The relevance of focal triggers in persistent atrial fibrillation (PerAF) and long-standing persistent atrial fibrillation (LSPAF) has not been previously investigated.
We prospectively evaluated the ...prevalence and distribution of AF triggers in patients referred for catheter ablation of PerAF and LSPAF.
We analyzed consecutive patients undergoing first time AF ablation who underwent a standardized trigger protocol including cardioversion of induced or spontaneous AF and infusion of up to 20 μg of isoproterenol for 15-20 minutes either before or after pulmonary vein (PV) isolation accomplished. Triggers were defined as AF/sustained atrial tachyarrhythmia or repetitive atrial premature depolarizations.
A total of 2168 patients were included (mean age 57 ± 11 years; 1636 75% men), with 1531 patients having paroxysmal AF (PAF) (71%), 496 having PerAF (23%), and 141 having LSPAF (7%). PV triggers were found in 1398 patients with PAF (91%), 449 patients with PerAF (91%), and 129 patients with LSPAF (91%) (P = .856 for comparison across groups). Non-PV triggers were elicited in a total of 234 patients (11%), and the prevalence was similar across the different types of AF (PAF, 165 11%; PerAF, 54 11%; LSPAF, 15 11%; P = .996 for comparison across groups).
PVs are the main AF trigger site in patients with PerAF and LSPAF, with an overall prevalence similar to that found in patients with PAF. These results support the current recommendations for PV isolation as the cornerstone of catheter ablation to eliminate AF triggers in PerAF and LSPAF.
Localization, Mapping, and Ablation of Outflow Tract Ventricular Arrhythmias
The outflow tract (OT) regions of the right and left ventricles, common sites of origin for idiopathic ventricular ...arrhythmias (VA), have complex three‐dimensional anatomical relationships. The understanding of in situ or “attitudinal” relationships not only informs the electrocardiographic interpretation of VA site of origin, but also facilitates their catheter‐based mapping and ablation strategies. By viewing each patient as his or her own “control,” the expected changes in ECG morphology (i.e., frontal plane QRS axis and precordial transition) between adjacent intracardiac structures (e.g., RVOT and aortic root) can be reliably predicted. Successful mapping of OT VAs involve a combination of activation and pacemapping guided by fluoroscopy, electroanatomical mapping, and intracardiac echocardiography. The purpose of this manuscript is to provide a simple, reliable strategy for catheter based mapping and ablation of OT VAs. We also discuss 2 specific challenges in OT VA mapping: (1) differentiating posterior RVOT from right coronary cusp VA origin; and (2) mapping VAs originating from the LV summit.
COVID-19 and cardiac arrhythmias Bhatla, Anjali; Mayer, Michael M; Adusumalli, Srinath ...
Heart rhythm,
09/2020, Volume:
17, Issue:
9
Journal Article
Peer reviewed
Open access
Early studies suggest that coronavirus disease 2019 (COVID-19) is associated with a high incidence of cardiac arrhythmias. Severe acute respiratory syndrome coronavirus 2 infection may cause injury ...to cardiac myocytes and increase arrhythmia risk.
The purpose of this study was to evaluate the risk of cardiac arrest and arrhythmias including incident atrial fibrillation (AF), bradyarrhythmias, and nonsustained ventricular tachycardia (NSVT) in a large urban population hospitalized for COVID-19. We also evaluated correlations between the presence of these arrhythmias and mortality.
We reviewed the characteristics of all patients with COVID-19 admitted to our center over a 9-week period. Throughout hospitalization, we evaluated the incidence of cardiac arrests, arrhythmias, and inpatient mortality. We also used logistic regression to evaluate age, sex, race, body mass index, prevalent cardiovascular disease, diabetes, hypertension, chronic kidney disease, and intensive care unit (ICU) status as potential risk factors for each arrhythmia.
Among 700 patients (mean age 50 ± 18 years; 45% men; 71% African American; 11% received ICU care), there were 9 cardiac arrests, 25 incident AF events, 9 clinically significant bradyarrhythmias, and 10 NSVTs. All cardiac arrests occurred in patients admitted to the ICU. In addition, admission to the ICU was associated with incident AF (odds ratio OR 4.68; 95% confidence interval CI 1.66-13.18) and NSVT (OR 8.92; 95% CI 1.73-46.06) after multivariable adjustment. Also, age and incident AF (OR 1.05; 95% CI 1.02-1.09) and prevalent heart failure and bradyarrhythmias (OR 9.75; 95% CI 1.95-48.65) were independently associated. Only cardiac arrests were associated with acute in-hospital mortality.
Cardiac arrests and arrhythmias are likely the consequence of systemic illness and not solely the direct effects of COVID-19 infection.
The moderator band (MB) can be a source of premature ventricular contractions (PVCs), monomorphic ventricular tachycardia (VT), and idiopathic ventricular fibrillation (IVF).
The purpose of this ...study was to define the electrocardiographic (ECG) characteristics and procedural techniques to successfully identify and ablate MB PVCs/VT.
In 10 patients with left bundle branch block morphology PVCs/VT, electroanatomic mapping in conjunction with intracardiac echocardiography (ICE) localized the site of origin of the PVCs to the MB. Clinical characteristics of the patients, ECG features, and procedural data were collected and analyzed.
Seven patients presented with IVF and 3 presented with monomorphic VT. In all patients, the ventricular arrhythmias (VAs) had a left bundle branch block QRS with a late precordial transition (>V4), a rapid downstroke of the QRS in the precordial leads, and a left superior frontal plane axis. Mean QRS duration was 152.7 ± 15.2 ms. Six patients required a repeat procedure. After mean follow-up of 21.5 ± 11.6 months, all patients were free of sustained VAs, with only 1 patient requiring antiarrhythmic drug therapy and 1 patient having isolated PVCs no longer inducing VF. There were no procedural complications.
VAs originating from the MB have a distinctive morphology and often are associated with PVC-induced ventricular fibrillation. Catheter ablation can be safely performed and is facilitated by ICE imaging.
Radiofrequency ablation of multiple or unmappable ventricular tachycardias (VTs) remains a challenge with unclear end points. We present our experience with a new strategy isolating core elements of ...VT circuits.
Patients with structural heart disease presenting for VT radiofrequency ablation at 2 centers were included. Strategy involved entrainment/activation mapping if VT was hemodynamically stable, and voltage mapping with electrogram analysis and pacemapping. Core isolation (CI) was performed incorporating putative isthmus and early exit site(s) based on standard criteria. If VT was noninducible, the dense scar (<0.5 mV) region was isolated. Successful CI was defined by exit block (20 mA at 2 ms) within the isolated region. VT inducibility was also assessed. Forty-four patients were included (mean age, 63; 95% male; 73% ischemic cardiomyopathy; mean left ventricular ejection fraction, 31%; 68% with multiple unstable VTs mean, 3+2). CI area was 11+12 versus 55+40 cm(2) total scar area. Additional substrate modification was performed in 27 (61%), and epicardial radiofrequency ablation was performed in 4 (9%) patients. CI was achieved in 37 (84%) and led to better VT-free survival (log rank P=0.013).
CI is a novel strategy with a discrete and measurable end point beyond VT inducibility to treat patients with multiple or unmappable VTs. The CI region can be selected based on standard characterization of suspected VT isthmus surrogates thus limiting ablation target size. Exit block within the isolated area is achievable in most and may further improve long-term success.
Efficacy of endocardial ventricular tachycardia (VT) ablation in arrhythmogenic right ventricular cardiomyopathy/dysplasia may be limited by epicardial VT, right ventricular thickening, or both. We ...sought to characterize the endocardial versus epicardial substrate, measure right ventricular free wall thickness, and determine epicardial ablation efficacy in patients with right ventricular cardiomyopathy/dysplasia.
Thirteen consecutive patients (3 female; aged 43+/-15 years; range, 17 to 70 years) undergoing endocardial and epicardial sinus rhythm voltage mapping and epicardial VT ablation after failed endocardial VT ablation were included. In each patient, the low bipolar voltage area (<1.0 mV for epicardium and <1.5 mV for endocardium) was more extensive on the epicardium (95+/-47 versus 38+/-32 cm(2); P<0.001) and was uniformly marked by multicomponent and late electrograms. The basal right ventricular thickness assessed by electroanatomic map was >10 mm in 6 of 13 patients compared with 5 to 10 mm in 4 reference patients without structural disease. Twenty-seven VTs were targeted on the epicardium with the use of activation, entrainment, or pace mapping with focal/linear ablation and targeting of late potentials. Epicardial VTs were targeted opposite normal endocardium in 10 patients (77%) and/or opposite ineffective endocardial ablation sites in 11 patients (85%). During 18+/-13 months, 10 of the 13 patients (77%) had no VT, with 2 patients having only a single VT at 2 and 38 months, respectively.
Patients with right ventricular cardiomyopathy/dysplasia and VT after endocardial ablation have a more extensive epicardial area of electrogram abnormalities and frequently have basal right ventricular wall thickening. Epicardial substrate and VT mapping identifies targets, and ablation results in VT control.
Left ventricular (LV) scar on late gadolinium enhancement (LGE) cardiac magnetic resonance has been correlated with life-threatening arrhythmic events in patients with apparently idiopathic ...ventricular arrhythmias (VAs). We investigated the prognostic significance of a specific LV-LGE phenotype characterized by a ringlike pattern of fibrosis.
A total of 686 patients with apparently idiopathic nonsustained VA underwent contrast-enhanced cardiac magnetic resonance. A ringlike pattern of LV scar was defined as LV subepicardial/midmyocardial LGE involving at least 3 contiguous segments in the same short-axis slice. The end point of the study was time to the composite outcome of all-cause death, resuscitated cardiac arrest because of ventricular fibrillation or hemodynamically unstable ventricular tachycardia and appropriate implantable cardioverter defibrillator therapy.
A total of 28 patients (4%) had a ringlike pattern of scar (group A), 78 (11%) had a non-ringlike pattern (group B), and 580 (85%) had normal cardiac magnetic resonance with no LGE (group C). Group A patients were younger compared with groups B and C (median age, 40 vs 52 vs 45 years;
<0.01), more frequently men (96% vs 82% vs 55%;
<0.01), with a higher prevalence of family history of sudden cardiac death or cardiomyopathy (39% vs 14% vs 6%;
<0.01) and more frequent history of unexplained syncope (18% vs 9% vs 3%;
<0.01). All patients in group A showed VA with a right bundle-branch block morphology versus 69% in group B and 21% in group C (
<0.01). Multifocal VAs were observed in 46% of group A patients compared with 26% of group B and 4% of group C (
<0.01). After a median follow-up of 61 months (range, 34-84 months), the composite outcome occurred in 14 patients (50.0%) in group A versus 15 (19.0%) in group B and 2 (0.3%) in group C (
<0.01). After multivariable adjustment, the presence of LGE with ringlike pattern remained independently associated with increased risk of the composite end point (hazard ratio, 68.98 95% CI, 14.67-324.39,
<0.01).
In patients with apparently idiopathic nonsustained VA, nonischemic LV scar with a ringlike pattern is associated with malignant arrhythmic events.
Ventricular tachyarrhythmias are an important cause of morbidity and mortality in cardiac sarcoidosis. To date, the prevalence and incidence of ventricular tachycardia/ventricular fibrillation ...(VT/VF) in this population remain unknown.
To determine the prevalence and incidence of ventricular tachyarrhythmias in patients with cardiac sarcoidosis and to identify the clinical attributes associated with appropriate implantable cardioverter-defibrillator (ICD) therapies.
We studied 45 patients with ICDs, biopsy-proven systemic sarcoidosis, and cardiac involvement, as evidenced by histopathology, cardiac magnetic resonance imaging, and/or (18)F-fluoro-2-deoxyglucose-positron emission tomography imaging. Device logs and medical records were retrospectively reviewed.
Appropriate ICD therapies for VT/VF were observed in 37.8% of the patients with an incidence of 15% per year. Inappropriate ICD therapies occurred in 13.3% of the patients. Longer ICD follow-up (4.5 ± 3.1 years vs 1.5 ± 1.5 years; P = .001), depressed left ventricular ejection fraction (35.5% ± 15.5% vs 50.9% ± 15.5%; P = .002), and complete heart block (47.1% vs 17.9%; P = .048) were associated with appropriate ICD therapy. While there was no significant difference in the total number of shocks/antitachycardia pacing-terminated events between primary (n = 29) and secondary (n = 16) prevention groups, there was a trend toward more events in the secondary prevention arm after 2 years.
Ventricular tachyarrhythmias requiring ICD therapy were common in patients with cardiac sarcoidosis, with an estimated incidence rate of 15% per year. Longer follow-up, left ventricular systolic dysfunction, and complete heart block were associated with VT/VF. Patients with primary prevention ICDs had high rates of appropriate ICD therapy but not as high as did secondary prevention patients. In the absence of reliable risk stratification techniques, consideration should be given to prophylactic ICD implantation in patients with cardiac sarcoidosis.
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