Cardiac radioablation of incessant ventricular tachycardia in patients with terminal heart failure under permanent left ventricular assist device therapy-description of two cases.

PURPOSE: Cardiac radioablation (cRA) using a stereotactic single-session radioablative approach has recently been described as a possible treatment option for patients with otherwise untreatable recurrent ventricular tachycardia (VT). There is very limited experience in cRA for patients undergoing left ventricular assist device (LVAD) therapy. We present clinical experiences of two patients treated with cRA for incessant VT under long-term LVAD therapy. METHODS: Two male patients (54 and 61 years old) with terminal heart failure under LVAD therapy (both patients for 8 years) showed incessant VT despite extensive antiarrhythmic drug therapy and repeated catheter ablation. cRA with a single dose of 25 Gy was applied as a last resort strategy under compassionate use in both patients following an electroanatomical mapping procedure. RESULTS: Both patients displayed ongoing VT during and after the cRA procedure. Repeated attempts at post-procedural rhythm conversion failed in both patients; however, one patient was hemodynamically stabilized and could be discharged home for several months before falling prey to a fatal bleeding complication. The second patient initially stabilized for a few days following cRA before renewed acceleration of running VT required bilateral ablation of the stellate ganglion; the patient died 50 days later. No immediate side effects of cRA were detected in either patient. CONCLUSION: cRA might serve as a last resort strategy for patients with terminal heart failure undergoing LVAD therapy and displaying incessant VT. Intermediate- and long-term outcomes of these seriously ill patients often remain poor; therefore, best supportive care strategies should also be evaluated as long as no clear beneficial effects of cRA procedures can be shown. For patients treated with cRA under running ventricular rhythm abnormality, strategies for post-procedural generation of stabilized rhythm have to be established.

Cardiac radiotherapy transiently alters left ventricular electrical properties and induces cardiomyocyte-specific ventricular substrate changes in heart failure.

AIMS: Ongoing clinical trials investigate the therapeutic value of stereotactic cardiac radioablation (cRA) in heart failure patients with ventricular tachycardia. Animal data indicate an effect on local cardiac conduction properties. However, the exact mechanism of cRA in patients remains elusive. Aim of the current study was to investigate in vivo and in vitro myocardial properties in heart failure and ventricular tachycardia upon cRA. METHODS AND RESULTS: High-density 3D electroanatomic mapping in sinus rhythm was performed in a patient with a left ventricular assist device and repeated ventricular tachycardia episodes upon several catheter-based endocardial radio-frequency ablation attempts. Subsequent to electroanatomic mapping and cRA of the left ventricular septum, two additional high-density electroanatomic maps were obtained at 2- and 4-month post-cRA. Myocardial tissue samples were collected from the left ventricular septum during 4-month post-cRA from the irradiated and borderzone regions. In addition, we performed molecular biology and mitochondrial density measurements of tissue and isolated cardiomyocytes. Local voltage was altered in the irradiated region of the left ventricular septum during follow-up. No change of local voltage was observed in the control (i.e. borderzone) region upon irradiation. Interestingly, local activation time was significantly shortened upon irradiation (2-month post-cRA), a process that was reversible (4-month post-cRA). Molecular biology unveiled an increased expression of voltage-dependent sodium channels in the irradiated region as compared with the borderzone, while Connexin43 and transforming growth factor beta were unchanged (4-month post-cRA). Moreover, mitochondrial density was decreased in the irradiated region as compared with the borderzone. CONCLUSION: Our study supports the notion of transiently altered cardiac conduction potentially related to structural and functional cellular changes as an underlying mechanism of cRA in patients with ventricular tachycardia.

Left atrial conduction times and regional velocities in persistent atrial fibrillation patients with and without fibrotic atrial cardiomyopathy.

Despite the progress in understanding left atrial substrate and arrhythmogenesis, only little is known about conduction characteristics in atrial fibrillation patients with various stages of fibrotic atrial cardiomyopathy (FACM). This study evaluates left atrial conduction times and conduction velocities based on high-density voltage and activation maps in sinus rhythm (CARTO®3 V7) of 53 patients with persistent atrial fibrillation (LVEF 60% (55-60 IQR), LAVI 39 ml/m2 (31-47 IQR), LApa 24 ± 6 cm2). Measurements were made in low voltage areas (LVA ≤ 0.5 mV) and normal voltage areas (NVA ≥ 1.5 mV) at the left atrial anterior and posterior walls. Maps of 28 FACM and 25 no FACM patients were analyzed (19 FACM I/II, 9 FACM III/IV, LVA 14 ± 11 cm2). Left atrial conduction time averaged to 110 ± 24 ms but was shown to be prolonged in FACM (119 ms, + 17%) when compared to no FACM patients (101 ms, p = 0.005). This finding was pronounced in high-grade FACM (III/IV) (133 ms, + 31.2%, p = 0.001). In addition, the LVA extension correlated significantly with the left atrial conduction time (r = 0.56, p = 0.002). Conduction velocities were overall slower in LVA than in NVA (0.6 ± 0.3 vs. 1.3 ± 0.5 m/s, -51%, p < 0.001). Anterior conduction appeared slower than posterior, which was significant in NVA (1 vs. 1.4 m/s, -29%, p < 0.001) but not in LVA (0.6 vs. 0.8 m/s, p = 0.096). FACM has a significant influence on left atrial conduction characteristics in patients with persistent atrial fibrillation. Left atrial conduction time prolongs with the grade of FACM and the quantitative expanse of LVA up to 31%. LVAs show a 51% conduction velocity reduction compared to NVA. Moreover, regional conduction velocity differences are present in the left atrium when comparing anterior to posterior walls. Our data may influence individualized ablation strategies.

Second generation of cryoballoons can improve efficiency of cryoablation for atrial fibrillation.

BACKGROUND: We investigated whether the new second generation of cryoballoons can improve the efficiency and safety of cryoablation for atrial fibrillation (AF) during ablation and in terms of outcome. METHODS: Data of AF patients consecutively treated with a single 28-mm cryoballoon were analyzed. Patients were divided into two groups: the G1 group was treated with the first-generation cryoballoons (ArcticFront) and G2 with the second generation (ArcticFront Advance). Failure of cryoablation treatment was defined as detection of an episode of AF, atrial flutter, or atrial tachycardia lasting ≥ 30 seconds during 3-month follow-up. Left atrial diameter (LAD) was measured by transthoracic echocardiography before cryoablation. RESULTS: One hundred twenty-five patients (group G1/G2: 57/68) were enrolled. Mean total time of the whole procedure, cryomapping, and cryoablation was shorter with G2 than with G1 (P < 0.05). No complication occurred with G1 whereas with G2 the complication rate was 8.8%. During mean 12 ± 4 months follow-up, the overall success rate of cryoablation was 76.0% (95/125); it was higher with G2 (89.7% [61/68] vs 59.7% [34/57], P < 0.001). Patients in whom treatment failed had larger LAD (48 ± 8 mm vs 44 ± 6 mm, P = 0.002) than those in whom it succeeded. Type of cryoballoon (relative risk [RR] = 5.75 [2.16, 15.27], P < 0.0001) and LAD (RR = 0.90 [0.83, 0.97], P = 0.0043) were shown in multivariable analysis to be individually related to the difference in success rate. CONCLUSION: Ablation for AF with the new generation of cryoballoons is associated with higher success rate of pulmonary vein isolation and better outcome. However, more complications occurred during the early stage of application of the G2 cryoballoon.

Prolonged ablation on critical segments of pulmonary vein ostia in paroxysmal atrial fibrillation: a prospective randomized controlled study.

INTRODUCTION: Electrical reconnection of the pulmonary veins (PVs) plays a key role in the recurrence of atrial fibrillation (AF) after ablative treatment. This randomized controlled study tested the hypothesis that prolonged ablations, on areas that may be critical for left atrial (LA)-PV conduction, can significantly reduce the rate of acute PV reconnection and AF recurrence. METHODS: Patients with paroxysmal AF were randomly assigned to either a control or an add-on group.Ostial PV isolation (PVI) was performed by point-to-point RF ablation (irrigated tip, 30 Watts, 30 seconds).An ostial segment was assumed to be critical for LA-PV connection if any of the following reactions occurred during RF application: (1) sudden delay of LA-PV conduction, (2) change of activation sequence,and (3) PVI. In this case, RF application was prolonged from 30 seconds to 90 seconds in the add-on group only. RESULTS: A total of 131 patients (58 ± 11 years, 47 female) were assigned to a control (n = 64) and an add-on (n = 67) group. Ablation time was longer in the add-on (48 ± 16 minutes vs 37 ± 15 minutes, P = 0.03). Acute PV reconnection was observed in 20 of 64 controls and in eight of 66 add-on patients (31% vs 12%, P < 0.001). During a follow-up of 26 months, AF recurred in 33 of 64 controls and in 16 of 66 add-on patients (52% vs 24%, P = 0.001) after a single ablation procedure. CONCLUSIONS: Prolonged radiofrequency application on critical segments of LA-PV connection is a safe and effective ablative strategy that significantly reduces acute PV reconnection and AF recurrence rates after a single ablation procedure for paroxysmal AF.

Precordial electrode placement for optimal ECG monitoring: implications for ambulatory monitor devices and event recorders.

INTRODUCTION: Detection of QRS complexes, P-waves and atrial fibrillation f-waves in electrocardiographic (ECG) signals is critical for the correct diagnosis of arrhythmias. We aimed to find the best bipolar lead (BL) with the highest signal amplitude and shortest inter-electrode spacing. METHODS: ECG signals (120 seconds) were recorded in 36 patients with 16 precordial electrodes placed in a standardized pattern. An average signal was analysed for each of 120 possible BLs obtained by calculating the difference between pairs of unipolar leads. Peak-to-peak amplitudes of QRS waves (50ms around R-peak) and P waves (270-70ms before R-peak) were calculated. For patients with atrial fibrillation, power of the fibrillatory (f) wave was used instead. Maximum values at each distance were considered and differentiation analysis was performed based on incremental changes (amplitude to distance). RESULTS: There was a significant correlation between distance and QRS-amplitude (r=0.78, p<0.001), P-wave amplitude (r=0.60, p<0.01) and f-wave power (r=0.79, p<0.001). The range of values was: QRS-amplitude 0.7-2.33mV, P-wave amplitude 0.07-0.18mV, and f-wave power 0.55-2.12mV(2)/s. The maximum value for the shortest distance was on a heart-aligned axis over the left ventricle for the QRS complex (1.9mV at 8.7cm) and over the atria for the P-wave (0.98mV) and f-waves (1.45mV(2)/s at 8cm, respectively). CONCLUSION: There is a strong positive correlation between electrode distance and ECG signal-amplitude. Distance of 8cm on a heart-aligned axis and over the relevant heart-chamber provides the highest signal amplitude for the shortest distance. These findings are essential for the design and use of ambulatory monitoring devices.

Mechanistic assessment and ablation of left ventricular assist device related ventricular tachycardia in patients with severe heart failure.

Aims: Left-ventricular-assist-devices (lvad) are an established treatment for patients with severe heart failure with reduced ejection fraction (HF) and reduce mortality. However, HF patients have significant substrate for ventricular tachycardia (VT) and the lvad itself might be pro-arrhythmogenic. We investigated the mechanism of VT in lvad-patients in relation to the underlying etiology and provide in silico and ex-vivo data for ablation in these HF patients. Methods and Results: We retrospectively analyzed invasive electrophysiological (EP) studies of 17 patients with VT and lvad. The mechanism of VT was determined using electroanatomical, entrainment and activation time mapping. Ischemic cardiomyopathy was present in 70% of patients. VT originated from the lvad region in >30%. 1/6 patients with VT originating from the lvad region had episodes before lvad implantation, while 7/11 patients with VT originating from other regions had episodes before implantation. Number and time of radiofrequency (RF)-ablation lesions were not different between VTs originating from the lvad or other regions. Long-term freedom from VT was 50% upon ablation in patients with VT originating from the lvad region and 64% if ablation was conducted in other regions. To potentially preemptively mitigate lvad related VT in patients undergoing lvad implantation, we obtained in silico derived data and performed ex-vivo experiments targeting ventricular myocardium. Of the tested settings, application of 25 W for 30 s was safe and associated with optimal lesion characteristics. Conclusion: A significant percentage of patients with lvad undergoing VT ablation exhibit arrhythmia originating in close vicinity to the device and recurrence rates are high. Based on in silico and ex-vivo data, we propose individualized RF-ablation in selected patients at risk for/with lvad related VT.

Clinical outcomes of cryoballoon ablation for pulmonary vein isolation: Impact of intraprocedural heart rhythm.

BACKGROUND: The current study sought to assess the impact of the intraprocedural heart rhythm (sinus rhythm [SR] vs. atrial fibrillation [AF]) on acute procedural characteristics, durability of pulmonary vein isolation (PVI) and long-term clinical outcomes of cryoballoon (CB) ablation. METHODS: A total of 195 patients with symptomatic paroxysmal (n = 136) or persistent AF (n = 59) underwent CB-based PVI. Ablation procedures were either performed in SR (SR group; n = 147) or during AF (AF group; n = 48). Persistent AF was more frequent in the AF group than in the SR group (62% vs. 20%). All other patient baseline characteristics did not differ between the two groups. RESULTS: The nadir temperature during the CB applications was significantly lower in the AF group than in patients in the SR group (-49 [interquartile range, -44; -54]°C vs. -47 [-42; -52]°C, p = 0.002). Median procedure and fluoroscopy times as well as the rate of real-time recordings were not different between the two groups. Repeat ablation for the treatment of atrial arrhythmia recurrence was performed in 60 patients (SR: 44 [30%] patients; AF: 16 [33%] patients), with a trend towards a lower rate of pulmonary vein reconnections in the AF group (p = 0.07). There was no difference in 3-year arrhythmia-free survival (p = 0.8). CONCLUSIONS: Cryoballoon-based PVI during AF results in lower nadir balloon temperatures and a trend towards a higher durability of PVI as compared to procedures performed in SR. The rate of real-time PVI recordings was not affected by the intraprocedural heart rhythm.

Minimally invasive approach to the treatment of atrial fibrillation: Concomitant Convergent and LARIAT procedure.

The Convergent procedure comprises epi- and endocardial ablation of the left atrium and represents an effective alternative to conventional endocardial ablation in patients with therapy-resistant atrial fibrillation. The LARIAT approach allows the epi- and endocardial closure of the left atrial appendage and effectively reduces the risk of stroke in patients with atrial fibrillation. In this video tutorial, we provide step-by-step guidance through the concomitant Convergent and LARIAT procedures.

Cardiovascular magnetic resonance imaging for accurate sizing of the left atrium: predictability of pulmonary vein isolation success in patients with atrial fibrillation.

PURPOSE: To prospectively determine the most reproducible approach for left-atrial size assessment using cardiovascular magnetic resonance (CMR) imaging in patients with atrial fibrillation and its value for prediction of pulmonary vein isolation (PVI) treatment success. MATERIALS AND METHODS: Eighty patients underwent CMR imaging prior to PVI; the CMR examination included standard cine sequences, a multislice cine sequence in 4-chamber orientation with full left-atrial coverage, and a contrast-enhanced MR angiography of the left atrium. Left-atrial size was determined as: diameter, area, volume segmented from angiography, and diastolic/systolic volumes from cine imaging (Simpson's rule). All measurements were carried out by two independent observers and repeated by one observer to assess inter- and intrareader variability. Treatment success was defined as persisting sinus rhythm after PVI (follow-up period 12.6 ± 6.6 months). RESULTS: All left-atrial measurements showed substantial intrareader agreement. Interreader agreement was substantial for diastolic/systolic left-atrial volumes only. Calculated bias was found to be minimal (0.1%-4.9%). Predictability of PVI treatment success was best using cine volumetric measurements (cutoff value for diastolic volume, 112 mL) yielding a sensitivity and specificity of 80% and 70%, respectively. CONCLUSION: Left-atrial volumetry based on cine imaging represented the most reproducible approach to determine left-atrial size. PVI success was predicted best using cine volumetry.

Intraprocedural imaging of left atrium and pulmonary veins: a comparison study between rotational angiography and cardiac computed tomography.

BACKGROUND: Atrial fibrillation (AF) ablation is facilitated by anatomical visualization of the left atrium (LA) and the pulmonary veins (PVs). The purpose of this study was to compare accuracy, radiation exposure, and costs between three-dimensional atriography (3D-ATG) and cardiac computed tomography (CCT). METHODS: Seventy patients with an indication for AF ablation were included. Contrast-enhanced CCT was performed preoperatively for all patients. In addition, intraoperative 3D-ATG was performed with contrast medium injection either indirectly into the pulmonary arteries during a breath-hold (Ind.-RTA, n = 25) or directly into the LA, during adenosine-induced asystole (Ad.-RTA, n = 23), or rapid ventricular pacing (VP-RTA, n = 22). We evaluated vertical ostial PV diameters and LA volume, time needed to perform, radiation exposure, and procedural cost for each imaging method. RESULTS: The correlation coefficient between 3D-ATG and CCT for the ostial PV diameters was r = 0.83 for Ind.-RTA, 0.91 for Ad.-RTA, and 0.88 for the VP-RTA method (P > 0.05). The volume correlations were r = 0.87 for Ind.-RTA, 0.82 for Ad.-RTA, and 0.8 for VP-RTA (P > 0.05). Time to perform was 13 ± 5 minutes for ATG and 46 ± 9 minutes for CCT (P < 0.05). Effective radiation dose was 2.2 ± 0.2 mSv for ATG and 20.4 ± 7.4 mSv for CCT (P < 0.05). The procedural cost was estimated at 91-95 € for ATG and at 126-151 € for CCT. CONCLUSIONS: 3D-ATG is an intraprocedural imaging modality that provides anatomical accuracy comparable to that of CCT with significantly lower radiation dose, in less time and at less financial expense (PACE 2011; 34:315-322).

A novel cryoballoon technique for mapping and isolating pulmonary veins: a feasibility and efficacy study.

INTRODUCTION: The study was designed to evaluate the feasibility and efficacy of a simplified cryoballoon technique in which a microcircular catheter was introduced into the central lumen of a cryoballoon catheter for the purpose of recording pulmonary vein (PV) potentials during ablation procedures and without interchanging catheters. METHODS AND RESULTS: A total of 23 consecutive patients with paroxysmal atrial fibrillation (AF) were enrolled. A single transseptal puncture was made and a cryoballoon catheter was inserted into the left atrium. A 6-pole mapping catheter with a 0.035-inch shaft diameter was introduced into the PV through the central lumen of the cryoballoon catheter. In addition to the function as a recording device, the mapping catheter was also used as a "guide-wire" during the procedure. A total of 84 PVs (84/92, 91.3%) were completely isolated using this novel cryoballoon technique. In 43 of the 84 veins (51.2%), isolation was observed in real time during the cryoablation; in the remaining 41 veins (48.8%), isolation was confirmed immediately post ablation attempt with the mapping catheter. Procedure time was 152.7 +/- 54.9 minutes, and fluoroscopy time was 33.2 +/- 17.3 minutes. At follow-up (7.4 months, range 2-18 months), 17 (73.9%) patients were free from AF. There was 1 occurrence of phrenic nerve palsy during ablation of a right superior PV, which fully resolved after 1 month. CONCLUSION: The use of a cryoballoon catheter equipped with a 6-pole micromapping catheter inserted through its central lumen for the purpose of mapping and ablation during PV isolation procedures is both feasible and effective.

Optimal fluoroscopic projections for angiographic imaging of the pulmonary vein ostia: lessons learned from the intraprocedural reconstruction of the left atrium and pulmonary veins.

AIMS: Electrical isolation of the pulmonary veins (PVs) is the cornerstone of the ablative treatment of atrial fibrillation. Selective angiography of the PVs in standard fluoroscopic projections is often used for intraprocedural identification of PVs and their ostia. Variable spatial orientation and significant variability of PV anatomy are important limitations of this imaging approach. METHODS AND RESULTS: Sixty patients undergoing a PV isolation procedure received intraprocedural rotational angiography and three-dimensional reconstruction of the left atrium (LA) and PVs. For each patient, 33 angiographic projections were independently evaluated [right anterior oblique (RAO) 80 degrees to left anterior oblique (LAO) 80 degrees, in steps of 5 degrees] by two physicians in order to identify the optimal projections of the PV ostia according to the following definition: Sagittal plane: (i) clear identification of both superior and inferior segments of the LA-PV junction and (ii) no overlapping between LA (and/or left atrial appendage) and PV ostium. Frontal plane: (i) clear identification of all four quadrants of the PV ostium and (ii) fluoroscopic angles at which the maximal horizontal ostial diameter is visualized. A successful reconstruction of the LA and all PVs was obtained in 58 (97%) patients. An optimal ostial projection in a sagittal plane was identified for all four PVs. The optimal ostial projection was RAO 5 degrees for the right superior PVs in 57 out of 58 patients (98%), RAO 55 degrees for the right inferior PVs in 54 out of 58 patients (93%), LAO 45 degrees for the left superior PVs in 46 out of 58 patients (80%), and LAO 60 degrees for the left inferior PVs in 48 out of 58 patients (83%). An optimal ostial projection in a frontal plane was identified only for the inferior PVs. The optimal ostial projection was LAO 40 degrees for the right inferior PVs in 55 out of 58 patients (95%) and RAO 45 degrees for the left inferior PVs in 51 out of 58 patients (88%). CONCLUSION: If selective angiography is to be used to delineate anatomy and location of the PV ostia to guide PV isolation, different fluoroscopic projections are required for different PVs. The preselected RAO and LAO projections proposed in our study result in optimal angiographic projections of all PV ostia in at least one plane in the majority of patients.

Long-term left atrial remodeling after ablation of persistent atrial fibrillation: 7-year follow-up by cardiovascular magnetic resonance imaging.

PURPOSE: Restoration of sinus rhythm in patients with persistent atrial fibrillation (ps. AF) induces reverse atrial remodeling and improvement of left ventricular function. We evaluated the effect of ablative treatment on cardiac remodeling after a long follow-up period of 7 years by cardiovascular magnetic resonance (CMR). METHODS: Patients with symptomatic ps. AF underwent CMR within 7 days prior to the ablation procedure. Left atrial and ventricular volumes were measured. All patients underwent circumferential pulmonary vein isolation. At the end of follow-up (FU), a CMR and 7-day ECG registration were performed. RESULTS: Forty-two patients (67 ± 9 years) were included. After a FU of 86 ± 13 months, 23 patients had a successful outcome. In these patients, LVEF improved from 56 ± 5 to 62 ± 4% (p = 0.02), but left atrial volume and ejection fraction (LAV, LAEF) remained unchanged (105 ± 25 to 98 ± 34, p = 0.44; 34 ± 10 to 36 ± 11, p = 0.6, respectively). In 14 patients with a BMI < 30 and no left ventricular hypertrophy (LVH), LAV decreased (104 ± 30 to 82 ± 26 ml, p = 0.01) and LAEF improved (33 ± 12 to 40 ± 11%, p = 0.03). In 9 patients with successful outcome and either BMI ≥ 30 or LVH, LAV increased (110 ± 26 to 125 ± 30 ml, p = 0.03) and LAEF deteriorated (35 ± 11 to 31 ± 10%, p = 0.04). CONCLUSIONS: Successful ablative treatment of atrial fibrillation is associated with reverse left atrial remodeling and improvement of left atrial and ventricular function. In patients with a BMI ≥ 30 or left ventricular hypertrophy, further left atrial enlargement occurs despite successful outcome.

Isolated atrial amyloidosis suspected by electrophysiological voltage mapping and diagnosed by 99m Tc-DPD scintigraphy.

We present not-yet-seen multimodal images of a 55-year-old female patient with isolated atrial amyloidosis (IAA) who clinically suffered from multiple atrial arrhythmias and heart failure symptoms with preserved left ventricular ejection fraction. We aim to show structural and functional abnormalities detected by electrophysiological voltage mapping, cardiac magnetic resonance imaging (MRI) [cMRI; atrial strain measurements, late gadolinium enhancement (LGE) visualization], and 99m Tc-DPD scintigraphy. Bipolar voltage mapping performed during two electrophysiological procedures showed diffuse left atrial low-voltage areas (bipolar < 0.5 mV) and also a moderately diseased right atrium suspected of infiltrative cardiomyopathy. Catheter ablation did successfully treat a left atrial and two right atrial focal tachycardias. For further diagnostics, a 3T cMRI was performed, revealing a subendocardial circumferential left atrial LGE and pathological atrial strain measurements, especially during conduit and reservoir phase. Afterwards, nuclear imaging with 559 MBq of 99m Tc-DPD was performed. The scan revealed amyloid infiltration of the left atrium. Neither an uptake in the ventricular myocardium nor an extra-cardiac uptake of DPD was seen. Genetic testing for transthyretin amyloidosis mutations in this patient was negative, and peripheral neuropathy was ruled out by electromyogram analysis. The synopsis of these findings reveals IAA as the most possible diagnosis and showed isolated atrial nuclear tracer uptake with 99m Tc-DPD scintigraphy for the first time. Non-invasive imaging techniques might help in suggesting IAA but need further investigation.

Reconstructing and registering three-dimensional rotational angiogram of left atrium during ablation of atrial fibrillation.

BACKGROUND: Three-dimensional (3D) image of left atrium (LA) can greatly facilitate ablation of atrial fibrillation (AF). Reconstructing method using computed tomography (CT) has certain limitations. The 3D image of LA can be intraprocedurally reconstructed by a rotational angiography technique. METHODS: Forty-six patients undergoing AF ablation were included in this study. Preprocedural CT imaging and intraprocedural reconstructing 3D rotational angiogram (3DRA) of LA were performed in all the patients. Rapid ventricular pacing (RVP, 300 ms) was used to inhibit the drainage of atrium. During RVP, contrast medium was injected into the LA, and rotational angiography was performed. The 3DRA was reconstructed and was registered with the live fluoroscopy. The 3DRA was evaluated in comparison to the CT image. In the navigation of the registered 3DRA, the ablation of AF was performed. RESULTS: Forty-four 3DRAs (95.7%) were successfully reconstructed and registered with the live fluoroscopy. The LA anatomy was delineated in the 3DRA in comparison to a CT image. AF ablation was successfully performed in the 44 patients in the navigation of the registered 3DRA. There were good correlations in the PV ostial diameter and the LA volume as assessed by 3DRA in comparison to a CT image (r>=0.87). The radiation exposure in rotational angiography was substantially less than that in CT scanning (2.7+/-0.9 mSv vs. 24.9+/-3.1 mSv, P<0.001). CONCLUSIONS: It is feasible to reconstruct and register the 3DRA with live fluoroscopy using the RVP method during the ablation of AF.

Atrial fibrillation ablation strategies and outcome in patients with heart failure: insights from the German ablation registry.

BACKGROUND: Heart failure (HF) and atrial fibrillation (AF) often coexist, but data on the prognostic value of differing ablation strategies according to left ventricular ejection fraction (LVEF) are rare. METHODS AND RESULTS: From January 2007 until January 2010, 728 patients with HF were enrolled in the multi-center German ablation registry prior to AF catheter ablation. Patients were divided into three groups according to LVEF: HF with preserved LVEF (≥ 50%, HFpEF, n = 333), mid-range LVEF (40-49%, HFmrEF, n = 207), and reduced LVEF (< 40%, HFrEF, n = 188). Ablation strategies differed significantly between the three groups with the majority of patients with HFpEF (83.4%) and HFmrEF (78.4%) undergoing circumferential pulmonary vein isolation vs. 48.9% of patients with HFrEF. The latter underwent ablation of the atrioventricular (AV) node in 47.3%. Major complications did not differ between the groups. Kaplan-Meier survival analysis demonstrated a significant mortality increase in patients with HFrEF (6.1% in HFrEF vs. 1.5% in HFmrEF vs. 1.9% in HFpEF, p = 0.009) that was limited to patients undergoing ablation of the AV node. CONCLUSIONS: Catheter ablation strategies differ significantly in patients with HFpEF, HFmrEF, and HFrEF. In almost 50% of patients with HFrEF AV-node ablation was performed, going along with a significant increase in mortality rate. These results should raise efforts to further evaluate the prognostic effect of ablation strategies in HF patients.

Steerable sheath catheter navigation for ablation of atrial fibrillation: a case-control study.

BACKGROUND: Lack of stable access to all desired ablation target sites is one of the limitations for efficacious circumferential left atrial (LA) pulmonary vein (PV) ablation. Targeting that, new catheter navigation technologies have been developed. The aim of this study was to describe atrial fibrillation (AF) mapping and ablation using manually controlled steerable sheath catheter navigation and to compare it against an ablation approach with a nonsteerable sheath. METHODS AND RESULTS: In this case-control-analysis 245 consecutive patients (controls) treated with circumferential left atrial PV ablation were matched with 105 subsequently consecutive patients (cases) ablated with a similar line concept but mapping and ablation performed with a manually controlled steerable sheath. One hundred sixty-six patients were selected to be included into 83 matched patient pairs. Ablation success was measured with serial 7-day Holter electrocardiograms. Patients ablated with the steerable sheath showed an increase in the success rate (freedom from AF) from 56% to 77% (P = 0.009) after a single procedure and 6 months of follow-up. With respect to procedural data no difference could be found for procedure time, fluoroscopy time, irradiation dose, and radiofrequency (RF) burning time. With the steerable sheath mean procedural RF power (33 +/- 9 vs 41 +/- 4 W; P < 0.0005) and total RF energy delivery (97,498 vs 111,864 J; P < 0.005) were significantly lower and the rate of complete PV isolation significantly increased from 10% to 52% (P < 0.0005). The complication rate was the same in both groups. Among different arrhythmia, procedure, and patient characteristics, the lack of early postinterventional arrhythmia recurrences was the only but powerful predictor for long-term ablation success. CONCLUSIONS: An AF mapping and ablation approach solely using a manually controlled steerable sheath for catheter navigation improved the outcome of circumferential left atrial PV ablation at similar intervention times and similar complication rates. The 6-month success rate after a single LA intervention increased from 56% to 77%.

Clinical impact of repolarization changes in supine versus upright body position.

BACKGROUND: The impact of postural changes on various electrocardiography (ECG) characteristics has only been assessed in a few small studies. This large prospective trial was conducted to confirm or refute preliminary data and add important results with immediate impact on daily clinical practice. METHODS: ECGs in supine and upright position from 1028 patients were analyzed. Evaluation was made according to changes in T-wave vector and direction, ST-segment deviation, heart rate, QT interval and QTc interval was performed. Findings were correlated with the medical history of patients. RESULTS: Positional change from supine to upright resulted in a significantly increased heart rate (8.05 ± 7.71 bpm) and a significantly increased QTc interval after Bazetts (18 ± 23.45 ms) and Fridericas (8.84 ± 17.30) formula. In the upright position significantly more T-waves turned negative (14.7%) than positive (5.7%). ST elevation was recorded in only 0.4% and ST depression in not more than 0.2% of all patients. CONCLUSIONS: The majority of the patients do not show significant morphological changes in their ECG by changing the body position from supine to upright. Changes of QTc time instead, are significant and the interval might be overestimated in upright. Therefore assessment of the QTc interval should strictly be done in a supine position.

Perception of atrial fibrillation before and after radiofrequency catheter ablation: relevance of asymptomatic arrhythmia recurrence.

BACKGROUND: The objective of this study was to assess the incidence and impact of asymptomatic arrhythmia in patients with highly symptomatic atrial fibrillation (AF) who qualified for radiofrequency (RF) catheter ablation. METHODS AND RESULTS: In this prospective study, 114 patients with at least 3 documented AF episodes together with corresponding symptoms and an ineffective trial of at least 1 antiarrhythmic drug were selected for RF ablation. With the use of CARTO, circumferential lesions around the pulmonary veins and linear lesions at the roof of the left atrium and along the left atrial isthmus were placed. A continuous, 7-day, Holter session was recorded before ablation, right after ablation, and after 3, 6, and 12 months of follow-up. During each 7-day Holter monitoring, the patients recorded quality and duration of any complaints by using a detailed symptom log. More than 70,000 hours of ECG recording were analyzed. In the 7-day Holter records before ablation, 92 of 114 patients (81%) had documented AF episodes. All episodes were symptomatic in 35 patients (38%). In 52 patients (57%), both symptomatic and asymptomatic episodes were recorded, whereas in 5 patients (5%), all documented AF episodes were asymptomatic. After ablation, the percentage of patients with only asymptomatic AF recurrences increased to 37% (P<0.05) at the 6-month follow-up. An analysis of patient characteristics and arrhythmia patterns failed to identify a specific subset who were at high risk for the development of asymptomatic AF. CONCLUSIONS: Even in patients presenting with highly symptomatic AF, asymptomatic episodes may occur and significantly increase after catheter ablation. A symptom-only-based follow-up would substantially overestimate the success rate. Objective measures such as long-term Holter monitoring are needed to identify asymptomatic AF recurrences after ablation.