardiac rhythm device (CRD) implantations under dabigatran vs. rivaroxaban in a real-world cohort. METHODS AND RESULTS: We analysed 176 consecutive procedures performed in 93 patients treated peri-interventionally with dabigatran and 83 patients with rivaroxaban, respectively. Post-operative bleeding complications and thrombo-embolic events occurring within 30 days were compared. There were no significant differences in baseline characteristics between patients in the dabigatran and the rivaroxaban group. Most of the patients in both the groups received dual chamber or cardiac resynchronization devices (71 vs. 78%) as opposed to single-chamber systems (29 vs. 22%). In the dabigatran group, two (2%) bleeding complications (two pocket haematomas) were observed in comparison with four (5%, three pocket haematomas and one pericardial effusion) in the rivaroxaban group (P = 0.330). Three complications in the rivaroxaban group necessitated surgical intervention as opposed to none in the dabigatran group (P = 0.064). One case of a transient ischaemic attack occurred in the dabigatran group (P = 0.343). CONCLUSION: Bleeding and thrombo-embolic complications in patients treated with dabigatran or rivaroxban are rare. Further and larger studies are warranted to define the optimal anticoagulation management in patients with a need for oral anticoagulation and CRD interventions.

The predictive value of echocardiographic parameters associated with left ventricular diastolic dysfunction on short- and long-term outcomes of catheter ablation of atrial fibrillation.

AIMS: Recurrence of atrial fibrillation (AF) is frequently observed after AF catheter ablation. However, the predictive value of echocardiographic parameters associated with left ventricular diastolic dysfunction (LVDD) has not been well studied. METHODS AND RESULTS: In 124 consecutive patients (mean age 61 ± 10 years, 60% male) with paroxysmal (n = 70) or persistent AF (n = 54) undergoing AF catheter ablation, mitral early diastolic peak (E-wave) and late peak (A-wave) velocities, E/A ratio, deceleration time (DT) of mitral early velocity, early diastolic mitral annulus peak velocity (e'), and E/e' ratio were determined by transthoracic echocardiography. Early (ERAF) and late AF recurrence (LRAF) were monitored with 7-day Holter electrocardiograms directly after catheter ablation and after 6 and 12 months. Early AF recurrence occurred in 34% of the patients, while LRAF was observed in 27% of the patients. Patients with ERAF had higher E-wave (0.9 ± 0.2 vs. 0.8 ± 0.2 m/s, P = 0.035) and lower A-wave velocity (0.5 ± 0.2 vs. 0.6 ± 0.2 m/s, P = 0.038), higher E/A ratio (1.8 ± 0.9 vs. 1.5 ± 0.9, P = 0.089), and slower DT (214 ± 67 vs. 243 ± 68 ms, P = 0.073), while E/e', left atrial diameter, and left ventricular ejection fraction were similar. In multivariable regression analysis, the E/A ratio was the only independent predictor of ERAF (odds ratio 2.905, 95% confidence interval 1.072-7.870, P = 0.036). None of the echocardiographic parameters influenced the late therapy outcome. CONCLUSION: Early results of the catheter ablation, but not the late rhythm outcome, are influenced by an impaired mitral inflow pattern, which is associated with LVDD.

Comparison of dabigatran and uninterrupted warfarin in patients with atrial fibrillation undergoing cardiac rhythm device implantations. Case-control study.

BACKGROUND: The incidence of postoperative complications following pacemaker or implantable cardioverter-defibrillator implantations in patients treated with new oral anticoagulation agents has not been studied. Here we present a first comparison of complications after cardiac rhythm device (CRD) implantations in patients with atrial fibrillation (AF) treated with dabigatran or uninterrupted warfarin. METHODS AND RESULTS: Using a case-control study design, we compared complications within 30 days after 236 CRD procedures performed under uninterrupted warfarin (n=118) or interrupted dabigatran (n=118).There were no significant differences in the baseline characteristics of both groups. In the warfarin group, 9 (8%) pocket hematomas were observed vs. 3 (3%) in the dabigatran group (P=0.075). Two complications in the warfarin group necessitated surgical intervention as opposed to none in the dabigatran group (P=0.156). The postprocedural blood loss expressed as a drop in hemoglobin was significantly greater in the warfarin group (-0.9±0.7 vs. -0.5±0.4 mmol/L, P=0.023). In the dabigatran group, 1 case of transient ischemic attack occurred. The mean time to hospital discharge was shorter in patients treated with dabigatran (2.5±2.3 vs. 3.8±4.1 days, P=0.02). CONCLUSIONS: The incidence and severity of bleeding complications may be lower in patients treated with periprocedurally discontinued dabigatran when compared with uninterrupted warfarin therapy. Further evaluation of peri-interventional complications and establishment of an optimal anticoagulation management protocol are needed.

Comparison of Dabigatran and Uninterrupted Warfarin in Patients With Atrial Fibrillation Undergoing Cardiac Rhythm Device Implantations.

Background:The incidence of postoperative complications following pacemaker or implantable cardioverter-defibrillator implantations in patients treated with new oral anticoagulation agents has not been studied. Here we present a first comparison of complications after cardiac rhythm device (CRD) implantations in patients with atrial fibrillation (AF) treated with dabigatran or uninterrupted warfarin.Methods and Results:Using a case-control study design, we compared complications within 30 days after 236 CRD procedures performed under uninterrupted warfarin (n=118) or interrupted dabigatran (n=118).There were no significant differences in the baseline characteristics of both groups. In the warfarin group, 9 (8%) pocket hematomas were observed vs. 3 (3%) in the dabigatran group (P=0.075). Two complications in the warfarin group necessitated surgical intervention as opposed to none in the dabigatran group (P=0.156). The postprocedural blood loss expressed as a drop in hemoglobin was significantly greater in the warfarin group (-0.9±0.7 vs. -0.5±0.4 mmol/L, P=0.023). In the dabigatran group, 1 case of transient ischemic attack occurred. The mean time to hospital discharge was shorter in patients treated with dabigatran (2.5±2.3 vs. 3.8±4.1 days, P=0.02).Conclusions:The incidence and severity of bleeding complications may be lower in patients treated with periprocedurally discontinued dabigatran when compared with uninterrupted warfarin therapy. Further evaluation of peri-interventional complications and establishment of an optimal anticoagulation management protocol are needed.

Additional diagnostic and prognostic value of copeptin ultra-sensitive for diagnosis of non-ST-elevation myocardial infarction in older patients presenting to the emergency department.

BACKGROUND: Identifying older patients with non-ST- elevation myocardial infarction (NSTEMI) within the very large proportion with elevated high-sensitive cardiac troponin T (hs-cTnT) is a diagnostic challenge because they often present without clear symptoms or electrocardiographic features of acute coronary syndrome to the emergency department (ED). We prospectively investigated the diagnostic and prognostic performance of copeptin ultra-sensitive (copeptin-us) and hs-cTnT compared to hs-cTnT alone for NSTEMI at prespecified cut-offs in unselected older patients. METHODS: We consecutively enrolled 306 non-surgical patients ≥70 years presenting to the ED. In addition to clinical examination, copeptin-us and hs-cTnT were measured at admission. Two cardiologists independently adjudicated the final diagnosis of NSTEMI after reviewing all available data. All patients were followed up for cardiovascular-related death within the following 12 months. RESULTS: NSTEMI was diagnosed in 38 (12%) patients (age 81±6 years). The combination of copeptin-us ≥14 pmol/L and hs-cTnT ≥0.014 µg/L compared to hs-cTnT ≥0.014 µg/L alone had a positive predictive value of 21% vs. 19% to rule in NSTEMI. The combination of copeptin-us <14 pmol/L and hs-cTnT <0.014 µg/L compared to hs-cTnT <0.014 µg/L alone had a negative predictive value of 100% vs. 99% to rule out NSTEMI. Hs-cTnT ≥0.014 µg/L alone was significantly associated with outcome. When copeptin-us ≥14 pmol/L was added, the net reclassification improvement for outcome was not significant (p=0.809). CONCLUSIONS: In unselected older patients presenting to the ED, the additional use of copeptin-us at predefined cut-offs may help to reliably rule out NSTEMI but may not help to increase predicted risk for outcome compared to hs-cTnT alone.

Twelve-month efficacy of second-generation cryoballoon ablation for atrial fibrillation performed at community hospitals: results of the German register on cryoballoon ablation in local hospitals (regional).

BACKGROUND: The 12-month follow-up (F/U) efficacy of CBA PVI performed at community hospitals for treatment of symptomatic paroxysmal and persistent atrial fibrillation (AF) is unknown. This study determined the 12-month efficacy of pulmonary vein isolation (PVI) using cryoballoon ablation (CBA) performed at community hospitals with limited annual case numbers. METHODS: This registry study included 983 consecutive patients (pts) from 19 hospitals, each with an annual procedural volume of < 100 PVI procedures/year. Pts underwent CBA PVI for paroxysmal AF (n = 520), persistent AF (n = 423), or redo PVI (n = 40). The primary endpoint was frequency of documented recurrent AF, the occurrence of atrial flutter or tachycardia following a 90-day period after the index ablation and up to 12 months. The frequency of repeat ablation was determined. RESULTS: Isolation of all PVs was documented in 98% of pts at the end of the procedure. Twelve-month F/U data could be obtained in 916 pts. A 24-h ECG registration was performed in 641 pts (70.0%); in 107 pts (16.7%) of them, recurrent AF was documented. The primary endpoint was met in 193 F/U pts (21.1%). It occurred in 80/486 F/U pts with paroxysmal AF (16.4%), and in 107/390 F/U pts with persistent AF (27.4%). Redo PVI was performed in 71 pts (7.8%), and atrial flutter ablation was performed in 12 pts (1.4%). CONCLUSIONS: CBA PVI for paroxysmal or persistent AF can be performed at community hospitals with adequate rates of 12-month symptom freedom and arrhythmia recurrence. The study was registered at the German register of clinical studies (DRKS00016504).

How-to: Focus Cardiac Ultrasound in acute settings.

Focus cardiac ultrasound (FoCUS) provides vital information at at the bedside which has the potential of improving outcomes in the acute settings. FoCUS could help the clinicians in their daily clinical decision-making while applied within the clinical context as an extension of bedside clinical examination. FoCUS practitioners should be aware of their own limitations with the importance of the timely referral for comprehensive Echocardiography whenever required.

Level 1 of Entrustable Professional Activities in adult echocardiography: a position statement from the EACVI regarding the training and competence requirements for selecting and interpreting echocardiographic examinations.

The goal of Level 1 training in echocardiography is to enable the trainee to select echocardiography appropriately for the evaluation of a specific clinical question, and then to interpret the report. It is not the goal of Level 1 training to teach how to perform the examination itself-that is the goal of higher levels of training. However, understanding the principles, indications, and findings of this crucial technique is valuable to many medical professionals including outside cardiology. This should be seen as part of a general understanding of cardiac imaging modalities. The purpose of this position statement is to define the scope and outline the general requirements for Level 1 training and competence in echocardiography. Moreover, the document aims to make a clear distinction between Level 1 competence in echocardiography and focus cardiac ultrasound (FoCUS).

Echocardiography in aortic diseases: EAE recommendations for clinical practice.

Echocardiography plays an important role in the diagnosis and follow-up of aortic diseases. Evaluation of the aorta is a routine part of the standard echocardiographic examination. Transthoracic echocardiography (TTE) permits adequate assessment of several aortic segments, particularly the aortic root and proximal ascending aorta. Transoesophageal echocardiography (TOE) overcomes the limitations of TTE in thoracic aorta assessment. TTE and TOE should be used in a complementary manner. Echocardiography is useful for assessing aortic size, biophysical properties, and atherosclerotic involvement of the thoracic aorta. Although TOE is the technique of choice in the diagnosis of aortic dissection, TTE may be used as the initial modality in the emergency setting. Intimal flap in proximal ascending aorta, pericardial effusion/tamponade, and left ventricular function can be easily visualized by TTE. However, a negative TTE does not rule out aortic dissection and other imaging techniques must be considered. TOE should define entry tear location, mechanisms and severity of aortic regurgitation, and true lumen compression. In addition, echocardiography is essential in selecting and monitoring surgical and endovascular treatment and in detecting possible complications. Although other imaging techniques such as computed tomography and magnetic resonance have a greater field of view and may yield complementary information, echocardiography is portable, rapid, accurate, and cost-effective in the diagnosis and follow-up of most aortic diseases.

Preserved cardiac synchrony and function with single-site left ventricular epicardial pacing during mid-term follow-up in paediatric patients.

AIMS: Right ventricular (RV) pacing may cause dyssynchronous left ventricular (LV) contraction and systolic dysfunction. Left ventricular-based pacing may prevent such deterioration. The aim of this study was to evaluate ventricular synchrony and function with permanent LV pacing (LVP) vs. RV pacing (RVP) in paediatric patients with normal cardiac anatomy. METHODS AND RESULTS: Twenty-five paediatric patients with normal cardiac anatomy and single-site epicardial RV apex pacing (RVP, n=10, pacing duration: 7.9+/-2.9 years) or LV free wall pacing (LVP, n=15, pacing duration: 4.3+/-2.6 years) for complete heart block were enrolled. A total of 15 healthy children served as a control group. Conventional echocardiography, myocardial circumferential (LV), and longitudinal (RV) 2D strain (2Ds) analysis were obtained. Paced QRS duration did not differ between groups (P=0.915). Interventricular mechanical delay (LVP: 17+/-10, RVP: 62+/-15 ms; P<0.0001), septal-to-posterior wall motion delay (LVP: 59+/-23, RVP: 294+/-84 ms; P<0.0001), septal-to-lateral wall motion delay (LVP: 40+/-19, RVP: 59+/-12 ms; P=0.009), and LV mechanical delay (LVP: 35+/-9, RVP: 63+/-17 ms; P<0.0001) were preserved for LVP but not for RVP. Right ventricular mechanical delay was similar among paced groups (P=0.639). Left ventricular ejection fraction was normal for LVP but not for RVP (LVP: 60+/-6%, RVP: 45+/-6%; P=0.012). Left ventricular pacing did not differ from controls for synchrony or function. CONCLUSION: Conventional and 2Ds echocardiographic measurements indicate preserved LV synchrony and function in paediatric patients with LVP compared with RVP. Permanent LVP has no impact on RV synchrony.

Left ventricular dyssynchrony from right ventricular pacing depends on intraventricular conduction pattern in intrinsic rhythm.

AIMS: Right ventricular pacing (RVP) prolongs ventricular activation and may induce mechanical dyssynchrony. We hypothesized that the severity of RVP-associated ventricular mechanical dyssynchrony may depend on the intrinsic intraventricular conduction pattern. METHODS AND RESULTS: Sixty-five patients with a single- or dual-chamber RV pacemaker were included. Forty-seven patients with ejection fraction (EF) 35% and no BBB served as a control group. Echocardiographic dyssynchrony parameters [aortic pre-ejection delay (AoPEP), interventricular mechanical delay, delayed posterior left ventricular wall motion, and septal-to-posterior wall motion delay (SPWMD)] were evaluated in all patients with and without RVP. No dyssynchrony was found in patients with no BBB, RBBB, and in the control group, whereas LBBB patients showed significant dyssynchrony in AoPEP and SPWMD. RVP had a significant negative impact on all dyssynchrony parameters in patients with no BBB or LBBB. RVP induced significantly less severe dyssynchrony in RBBB patients. With RVP 100, 94, 56 and 16% of patients with LBBB, without BBB, RBBB, and from the control group, respectively, fulfilled the CARE-HF criteria for ventricular dyssynchrony. CONCLUSION: RVP worsens mechanical ventricular dyssynchrony in patients with reduced EF. These effects are most pronounced in patients with either normal QRS width or LBBB during intrinsic rhythm. In contrast, patients with an RBBB during intrinsic rhythm without RVP evidenced a better preserved haemodynamic function and mechanical synchrony with RVP, despite a comparable extent of pacing-induced QRS prolongation.