Mean Left Atrial Research Articles

Epicardial Ultrasonic Ablation of Atrial Fibrillation During Concomitant Cardiac Surgery Is a Valid Option in Patients With Ischemic Heart Disease

Surgical therapy of atrial fibrillation concomitant to coronary bypass grafting using epicardial Ultrasound technology was assessed after a minimum 6-month follow-up. A cohort of 98 consecutive patients with a mean age of 72+/-7.58 years and a primary diagnosis of ischemic heart disease had surgery for structural disease. Coronary artery bypass grafting was isolated (n=51) or associated (n=47) with various combinations of aortic, mitral, tricuspid, and left ventricular restoration surgery. Atrial fibrillation duration ranged from 6 to 360 months (mean 71 months) and was permanent in 47 patients, paroxysmal in 34, and persistent in 17. Left atrial mean diameter was 48+/-6.71 mm. A circumferential ablation was performed off-pump, before the concomitant procedure, and was always associated with an epicardial mitral line lesion using the same technology. At 3-, 6-, and 12-month visits, patients were routinely evaluated by physical examination, ECG, chest X-ray, and 24-hour Holter. There were 1 early death (1%) and 4 extracardiac late deaths. A pacemaker was implanted in 4 patients. Mean follow-up time was 325 days, 2 patients being lost to follow-up. Freedom from atrial fibrillation and flutter at the 6-month visit was 84% for the entire population, 76% in patients with permanent, and 91% in patients with paroxysmal atrial fibrillation. At the 1-year visit, 85% were free from atrial fibrillation or flutter. Epicardial beating heart ablation using therapeutic ultrasound is safe, reliable, and can easily treat atrial fibrillation in a difficult surgical population of patients with primary ischemic heart disease.

Validation of a Simplified Method to Determine Left Atrial Volume by Computed Tomography in Patients With Atrial Fibrillation

The success of catheter ablation of atrial fibrillation (AF) is highly dependent on a preprocedural assessment of the size and shape of the left atrium. The most precise method to determine left atrial (LA) volume using computed tomography requires manually tracing the LA area of each cross-sectional image. This is a labor-intensive and time-consuming technique. The purpose of this study was to compare LA volume derived using the "gold-standard" multiple-slice technique with LA volume estimated using 3 orthogonal LA dimensions in patients with AF. The patient population was composed of 100 patients referred for catheter ablation of AF (87 men, mean age 57 +/- 12 years). AF was paroxysmal in 49 patients and persistent in 51. Each patient underwent computed tomography before catheter ablation, and LA volume was measured using the 2 methods. The mean LA volume measured using the multiple-slice technique was 136 +/- 46 ml. According to the simpler estimation approach, the mean LA volume was 112 +/- 41 ml. A close correlation was noted between atrial volumes determined using the 2 methods (r = 0.91, p <0.001). There was a mean underestimation of LA volume by the estimation technique of 17 +/- 13%. In conclusion, the results of this study reveal that LA volume determined using an estimation approach correlates closely with true LA volume as determined using the gold-standard multiple-slice approach. This estimation approach underestimates true LA volume by approximately 20%.

Significance of Left Atrial Volume in Patients < 20 Years of Age With Hypertrophic Cardiomyopathy

Left atrial (LA) enlargement is an indicator of chronic elevation in left ventricular (LV) end-diastolic pressure as well as diastolic dysfunction. There is a lack of data on the significance of LA volume in the pediatric population. The objective of this study was to elucidate the relation between LA volume and diastolic dysfunction, clinical symptoms, and exercise capacity in young patients with hypertrophic cardiomyopathy. All patients aged <20 years with obstructive hypertrophic cardiomyopathy who underwent evaluation at the Mayo Clinic from 2002 to 2006 were retrospectively identified. Reviews of the LA volume index and other traditional diastolic Doppler echocardiographic parameters, as well as clinical data, were performed. A total of 88 patients (66 male) were studied. The median age at evaluation was 14 years. The mean LA volume index was 39 +/- 19 ml/m(2). Additional echocardiographic parameters included a mean LV outflow gradient of 55 +/- 51 mm Hg, a mean E/E' ratio of 14.0 +/- 7.6, and a mean maximal septal wall thickness of 23 +/- 9 mm. On univariate linear regression analysis, LA volume index had an excellent correlation with diastolic dysfunction grade (p <0.001, r(2) = 0.6), LV outflow tract gradient, mitral E/E', and the degree of mitral regurgitation. LA volume index was also positively associated with symptom score (p = 0.005) and maximal oxygen consumption on exercise test (n = 22; p = 0.01). On multivariate analysis, LA volume index was related to diastolic dysfunction grade (p <0.001) and mean mitral regurgitation grade (p = 0.05). In conclusion, this study demonstrates the potential clinical importance of LA volume index in pediatric hypertrophic cardiomyopathy as a marker of the severity of underlying diastolic dysfunction, symptom score, and decreased exercise capacity. LA volume index has significant diagnostic and prognostic value in these patients.

Recommendations for the Evaluation of Left Ventricular Diastolic Function by Echocardiography

The assessment of left ventricular (LV) diastolic function should be an integral part of a routine examination, particularly in patients presenting with dyspnea or heart failure. About half of patients with new diagnoses of heart failure have normal or near normal global ejection fractions (EFs). These patients are diagnosed with “diastolic heart failure” or “heart failure with preserved EF.”1 The assessment of LV diastolic function and filling pressures is of paramount clinical importance to distinguish this syndrome from other diseases such as pulmonary disease resulting in dyspnea, to assess prognosis, and to identify underlying cardiac disease and its best treatment. LV filling pressures as measured invasively include mean pulmonary wedge pressure or mean left atrial (LA) pressure (both in the absence of mitral stenosis), LV end-diastolic pressure (LVEDP; the pressure at the onset of the QRS complex or after A-wave pressure), and pre-A LV diastolic pressure (Figure 1).Although these pressures are different in absolute terms, they are closely related, and they change in a predictable progression with myocardial disease, such that LVEDP increases prior to the rise in mean LA pressure. Figure 1 The 4 phases of diastole are marked in relation to high-fidelity pressure recordings from the left atrium (LA) and left ventricle (LV) in anesthetized dogs. The first pressure crossover corresponds to the end of isovolumic relaxation and mitral valve opening. In the first phase, left atrial pressure exceeds left ventricular pressure, accelerating mitral flow. Peak mitral E roughly corresponds to the second crossover. Thereafter, left ventricular pressure exceeds left atrial pressure, decelerating mitral flow. These two phases correspond to rapid filling. This is followed by slow filling, with almost no pressure differences. During atrial contraction, left atrial pressure again exceeds left ventricular pressure. The solid arrow points to left ventricular minimal pressure, the dotted arrow to left ventricular …

Impact of Septal Myectomy on Left Atrial Volume and Left Ventricular Diastolic Filling Patterns: An Echocardiographic Study of Young Patients with Obstructive Hypertrophic Cardiomyopathy

Septal myectomy in young patients with obstructive hypertrophic cardiomyopathy (HCM) can be performed with low mortality, and leads to excellent improvement in symptoms. Left atrial (LA) enlargement has been associated with exercise intolerance, severity of mitral regurgitation (MR), and left ventricular (LV) outflow tract (LVOT) obstruction in adults with HCM. Young patients (1-22 years of age) who had a septal myectomy for obstructive HCM between 2002 and 2005 were identified. Retrospective analyses of premyectomy and postmyectomy echocardiograms were performed. In this cohort of 32 patients (25 male), the average maximal LV wall thickness was 25 +/- 9 mm and LVOT maximal instantaneous gradient was 106 +/- 44 mm Hg. MR was present in all patients with a mean grade of 3 +/- 1. All patients had successful myectomy and there were no early deaths. After myectomy, LVOT maximal instantaneous gradient decreased to 17 +/- 13 mm Hg (P < .0001). Mean LA volume (LAV) index decreased from 52.1 +/- 2.2 to 33.2 +/- 11.9 mL/m(2) (P < .0001). Mean MR grade decreased to 2 +/- 1. Early mitral medial annular tissue Doppler velocity (E') increased from 6.2 +/- 1.9 to 13 +/- 2.6 cm/s (P < .043). A postmyectomy decrease in LAV index correlated with decrease in LVOT obstruction (P = .001) and change in degree of MR (P = .04). Septal myectomy not only reduces LVOT maximal instantaneous gradient and MR in young patients, but also results in decreased LAV index, and E/A and E/E' ratios. These hemodynamic improvements may contribute to the observed survival benefit and increased exercise tolerance observed after myectomy. This is the first series to demonstrate that LAV correlates closely with hemodynamic status in children with obstructive HCM and may be a significant predictor of clinical outcome in these patients.

Left Atrial Size and Mean Left Atrial Pressure are Reduced by Weight Loss in Obese Type 2 Diabetic Men

Left Atrial Size and Mean Left Atrial Pressure are Reduced by Weight Loss in Obese Type 2 Diabetic Men

Impairment of the Atrial Substrates by Chronic Cigarette Smoking in Patients with Atrial Fibrillation

Smoking is a major risk factor for cardiovascular disease. The impact of smoking on the right and left atrial substrates is unknown. This study included 88 patients (age 50 +/- 13 years, M/F = 71/17) who underwent four pulmonary veins isolation (PVI) for paroxysmal atrial fibrillation (AF). The mean voltage and total activation time of the individual atria were obtained by using a NavX mapping system, and were compared between the patients with and without a previous smoking history. The dose effect was evaluated by the smoking intensity-duration, defined as the number of packs per day plus how many years they had been smoking. The right atrial (RA) mean voltage was lower in the patients with a previous history of smoking than in those without a history of smoking (1.92 +/- 0.49 vs 2.17 +/- 0.56 mV, P < 0.05). The left atrial (LA) mean voltage was similar between the two groups (1.73 +/- 0.67 vs 1.82 +/- 0.48 mV, P = 0.488). Further, the total activation time of the RA was longer in the patients with a previous history of smoking than in those without a history of smoking, but not so for the LA. Furthermore, the voltage reduction in the RA was related to the smoking intensity-duration (Pearson's correlation, r = 0.650, P < 0.001). In patients with atrial fibrillation, the RA mean voltage and total activation time were significantly correlated to smoking and had a dose-dependent effect.

Abstract 2441: A Controlled Randomized Trial of Biatrial Ablation for Curing Long-lasting Permanent Atrial Fibrillation (The Decomplex Trial)

Background: patients with long-lasting permanent atrial fibrillation (AF) are often destined to remain in AF life-long. In this cohort outcomes of ablation techniques are disappointing, with 20 –74% success rate and 30 –50% repeat procedure. The adjunctive clinical benefit of targeting multiple right and left atrial (LA) sites beyond the pulmonary vein (PV)-LA junction with the aim of achieving acute AF termination has not been prospectively evaluated in a randomized study. Methods and results: 60 patients with permanent atrial fibrillation of more than 1 year duration, with early recurrence after electrical cardioversion and medical therapy with one or more antiarrhythmic agents were enrolled (mean age 59±10, mean AF duration 60 months, mean LA dimension 44±7 mm, left ventricular EF &gt;40% in all) and randomized to standard circumferential PV ablation (CPVA, control group, N=30) or an extended CPVA schema targeting also inferior LA, atrial septum, LA appendage, coronary sinus and right atrium (test group, N=30). In the test group the procedural endpoint was sinus rhythm (SR) restoration by radiofrequency energy; at each step average cycle length was measured and ablation was stopped if patient gained SR. In the control group the standard CPVA technique was applied. All patient transmitted daily transtelephonic ECG strips whereas at 3, 6 and 12 months an echocardiogram and a 48 hour Holter was obtained. Antiarrhythmic drug therapy was continued for 3 months after ablation in both group (blanking period in which patients were allowed to undergo electrical cardioversion). AF terminated in 5% and 55% of control and test subjects; mean procedure duration was 66 and 88 minutes in the 2 groups; No significant complications occurred in both groups. After a mean follow-up of 4 months, 67% of control patients were sinus as compared with 83% in the test group (p&lt;0.05). 2 and 2 patient undergoing a repeat procedure for recurrent AF for AF (N=2) and AT (N=2). Acute AF termination was the strongest endpoint of SR maitainance (p&lt;0.01) Conclusion: Preliminary data show that a modified CPVA ablation strategy in patients with permanent AF is associated with acute AF termination in 55% of patients and achieves medium term restoration and maintenance of sinus rhythm in 83% of patients.

Echocardiographic and Hemodynamic Findings in Patients With Mitral Stenosis Undergoing Percutaneous Mitral Commissurotomy Comparing Those With Chronic Atrial Fibrillation Versus Those With Normal Sinus Rhythm

Chronic atrial fibrillation (AF) is common in patients with mitral stenosis (MS). Because AF induces electrical and mechanical remodeling of the left atrium, left atrial (LA) compliance is likely to be changed in its presence. This study was performed to investigate the influence of AF on LA compliance in patients with moderate to severe MS. Data were analyzed for 356 patients (282 women; mean age 40 +/- 11 years; range 17 to approximately 71) who were registered in the percutaneous mitral commissurotomy database. Mean LA pressure was lower (21 +/- 7 vs 26 +/- 8 mm Hg; p <0.001), but LA volume was higher in the AF than sinus-rhythm group (126 +/- 62 vs 74 +/- 27 ml; p <0.001), indicating higher LA compliance, which was further confirmed by lower LA v wave at catheterization in the AF group (27 +/- 9 for AF vs 32 +/- 10 mm Hg for sinus rhythm; p <0.001). In conclusion, the presence of AF has a significant influence on LA compliance in patients with moderate to severe MS.

Blinded correlation study of three-dimensional electro-anatomical image integration and phased array intra-cardiac echocardiography for left atrial mapping

The purpose of this study was to compare, in a prospective and operator-blinded fashion, the mapping accuracy of the three-dimensional (3D) electro-anatomical image integration and phased array intracardiac echocardiography (ICE) as a real-time imaging modality. Prospectively, 18 patients undergoing pulmonary vein antrum isolation (PVAI) were included. Patients underwent a cardiac computerized tomography scan to define PV and left atrial (LA) anatomy. Image segmentation and integration was performed by CARTOMERGE, followed by 3D volume rendering and image integration. Error profiles between ICE-guided to CARTO and CARTO-guided to ICE were performed in an operator-blinded fashion over PV predetermined points. All patients underwent successful PVAI. The mean age was 55 +/- 10 years, with a mean LA size of 4.5 +/- 0.3 cm. CARTOMERGE-guided catheter positioning was subject to spatial errors on the order of 0.5-1.0 cm relative to ICE imaging, with greatest magnitude near the LA appendage (LAA) and least near the RIPV. The magnitude of spatial error between these two methods is demonstrable regardless of the choice of reference. During electro-anatomical mapping of the LA, CARTO-guided navigation is associated with considerable spatial error relative to anatomic features as identified by ICE. Adjunctive real-time imaging is needed to ensure accurate delivery of radiofrequency lesions.

An integrated approach to determine left atrial volume, mass and function in hypertrophic cardiomyopathy by two-dimensional echocardiography

MethodsThe study included 25 hypertrophic cardiomyopathy (HCM) patients (15 non-obstructive and 10 obstructive) and 25 controls for assessment of left atrial (LA) volume, mass and function by two-dimensional echocardiography. Measurement included mean LA diameter (LAD), LA mass = {(mean LAD + anterior LA wall + posterior LA wall)3 − mean LAD3} × 0.8 + 0.6, LA volume = [(8/3 π L · A1 · A2), where L is LA length, A1 and A2 are LA area in 4-chambers and 2-chambers, respectively] including maximum (Vmax), minimum (Vmin), and pre-atrial contraction (Vpre-A), total atrial stroke volume (TA-SV), TA emptying fraction (TA-EF), active atrial SV (AA-SV), AA-EF, passive atrial SV (PA-SV), PA-EF, atrial expansion index (AEI), and LA kinetic energy (LA-KE) = ½ × AA-SV × P × V2.ResultsLAD, LA mass, Vmax, Vmin, and Vpre-A were significantly higher in HCM than controls. TA-SV and TA-EF were comparable in both HCM subgroups and controls. AA-SV and LA-KE were significantly higher in both HCM subgroups than controls. LA-KE was significantly higher in obstructive HCM than non-obstructive (P < 0.001). PA-EF and AEI were significantly lower in obstructive HCM than controls (P < 0.05).ConclusionHCM is associated with increased LA size and augmented LA pump function especially obstructive type. LA conduit and reservoir functions are impaired in obstructive HCM.

Age‐ and Sex‐Related Differences in the Tissue Doppler Imaging Parameters of Left Ventricular Diastolic Dysfunction

The effect of age and gender on tissue Doppler imaging measurements comparing the septal and mitral annulus needs to be investigated. We investigated in 276 outpatients in a university cardiology practice the relationship of age and gender to left atrial (LA) size, LA volume, mitral pulse-wave Doppler E/A ratio, E/Ea ratios by tissue Doppler image of mitral annular velocity (TDI), and left ventricular diastolic dysfunction (LVDD) by TDI. Mitral E/A inflow was statistically decreased with age. E/Ea ratios of the lateral and mean of both lateral and septal annulus showed a statistical increase with age, while the E/Ea ratio of the septal annulus did not correlate with age. When comparing men and women of all ages, the mean LA volume for men was 59.2 cm3 +/- 24.36 cm3 versus 48.54 cm3 +/- 16.14 cm3 (P-value < 0.0001) and the mean LA size was 4.0 + 0.51 cm for men and 3.65 + 0.47 for women (P-value < 0.0001). There was no statistical difference between men and women when looking at mitral E/A inflow ratio, deceleration time, E/Ea ratio of the septal annulus, E/Ea ratio of the lateral annulus, E/Ea ratio of the mean of both septal and lateral annulus, and grades of LVDD. In patients 70 years of age or older, the mean diastolic grade was mild-to-moderate LVDD when using lateral or mean of septal and lateral annular measurements. When only the septal annular measurements were used to determine diastolic grade, all four age groups showed a mean of mildly to moderately impaired LVDD and showed no correlation with age. There were no differences in tissue Doppler imaging measurements between men and women.

Effects of Stepwise Ablation of Chronic Atrial Fibrillation on Atrial Electrical and Mechanical Properties

This study sought to evaluate the effects of stepwise catheter ablation of chronic atrial fibrillation (AF) on atrial electrical and mechanical properties. Although stepwise catheter ablation of chronic AF is associated with acute arrhythmia termination and a favorable clinical outcome, atrial tissue damage following the procedure has not been evaluated. Forty patients who had previously undergone catheter ablation of chronic AF were studied. In the index procedure, termination of AF was achieved by catheter ablation alone in 36 of 40 patients (90%). Electroanatomical mapping was performed in sinus rhythm > or =1 month after the index procedure, during which the surface area of scar (bipolar voltage of <0.05 mV), low-voltage tissue (<0.5 mV), and atrial propagation were evaluated. Left atrial (LA) mechanical function was assessed by transthoracic echocardiography. Electroanatomical mapping showed areas of scar and low-voltage accounting for 31% +/- 12% and 32% +/- 17% of the total LA surface area respectively, with the ablated pulmonary vein region accounting for 20% +/- 4% of the LA surface area. The area of scar outside the pulmonary vein region represented 14% +/- 12% of the LA surface area using the initial randomized ablation strategy, and 6% +/- 8% (p = 0.02) using a specific ablation strategy. Atrial conduction was diversely affected by ablation with a wide range of LA conduction times observed (range 100 to 360 ms). The LA contraction was shown in all patients by the presence of late diastolic mitral flow (37 +/- 15 cm/s) and a mean LA active emptying fraction of 18 +/- 11%. At 9 +/- 5 months of follow-up, 39 patients (98%) were in sinus rhythm. Stepwise ablation achieving sinus rhythm in patients with chronic AF has a significant impact on LA electrical activity but is associated with recovery of LA function.

Percutaneous transmitral balloon commissurotomy (PTMC): Procedural success and immediate results at Ahmed Gasim Cardiac Center

Background: Balloon valvuloplasty for stenosed mitral and pulmonary valves has been practiced with good results for the last two years in Ahmed Gasim Cardiac Centre, Khartoum Sudan. Objectives: The aim of this study is to audit percutaneous trans-mitral balloon commissurotomy [PTMC] in our current set up. Methods: One hundred and eight patients underwent percutaneous transvenous mitral commissurotomy (PTMC) from April- 2004 to December-2005 in Ahmed Gasim cardiac center. Results: 67% percent of the patients were females. Age range was from 13years to 65years and the mean age was 27years. 27% were under 21 years of age and 12% had special problems. The procedural success was achieved in 94.5% patients, in two patients we failed to dilate a tough septum, in other two the balloon got stuck to the septum and failed to cross the MV, while two patients had successful emergency MVR (due to inadvertent puncture of the RA and cardiac tamponade). There was no mortality related to the procedure, significant mitral regurgitation of > grade 2 didn't occur. No patient developed systemic embolization. Optimal results were achieved in 91.6% patients and in 92% of the patients with special problems. Hemodynamic data in the Cath. Lab showed left atrial mean (±SD) pressure dropped from 32 (±3.2) mmHg to 12 (±2.4) mmHg. LA-LV gradient dropped from an average of 25 to 5 mmHg. Echocardiographic assessment showed mean (±SD) mitral valve area increased from 0.86 (±0.19) cm2 to 1.9 (±0.5) cm2 (p

Two-Dimensional Echocardiographic Methods for Assessment of Left Atrial Volume

Left atrial (LA) size is an important predictor of cardiovascular events. Various methods of LA volume assessment exist, but their differences have not been defined. This prospective study included 631 patients (331 men; mean age of 68 +/- 14 years) without a history of atrial arrhythmias, stroke, valvular heart disease, pacemaker implantation, or congenital heart disease. All underwent echocardiography with comprehensive diastolic function assessment and LA volume measurement by 3 commonly used methods: biplane area-length, biplane Simpson's method, and the prolate-ellipsoid method. Mean LA volumes were 39 +/- 14 ml/m2 by the area-length method, 38 +/- 13 ml/m2 by the Simpson's method, and 32 +/- 14 ml/m2 by the prolate-ellipsoid method. In 92% of patients, the prolate measurement was smaller than the 2 biplane methods. Pairwise correlations (r) were 0.98 for area-length versus Simpson's, 0.85 for prolate versus area-length, and 0.86 for prolate versus Simpson's (all p values <0.001). For distinguishing normal (n = 62) from pseudonormal diastolic function (n = 240) using receiver-operating curve analysis, areas under the curves were 0.76, 0.78, and 0.75 for the area-length, Simpson's, and prolate methods, respectively (all p values <0.001, no significant intermethod differences). In conclusion, our findings suggest that there are systematic differences among existing LA volume methods. Biplane area-length and Simpson's methods compare closely, whereas the prolate-ellipsoid method generally yields smaller volumes.

Prognostic Significance of Left Atrial Size in Patients With Hypertrophic Cardiomyopathy (from the Italian Registry for Hypertrophic Cardiomyopathy)

This study assessed left atrial (LA) dimension as a potential predictor of outcome in hypertrophic cardiomyopathy (HC). From the Italian Registry for Hypertrophic Cardiomyopathy, 1,491 patients (mean age 47 +/- 17 years; 61% men; 19% obstructive), followed for 9.4 +/- 7.4 years after the initial echocardiographic evaluation, constituted the study group. The mean LA transverse dimension was 43 +/- 9 mm and was larger in patients with severe symptoms (48 +/- 9 mm for New York Heart Association classes III and IV vs 42 +/- 9 mm for classes I and II, p <0.001), atrial fibrillation (47 +/- 9 vs 42 +/- 8 mm in sinus rhythm, p <0.001), and left ventricular outflow obstruction (46 +/- 9 mm for >or=30 mm Hg at rest vs 42 +/- 9 mm for <30 mm Hg at rest, p <0.001). On univariate analysis, each 5-mm increase in LA size was associated with a hazard ratio (HR) of 1.2 for all-cause mortality (p <0.0001). On multivariate analysis, a LA dimension >48 mm (the 75th percentile) had a HR of 1.9 for all-cause mortality (p = 0.008), 2.0 for cardiovascular death (p = 0.014), and 3.1 for death related to heart failure (p = 0.008) but was unassociated with sudden death (p = 0.81). Similar results were obtained after the exclusion of patients with atrial fibrillation (HR 1.7, p = 0.008) or outflow obstruction (HR 1.8, p = 0.003). The predictive power of LA dimension >48 mm was also validated in an independent HC cohort from the United States, with similar HRs (1.8 for all-cause mortality, p = 0.019). In conclusion, in a large cohort of patients with HC from a nationwide registry, a marked increase in LA dimension were predictive of long-term outcome, independent of co-existent atrial fibrillation or outflow obstruction. LA dimension is a novel and independent marker of prognosis in HC, particularly relevant to the identification of patients at risk for death related to heart failure.

Catheter‐based decompression of the left atrium in patients with hypoplastic left heart syndrome and restrictive atrial septum is safe and effective

Infants with hypoplastic left heart syndrome (HLHS) and restrictive or intact atrial septum (rAS) present with cyanosis, pulmonary edema, and are critically ill. A previous report from our institution on emergent Norwood for HLHS with rAS showed 10% survival. We hypothesized that transcatheter left atrial (LA) decompression in HLHS with rAS would safely and effectively relieve LA hypertension, improve oxygenation, and improve Norwood survival. Between 1996 and 2004, 30 patients with HLHS and rAS underwent cardiac catheterization for pre-Norwood intervention. Twenty-eight atrial septostomies were performed: 23 static balloon dilations, 4 Rashkind septostomies, and 1 intra-atrial stent. Two procedures were aborted due to perforation (n = 1) or inability to enter the LA (n = 1). Eight total patients required surgical septectomy, for a failure rate of 27%. There were no catheter-related mortalities, although two patients died within 36 hr of the procedure after surgical septectomy. Major complications occurred in three patients (10%)--atrial perforations requiring intervention. Mean atrial septal defect gradient fell from 16.7 +/- 4.9 to 6.3 +/- 3.4 mm Hg (P < 0.001; n = 18). Mean LA pressure dropped from 21.8 +/- 5.5 to 13.1 +/- 6.5 mm Hg (P < 0.001; n = 16). Mean PaO(2) rose from 29.5 +/- 9.1 to 36.5 +/- 5.1 torr (P < 0.001; n = 23). Seventeen of 30 patients (57%) survived to discharge from Norwood. Thirteen have undergone hemi-Fontan and nine Fontan. Sixteen of 22 successful decompressions (73%) survived to discharge. Transcatheter decompression of the LA for patients with HLHS and rAS can be performed safely, reduces the transatrial gradient, and improves oxygenation. Catheter intervention improves survival compared to historical controls undergoing emergent Norwood.

Left Atrial Size Is a Poor Predictor of Pathology in the Older Patient: Preliminary Observations

The goal of this study was to determine the relationship between left atrial (LA) size and pathology in humans. We evaluated 14 patients (age 60 +/- 14 years, range 25-77, 9 males) who had died at our hospital. Eight patients were in sinus rhythm, 3 had paroxysmal atrial fibrillation (PAF), and 3 were in established atrial fibrillation (AF). LA size was calculated at transthoracic echocardiography (TTE) prior to death. At autopsy, histology of the dissected LA was examined at the appendage (APP), transverse sinus (TS), oblique sinus (OS), crux, and oval fossa. The severity of hypertrophy (HTY) and fibrosis (FIB) was determined by histochemistry. Mean LA weight was 37 +/- 11 g. One patient with PAF had amyloid. LA size by TTE was associated with LA weight (R = 0.6, P = 0.029). Increased age was associated with less severe APP FIB (P = 0.04). Younger patients tended to have less severe APP HTY (P = 0.09), and TS FIB (P = 0.12). Severity of atrial HTY and FIB was similar in APP and TS (P = NS). There was no relationship between abnormal atrial histology with LA volume or cardiac rhythm. Five patients had LA dilatation (LA end systolic volume index >30 ml/m(2)). Of those patients with normal LA size, 6 (75%) had APP FIB, 8 (100%) had APP HTY, 7 (88%) had TS FIB, 8 (100%) had TS HTY, and 7 (88%) had OS HTY. Abnormal LA histology is common in patients who have normal LA size by TTE. Microscopic atrial disease is associated with aging, and may represent a precursor state for LA dilatation or AF.

Left Atrial Volume in Normal Japanese Adults

Two-dimensional (D) echocardiography-derived left atrial (LA) volume has been shown to provide a more accurate assessment of LA size than the M-mode LA dimension. Our objective was to provide reference ranges of LA volume in healthy Japanese adults. The study subjects consisted of 105 Japanese adults, with a mean age of 39+/-13 years (range 20-63 years old). All subjects had normal ejection fraction (>55%), no wall motion abnormalities, normal diastolic function, no valvular disease, and normal sinus rhythm. The maximum LA volume, at left ventricular end-systole just before the opening of the mitral valve, was measured by using the bi-apical (4- and 2-chamber views) Simpson's rule. Both the absolute LA volume and the volume corrected by body surface area (LA volume index) were obtained. The LA volume ranged from 21 to 53 ml (mean 37+/-8 ml) and the LA volume index ranged from 13 to 30 ml/m(2) (mean 22+/-4 ml/m(2)). The mean LA volume index + 2SDs was 30 ml/m(2). Recognition of the upper limits of LA volume in normal Japanese subjects is of particular clinical relevance because it offers the opportunity of pathological LA remodeling diagnosis.

Correlation of Left Atrial Size With P-Wave Duration in Interatrial Block

Interatrial block (IAB) [P-wave duration > or = 110 ms] is associated with left atrial (LA) enlargement (LAE) and pathophysiologic derangements that result in atrial tachyarrhythmias, LA electromechanical dysfunction, and embolism. However, there has been no study addressing the direct correlation of P-wave duration in IAB and LAE. One hundred eighty-one consecutive patients who were admitted to a tertiary care teaching hospital over 5 consecutive days were screened for past transthoracic echocardiogram evaluations and were then matched with ECGs done within 10 days of these echocardiographic investigations. ECGs were evaluated for presence of IAB, and patients were subsequently classified into two groups: control patients and patients with IAB. Patients were also matched for common comorbidities. Mean, SD of age, Pearson correlation coefficient (r), p values, and multivariate and linear regression analyses were analyzed for the investigated variables of LA size, left ventricular hypertrophy (LVH), posterior wall thickness, septal thickness, and P-wave duration. From the sample (n = 66; mean age +/- SD, 71.3 +/- 13.7; female gender, 48.5%), the mean LA size in the control group was 36.7 +/- 4.01 mm and for the group of patients with IAB (n = 38) was 42.2 +/- 7.25 mm (p = 0.004). Linear regression analysis revealed that P-wave duration was significantly correlated with LA size (p = 0.0002, r = 0.606). Degree of conduction delay in IAB (P-wave duration) is an independent, direct correlate of LAE, and the regression equation (LA size [in millimeters] = 2.47 +/- 0.29 x P-wave duration [in milliseconds]) could be used to estimate LAE.