Prevalence of left atrial appendage thrombus and spontaneous echo contrast on transesophageal echocardiography in patients scheduled for pulmonary vein isolation.

BACKGROUND: To avoid causing a thromboembolic event in patients undergoing catheter ablation for atrial fibrillation (AF), patients are treated with oral anticoagulants (OAC) prior to the procedure. Despite being on anticoagulants, some patients develop a left atrial appendage thrombus (LAAT). To exclude the presence of LAAT, transesophageal ultrasound (TEE) is performed in all patients prior to the procedure. We hypothesized continuous treatment with anticoagulants would result in a low prevalence of LAAT, in patients with low CHA2DS2-VASc score. METHOD: Medical records of consecutive patients planned to undergo AF ablation at Lund University Hospital during the years 2018-2020 were reviewed retrospectively. Examination protocols from transesophageal and transthoracic echocardiography were examined for LAAT and spontaneous echo contrast (SEC). Patients with LAAT and SEC were compared to patients without using Mann-Whitney U-test and Pearson Chi-squared analysis to test for correlation. RESULTS: Of 553 patients, three patients (0.54%) had LAAT, and 18 (3.25%) had spontaneous contrast (SEC). Patients with LAAT or SEC had a higher CHA2DS2-VASc score, more often presented in AF at TEE and less often had a normal sized left atrium. CONCLUSION: There is a low prevalence of LAAT and SEC in patients with AF scheduled for pulmonary vein isolation. Patients with SEC or LAAT tend to have paroxysmal AF less often and more often presented in AF at admission. No patients with CHA2DS2-VASc 0, paroxysmal AF, normal sized left atrium and sinus rhythm at TEE were found to have LAAT or SEC.

Antibiotic prescription in bone augmentation and dental implant procedures: a multi-center study.

BACKGROUND: Adherence to antibiotic recommendations and safety aspects of restrictive use are important components when combating antibiotic resistance. The primary aim of this study was to assess the impact of national guidelines on antibiotic prescriptions for bone augmentation procedures among dentists working at three specialized clinics. The secondary aim was to assess the occurrence of postoperative infections. METHODS: Medical charts of 400 patients treated with bone augmentation were reviewed: 200 in the years 2010-2011 and 200 in 2014-2015. The Swedish national recommendations for antibiotic prophylaxis were published in 2012. RESULTS: There was a wide variation in antibiotic regiments prescribed throughout the study. The number of patients treated with antibiotic prophylaxis in a single dose of 2 g amoxicillin, and treated as advocated in the national recommendations, was low and decreasing between the two time periods from 25% (n = 50/200) in 2010-2011 to 18.5% (n = 37/200) in 2014-2015. The number of patients not given any antibiotics either as a prophylactic single dose or during the postoperative phase increased (P < 0.001). The administration of a 3-7-days antibiotic prescription increased significantly from 25.5% in 2010-2011 to 35% in 2014-2015. The postoperative infection rates (4.5% and 6.5%) were without difference between the studied periods. Smoking and omitted antibiotic prophylaxis significantly increased the risk of postoperative infection. Logistic regression analyses showed that patient male gender and suffering from a disease were predictive factors for the clinician to adhere to the guidelines. CONCLUSIONS: After introduction of national recommendations for antibiotic prophylaxis before bone augmentation procedures, the patient group receiving a single preoperative dose decreased while the group not given antibiotic prophylaxis increased. There was no difference in occurrence of postoperative infections between the two time periods. The results indicate a need for educational efforts and strategies for implementation of antibiotic prudence and awareness among surgeons performing bone augmentation procedures.

Study of ECG-derived atrial fibrillatory rate for prediction of the outcome of cardioversion of short duration atrial fibrillation (CASAF).

AIMS: The present study aimed at testing the hypothesis that atrial fibrillatory rate (AFR) is predictive of sinus rhythm maintenance after electrical cardioversion. METHODS AND RESULTS: The study comprised 32 patients admitted for cardioversion of atrial fibrillation of short duration (mean duration 3.8 ± 7.7 days). AFR was estimated using frequency power spectrum analysis of QRST-cancelled ECG. At six-weeks follow-up 22% of the patients had relapsed to AF. The pre-cardioversion mean AFR of those was 332 ± 64 fpm compared to 378 ± 59 fpm among patients maintaining sinus rhythm (p = 0.12). CONCLUSION: AFR was not predictive of sinus rhythm maintenance in patients of short duration AF undergoing cardioversion. This is in stark contrast with the earlier reported findings. CLINICAL TRIAL REGISTRATION: NCT02112318 (http://www. CLINICALTRIALS: gov).

Cardiac tamponades related to interventional electrophysiology procedures are associated with higher risk of short-term hospitalization for pericarditis but favourable long-term outcome.

AIMS: To investigate the association of iatrogenic cardiac tamponades as a complication of invasive electrophysiology procedures (EPs) and mortality as well as serious cardiovascular events in a nationwide patient cohort during long-term follow-up. METHODS: From the Swedish Catheter Ablation Registry between 2005 and 2019, a total of 58 770 invasive EPs in 44 497 patients were analysed. From this, all patients with periprocedural cardiac tamponades related to invasive EPs were identified (n = 200; tamponade group) and matched (1:2 ratio) to a control group (n = 400). Over a follow-up of 5 years, the composite primary endpoint-death from any cause, acute myocardial infarction, transitory ischaemic attack (TIA)/stroke, and hospitalization for heart failure-revealed no statistically significant association with cardiac tamponade [hazard ratio (HR) 1.22 (95% CI, 0.79-1.88)]. All single components of the primary endpoint as well as cardiovascular death revealed no statistically significant association with cardiac tamponade. Cardiac tamponade was associated with a significantly higher risk with hospitalization for pericarditis [HR 20.67 (95% CI, 6.32-67.60)]. CONCLUSION: In this nationwide cohort of patients undergoing invasive EPs, iatrogenic cardiac tamponade was associated with an increased risk of hospitalization for pericarditis during the first months after the index procedure. In the long-term, however, cardiac tamponade revealed no significant association with mortality or other serious cardiovascular events.

Acute echocardiographic and hemodynamic response to his-bundle pacing in patients with first-degree atrioventricular block.

BACKGROUND: Atrial pacing and right ventricular (RV) pacing are both associated with adverse outcomes among patients with first-degree atrioventricular block (1°AVB). His-bundle pacing (HBP) provides physiological activation of the ventricle and may be able to improve both atrioventricular (AV) and inter-ventricular synchrony in 1°AVB patients. This study evaluates the acute echocardiographic and hemodynamic effects of atrial, atrial-His-bundle sequential (AH), and atrial-ventricular (AV) sequential pacing in 1°AVB patients. METHODS: Patients with 1°AVB undergoing atrial fibrillation ablation were included. Following left atrial (LA) catheterization, patients underwent atrial, AH- and AV-sequential pacing. LA/left ventricular (LV) pressure and echocardiographic measurements during the pacing protocols were compared. RESULTS: Thirteen patients with 1°AVB (mean PR 221 ± 26 ms) were included. The PR interval was prolonged with atrial pacing compared to baseline (275 ± 73 ms, p = .005). LV ejection fraction (LVEF) was highest during atrial pacing (62 ± 11%), intermediate with AH-sequential pacing (59 ± 7%), and lowest with AV-sequential pacing (57 ± 12%) though these differences were not statistically significant. No significant differences were found in LA or LV mean pressures or LV dP/dT. LA and LV volumes, isovolumetric times, electromechanical delays, and global longitudinal strains were similar across pacing protocols. CONCLUSION: Despite pronounced PR prolongation, the acute effects of atrial pacing were not significantly different than AH- or AV-sequential pacing. Normalizing atrioventricular and/or inter-ventricular dyssynchrony did not result in acute improvements in cardiac output or loading conditions.

Safety of continuous left atrial phased-array intracardiac echocardiography during left atrial ablation for atrial fibrillation.

Background: Pulmonary vein (PV) isolation using radiofrequency ablation (RFA) to treat atrial fibrillation (AF) requires delivery of contiguous transmural lesions at the PV antra while avoiding injury to the esophagus. Continuous 2-dimensional phased-array intracardiac echocardiography (ICE) from within the left atrium (LA) can provide consistent high-resolution images of catheter tip contact and location during ablation. Objective: The purpose of this study was to compare near-term safety outcomes of therapeutic AF ablation with and without ICE imaging from within the LA. Methods: The study cohort included 590 consecutive patients undergoing RFA for AF including continuous ICE imaging during ablation from within either the right atrium (RA) or the LA. Subjects were followed prospectively, and periprocedural complications within 30 days were identified and recorded. Results: All subjects had RA ICE imaging to guide transseptal catheterization. Ultrasound imaging from both RA and LA was used in 243 (41.2%). Respectively, the LA vs RA only imaging cohorts were comparable with respect to age (median 64 [interquartile range 57.4-71.2] years vs 64 [56.2-70.6] years; P = .425); history of hypertension (64.0% vs 67.2%; P = .421); diabetes mellitus (23.1% vs 19.4%; P = .268); previous cerebrovascular accident/transient ischemic attack (10.8% vs 8.4%; P = .331); and AF type (P = .241). There were no significant differences in major complications within 30 days between the 2 cohorts (P = .649) and no identified cases of esophageal or phrenic nerve injury or PV stenosis. Conclusions: Routine continuous LA ICE imaging seems to be safe and holds potential to facilitate lesion delivery during RFA for AF.

Respiratory Induced Modulation in f-Wave Characteristics During Atrial Fibrillation.

The autonomic nervous system (ANS) is an important factor in cardiac arrhythmia, and information about ANS activity during atrial fibrillation (AF) may contribute to personalized treatment. In this study we aim to quantify respiratory modulation in the f-wave frequency trend from resting ECG. First, an f-wave signal is extracted from the ECG by QRST cancelation. Second, an f-wave model is fitted to the f-wave signal to obtain a high resolution f-wave frequency trend and an index for signal quality control ( S ). Third, respiratory modulation in the f-wave frequency trend is extracted by applying a narrow band-pass filter. The center frequency of the band-pass filter is determined by the respiration rate. Respiration rate is estimated from a surrogate respiration signal, obtained from the ECG using homomorphic filtering. Peak conditioned spectral averaging, where spectra of sufficient quality from different leads are averaged, is employed to obtain a robust estimate of the respiration rate. The envelope of the filtered f-wave frequency trend is used to quantify the magnitude of respiratory induced f-wave frequency modulation. The proposed methodology is evaluated using simulated f-wave signals obtained using a sinusoidal harmonic model. Results from simulated signals show that the magnitude of the respiratory modulation is accurately estimated, quantified by an error below 0.01 Hz, if the signal quality is sufficient ( S > 0 . 5 ). The proposed method was applied to analyze ECG data from eight pacemaker patients with permanent AF recorded at baseline, during controlled respiration, and during controlled respiration after injection of atropine, respectively. The magnitude of the respiratory induce f-wave frequency modulation was 0.15 ± 0.01, 0.18 ± 0.02, and 0.17 ± 0.03 Hz during baseline, controlled respiration, and post-atropine, respectively. Our results suggest that parasympathetic regulation affects the magnitude of respiratory induced f-wave frequency modulation.

Orthogonal P-wave morphology, conventional P-wave indices, and the risk of atrial fibrillation in the general population using data from the Finnish Hospital Discharge Register.

AIMS: Identifying subjects at high and low risk of atrial fibrillation (AF) is of interest. This study aims to assess the risk of AF associated with electrocardiographic (ECG) markers linked to atrial fibrosis: P-wave prolongation, 3rd-degree interatrial block, P-terminal force in lead V1, and orthogonal P-wave morphology. METHODS AND RESULTS: P-wave parameters were assessed in a representative Finnish population sample aged ≥30 years (n = 7217, 46.0% male, mean age 51.4 years). Subjects (n = 5489) with a readable ECG including the orthogonal leads, sinus rhythm, and a predefined orthogonal P-wave morphology type [positive in leads X and Y and either negative (Type 1) or ± biphasic (Type 2) in lead Z; Type 3 defined as positive in lead X and ± biphasic in lead Y], were followed 10 years from the baseline examinations (performed 1978-80). Subjects discharged with AF diagnosis after any-cause hospitalization (n = 124) were defined as having developed AF. Third-degree interatrial block was defined as P-wave ≥120 ms and the presence of ≥2 ± biphasic P waves in the inferior leads. Hazard ratios (HRs) and confidence intervals (CIs) were assessed with Cox models. Third-degree interatrial block (n = 103, HR 3.18, 95% CI 1.66-6.13; P = 0.001) and Type 3 morphology (n = 216, HR 3.01, 95% CI 1.66-5.45; P < 0.001) were independently associated with the risk of hospitalization with AF. Subjects with P-wave <110 ms and Type 1 morphology (n = 2074) were at low risk (HR 0.46, 95% CI 0.26-0.83; P = 0.006), compared to the rest of the subjects. CONCLUSION: P-wave parameters associate with the risk of hospitalization with AF.

Gender and age differences in symptoms and health-related quality of life in patients with atrial fibrillation referred for catheter ablation.

BACKGROUND: Primary indication for catheter ablation of atrial fibrillation (AF) is to reduce symptoms and improve health-related quality of life (HRQoL). There are data showing differences between the genders and between younger and older patients. To evaluate this, we studied a large Scandinavian cohort of patients referred for catheter ablation of AF. METHODS: Consecutive patients filled out the ASTA questionnaire, assessing symptoms, HRQoL, and perception of arrhythmia, prior to ablation. Patients were recruited from four Swedish and one Danish tertiary center. RESULTS: A total of 2493 patients (72% men) filled out the ASTA questionnaire. Women experienced eight of the nine ASTA scale symptoms more often than men. Patients <65 years reported four symptoms more often, only tiredness was more frequent in those ≥65 years (P = .007). Women and patients <65 years experienced more often palpitations and regarding close to fainting and this was more common among women, no age differences were seen. Women and men scored differently in 10 of the 13 HRQoL items. Only negative impact on sexual life was more common in men (P < .001). Older patients reported more negative influence in four of the HRQoL items and the younger in one; ability to concentrate. CONCLUSIONS: Women experienced a more pronounced symptom burden and were more negatively affected in all HRQoL concerns, except for the negative impact on sexual life, where men reported more influence of AF. Differences between age groups were less pronounced. Disease-specific patient-reported outcomes measures (PROMs) add important information where gender differences should be considered in the care.

Genetic variants on chromosomes 7p31 and 12p12 are associated with abnormal atrial electrical activation in patients with early-onset lone atrial fibrillation.

BACKGROUND: Abnormal P-wave morphology (PWM) has been associated with a history of atrial fibrillation (AF) in earlier studies. Although lone AF is believed to have substantial genetic basis, studies on associations between single nucleotide polymorphisms (SNP) linked to lone AF and PWM have not been reported. We aimed to assess whether SNPs previously associated with lone AF (rs2200733, rs13376333, rs3807989, and rs11047543) are also linked to P-wave abnormalities. METHODS: Four SNPs were studied in 176 unrelated individuals with early-onset lone AF (age at onset <50 years), median age 38 years (19-63 years), 149 men. Using sinus rhythm ECG, orthogonal PWM was classified as Type 1-positive in leads X and Y and negative in lead Z, Type 2-positive in leads X and Y and biphasic (-/+) in lead Z, Type 3-positive in lead X and biphasic in lead Y (+/-), and the remaining as atypical. RESULTS: Two SNPs were found to be significantly associated with altered P-wave morphology distribution: rs3807989 near the gene CAV1/CAV2 and rs11047543 near the gene SOX5. Both SNPs were associated with a higher risk of non-Type 1 P-wave morphology (rs3807989: OR = 4.8, 95% CI = 2.3-10.2, p < 0.001; rs11047543: OR = 4.7, 95% CI = 1.1-20.5, p = 0.04). No association was observed for rs2200733 and rs13376333. CONCLUSION: In this study, the two variants rs3807989 and rs11047543, previously associated with PR interval and lone AF, were associated with altered P-wave morphology distribution in patients with early-onset lone AF. These findings suggest that common genetic variants may modify atrial conduction properties.

A decade of catheter ablation of cardiac arrhythmias in Sweden: ablation practices and outcomes.

AIMS: Catheter ablation is considered the treatment of choice for many tachyarrhythmias, but convincing 'real-world' data on efficacy and safety are lacking. Using Swedish national registry data, the ablation spectrum, procedural characteristics, as well as ablation efficacy and reported adverse events are reported. METHODS AND RESULTS: Consecutive patients (≥18 years of age) undergoing catheter ablation in Sweden between 01 January 2006 and 31 December 2015 were included in the study. Follow-up (repeat ablation and vital status) was collected through 31 December 2016. A total of 26 642 patients (57 ± 15 years, 62% men), undergoing a total of 34 428 ablation procedures were included in the study. In total, 4034 accessory pathway/Wolff-Parkinson-White syndrome (12%), 7358 AV-nodal re-entrant tachycardia (21%), 1813 atrial tachycardia (5.2%), 5481 typical atrial flutter (16%), 11 916 atrial fibrillation (AF, 35%), 2415 AV-nodal (7.0%), 581 premature ventricular contraction (PVC, 1.7%), and 964 ventricular tachycardia (VT) ablations (2.8%) were performed. Median follow-up time was 4.7 years (interquartile range 2.7-7.0). The spectrum of treated arrhythmias changed over time, with a gradual increase in AF, VT, and PVC ablation (P < 0.001). Decreasing procedural times and utilization of fluoroscopy with time, were seen for all arrhythmia types. The rates of repeat ablation differed between ablation types, with the highest repeat ablation seen in AF (41% within 3 years). The rate of reported adverse events was low (n = 595, 1.7%). Death in the immediate period following ablation was rare (n = 116, 0.34%). CONCLUSION: Catheter ablations have shifted towards more complex procedures over the past decade. Fluoroscopy time has markedly decreased and the efficacy of catheter ablation seems to improve for AF.

Orthogonal P-wave morphology is affected by intra-atrial pressures.

BACKGROUND: It has previously been shown that the morphology of the P-wave neither depends on atrial size in healthy subjects with physiologically enlarged atria nor on the physiological anatomical variation in transverse orientation of the left atrium. The present study aimed to investigate if different pressures in the left and right atrium are associated with different P-wave morphologies. METHODS: 38 patients with isolated, increased left atrial pressure, 51 patients with isolated, increased right atrial pressure and 76 patients with biatrially increased pressure were studied. All had undergone right heart catheterization and had 12-lead electrocardiographic recordings, which were transformed into vectorcardiograms for detailed P-wave morphology analysis. RESULTS: Normal P-wave morphology (type 1) was more common in patients with isolated increased pressure in the right atrium while abnormal P-wave morphology (type 2) was more common in the groups with increased left atrial pressure (P = 0.032). Moreover, patients with increased left atrial pressure, either isolated or in conjunction with increased right atrial pressure, had significantly more often a P-wave morphology with a positive deflection in the sagittal plane (P = 0.004). CONCLUSION: Isolated elevated right atrial pressure was associated with normal P-wave morphology while left-sided atrial pressure elevation, either isolated or in combination with right atrial pressure elevation, was associated with abnormal P-wave morphology.

Long-term outcomes of the current remote magnetic catheter navigation technique for ablation of atrial fibrillation.

OBJECTIVES: Comparisons between remote magnetic (RMN) and manual catheter navigation for atrial fibrillation (AF) ablation have earlier been reported with controversial results. However, these reports were based on earlier generations of the RMN system. DESIGN: To evaluate the outcomes of the most current RMN system for AF ablation in a larger patient population with longer follow-up time, 112 patients with AF (78 paroxysmal, 34 persistent) who underwent AF ablation utilizing RMN (RMN group) were compared to 102 AF ablation patients (72 paroxysmal, 30 persistent) utilizing manual technique (Manual group). RESULTS: The RMN group was associated with significantly shorter fluoroscopy time (10.4 ± 6.4 vs. 16.3 ± 10.9 min, p < .001) but used more RF energy (64.1 ± 19.4KJ vs. 54.3 ± 24.1 KJ, p < .05), while total procedure time showed no significant difference (201 ± 35 vs. 196 ± 44 min, NS). After 39 ± 9/44 ± 10 months of follow-up, AF-free rates at 1year, 2 years and 3.5 years post ablation were 63%, 46% and 42% in the RMN group vs. 60%, 32% and 30% (survival analysis p < .05) in the Manual group, whereas clinically effective rates were 82%, 73% and 70% for the former vs. 70%, 56% and 49% for the latter (survival analysis p < .005). CONCLUSION: Differing from previous reports, our data from a larger patient population and longer follow-up time demonstrates that compared to manual technique, the most current RMN technique is associated with better procedural and clinical outcomes for AF ablation.

Physiological variation in left atrial transverse orientation does not influence orthogonal P-wave morphology.

BACKGROUND: It has previously been demonstrated that orthogonal P-wave morphology in healthy athletes does not depend on atrial size, but the possible impact of left atrial orientation on P-wave morphology remains unknown. In this study, we investigated if left atrial transverse orientation affects P-wave morphology in different populations. METHODS: Forty-seven patients with atrial fibrillation, 21 patients with arrhythmogenic right ventricular cardiomyopathy, 67 healthy athletes, and 56 healthy volunteers were included. All underwent cardiac magnetic resonance imaging or computed tomography and the orientation of the left atrium was determined. All had 12-lead electrocardiographic recordings, which were transformed into orthogonal leads and orthogonal P-wave morphology was obtained. RESULTS: The median left atrial transverse orientation was 87 (83, 91) degrees (lower and upper quartiles) in the total study population. There was no difference in left atrial transverse orientation between individuals with different orthogonal P-wave morphologies. CONCLUSIONS: The physiological variation in left atrial orientation was small within as well as between the different populations. There was no difference in left atrial transverse orientation between subjects with type 1 and type 2 P-wave morphology, implying that in this setting the P-wave morphology was more dependent on atrial conduction than orientation.