Inappropriate sinus tachycardia (IST) is a common observation in patients with post-COVID-19 syndrome (PCS) but has not yet been fully described to date. To investigate the prevalence and the ...mechanisms underlying IST in a prospective population of PCS patients. Consecutive patients admitted to the PCS Unit between June and December 2020 with a resting sinus rhythm rate ≥ 100 bpm were prospectively enrolled in this study and further examined by an orthostatic test, 2D echocardiography, 24-h ECG monitoring (heart rate variability was a surrogate for cardiac autonomic activity), quality-of-life and exercise capacity testing, and blood sampling. To assess cardiac autonomic function, a 2:1:1 comparative sub-analysis was conducted against both fully recovered patients with previous SARS-CoV-2 infection and individuals without prior SARS-CoV-2 infection. Among 200 PCS patients, 40 (20%) fulfilled the diagnostic criteria for IST (average age of 40.1 ± 10 years, 85% women, 83% mild COVID-19). No underlying structural heart disease, pro-inflammatory state, myocyte injury, or hypoxia were identified. IST was accompanied by a decrease in most heart rate variability parameters, especially those related to cardiovagal tone: pNN50 (cases 3.2 ± 3 vs. recovered 10.5 ± 8 vs. non-infected 17.3 ± 10; p < 0.001) and HF band (246 ± 179 vs. 463 ± 295 vs. 1048 ± 570, respectively; p < 0.001). IST is prevalent condition among PCS patients. Cardiac autonomic nervous system imbalance with decreased parasympathetic activity may explain this phenomenon.
Catheter ablation (CA) is a highly effective therapy for the treatment of paroxysmal atrial fibrillation (AF) when compared with antiarrhythmic drug therapy (ADT). No randomized studies have compared ...the two strategies in persistent AF. The present randomized trial aimed to compare the effectiveness of CA vs. ADT in treating persistent AF.
Patients with persistent AF were randomly assigned to CA or ADT (excluding patients with long-standing persistent AF). Primary endpoint at 12-month follow-up was defined as any episode of AF or atrial flutter lasting >24 h that occurred after a 3-month blanking period. Secondary endpoints were any atrial tachyarrhythmia lasting >30 s, hospitalization, and electrical cardioversion. In total, 146 patients were included (aged 55 ± 9 years, 77% male). The ADT group received class Ic (43.8%) or class III drugs (56.3%). In an intention-to-treat analysis, 69 of 98 patients (70.4%) in the CA group and 21 of 48 patients (43.7%) in the ADT group were free of the primary endpoint (P = 0.002), implying an absolute risk difference of 26.6% (95% CI 10.0-43.3) in favour of CA. The proportion of patients free of any recurrence (>30 s) was higher in the CA group than in the ADT group (60.2 vs. 29.2%; P < 0.001) and cardioversion was less frequent (34.7 vs. 50%, respectively; P = 0.018).
Catheter ablation is superior to medical therapy for the maintenance of sinus rhythm in patients with persistent AF at 12-month follow-up.
NCT00863213 (http://clinicaltrials.gov/ct2/show/NCT00863213).
Abstract Objectives The aim of this study was to test the feasibility and usefulness of a new delayed-enhancement cardiac magnetic resonance (DE-CMR)–guided approach to ablate gaps in redo ...procedures. Background Recurrences of atrial fibrillation (AF) after pulmonary vein isolation (PVI) may be related to gaps at the ablation lines. DE-CMR allows identification of radiofrequency lesions and gaps (CMR gaps). Methods Fifteen patients undergoing repeated AF ablations were included (prior procedure was PVI in all patients and roof-line ablation in 8 patients). Pre-procedure 3-dimensional (3D) DE-CMR was performed with a respiratory-navigated (free-breathing) and electrocardiographically gated inversion-recovery gradient-echo sequence (voxel size 1.25 × 1.25 × 2.5 mm). Endocardium and epicardium were manually segmented to create a 3D reconstruction (DE-CMR model). A pixel signal intensity map was projected on the DE-CMR model and color-coded (thresholds 40 ± 5% and 60 ± 5% of maximum intensity). The DE-CMR model was imported into the navigation system to guide the ablation of CMR gaps, with the operator blinded to electrical data. Fifteen conventional procedures were used as controls to compare procedural duration, radiofrequency, and fluoroscopy times. Results Fifteen patients (56 pulmonary veins PVs; 57 ± 8 years of age; 9 with paroxysmal AF) were analyzed. In total, 67 CMR gaps were identified around PVs (mean 4.47 gaps/patient; median length 13.33 mm/gap) and 9 at roof line. All of the electrically reconnected PVs (87.5%) had CMR gaps. The site of electrical PV reconnection (assessed by circular mapping catheter) matched with a CMR gap in 79% of PVs. CMR-guided ablation led to reisolation of 95.6% of reconnected PVs (median radiofrequency time of 13.3 interquartile range: 7.5 to 21.7 min/patient) and conduction block through the roof line in all patients (1.4 interquartile range: 0.7 to 3.1 min/patient). Compared with controls, the CMR-guided approach shortened radiofrequency time (1,441 ± 915 s vs. 930 ± 662 s; p = 0.026) but not the procedural duration or fluoroscopy time. Conclusions DE-CMR can successfully guide repeated PVI procedures by accurately identifying and localizing gaps and may reduce procedural duration and radiofrequency application time.
Identification of left atrial (LA) fibrosis through late gadolinium-enhanced cardiac magnetic resonance (LGE-CMR) remains controversial due to the heterogeneity and lack of reproducibility of ...proposed methods. Our aim is to describe a normalized, reproducible, standardized method to evaluate LA fibrosis through LGE-CMR.
Electrocardiogram- and respiratory-gated 3-Tesla LGE-CMR was performed in 10 healthy young volunteers and 30 patients with atrial fibrillation (AF): 10 with paroxysmal AF, 10 with persistent AF, and 10 with a previous AF ablation procedure. Local image intensity ratio (IIR) of the LA was calculated as the absolute pixel intensity to mean blood pool intensity ratio. The healthy atrial tissue threshold was defined in young healthy volunteers (upper limit of normality set at IIR tissue mean plus 2 SDs). Dense atrial scarring was characterized in patients with previous radiofrequency-induced scarring (post-AF ablation patients). Validation groups consisted of patients with paroxysmal and persistent AFs. The upper limit of normal IIR was 1.20; IIR values higher than 1.32 (60% of mean maximum pixel intensity in post-ablation patients) were considered dense scar. Image intensity ratio values between 1.2 and 1.32 identified interstitial fibrosis. Patients with paroxysmal and persistent AFs had less atrial fibrotic tissue compared with post-ablation patients. Endocardial bipolar voltage was correlated to IIR values.
An IIR of 1.2 identifies the upper limit of normality in healthy young individuals. An IIR of >1.32 defines dense atrial fibrosis in post-ablation patients. Our results provide a consistent, comparable, and normalized tool to assess atrial arrhythmogenic substrate.
Left Atrial Sphericity Predicts AF Ablation Outcome
Background
Atrial fibrillation (AF) ablation outcome is mainly determined by atrial remodeling that, nowadays, is only estimated through clinical ...presentation (persistent vs. paroxysmal) and left atrial (LA) dimension. The aim of the study was to stage the atrial remodeling process using the Left Atrial Sphericity (LASP) and determine whether this technique may help to predict AF ablation outcome.
Methods
Consecutive patients who underwent contrast‐enhanced cardiac magnetic resonance angiography before AF ablation were included in the study. Three‐dimensional reconstruction of LA excluding pulmonary veins and the LA appendage was used to define the LA cavity. The LASP was automatically obtained with self‐customized software.
Results
106 patients were included and categorized in 3 groups (Gs): discoid‐LA (G1), intermediate‐LA (G2), and spherical‐LA (G3). The G3 patients had larger LA anteroposterior diameter than G1 and G2 patients (47 ± 7 vs 43 ± 6 and 39 ± 5mm; P < 0.001), greater LA volume (90 ± 39 vs 86 ± 24 and 73 ± 20 mm; P = 0.012), and higher prevalence of persistent AF (75% vs 48% and 29%; P = 0.034) structural heart disease (75% vs 19% and 19%; P < 0.001), and AF recurrence at 12 months follow‐up (58% vs 29% and 5%, P < 0.001). The LASP had linear correlation to predicted probability of recurrence. Multivariate analysis identified LASP (OR 1.320 1.096–1.591, P = 0.004) and hypertension (OR 3.694 1.282–10.645; P = 0.016) as independent risk factors for arrhythmia recurrence.
Conclusion
Left Atrial Sphericity is a new independent predictor of recurrence after AF ablation and may be useful in selecting the best candidates for AF ablation.
The role of high-intensity exercise and other emerging risk factors in lone atrial fibrillation (Ln-AF) epidemiology is still under debate. The aim of this study was to analyse the contribution of ...each of the emerging risk factors and the impact of physical activity dose in patients with Ln-AF.
Patients with Ln-AF and age- and sex-matched healthy controls were included in a 2:1 prospective case-control study. We obtained clinical and anthropometric data transthoracic echocardiography, lifetime physical activity questionnaire, 24-h ambulatory blood pressure monitoring, Berlin questionnaire score, and, in patients at high risk for obstructive sleep apnoea (OSA) syndrome, a polysomnography. A total of 115 cases and 57 controls were enrolled. Conditional logistic regression analysis associated height odds ratio (OR) 1.06 1.01-1.11, waist circumference (OR 1.06 1.02-1.11), OSA (OR 5.04 1.44-17.45), and 2000 or more hours of cumulative high-intensity endurance training to a higher AF risk. Our data indicated a U-shaped association between the extent of high-intensity training and AF risk. The risk of AF increased with an accumulated lifetime endurance sport activity ≥ 2,000 h compared with sedentary individuals (OR 3.88 1.55-9.73). Nevertheless, a history of <2000 h of high-intensity training protected against AF when compared with sedentary individuals (OR 0.38 0.12-0.98).
A history of ≥ 2,000 h of vigorous endurance training, tall stature, abdominal obesity, and OSA are frequently encountered as risk factors in patients with Ln-AF. Fewer than 2000 total hours of high-intensity endurance training associates with reduced Ln-AF risk.
Introduction
Recurrences after atrial fibrillation (AF) ablation are still common. Among the reported clinical and imaging predictors of recurrences, diagnosis‐to‐ablation time (DAT) has been defined ...as a predictor of ablation outcome in single‐center studies. We aimed to validate DAT in a multicenter real‐life cohort.
Methods
This was a multicenter study including consecutive patients undergoing first paroxysmal and persistent AF ablation with radiofrequency or cryoballoon catheters during 2013. Cox proportional hazard regression models were performed to identify predictors of recurrence.
Results
In total, 309 patients were included across nine centers (71% men, 57 ± 10 years old, 46% with hypertension, and 66% with CHA2DS2‐VASc ≤ 1). Most patients had paroxysmal AF (67%) and underwent radiofrequency ablation (68%) with a median DAT of 51 (43) months. Patients with DAT ≤ 1 year (16.6%) were less likely to have repeat procedures (4% vs 18%; P = .017). The adjusted proportional hazards Cox model identified hypertension (P = .005), heart failure (P = .011), nonparoxysmal AF (P = .038), DAT > 1 year (P = .007), and LA diameter (P = .026) as independent predictors for AF recurrence. DAT > 1 year was the only modifiable factor independently associated with recurrence (HR 4.2 95% CI, 1.5‐11.9)
Conclusion
Diagnosis‐to‐ablation time is a modifiable factor independently associated with recurrent arrhythmia and repeat ablation after first AF ablation. An early intervention strategy during the first year from AF diagnosis might improve outcomes.
To better understand heart failure with preserved ejection fraction (HFpEF), we need to better characterize the transition from asymptomatic pre-HFpEF to symptomatic HFpEF. The current emphasis on ...left ventricular diastolic dysfunction must be redirected to microvascular inflammation and endothelial dysfunction that leads to cardiomyocyte remodeling and enhanced interstitial collagen deposition. A pre-HFpEF patient lacks signs or symptoms of heart failure (HF), has preserved left ventricular ejection fraction (LVEF) with incipient structural changes similar to HFpEF, and possesses elevated biomarkers of cardiac dysfunction. The transition from pre-HFpEF to symptomatic HFpEF also involves left atrial failure, pulmonary hypertension and right ventricular dysfunction, and renal failure. This review focuses on the non-left ventricular mechanisms in this transition, involving the atria, right heart cavities, kidneys, and ultimately the currently accepted driver-systemic inflammation. Impaired atrial function may decrease ventricular hemodynamics and significantly increase left atrial and pulmonary pressure, leading to HF symptoms, irrespective of left ventricle (LV) systolic function. Pulmonary hypertension and low right-ventricular function are associated with the incidence of HF. Interstitial fibrosis in the heart, large arteries, and kidneys is key to the pathophysiology of the cardiorenal syndrome continuum. By understanding each of these processes, we may be able to halt disease progression and eventually extend the time a patient remains in the asymptomatic pre-HFpEF stage.
Abstract Introduction Atrial fibrillation (AF) is a recognized treatable cause of tachycardiomyopathy (TMP), with class IIb indication for catheter ablation (CA). The aim of this study is to analyze ...the prevalence, clinical characteristics and effect of CA in patients with TMP and to evaluate TMP as a prognostic factor for AF recurrence in these patients (TMP group), compared to controls with normal left ventricular ejection fraction (LVEF) and patients with heart failure due to structural cardiomyopathy (HF group). Methods and results The study groups included 659 consecutive patients undergoing CA between 2003 and 2011: TMP group ( n = 61), HF group ( n = 36) and control group ( n = 562). Compared to controls, patients with TMP were younger, had a shorter AF course and more often had persistent AF. Regarding echocardiographic parameters, the TMP group had lower LVEF (40% vs. 62%, P < 0.05), larger left atrial diameter (LAD: 46 vs. 41 mm, P < 0.05) and LV end-diastolic diameter (LVEDD: 55 vs. 51 mm, P < 0.05) compared to controls, with significant improvement at six-month follow-up, including those patients with AF recurrence. The probability of being arrhythmia-free did not differ between the TMP group and the other groups after a first or last procedure. The only independent predictor of AF recurrence was LAD. Conclusions Patients with tachycardiomyopathy secondary to AF benefit from CA, with a significant improvement in LVEF, LVEDD and LAD. The outcome after CA of this group did not differ from patients with no structural cardiomyopathy.
Catheter contact force (CF) has a strong correlation with lesion formation during radiofrequency ablation. Delayed-enhancement cardiac magnetic resonance (DE-CMR) provides lesion information in ...patients with prior atrial fibrillation (AF) ablation.
The aim of this study was to determine the CF threshold to create permanent lesions detected by DE-CMR.
A total of 36 patients referred for AF ablation were included. A CF catheter was used during the ablation procedure, and DE-CMR was performed 3 months after the ablation procedure. Eighteen pulmonary vein (PV) segments were defined, and 3-dimensional (3D) reconstructions of the left atrium (LA) derived from the DE-CMR images were obtained. One observer evaluated the presence of any discontinuity of previous ablation lesions (gap) in the 3D reconstructions of the LA, and another observer (blinded to the gap findings) determined the minimum CF value in each PV segment.
The PV segments where a gap was observed had a lower maximal CF value than did the segments without gap in the 3D LA reconstructions (6.7 ± 4.4 g vs 12.2 ± 4.7 g; P < .001). In receiver operating characteristic analysis, a CF threshold of >8 g provided 73% sensitivity and 81% specificity in the prediction of a complete PV lesion (positive predictive value PPV 84%). A CF threshold of >12 g had a specificity of 94% and increased the PPV to 91% in creating a complete lesion in the LA wall (area under the curve 0.834).
A CF threshold of >12 g H5H20 predicts a complete lesion with high specificity and PPV when a dragging ablation strategy is used in AF ablation.
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