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ObjectiveTo characterize the cardiac phenotype associated with the novel pathogenic variant (c.1526del) of LMNA gene, which we identified in a large, six-generation family.Methods and ResultsA family tree was constructed. The clinical data of living and deceased family members were collected. DNA samples from 7 family members were analyzed for LMNA mutations using whole-exome high-throughput sequencing technology. The clinical presentation of pathogenic variant carriers was evaluated. In this six-generation family (n = 67), one member experienced sudden death at the age of 40-years-old. Three pathogenic variant carriers were identified to possess a novel heterozygous deletion mutation in LMNA gene (HGVS: NM_170707.4, c.1526del) located at exon 9 of LMNA chr1:156137145, which creates a premature translational stop signal (p.Pro509Leufs*39) in the LMNA gene and results in an mutant lamin A protein product. The main symptoms of the pathogenic variant carriers were palpitation, fatigue, and syncope, which typically occurred around 20-years-old. AV-conduction block and non-sustained ventricular tachycardia were the first signs of disease and would rapidly progress to atrial standstill around 30-years-old. Significant right atrial enlargement and bicuspid aortic valve malformation was also commonly seen in patients who carried this pathogenic variant.ConclusionThe pathogenic variant of c.1526del p.P509Lfs*39 was a frameshift deletion located at exon 9 of LMNA chr1:156137145 and causes severe right atrial enlargement, sick sinus syndrome, atrial standstill, ventricular tachycardia, and bicuspid aortic valve malformation. Our findings expand the phenotypic spectrum of novel LMNA gene mutations.

Idiopathic dilatation of the right atrium is a rare malformation characterized by disproportionate growth of the right atrium in the absence of a cause that justifies it. We present the case of a patient with idiopathic dilatation of the right atrium diagno-sed since fetal life. [ABSTRACT FROM AUTHOR]

Background: Right atrial area (RAA) is a prognostic factor in human patients with pulmonary arterial hypertension (PAH). Reference intervals for RAA have been described in healthy dogs. Objectives: To evaluate RAA indexed to the body surface area in dogs with PAH as an indicator of right atrial size, PAH severity and right‐sided congestive heart failure (R‐CHF). Animals: A total of 119 client‐owned dogs, 48 dogs with PAH and 71 control dogs. Methods: Prospective observational study. Pulmonary arterial hypertension was classified according to the tricuspid regurgitation pressure gradient (TRPG) as mild (36–50 mmHg), moderate (51–75 mmHg), or severe (>75 mmHg). The RAA index was calculated as the RAA divided by body surface area. Results: The RAA index was higher in dogs with moderate PAH (13.3 cm2/m2; range, 3.4–24.7 cm2/m2) and severe PAH (12.1 cm2/m2; range, 5.4–21.8 cm2/m2) than in those with mild PAH (6.7 cm2/m2; range, 4.8–10.7 cm2/m2) or in controls (7.3 cm2/m2; range, 4.2–10.2 cm2/m2; P < 0.001). The RAA index was higher (P < 0.0001) in dogs with R‐CHF (17.5 cm2/m2; range, 12.7–24.7 cm2/m2) compared to those without R‐CHF (7.6 cm2/m2; range, 4.4–19.4 cm2/m2). The most accurate cutoff value of the RAA index to identify R‐CHF was >12.3 cm2/m2 (sensitivity, 100%; specificity, 89.5%). In dogs with PAH, severity of tricuspid regurgitation (TR) was the only independent predictor of RAA index based on multivariate analysis (P < 0.02). Conclusions and Clinical Importance: The RAA index can be used to evaluate right atrial size in dogs and may be more effective than TRPG in predicting R‐CHF in dogs with PAH. The severity of TR is the main determinant of the RAA index in dogs with PAH. [ABSTRACT FROM AUTHOR]

Previous attempts to validate ECG criteria for right atrial (RA) enlargement (RAE) have been limited by sample sizes and lack of accepted standards for measuring RA size. New guidelines have recommended that RA volume (RAV) be used to determine RA size. Since these guidelines were released, no studies have been published that correlate RAE by ECG to RAV using the new standards. We aimed to validate previously proposed ECG criteria for RAE, commonly called P pulmonale, and to establish whether a correlation exists between P wave amplitudes and RAV as determined by echocardiogram in patients from the pulmonary hypertension (PHT) clinic. We identified patients from the PHT clinic that had an echocardiogram and ECG done at most 30days apart. We defined increased P wave amplitude as ≥2mm in lead II and ≥1mm in lead V1. The RA was determined to be enlarged if the RAV index (RAVI) was ≥39mL/m2 for men and ≥33mL/m2 for women. Patients were stratified into four groups: those with P II≥2mm, those with P V1≥1mm, those that met both criteria, and those that met neither. Right atrial volumes were then compared. Sixty-three patients were included in the study (7 men, 56 women). Three men and 36 women had an ECG that met criteria for P pulmonale. Five men and 28 women had an enlarged RA on echocardiogram. Sixty-nine percent of ECGs that met criteria for RAE were associated with increased RAV by echocardiogram. The specificity of each of the ECG criteria for P pulmonale at detecting RAE was 100% for men. The criterion with the highest specificity among women was P II≥2mm AND P V1≥1mm (94%). The least specific criterion for women was P II≥2mm (70%). The sensitivity of each criterion was much lower. The most sensitive criteria for men and women were P V1≥1mm (66.6%) and P II≥2mm (48%), respectively. The correlation of P wave amplitude in leads II and V1 and RAVI was not statistically significant for any of the ECG criteria for P pulmonale. In patients from the PHT clinic, the specificity of P pulmonale for detecting RAE is high, but the sensitivity is relatively low. These results suggest that in PHT, P pulmonale can be used to confirm that the RA is enlarged, but it is not a reliable test for diagnosing RAE. [ABSTRACT FROM AUTHOR]

Objective The long-term outcomes of catheter ablation of atrial fibrillation (AF) developing post-cardiac valve replacement (VR) remain undefined. Methods and results Eighty-nine post-VR patients with AF (44% longstanding persistent AF, LSP-AF) were enrolled. Cumulative success rate of circumferential pulmonary vein ablation (CPVA for paroxysmal AF) and bidirectional block of lines and disappearance of complex fractionated atrial electrograms (CFAEs for persistent and LSP-AF) as index and repeat procedural endpoints reached 57% (mean, 1.3 procedures) during the first year, and dropped to 42% at median follow-up of 40 months (range, 24–70 months) for multiple procedures (mean, 1.6 ± 0.9 [1–5]); incidence of procedural complications was similar to that of conventional procedures. In multivariate analysis, larger right atrium (RA, 9.40 [2.64–33.36]; P = 0.001) and rheumatic valvular disease etiology (OR, 5.49 [95% CI, 1.26–23.96]; P = 0.023) were significant independent predictors of recurrent atrial tachyarrhythmia (ATa); in contrast, long-term freedom from ATa was comparable between single and double valve replacement groups (42.1% vs. 43.7%, P = 0.880), or mechanical and bioprosthetic valves groups (41.7% vs. 50.0%, P = 0.620). Conclusion In this single-center prospective study, treatment of post-VR AF with commonly used ablation strategies including CPVA and linear and CFAE ablation had limited long-term success, with ATa recurrence risk appearing higher in the setting of RA enlargement and rheumatic valvular disease and unrelated to valves characteristics. [ABSTRACT FROM AUTHOR]

Right atrial (RA) size may become a very useful, easily obtainable, echocardiographic variable in patients with congenital heart disease (CHD) with right-heart dysfunction; however, according studies in children are lacking. We investigated growth-related changes of RA dimensions in healthy children. Moreover, we determined the predictive value of RA variables in both children with secundum atrial septal defect (ASD) and children with pulmonary hypertension (PH) secondary to CHD (PH-CHD). This is a prospective study in 516 healthy children, in 80 children with a secundum ASD (>7 mm superior-inferior dimension), and in 42 children with PH-CHD. We determined three RA variables, i.e., end-systolic major-axis length, end-systolic minor-axis length, and end-systolic area, stratified by age, body weight, length, and surface area. RA end-systolic length and area z scores were increased in children with ASD and PH-CHD when compared to those variables in the healthy control population. Using the Youden Index to determine the best cutoff scores in sex- and age-specific RA dimensions, we observed a sensitivity and specificity up to 94 and 91 %, respectively, in ASD children and 98 and 94 %, respectively, in PH-CHD children. We provide normal values ( z scores −2 to +2) for RA size and area in a representative, large pediatric cohort. Enlarged RA variables with scores >+2 were predictive of secundum ASD and PH-CHD. Two-dimensional determination of RA size can identify enlarged RAs in the setting of high volume load (ASD) or pressure load (PH-CHD). [ABSTRACT FROM AUTHOR]

A giant right coronary artery aneurysm (60 × 70 mm in size) was incidentally found by chest X-ray as an abnormal right atrial enlargement, and it needed surgical resection. Although the majority of giant coronary artery aneurysms present with symptoms of coronary ischemia, this case presented without any specific symptom. This study indicates that when chest X-ray shows abnormal atrial enlargement, a differential diagnosis of giant coronary artery aneurysm may need to be considered. [ABSTRACT FROM AUTHOR]

Introduction: Azimilide dihydrochloride blocks both the rapid (IKr) and slow (IKs) components of the delayed rectified K+ current; dofetilide blocks only IKr. Their efficacies were assessed on atrial flutter reentrant circuits in dogs with surgically induced right atrial enlargement. Methods and Results: Multiple biopsies of the tricuspid valve and banding of the pulmonary artery in male mongrel dogs made them susceptible, about 3 weeks postoperatively, to stimulation-induced sustained (5 min or longer) atrial flutter. Azimilide 3 mg/kg administered intravenously (IV) terminated flutter in 8 of 8 dogs, but a slower, nonsustained arrhythmia could be reinduced in 5. In these 5 dogs, azimilide 10 mg/kg terminated flutter and prevented reinduction. This dose increased effective refractory period significantly more in the slow conduction zone (25%) than in the normal zone (17%) and increased flutter cycle length (37%). Termination followed progressive conduction delay in the slow zone of the reentrant circuit. Dofetilide 1 μg/kg IV terminated flutter in 6 of 6 dogs, but the arrhythmia could be reinduced. At 3 μg/kg, flutter terminated in all dogs and could not be reinduced. Dofetilide also increased the effective refractory period significantly more in the slow zone (17%) than in the normal zone (12%) and increased cycle length (33%), leading to interruption of the arrhythmia circuit. Conclusion: In the canine right atrial enlargement model of circus movement atrial flutter, both azimilide 10 mg/kg IV and dofetilide 3 μg/kg IV were 100% effective in terminating flutter and preventing reinduction. Efficacy relied on a similar mechanism of differentially prolonged refractoriness in the slow conduction component of the reentrant circuit where drug-induced termination occurred. [ABSTRACT FROM AUTHOR]

The Chiari network, a congenital remnant of fetal membrane in the right atrium, is infrequently associated with complications, such as supraventricular tachyarrhythmias. There have however been no known reports of basic electrocardiographic significance of the Chiari network. We present three consecutive cases of Chiari network found in the presence of abnormal interatrial conduction (P-waves ≥110 ms), which is a potential predictor of atrial tachyarrhythmias. Copyright © 2007 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background: Right atrium (RA) enlargement in uncorrected atrial septal defect (ASD) is due to chronic volume overload. Several electrocardiogram (ECG) criteria had been proposed for screening RA enlargement. This study aimed to compare the accuracy of ECG criteria in detecting RA enlargement in adults with uncorrected ASD. Methods: This was a cross-sectional study involving 120 adults with uncorrected secundum ASD. The subjects underwent ECG examination, transthoracic echocardiography, and right heart catheterization. An RA enlargement was determined with RA volume index by transthoracic echocardiography. Various ECG and combined ECG criteria were evaluated. Statistical analysis was performed to analyze the sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV). Results: An RA enlargement was detected in 64.2% subjects. The P wave height > 2.5 mm in lead II criterion had the best specificity (100%) and PPV (100%), but low sensitivity (19%) and accuracy (48%). The combined 2 ECG criteria (QRS axis > 90°, R/S ratio > 1 in V1) had 82% sensitivity, 56% specificity, 73% accuracy, 77% PPV, and 63% NPV. The combined 3 ECG criteria (QRS axis > 90°, R/S ratio > 1 in V1, and P wave height > 1.5 mm in V2) had 35% sensitivity, 86% specificity, 53% accuracy, 82% PPV, and 43% NPV. Conclusions: The combined 2 ECG criteria (QRS axis > 90° and R/S ratio > 1 in V1) had increased sensitivity, better accuracy, and more balance of PPV and NPV as compared with P wave > 2.5 mm in II criterion and combined 3 ECG criteria to diagnose RA enlargement in adults with uncorrected ASD. [ABSTRACT FROM AUTHOR]

Summary: We report two cases of idiopathic atrial dilatation in two adult siblings, a brother and a sister. The first patient was a 36-year-old man who was referred to our institution for evaluation of atrial fibrillation and syncopes. Transthoracic echocardiography revealed an enlarged right atrium accompanied by a severe tricuspid regurgitation associated with annular dilatation. The diagnosis of idiopathic atrial enlargement was made after all other lesions known to produce it have been excluded. The patient did not consent to the proposed cardiothoracic surgical treatment so he remained on conservative therapy. On electrocardiography, atrial standstill was noted, resulting in the implantation of a VVI cardiac pacemaker one year later. After an asymptomatic period, the patient suffered sudden death at the age of 40 years. His 45-year-old sister suffering from the same symptoms was also referred for examination, also to be diagnosed with idiopathic atrial dilatation and severe tricuspid regurgitation. Idiopathic dilatation of the right atrium, although a rare disorder, should not be forgotten as differential diagnosis for enlarged right atrium. Transthoracic echocardiography is the most commonly used technique and in our cases it was sufficient for establishing the diagnosis. [Copyright &y& Elsevier]