Normal Left Atrial Dimensions Research Articles

Left atrial changes in early stages of heart failure with preserved ejection fraction.

Increased left atrial (LA) mass was introduced as a compensatory mechanism in heart failure (HF) patients. Furthermore, atrial conduction time and LA emptying fraction is are deteriorated in HF with preserved ejection fraction (HFpEF). The aim of this study was to assess the early LA changes in HFpEF patients. In 79 consecutive patients with HFpEF (age 61±8years, NYHA class I-III, LV EF ≥45%), a complete 2-dimensional, M-mode, and Doppler echocardiographic study was performed. According to the diastolic dysfunction (DD), patients were divided into three groups: Group I-29 healthy subjects (control group); Group II-HFpEF patients with mild DD; and Group III-HFpEF patients with moderate DD. The LV mass was increased (P<.05), septal s', lateral s', septal and lateral MAPSE were decreased (P<.05, for all), E/e' ratio was increased (P<.001), LA mass and minimal volume were increased (P<.001, P<.05), LA emptying fraction was decreased (P<.05), and LA dyssynchrony was deteriorated (P<.05) in patients with mild DD compared to controls. These changes were of the same nature in patients with moderate LV DD. In early stage of DD, in patients with HFpEF, in addition to LV hypertrophy and compromised LV longitudinal systolic function, the LA emptying fraction is reduced, LA mass and LAV min are increased and LA dyssynchrony is significant, despite normal LA dimensions. These findings suggest early LA function deterioration irrespective of normal cavity measurements, hence a need for optimum therapy.

Usefulness of Preoperative Cardiac Dimensions to Predict Success of Reverse Cardiac Remodeling in Patients Undergoing Repair for Mitral Valve Prolapse

Mitral valve repair for mitral regurgitation (MR) is currently recommended based on the degree of MR and left ventricular (LV) function. The present study examines predictors of reverse remodeling after repair for degenerative disease. We retrospectively identified 439 patients who underwent repair for myxomatous mitral valve degeneration and had both pre- and postoperative echocardiographic data available. Patients were categorized based on left atrial (LA) diameter and LV diameter standards of the American Society of Echocardiography. The outcome of interest was the degree of reverse remodeling on all heart dimensions at follow-up. Mean age was 57 ± 12 years, and 37% of patients were women. Mean preoperative LV end-diastolic diameter was 5.8 ± 0.7 cm, LV end-systolic diameter 3.5 ± 0.6 cm, LA 4.7 ± 0.7 cm, and median ejection fraction 60%. Median observation time was 81 months, and time to postoperative echocardiography was 38 months. Overall, 95% of patients had normal LV diastolic dimensions postoperatively, 93% normal LV systolic dimensions, and 37% normal LA dimensions. A Cox regression analysis showed that moderate (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.3 to 3.4) or severe preoperative LA dilatation (OR 2.7, 95% CI 1.7 to 4.4), abnormal preoperative LV end-systolic dimensions (OR 1.3, 95% CI 1.1 to 1.5), and age in years (OR 1.02, 95% CI 1.01 to 1.03) were predictive of less reverse remodeling on follow-up. In conclusion, preoperative LV end-systolic dimensions and LA dilatation substantially affect the likelihood of successful LA remodeling and normalization of all heart dimensions after mitral valve repair for MR. These findings support early operation for MR before the increase in heart dimensions is nonreversible.

Left atrial dimensions in growth and development: Normal limits for two-dimensional echocardiography

Reference values for normal left atrial dimensions have been based primarily on blind M-mode measurements, with no reports based on two-dimensional echocardiography to provide a comprehensive analysis of the two-dimensional measurements from infancy to old age. This report analyzes the left atrial dimensions from two-dimensional echocardiographic studies in 268 normal healthy subjects to determine normal limits and relations among linear, area and volume measurements of the left atrium.The group mean values change with body size, fitting well to the exponential growth model (r = 0.78 to 0.92). The variance about the mean (which determines normal limits) is represented effectively by a quadratic function of body surface area (r = 0.84 to 0.99). The variables determined by this modeling simplify evaluation of normal limits for any body size at any desired level of confidence, and the data are useful reference standards for interpretation of two-dimensional echocardiograms.

In vivo validation of the origin of the esophageal electrocardiogram

Esophageal electrocardiography is a clinical and investigational technique that is useful for determining atrial conduction intervals, analyzing atrial rhythms and mapping conduction pathways. Although the left atrial origin of the esophageal electrocardiogram has long been implied, recently that origin has been questioned. In the present study, the origin of the esophageal deflection is defined by direct right and left atrial mapping studies performed with simultaneous esophageal electrograms obtained from three positions (high, mid and low). Seven patients with normal left atrial dimensions (group I) and five patients with left atrial enlargement (group II) underwent transseptal catheterization during the course of electrophysiologic study. In group I (normal left atrial dimensions), conduction time from the high right atrium to each of the three esophageal positions corresponded to conduction times to left atrial sites ranging from 1 to 3 cm lateral to the left interatrial septum. The mid- and low esophageal conduction times were all significantly longer than conduction time to the left side of the septum (p less than 0.05). In group II (enlarged left atrium), conduction times to each of the esophageal sites corresponded to conduction times to left atrial sites lying between the mid-left atrium and a point 1 cm lateral to the left side of the septum. A significant trend toward longer conduction time to the mid-esophageal position than to the left septum was noted (p less than 0.1). In both groups, conduction times measured with the esophageal catheter were significantly longer than conduction time to the right interatrial septum (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of intravenous procainamide infusion in converting atrial fibrillation to sinus rhythm. Relation to left atrial size.

The efficacy of intravenous procainamide, infused at 30 mg/min to a maximum dose of 20 mg/kg, in converting atrial fibrillation was evaluated under electrocardiographic and blood pressure control in 21 patients. Nine patients had atherosclerotic heart disease, seven had valvular lesions, five had hypertension, and six had no apparent heart disease. Nine patients (converters), who reverted to sinus rhythm at a mean dose of procainamide of 13.3 +/- 3.6 mg/kg (mean plasma concentration, 7.4 +/- 3.9 micrograms/ml) had normal echocardiographic left atrial diameters. All but one of the remainder, the 12 non-converters, who received a mean drug dose of 13.1 +/- 3.5 mg/kg (mean plasma concentration 13.9 +/- 7.6 micrograms/ml), had atrial diameters exceeding 4.0 cm. QRS and QTc intervals were not altered significantly in converters, but were prolonged significantly in non-converters. No serious side effects from the infusion were encountered. Intravenous procainamide infusion appears to be a safe and rapidly effective method of converting recent-onset atrial fibrillation to sinus rhythm in patients with normal left atrial dimensions.

Echocardiographic diagnosis: Pitfalls in the premature infant with a large patent ductus arteriosus

Thirty-one infants with clinical and radiographic evidence of a large left-to-right shunt across a patent ductus arteriosus underwent echocardiographic study to determine the magnitude of shunting. Seven patients were found to have a normal-left atrial dimensions and a normal left atrial/aortic root dimension at the time when physical and roentgenographic findings of a large PDA were most pronounced. In contrast, left ventricular end diastolic dimensions were excessive in these infants. After ductal closure (four, surgery; two, indomethacin, one, spontaneous) the left ventricular end diastolic dimension fell to the normal range. Optimal echocardiographic accuracy in infants with PDA should combine analysis of both atrial and ventricular dimensions; the former, used alone, may be misleading.

ECHOCARDIOGRAPHIC PITFALLS IN THE PREMATURE WITH LARGE PATENT DUCTUS ARTERIOSUS

The ultrasound-derived ratio of left atrial to aortic root dimensions (LA/Ao) is used commonly to assess the presence and magnitude of left to right shunting through the PDA in prematures. The results of the present study emphasize the hazards of overreliance on this echo index. Thus, seven of thirty-one consecutive premature infants with severe respiratory distress syndrome and clinical and radiographic evidence of significant ductal left to right shunting were found to have normal LA/Ao ratios, as well as normal absolute left atrial dimensions. The LA/Ao ratios remained normal in these respirator-bound infants despite clinical signs of severe cardiac decompensation. In four of these infants the PDA was ligated surgically, while in two indomethacin was effective. The remaining infant responded to digitalis, diuretics, and fluid restriction, and ultimately closed her PDA spontaneously. Abolition of ductal left to right shunting did not consistently change the LA/Ao ratios or absolute left atrial dimensions in this group. A major finding in these infants was the detection of abnormally enlarged left ventricular end diastolic dimensions in the presence of normal left atrial dimensions. Thus, maximum diagnostic accuracy can be achieved only by a comprehensive echocardiographic evaluation that combines analysis of both atrial and ventricular dimensions since the former, when used alone, may be misleading.