Atrial myxoma surgery and P-wave remodeling.

INTRODUCTION: Data regarding atrial electrocardiographic parameters in patients with atrial myxomas are scarce. METHODS: We aimed to study atrial electrocardiographic features in patients with atrial myxomas, before and after surgery. We also analyze the incidence of atrial fibrillation during follow-up and its correlation with different P-wave indexes. In total 32 patients in sinus rhythm that underwent atrial myxoma surgery were included. RESULTS: Mean age was 55.0 ± 12.6 years and 18 (56.3%) were women. Ten patients had left atrial enlargement (31.3%). Only one myxoma was located in the right atrium. At baseline seven cases of partial interatrial block (IAB) were detected (21.9%), two in the absence of left atrial enlargement. There were significant differences in atrial electrocardiographic indexes before and after surgery, including P-wave duration (108.9 ± 17.9 ms vs. 93.0 ± 12.4 ms; p < .001), partial IAB (21.9% vs. 3.1%; p = .012) and duration of P-wave terminal force in lead V1 negativity (-0.6 ± 0.3 vs. -0.5 ± 0.3 mm; p = .034). At a mean follow-up of 10.0 ± 5.5 years, 10 patients (31.3%) had experienced at least one episode of atrial fibrillation. Post-operative P-wave duration was associated with atrial fibrillation occurrence during follow-up (Hazard ratio: 0.90, 95% confidence interval: 0.83-0.98; p = .020). CONCLUSIONS: Abnormalities in atrial electrocardiographic indexes are common in atrial myxomas and frequently improve after surgery. Post-operative P-wave duration is associated with atrial fibrillation occurrence during follow-up.

Left atrial enlargement in competitive athletes and atrial electrophysiology.

INTRODUCTION AND OBJECTIVES: There are scarce data on left atrial (LA) enlargement and electrophysiological features in athletes. METHODS: Multicenter observational study in competitive athletes and controls. LA enlargement was defined as LA volume indexed to body surface area ≥ 34mL/m2. We analyzed its relationship with atrial electrocardiography parameters. RESULTS: We included 356 participants, 308 athletes (mean age: 36.4±11.6 years) and 48 controls (mean age: 49.3±16.1 years). Compared with controls, athletes had a higher mean LA volume index (29.8±8.6 vs 25.6±8.0mL/m2, P=.006) and a higher prevalence of LA enlargement (113 [36.7%] vs 5 [10.4%], P <.001), but there were no relevant differences in P-wave duration (106.3±12.5ms vs 108.2±7.7ms; P=.31), the prevalence of interatrial block (40 [13.0%] vs 4 [8.3%]; P=.36), or morphology-voltage-P-wave duration score (1.8±0.84 vs 1.5±0.8; P=.71). Competitive training was independently associated with LA enlargement (OR, 14.7; 95%CI, 4.7-44.0; P <.001) but not with P-wave duration (OR, 1.02; 95%CI, 0.99-1.04), IAB (OR, 1.4; 95%CI, 0.7-3.1), or with morphology-voltage-P-wave duration score (OR, 1.4; 95%CI, 0.9-2.2). CONCLUSIONS: LA enlargement is common in adult competitive athletes but is not accompanied by a significant modification in electrocardiographic parameters.

Baseline ECG and Prognosis After Transcatheter Aortic Valve Implantation: The Role of Interatrial Block.

Background The clinical significance of conduction disturbances after transcatheter aortic valve implantation has been described; however, little is known about the influence of baseline ECGs in the prognosis of these patients. Our aim was to study the influence of baseline ECG parameters, including interatrial block (IAB), in the prognosis of patients treated with transcatheter aortic valve implantation. Methods and Results The BIT (Baseline Interatrial Block and Transcatheter Aortic Valve Implantation) registry included 2527 patients with aortic stenosis treated with transcatheter aortic valve implantation. A centralized analysis of baseline ECGs was performed. Patients were divided into 4 groups: normal P wave duration (<120 ms); partial IAB (P wave duration ≥120 ms, positive in the inferior leads); advanced IAB (P wave duration ≥120 ms, biphasic [+/-] morphology in the inferior leads); and nonsinus rhythm (atrial fibrillation/flutter and paced rhythm). The mean age of patients was 82.6±9.8 years and 1397 (55.3%) were women. A total of 960 patients (38.0%) had a normal P wave, 582 (23.0%) had partial IAB, 300 (11.9%) had advanced IAB, and 685 (27.1%) presented with nonsinus rhythm. Mean follow-up duration was 465±171 days. Advanced IAB was the only independent predictor of all-cause mortality (hazard ratio [HR], 1.48; 95% CI, 1.10-1.98 [P=0.010]) and of the composite end point (death/stroke/new atrial fibrillation) (HR, 1.51; 95% CI, 1.17-1.94 [P=0.001]). Conclusions Baseline ECG characteristics influence the prognosis of patients with aortic stenosis treated with transcatheter aortic valve implantation. Advanced IAB is present in about an eighth of patients and is associated with all-cause death and the composite end point of death, stroke, and new atrial fibrillation during follow-up.

Relation of Interatrial Block to Cognitive Impairment in Patients ≥ 70 Years of Age (From the CAMBIAD Case-control Study).

The association between atrial fibrillation, stroke, and interatrial block (IAB) (P-wave duration ≥120 ms) is well recognized, particularly in the case of advanced IAB. We aimed to assess the association of IAB with mild cognitive impairment. Advanced Characterization of Cognitive Impairment in Elderly with Interatrial Block was a case-control multicenter study, conducted in subjects aged ≥70 years in sinus rhythm without significant structural heart disease. Diagnosis of mild cognitive impairment was performed by an expert geriatrician, internist, or neurologist in the presence of changes in cognitive function (Mini Mental State Examination score 20 to 25) without established dementia. A total of 265 subjects were included. Mean age was 79.6 ± 6.3 years and 174 (65.7%) were women; there were 143 cases with mild cognitive impairment and 122 controls with normal cognitive function. Compared with controls, cases had longer P-wave duration (116.2 ± 13.8 ms vs 112.5 ± 13.3 ms, p = 0.028), higher prevalence of IAB (73 [51.0%] vs 38 [31.1%], p = 0.001), higher prevalence of advanced IAB (28 [19.6%] vs 10 [8.2%], p = 0.002), and higher MVP ECG risk score (2.7 ± 1.4 vs 2.2 ± 1.3, p = 0.004). IAB was independently associated with mild cognitive impairment, both for partial (odds ratio 2.0, 95% CI: 1.1 to 3.9) and advanced IAB (odds ratio 2.8, 95% CI: 1.1 to 6.7). In conclusion, in subjects aged ≥70 years without significant structural heart disease, IAB is independently associated with mild cognitive impairment. This association is stronger in the case of advanced IAB.

Interatrial block and cognitive impairment in the BAYES prospective registry.

BACKGROUND: An association between interatrial block (IAB) (P wave duration ≥120 ms) and dementia has been suggested. Our objective was to assess the association of IAB with cognitive impairment (CI). METHODS: The prospective BAYES registry included 552 patients ≥70 years with structural heart disease without documented atrial fibrillation. Cognitive ability was assessed at baseline and every 6 months with the Pfeiffer test. The median follow-up was 22 months. RESULTS: Thirty patients (5.4%) had baseline CI, 20 patients with mild CI and 10 with moderate CI. Compared to patients without CI, patients with CI had higher mean age (80.4 ±â€¯6.5 vs. 76.8 ±â€¯5.4 years) and higher prevalence of advanced IAB (with biphasic P-wave ± in inferior leads) (14 [46.7%] vs. 122 [23.4%], p < .01). The prevalence of baseline CI was 2.7% in normal P-wave, 5.1% in partial IAB, and 10.3% in advanced IAB, p < .001. Advanced IAB was independently associated with baseline CI (odds ratio 4.9, 95% confidence interval 1.4-16.5), this was not the case with partial IAB (odds ratio 2.1, 95% confidence interval 0.5-7.4). The independent association with CI at follow-up existed both for partial IAB (hazard ratio 1.98, 95% confidence interval 1.18-3.33) and advanced IAB (hazard ratio 2.04, 95% confidence interval 1.19-3.51). CONCLUSION: In patients aged 70 years or more with structural heart disease who are in sinus rhythm advanced IAB is associated with baseline CI. There is also an association of partial and advanced IAB with CI during follow-up.

Association between interatrial block, left atrial fibrosis, and mechanical dyssynchrony: Electrocardiography-magnetic resonance imaging correlation.

INTRODUCTION: Advanced interatrial block (IAB) on a 12-lead electrocardiogram (ECG) is a predictor of stroke, incident atrial fibrillation (AF), and AF recurrence after catheter ablation. The objective of this study was to determine which features of IAB structural remodeling is associated with left atrium (LA) magnetic resonance imaging structure and function. METHODS/RESULTS: We included 152 consecutive patients (23% nonparoxysmal AF) who underwent preprocedural ECG and cardiac magnetic resonance (CMR) in sinus rhythm before catheter ablation of AF. IAB was defined as P-wave duration ≥120 ms, and was considered partial if P-wave was positive and advanced if P-wave had a biphasic morphology in inferior leads. From cine CMR and late gadolinium enhancement, we derived LA maximum and minimum volume indices, strain, LA fibrosis, and LA dyssynchrony. A total of 77 patients (50.7% paroxysmal) had normal P-wave, 52 (34.2%) partial IAB, and 23 (15.1%) advanced IAB. Patients with advanced IAB had significantly higher LA minimum volume index (25.7 vs 19.9 mL/m2 , P = .010), more LA fibrosis (21.9% vs 13.1%, P = .020), and lower LA maximum strain rate (0.99 vs 1.18, P = .007) than those without. Advanced IAB was independently associated with LA (minimum [P = .032] and fibrosis [P = .009]). P-wave duration was also independently associated with LA fibrosis (ß = .33; P = .049) and LA mechanical dyssynchrony (ß = 2.01; P = .007). CONCLUSION: Advanced IAB is associated with larger LA volumes, lower emptying fraction, and more fibrosis. Longer P-wave duration is also associated with more LA fibrosis and higher LA mechanical dyssynchrony.

Electrocardiogram and left atrial abnormality: Design of an observational study to clarify diagnostic criteria.

BACKGROUND: The criteria applied for diagnosis of left atrial (LA) abnormality using electrocardiogram (ECG) have high specificity but low sensitivity. In fact, some authors have suggested classifying P-wave anomalies associated with LA abnormality and interatrial block as "atrial abnormalities." The most widely known ECG criteria for LA abnormality include P-wave duration, morphology and voltage of P wave in inferior leads, presence of P-wave terminal force in V1 (PtfV1 ), and P-wave axis and area. PtfV1 has also been reported to vary according to misplacement of the V1 and V2 electrodes. METHODS: The objective of this observational cohort study is to determine the degree of correlation between ECG criteria for LA abnormality and left atrium volume and functionality, as determined by speckle tracking echocardiography. The study also aims to investigate the correlation between these echocardiographic parameters and PtfV1 value by placing the V1 and V2 electrodes in the second, third, and fourth intercostal spaces. RESULTS AND CONCLUSIONS: Our results could help to clarify whether the decrease in left atrial deformity, which is currently considered a surrogate target of fibrosis, correlates better with ECG criteria for LA abnormality than atrial volumes.

Advanced interatrial block and P-wave duration are associated with atrial fibrillation and stroke in older adults with heart disease: the BAYES registry.

AIMS: Advanced interatrial block (IAB), is an unrecognized surrogate of atrial dysfunction and a trigger of atrial dysrhythmias, mainly atrial fibrillation (AF). Our aim was to prospectively assess whether advanced IAB in sinus rhythm is associated with AF and stroke in elderly outpatients with structural heart disease, a group not previously studied. METHODS AND RESULTS: Prospective observational registry that included outpatients aged ≥70 years with structural heart disease and no previous diagnosis of AF. Patients were divided into three groups: normal P-wave duration (<120 ms), partial IAB (P-wave duration ≥120 ms, positive in the inferior leads), and advanced IAB [P-wave duration ≥120 ms, biphasic (plus/minus) morphology in the inferior leads]. Among 556 individuals, 223 had normal P-wave (40.1%), 196 partial IAB (35.3%), and 137 advanced IAB (24.6%). After a median follow-up of 694 days, 93 patients (16.7%) developed AF, 30 stroke (5.4%), and 34 died (6.1%). Advanced IAB was independently associated with AF -[hazard ratio (HR) 2.9, 95% confidence interval (CI) 1.7-5.1; P < 0.001], stroke [HR 3.8, 95% CI 1.4-10.7; P = 0.010), and AF/stroke (HR 2.6, 95% CI 1.5-4.4; P = 0.001). P-wave duration (ms) was independently associated with AF (HR 1.05, 95% CI 1.03-1.07; P < 0.001), AF/stroke (HR 1.04, 95% CI 1.02-1.06; P < 0.001), and mortality (HR 1.04, 95% CI 1.00-1.08; P = 0.021). CONCLUSIONS: The presence of advanced IAB in sinus rhythm is independently associated with AF and stroke in an elderly population with structural heart disease and no previous diagnosis of AF. P-wave duration was also associated with all-cause mortality.

Advanced interatrial block: A predictor of covert atrial fibrillation in embolic stroke of undetermined source.

AIMS: One third of ischemic strokes are of unknown etiology. Interatrial block (IAB) is a marker of atrial electromechanical dysfunction that may predispose to the development of atrial fibrillation (AF). We hypothesized that IAB, especially in its advanced form, could be a marker of covert AF in patients with embolic stroke of undetermined source (ESUS). METHODS: We reviewed a single center cohort of ESUS patients with no prior history of AF. According to P-wave analysis of baseline ECG we distinguished 3 groups: normal P-wave duration (P-wave < 120 ms), partial IAB (P-IAB, P-wave ≥ 120 ms) and A-IAB (A-IAB, P-wave ≥ 120 ms with biphasic morphology in inferior leads). Follow-up was done 1, 6 and 12 months after discharge; then every 6 months. AF episodes, frequent premature atrial contractions (PACs) (>1%) and atrial tachyarrhythmias (runs of >3 consecutive PACs) were detected on 24 h Holter. The primary endpoint was new-onset AF detection on follow-up by any means. RESULTS: A high prevalence of both P-IAB (n = 30, 40%) and A-IAB (n = 23, 31%) was found in 75 ESUS patients. After a 521 day mean follow-up, 14 patients (19%) were diagnosed of AF. A-IAB independently predicted AF diagnosis (p =0.042) on follow-up. 24 h Holter analysis showed greater frequency of PACs and atrial tachyarrhythmia episodes in patients with IAB (p = 0.0275). CONCLUSIONS: In this hypothesis-generating study, A-IAB in the setting of ESUS is an independent risk predictor of covert AF. Although additional randomized clinical trials are warranted, A-IAB identifies ESUS patients with advanced atrial disease that could potentially benefit from early oral anticoagulation in secondary prevention.

Rational and design of the Baseline Interatrial block and Transcatheter aortic valve implantation (BIT) registry.

BACKGROUND: Aortic stenosis (AS) is currently the most frequent heart valve disease. Symptomatic severe AS has a poor prognosis and transcatheter aortic valve implantation (TAVI) is becoming the therapy of choice in these patients. Changes in the conduction tissue after the procedure constitute one of the main limitations of TAVI, with a frequent need for a definitive pacemaker. Interatrial block (IAB) is defined as a prolonged P-wave duration and is related with atrial fibrosis. The presence of IAB could be a marker of conduction tissue abnormalities at other levels. No study has specifically analyzed the role of IAB as a predictor of the need for permanent pacemaker in patients with AS undergoing TAVI. METHODS: The Baseline Interatrial block and Transcatheter aortic valve implantation (BIT) registry will be performed in approximately 3000 patients with severe AS treated with TAVI. A centralized analysis of baseline ECGs will study the presence and type of IAB and other ECG data (rhythm, P-wave duration, PR and QRS intervals/intraventricular conduction disorders). Clinical follow-up will be carried out by local researchers. The primary endpoint will be the requirement of permanent pacemaker during post-TAVI hospitalization. As secondary objectives, the incidence of new onset AF, stroke, or mortality during follow-up will be analyzed. Secondary endpoints will include the incidence of new onset AF, stroke, or mortality during follow-up. CONCLUSION: The BIT registry will study, for the first time, the influence of previous IAB in the need of permanent pacemaker after TAVI: This large registry will also provide information regarding the association of this and other ECG parameters with prognosis.

Link between Brugada phenocopy and myocardial ischemia: Results from the International Registry on Brugada Phenocopy.

BACKGROUND: Brugada phenocopies clinical entities that have indistinguishable electrocardiographic (ECG) patterns from true congenital Brugada syndrome. However, they are induced by other clinical circumstances such as myocardial ischemia. The purpose of our study was to examine the clinical features and pathogenesis of ischemia-induced Brugada phenocopy (BrP). METHODS: Data from 17 cases of ischemia-induced BrP were collected from the International Registry (www.brugadaphenocopy.com). Data were extracted from these publications and authors were contacted to provide further insight into each case. RESULTS: Of the patients included in this study, 71% were male. Mean age was 59 ± 11 years (range: 38-76). Type-1 Brugada ECG pattern occurred in 15/17 (88%) of the cases, while a type-2 Brugada ECG pattern was observed in the other 2/17 (12%). In all cases, the Brugada ECG pattern resolved upon correction of the ischemia, indicating ischemia as the inducing circumstance. No arrhythmic events have been detected acutely or during the follow-up. Reported time to resolution ranged from 2 minutes to 5 hours. Provocative challenges using sodium channel blocking agents were performed in 7/17 cases (41%), and all failed to induce a Brugada ECG pattern (BrP Class A). The remaining 10/17 cases (59%) did not undergo provocative testing due to various clinical reasons. CONCLUSIONS: Myocardial ischemia is a commonly reported etiology of BrP. Importantly, this study found no association between BrP induced by myocardial ischemia and sudden cardiac death or malignant ventricular arrhythmias.

Second-degree interatrial block: A case series.

Advanced interatrial block (IAB) (P-wave ≥120 ms and biphasic P-wave in leads II, III and aVF) is a prevalent ECG pattern frequently associated with supraventricular arrhythmias and stroke, especially in patients with structural heart disease. Intermittent IAB is a much more poorly defined electrocardiographic entity with uncertain clinical significance. In this case series, we review and analyze eight cases of second degree intermittent IAB. In six cases, there is normalization of advanced IAB after a premature supraventricular or ventricular contraction, suggesting a functional block that temporarily recovers post extra-systolic pause. Recognition of intermittent IAB (second degree) may help further characterize the prognostic and clinical implications of this ECG pattern.

Advanced interatrial block is a surrogate for left atrial strain reduction which predicts atrial fibrillation and stroke.

BACKGROUND: The association between advanced interatrial block (aIAB) and atrial fibrillation (AF) is known as "Bayes' Syndrome." There is little information on the prognostic role that new speckle tracking echocardiographic (STE) imaging techniques could play in it. We have examined the relationship between left atrial (LA) STE and the prediction of new-onset AF and/or stroke in IAB patients. METHODS: This is an observational prospective and unicentric cohort study with 98 outpatients: 55 (56.2%) controls with normal ECG without IAB, 21 (21.4%) with partial IAB (pIAB) and 22 (22.4%) with aIAB. The end point was new-onset AF, ischemic stroke and the composite of both. RESULTS: During a mean follow-up of 1.9 (1.7-2.3) years, 20 patients presented the end point (18 new-onset AF and two strokes): 8 (14.5%) in the control group, 3 (14.3%) in pIAB and 9 (40.9%) in aIAB, p = 0.03. In multivariable comprehensive Cox regression analyses, a decrease in absolute value of strain rate during the booster pump function phase (SRa) was the only variable independently related to the appearance in the evolution of the end point, in the first model (age, P-wave duration and SRa): HR 19.9 (95% CI, 3.12-127.5), p = 0.002 and in the second (age, presence of aIAB and SRa): HR 24.2 (95% CI, 3.15-185.4), p = 0.002. CONCLUSIONS: In patients with IAB, a decrease in absolute value of LA SRa with STE predicts new-onset AF and ischemic stroke. Future studies should confirm our results and assess the prognostic usefulness of LA STE in patients with IAB.

Second-degree interatrial block: Brief review and concept.

The advanced interatrial block (A-IAB) (P ≥ 120 ms plus ± pattern in II, III and aVF) corresponds at atrial level, to right or left advanced bundle branch block at ventricular level, and it is well known that these patterns may be seen transiently in relation to taquicardia or bradycardia (tachycardia or bradycardia dependent right or left bundle branch block). We present for the first time, the same phenomenon at atrial level. In one case, the A-IAB appears in relation to tachycardization and in the other disappears during a pause induced by ventricular premature complex.