Assessment of left ventricular wall thickness and dimension: accuracy of a deep learning model with prediction uncertainty.

Left ventricular (LV) geometric patterns aid clinicians in the diagnosis and prognostication of various cardiomyopathies. The aim of this study is to assess the accuracy and reproducibility of LV dimensions and wall thickness using deep learning (DL) models. A total of 30,080 unique studies were included; 24,013 studies were used to train a convolutional neural network model to automatically assess, at end-diastole, LV internal diameter (LVID), interventricular septal wall thickness (IVS), posterior wall thickness (PWT), and LV mass. The model was trained to select end-diastolic frames with the largest LVID and to identify four landmarks, marking the dimensions of LVID, IVS, and PWT using manually labeled landmarks as reference. The model was validated with 3,014 echocardiographic cines and the accuracy of the model was evaluated with a test set of 3,053 echocardiographic cines. The model accurately measured LVID, IVS, PWT, and LV mass compared to study report values with a mean relative error of 5.40%, 11.73%, 12.76%, and 13.93%, respectively. The 𝑅2 of the model for the LVID, IVS, PWT, and the LV mass was 0.88, 0.63, 0.50, and 0.87, respectively. The novel DL model developed in this study was accurate for LV dimension assessment without the need to select end-diastolic frames manually. DL automated measurements of IVS and PWT were less accurate with greater wall thickness. Validation studies in larger and more diverse populations are ongoing.

Automated Atrial Fibrillation Diagnosis by Echocardiography without ECG: Accuracy and Applications of a New Deep Learning Approach.

BACKGROUND: Automated rhythm detection on echocardiography through artificial intelligence (AI) has yet to be fully realized. We propose an AI model trained to identify atrial fibrillation (AF) using apical 4-chamber (AP4) cines without requiring electrocardiogram (ECG) data. METHODS: Transthoracic echocardiography studies of consecutive patients ≥ 18 years old at our tertiary care centre were retrospectively reviewed for AF and sinus rhythm. The study was first interpreted by level III-trained echocardiography cardiologists as the gold standard for rhythm diagnosis based on ECG rhythm strip and imaging assessment, which was also verified with a 12-lead ECG around the time of the study. AP4 cines with three cardiac cycles were then extracted from these studies with the rhythm strip and Doppler information removed and introduced to the deep learning model ResNet(2+1)D with an 80:10:10 training-validation-test split ratio. RESULTS: 634 patient studies (1205 cines) were included. After training, the AI model achieved high accuracy on validation for detection of both AF and sinus rhythm (mean F1-score = 0.92; AUROC = 0.95). Performance was consistent on the test dataset (mean F1-score = 0.94, AUROC = 0.98) when using the cardiologist's assessment of the ECG rhythm strip as the gold standard, who had access to the full study and external ECG data, while the AI model did not. CONCLUSIONS: AF detection by AI on echocardiography without ECG appears accurate when compared to an echocardiography cardiologist's assessment of the ECG rhythm strip as the gold standard. This has potential clinical implications in point-of-care ultrasound and stroke risk stratification.

Usefulness of the Atrial Emptying Fraction to Predict Maintenance of Sinus Rhythm After Direct Current Cardioversion for Atrial Fibrillation.

Atrial volumes indexed to body surface area (AVI) are robust predictors of nonvalvular atrial fibrillation (AF) recurrence after direct current cardioversion (DCCV). The incremental value of atrial emptying fraction (EmF) compared with atrial volumes as a predictor for recurrent AF after DCCV has not been evaluated. We sought to compare the predictive ability of baseline left atrial (LA) EmF, right atrial (RA) EmF, LAVI, and RAVI for post-DCCV AF recurrence at 6 months. The first 95 patients enrolled in the AF Clinic Registry with adequate echocardiogram imaging constituted the study cohort. Each patient underwent echocardiogram within 6 months before cardioversion. Maximal LAVI and RAVI, LA EmF, and RA EmF were performed offline using 4-chamber single-plane Simpson's method, averaged over 5 cycles. The mean age of the study cohort was 64 ± 12 years, and 67% were men. Only 28 patients (29%) who underwent DCCV remained in sinus rhythm at 6 months of follow-up. The remaining, 67 (71%) had reverted to AF or underwent ablation during the 6 months of follow-up. The overall performance for prediction of AF recurrence was greatest for RA EmF, area under the receiver operator characteristic curve (AUC): RA EmF 0.92, LA EmF 0.89, RAVI 0.76, and LAVI 0.63. RA and LA EmF AUCs were significantly higher than for LAVI or RAVI (max p = 0.02). In conclusion, although RAVI and LAVI are strong predictors of AF recurrence after DCCV, RA and LA EmF outperformed in this cohort.

Right atrial volume is superior to left atrial volume for prediction of atrial fibrillation recurrence after direct current cardioversion.

BACKGROUND: The value of right atrial volume as a predictor for recurrence of atrial fibrillation (AF) after direct current cardioversion (DCCV) is unknown. METHODS: We sought to compare the performance of right atrial volume indexed to body surface area (RAVI), left atrial diameter, left atrial volume indexed to body surface area (LAVI), and biatrial volume index (BAVI) for the prediction of AF recurrence at 6 months after DCCV. This study included the first 95 consecutive patients from the AF Clinic at a large tertiary care hospital who underwent DCCV and who had an echocardiogram available within 6 months before DCCV. Maximal LAVI, RAVI, and BAVI were determined from the echocardiogram before DCCV. Electrocardiographic and clinical data were acquired at baseline, before cardioversion, and at each clinic visit. RESULTS: Of the 95 patients (64 male; mean age, 63 ± 12 years), history of systemic hypertension, diabetes mellitus, heart failure, and transient ischemic attack/stroke was present in 60 (63%), 14 (15%), 27 (28%), and 5 (5%) patients, respectively. Mean duration from AF diagnosis to DCCV was 3.5 ± 5.0 years. At 6 months after DCCV, 53 (56%) had reverted to AF. RAVI had superior predictive ability (area under the receiver operator characteristic curve: RAVI, 0.77; left atrial diameter, 0.54; LAVI, 0.64; and BAVI, 0.70). RAVI ≥ 42 mL/m(2) provided the best accuracy for prediction of recurrence (76% accuracy, 71% sensitivity, 83% specificity, 90% positive predictive value, and 56% negative predictive value). Best accuracy for LAVI was ≥ 48 mL/m(2) (70% accuracy, 53% sensitivity, 79% specificity, 85% positive predictive value; 43% negative predictive value). CONCLUSIONS: RAVI is superior to LAVI for the prediction of AF recurrence at 6 months after DCCV.

Best method for right atrial volume assessment by two-dimensional echocardiography: validation with magnetic resonance imaging.

AIM: Echocardiographic methods for estimating right atrial (RA) volume have not been standardized. Our aim was to evaluate two-dimensional (2D) echocardiographic methods of RA volume assessment, using RA volume by magnetic resonance imaging (MRI) as the reference. METHODS AND RESULTS: Right atrial volume was assessed in 51 patients (mean age 63 ± 14 years, 33 female) who underwent comprehensive 2D echocardiography and cardiac MRI for clinically indicated reasons. Echocardiographic RA volume methods included (1) biplane area length, using four-chamber view twice (biplane 4C-4C); (2) biplane area length, using four-chamber and subcostal views (biplane 4C-subcostal); and (3) single plane Simpson's method of disks (Simpson's). Echocardiographic RA volumes as well as linear RA major and minor dimensions were compared to RA volume by MRI using correlation and Bland-Altman methods, and evaluated for inter-observer reproducibility and accuracy in discriminating RA enlargement. All echocardiography volumetric methods performed well compared to MRI, with Pearson's correlation of 0.98 and concordance correlation ≥0.91 for each. For bias and limits of agreement, biplane 4C-4C (bias -4.81 mL/m(2) , limits of agreement ±9.8 mL/m(2) ) and Simpson's (bias -5.15 mL/m(2) , limits of agreement ±10.1 mL/m(2) ) outperformed biplane 4C-subcostal (bias -8.36 mL/m(2) , limits of agreement ±12.5 mL/m(2) ). Accuracy for discriminating RA enlargement was higher for all volumetric methods than for linear measurements. Inter-observer variability was satisfactory across all methods. CONCLUSIONS: Compared to MRI, biplane 4C-4C and single plane Simpson's are highly accurate and reproducible 2D echocardiography methods for estimating RA volume. Linear dimensions are inaccurate and should be abandoned.

Atrial fibrillation and heart failure: cause or effect?

Atrial fibrillation (AF) and heart failure (HF) are two epidemics of the century that have a close and complex relationship. The mechanisms underlying this association remain an area of ongoing intense research. In this review, we will describe the relationship between these two public health concerns, the mechanisms that fuel the development and perpetuation of both, and the evolving concepts that may revolutionize our approach to this dual epidemic.

Atrial remodeling in newly diagnosed drug-naive hypertensive subjects.

BACKGROUND: Systemic hypertension is a major risk factor for heart disease and stroke. Data regarding temporal relationship of left atrial (LA) remodeling to onset of hypertension are sparse. We aimed to quantitate LA structural and functional remodeling in newly diagnosed hypertensive patients. METHOD: We prospectively identified 380 patients with newly diagnosed systemic hypertension naive to drug therapy, and 380 age-matched control subjects without any history or evidence of hypertension. History or evidence of prior cardiovascular events, congenital or valvular heart disease, and renal dysfunction were exclusion criteria. Prevalence of LA enlargement, LA mechanical dysfunction expressed in total emptying fraction, left ventricular (LV) diastolic dysfunction, LV hypertrophy, and their interrelationships were assessed. RESULTS: Of the 380 newly diagnosed hypertensive patients, 285 (75%) had LA enlargement, 308 (81%) had LA mechanical dysfunction, and 19 (5%) had LVH. Diastolic dysfunction was present in 334 (88%) of the patients. Compared to the controls, the hypertensive group had larger maximal, minimal, and pre-A LA volumes (all P < 0.001). Total and active LA emptying fraction were significantly reduced (both P < 0.001). Total LA emptying fraction was strongly associated with systolic blood pressure [per 10 mmHg, HR 0.94 (0.89-0.98); P < 0.001], with stepwise decrease in LA emptying fraction of 6%, 10%, and 16% from the lowest (141-150 mmHg) to the top tertile of systolic blood pressure (>160 mmHg). CONCLUSION: In this drug-naive cohort with newly diagnosed hypertension, LA structural and functional remodeling, and LV diastolic dysfunction were common findings prior to initiation of drug treatment. LVH was uncommon. Impairment of LA mechanical function was evident even in the mildly hypertensive subgroup.

Left atrial volume: clinical value revisited.

Left atrial (LA) volume and function are robust markers of cardiovascular risks and adverse cardiac outcomes. With advances in imaging technology, including tissue Doppler, strain, and strain rate imaging, we can now determine LA volume and function more precisely and this is anticipated to augment our ability to risk stratify, incremental to clinical risk profiling. There is increasing evidence that LA remodeling is treatable and is reversible. Serial LA volume and function assessment may provide a simple and quantifiable way of determining severity of risk and treatment impact. While reverse LA remodeling is expected to improve cardiac outcomes, data to confirm this remain forthcoming.

Left atrial function: physiology, assessment, and clinical implications.

The interest in the left atrium (LA) has resurged over the recent years. In the early 1980s, multiple studies were conducted to determine the normal values of LA size. Over the past decade, LA size as an imaging biomarker has been consistently shown to be a powerful predictor of outcomes, including major public health problems such as atrial fibrillation, heart failure, stroke, and death. More recently, functional assessment of the LA has been shown to be, at least as, if not more robust, a marker of cardiovascular outcomes. Current available data suggest that the combined evaluation of LA size and LA function will augment prognostication. The aim of this review is to provide a critical appraisal of current echocardiographic techniques for the assessment of LA function and the implications of such assessment for prediction and disease prevention.

Is the standard weight-based dosing of dobutamine for stress testing appropriate for patients of widely varying body mass index?

BACKGROUND: Although a gradual increase in heart rate (HR) during dobutamine stress testing (DST) is desired, few data exists regarding whether this is similarly achieved in patients of widely varying body mass index (BMI). Whether difference in BMI contributes to variation in the hemodynamic and symptomatic response to dobutamine is also unknown. METHODS: From prospectively acquired data of 2776 consecutive patients who underwent DST according to standard weight-based clinical protocol, we classified patients into 4 groups of BMI (kg/m( 2)): <25 (normal), 25 to 29.9 (overweight), 30 to 39.9 (obese), and ≥ 40 (severely obese) and compared the rate of increase of HR, mean blood pressure, and development of symptoms for the groups. RESULTS: Age was 68 + 12 years, 52% were men, BMI was 29.8 + 6.6 kg/m(2) (range 14.5-81.4), 198 (7%) had BMI ≥ 40, and target HR was achieved in 2433 (88%). The rate of increase in HR was similar for each group of BMI after adjustment for age, gender, baseline HR, negative chronotropic use, and atropine administration. The percentage of patients in each group who achieved target HR was similar and the percentage of target HR achieved at each stage of dobutamine was essentially equivalent. Blood pressure responses and development of symptoms were similar in the 4 groups of BMI. Independent predictors of failure to achieve target HR included age, diabetes mellitus, treatment with negative chronotropic medications, and baseline HR; BMI was not a predictor (odds ratio [OR] 0.98, P = .086). CONCLUSION: The current weight-based protocol of dobutamine dosing for DST results in similar increases in HR and blood pressure for patients of widely varying BMI.

C-reactive protein, left atrial volume, and atrial fibrillation: a prospective study in high-risk elderly.

BACKGROUND: The data regarding the interrelationships of high-sensitive C-reactive protein (CRP), left atrial (LA) volume, and atrial fibrillation (AF) are sparse. Additionally, while LA volume has been shown to be useful for prediction of AF in low-to-moderate risk populations, its predictive value in clinically high-risk populations is unknown. METHODS: SAFHIRE (Study of Atrial Fibrillation in High Risk Elderly) is an ongoing prospective study of the pathophysiology of first AF in persons aged > or = 65 years with > or = 2 other AF risk factors [systemic hypertension, proven coronary artery disease, heart failure (HF), diabetes]. Participants are followed annually, and undergo an interview, physical examination, blood work, electrocardiogram, and echocardiogram assessment. RESULTS: Of 800 participants, mean age of 74 +/- 6 years, 34 developed first AF over 1.7+/- 0.9 years. A history of systemic hypertension and proven coronary artery disease was present in 97% and 78%, respectively. CRP was unrelated to LA volume on univariable or multivariable analyses (P > 0.10), and not predictive of first AF on univariable or multivariable models (all P > 0.10). Indexed LA volume was an independent predictor of first AF (unadjusted P< 0.0001; age and sex adjusted P = 0.0006; adjusted for multiple factors, HR 1.3/5 ml per m(2), 95% CI, 1.09 to 1.48, P = 0.001). CONCLUSION: In this elderly population at high clinical risk for the development of first AF, CRP was unrelated to LA volume and nonpredictive of first AF, while indexed LA volume was incremental to clinical risk factors for the prediction of first AF.

Integrating research into clinical practice: development of an echocardiography research unit.

Introducing a research program into an echocardiography clinical practice can pose many challenges. Some initial factors to consider are the possible effects on the current clinical schedule and the equipment and personnel resources required to support the research projects. More importantly, how can an organization successfully complete reliable and accurate research projects? Here, we describe our experience with establishing an echocardiography research center within our clinical echocardiography practice. In addition, we identify key staff roles, highlight our current research practice methods, and suggest essential components that may prove advantageous when incorporating echocardiography research into a clinical practice.

Acute weight gain and diastolic dysfunction as a potent risk complex for post stem cell transplant atrial fibrillation.

The management of atrial fibrillation (AF) following stem cell transplant (SCTX) is often challenging because of the universal presence of profound bone marrow suppression. The incidence of and risk factors for AF/flutter following SCTX are not well known. A total of 395 multiple myeloma (MM) patients consecutively underwent SCTX between 2002 and 2005 at the Mayo Clinic, and 383 of whom, mean age 57 +/- 9 years, had no history of evidence of AF/flutter constituted the study population. During 1,002 person-years of follow up, 39 (10%) patients developed first AF/flutter (incidence of 39 per 1,000 person years), and 28 of these (72%) occurred within 21 days of SCTX. In multivariable-adjusted analyses, weight gain of > or = 7% in the 1st week post-SCTX (HR 3.68; P = 0.0120) and presence of diastolic dysfunction at MM diagnosis (HR 2.294; P = 0.0082) were independent predictors of AF/flutter. The risk of AF/flutter post-SCTX increased by about ninefold when both factors were present. Compared to age and sex-matched MM patients without SCTX, the risk of AF/flutter differed significantly only over the 1st year after MM diagnosis, during which SCTX was performed for the majority. Beyond the 1st year, there was no significant difference in risk of AF/flutter between the two groups. The data suggested that SCTX was associated with significantly increased risk of first AF/flutter, which typically occurred within the first 21 days of the transplant. Weight gain of > or = 7% was strongly predictive of first AF/flutter, and the risk was augmented by the presence of diastolic dysfunction at baseline.

Minimum vs. maximum left atrial volume for prediction of first atrial fibrillation or flutter in an elderly cohort: a prospective study.

AIMS: We sought to compare the predictive power and reproducibility between minimum and maximum left atrial (LA) volume for the development of first atrial fibrillation (AF)/flutter. METHODS AND RESULTS: This prospective study included 574 adults, mean age 74+/-6 years, in sinus rhythm, and had no history or evidence of prior atrial arrhythmias. During a mean follow-up of 1.9+/-1.2 years, 30 (5.2%) developed first AF/flutter. The 3-year risk estimates of freedom from AF/flutter by tertiles of minimum and maximum LA volumes were, respectively, 97, 87, and 74% (P<0.0006) and 94, 85, and 78% (P=0.03). Minimum LA volume was incremental to clinical and other echocardiographic parameters of AF/flutter prediction [per tertile, hazard ratio (HR) 2.4], as was maximum LA volume (per tertile, HR 1.8) in a separate model. When both volumes were entered into the same model and adjusting for covariates, minimum but not maximum LA volume retained significance. However, in terms of interobserver reproducibility, maximum LA volume compared more favourably (mean difference 3.1+/-7.1 vs. 7.4+/-7.3 mL/m(2)). CONCLUSION: Minimal LA volume was an independent predictor of first AF/flutter. Although it was marginally superior to maximal LA volume in terms of predictive ability, the interobserver variability was greater.

Regional diastolic contour abnormalities during contrast stress echocardiography: improved detection of coronary artery disease.

BACKGROUND: Use of contrast improves detection of systolic regional wall motion abnormalities (RWMAs) during stress echocardiography. We evaluated regional diastolic contour abnormalities (RDCAs) that were associated with coronary artery disease (CAD). METHODS: From August of 2003 to September of 2004, we evaluated 89 patients who underwent contrast stress echocardiography (CSE) and coronary angiography within a 3-month period ("invasive" group) and 17 patients with lower CAD risk who underwent CSE only ("reference" group). RESULTS: RDCAs were present in 73 patients in the invasive group and were associated with higher Framingham risk scores (relative risk, 3.6; 95% confidence interval, 1.9-6.6). RDCAs were present in 1 patient in the reference group. When combined with RWMA, RDCA improved sensitivity of CSE from 78% to 97% and specificity from 26% to 59% (diagnostic threshold for CAD was 70% stenosis). CONCLUSION: RDCAs were a novel observation associated with higher CAD risk and improved the diagnostic accuracy of CSE.

Changing trends of hospital utilization in patients after their first episode of atrial fibrillation.

A marked increase in hospitalization for patients with atrial fibrillation (AF) has previously been noted. Whether this increase is related to a change in the prevalence of AF or a change in the pattern of practice with respect to the management of AF remains unclear. To determine the trends in hospital utilization after first AF in a community-based setting (Olmsted County, Minnesota), residents diagnosed with first AF from 1980 to 2000 were identified and followed until 2004. The primary outcome of interest was hospital admission for cardiovascular reasons. Of a total of 4,498 subjects (73 +/- 14 years old, 51% men), 2,503 (56%) were admitted to the hospital for cardiovascular causes >or=1 time during a mean follow-up of 5.5 +/- 5.0 years. Risk of first hospitalization was greatest during the first year of AF (cumulative incidence 31%, 95% confidence interval [CI] 30 to 32). First hospitalization was strongly related to age (p <0.0001) but not to sex (p = 0.38). From 1980 to 2000, the age-and sex-adjusted rate of first hospitalization increased, on average, by 2.5% a year (95% CI 1.8 to 3.2, p <0.0001), even after multivariable adjustment for co-morbidities. When we excluded all hospital admissions for the purposes of AF management, the increase in hospitalization was only 0.8% per year (95% CI 0.05 to 1.6, p = 0.04), which was no longer significant after multivariable adjustment for co-morbidities (p = 0.25). In conclusion, the marked increase in hospitalization after first AF diagnosis from 1980 to 2000 appeared to be largely driven by the changing practice pattern in AF management.

Obesity as a risk factor for the progression of paroxysmal to permanent atrial fibrillation: a longitudinal cohort study of 21 years.

AIMS: Obesity has been shown to be a risk factor for first atrial fibrillation (AF), but whether it is associated with progression from paroxysmal to permanent AF is unknown. METHODS AND RESULTS: In this longitudinal cohort study, Olmsted County, MN residents confirmed to have developed paroxysmal AF during 1980-2000 were identified and followed passively to 2006. The interrelationships of body mass index (BMI), left atrial (LA) size, and progression to permanent AF were analysed. Of a total of 3248 patients (mean age 71 +/- 15 years; 54% men) diagnosed with paroxysmal AF, 557 (17%) progressed to permanent AF (unadjusted incidence, 36/1000 person-years) over a median follow-up period of 5.1 years (interquartile range 1.2-9.4). Adjusting for age and sex, BMI independently predicted the progression to permanent AF (hazard ratio, HR 1.04, CI 1.03-1.06; P < 0.0001). Compared with normal BMI (18.5-24.9 kg/m(2)), obesity (30-34.9 kg/m(2)) and severe obesity (>or=35 kg/m(2)) were associated with increased risk for progression [HR 1.54 (CI 1.2-2.0; P = 0.0004) and 1.87 (CI 1.4-2.5; P < 0.0001, respectively)]. BMI remained highly significant even after multiple adjustments. In the subgroup with echocardiographic assessment (n = 744), LA volume was incremental to BMI for independent prediction of progression after multiple adjustments, and did not weaken the association between BMI and progression to permanent AF (HR 1.04; CI 1.02-1.05; P < 0.0001). CONCLUSION: There was a graded risk relationship between BMI and progression from paroxysmal to permanent AF. This relationship was not weakened by LA volume, which was independent of and incremental to BMI for the prediction of progression to permanent AF.

Echocardiographic assessment of left ventricular diastolic function and filling pressure in atrial fibrillation.

Diastolic dysfunction has been linked to 2 epidemics: atrial fibrillation (AF) and heart failure. The presence and severity of diastolic dysfunction are associated with an increased risk for first AF and first heart failure in patients with sinus rhythm. Furthermore, the risk for heart failure is markedly increased once AF develops. The evaluation of diastolic function once AF has developed remains a clinical challenge. The conventional use of Doppler echocardiography for the assessment and grading of diastolic dysfunction relies heavily on evaluating the relation of ventricular and atrial flow characteristics. The mechanical impairment of the left atrium and the variable cycle lengths in AF render the evaluation of diastolic function difficult. A few Doppler echocardiographic methods have been proved clinically useful for the estimation of diastolic left ventricular filling pressures in AF, but these appear to be underutilized. Several innovative methods are emerging that promise to provide greater precision in diastolic function assessment, but their clinical utility in AF remains to be established. In conclusion, this review provides an up-to-date discussion of the evaluation of diastolic function assessment in AF and how it may be important in the clinical management of patients with AF.

Left atrial reservoir function as a potent marker for first atrial fibrillation or flutter in persons > or = 65 years of age.

The aim of this prospective study was to evaluate the incremental value of left atrial (LA) function for the prediction of risk for first atrial fibrillation (AF) or atrial flutter. Maximum and minimum LA volumes were quantitated by echocardiography in 574 adults (mean age 74 +/- 6 years, 52% men) without a history or evidence of atrial arrhythmia. During a mean follow-up period of 1.9 +/- 1.2 years, 30 subjects (5.2%) developed electrocardiographically confirmed AF or atrial flutter. Subjects with new AF or atrial flutter had lower LA reservoir function, as measured by total LA emptying fraction (38% vs 49%, p <0.0001) and higher maximum LA volumes (47 vs 40 ml/m(2), p = 0.005). An increase in age-adjusted risk for AF or atrial flutter was evident when the cohort was stratified according to medians of LA emptying fraction (< or =49%: hazard ratio 6.5, p = 0.001) and LA volume (> or =38 ml/m(2): hazard ratio 2.0, p = 0.07), with the risk being highest for subjects with concomitant LA emptying fractions < or =49% and LA volume > or =38 ml/m(2) (hazard ratio 9.3, p = 0.003). LA emptying fraction (p = 0.002) was associated with risk for first AF or atrial flutter after adjusting for baseline clinical risk factors for AF or atrial flutter, left ventricular ejection fraction, diastolic function grade, and LA volume. In conclusion, reduced LA reservoir function markedly increases the propensity for first AF or atrial flutter, independent of LA volume, left ventricular function, and clinical risk factors.

Risk of dementia in stroke-free patients diagnosed with atrial fibrillation: data from a community-based cohort.

AIMS: To estimate the incidence of dementia after the first atrial fibrillation (AF), and its impact on survival in a community-based cohort. METHODS AND RESULTS: Olmsted County, Minnesota adult residents diagnosed with first AF during 1986-2000 were identified, and followed until 2004. The primary outcome was new detection of dementia. Interim stroke was censored in the analyses. Of 2837 subjects (71 +/- 15 years old) diagnosed with first AF and without any evidence of cognitive dysfunction or stroke at the time of AF onset, 299 were diagnosed with dementia during a median follow-up of 4.6 years [interquartile (IQR) range 1.5-7.9 years], and 1638 died. The Kaplan-Meier cumulative rate of dementia was 2.7% at 1 year and 10.5% at 5 years. After adjustment for age and sex, dementia was strongly related to advancing age [hazard ratio (HR)/10 years, 2.8; 95% confidence interval (CI), 2.5-3.2], but did not vary with sex (P = 0.52). The occurrence of post-AF dementia was associated with significantly increased mortality risk (HR 2.9; 95% CI 2.5-3.3), even after adjustment for multiple comorbidities, and did not vary with age (P = 0.75) or sex (P = 0.33). CONCLUSION: Dementia appeared common following the diagnosis of first AF, and was associated with premature death.