Comparison of echocardiography and radionuclide angiography as predictors of mortality in patients with left ventricular dysfunction (studies of left ventricular dysfunction).

Left ventricular (LV) systolic dysfunction, as indicated by a reduced LV ejection fraction (EF) is a potent predictor of cardiovascular mortality. Radionuclide angiography accurately and reproducibly assesses LVEF; however, echocardiography is used more frequently in clinical practice. Whether these methods predict similar mortality has not been fully investigated. We performed a retrospective analysis of patients with baseline radionuclide angiographic (RNA; n = 4,330) and echocardiographic (echo; n = 1,376) based EFs < or =0.35 who were enrolled in the Studies Of Left Ventricular Dysfunction (SOLVD) to address this hypothesis. After adjusting for important prognostic variables, the risk of death (RR 1.15; 95% confidence interval 1.01 to 1.30; p = 0.03) and of cardiovascular death (RR 1.15; 95% confidence interval 1.01 to 1.32; p = 0.04) was higher for patients with ECG-based EFs. To compare the 2 techniques across a range of EF values, we divided the cohort into tertiles of EF. The adjusted risk estimates for all-cause and cardiovascular mortality were similar within each tertile. Of note, the mortality difference in patients with echo- versus RNA-based EFs was most prominent in women. Further, patients with echo-based EFs had significantly higher mortality at sites where this technique was less frequently used to assess the EF. Thus, for a given EF < or =0.35, an echo-based value was associated with a higher risk of death compared with the RNA-based method of measurement. These data suggest that EF values determined by echocardiography and radionuclide angiography predict different mortality and this may, in part, be related to technical proficiency as well as patient characteristics.     

Role of left atrial size in risk stratification and prognosis of patients undergoing stress echocardiography.

OBJECTIVES: The purpose of this study was to evaluate the role of diastolic dysfunction as measured by left atrial (LA) size in patients undergoing stress echocardiography (SE). BACKGROUND: Left atrial size is a surrogate marker of diastolic function. However, its prognostic value in patients referred for SE is not well defined. METHODS: We evaluated 2,705 patients (60 +/- 13 years, 47% men) undergoing SE (56% dobutamine). Patients with significant mitral valve disease (mitral stenosis or > or = moderate mitral regurgitation) were excluded. Enlarged LA was defined as a LA size indexed to body surface area > or =2.4 cm/m2. Follow-up (mean 2.7 +/- 1.0 years) for nonfatal myocardial infarction or cardiac death (n = 122) was obtained. RESULTS: A dilated LA was able to further risk-stratify both the normal and abnormal SE groups. In the presence of a dilated LA, an abnormal SE portends a worse prognosis compared with patients with normal LA size. Cox proportional modeling showed that a dilated LA added incremental value over traditional risk factors, stress electrocardiographic, rest echocardiographic, and SE variables for the prediction of hard events (global chi-square increased from 90.4 to 113.1 to 176.1 to 184.4 to 190.5; p < 0.05 all groups). Left atrial size was a significant predictor of events independent of left ventricular systolic dysfunction and ischemia (relative risk = 1.84, 95% confidence interval 1.19 to 2.85; p = 0.006). CONCLUSIONS: In patients referred for stress echocardiography, LA size provides independent and incremental value over standard risk factors including left ventricular systolic dysfunction and ischemia. Left atrial size is a powerful prognosticator and should be routinely used in the prognostic interpretation of stress echocardiography.     

Left ventricular architecture and survival in African-Americans free of coronary heart disease (from the Atherosclerosis Risk in Communities [ARIC] study)

Published studies of the prognostic value of left ventricular (LV) hypertrophy and LV geometric pattern in African-Americans were based on referred or hospitalized patients with hypertension or coronary heart disease. All-cause mortality rates and survival associated with LV geometric pattern were determined using echocardiography in a population-based sample of middle-aged and elderly African-American men and women. During the third (1993 to 1995) visit of the ARIC Study, echocardiography was performed at the Jackson, Mississippi, field center on the cohort of 2,445 African-Americans aged 49 to 75 years. M-Mode LV echocardiographic measurements were available for 1,722 persons. Mortality data were available through December 31, 2003. During the follow-up period (median 8.8 years, maximum 10.4), 160 deaths were identified. In men, multivariable-adjusted hazard ratios for all-cause mortality (compared with men with normal LV geometry) were 1.75 (95% confidence interval [CI] 0.71 to 4.33) in those with concentric LV hypertrophy, 0.38 (95% CI 0.08 to 1.88) in those with eccentric LV hypertrophy, and 0.79 (95% CI 0.41 to 1.54) in those with concentric remodeling. In women, multivariable-adjusted hazard ratios for all-cause mortality (compared with women with normal LV geometry) were 1.17 (95% CI 0.48 to 2.84) in those with concentric LV hypertrophy, 1.23 (95% CI 0.46 to 3.28) in those with eccentric LV hypertrophy, and 1.17 (95% CI 0.60 to 2.28) in those with concentric remodeling. In conclusion, in this population-based cohort of middle-aged and elderly African-Americans free of coronary heart disease, adjustment for baseline differences in cardiovascular disease risk factors and LV mass greatly attenuated the strength of the association between LV pattern and all-cause mortality risk in women. In men, an association between concentric LV hypertrophy and mortality risk remained.     

Echocardiographic Abnormalities in the Assessment of Cardiac Organ Damage in Never-Treated Hypertensive Patients

Hypertension-related cardiac organ damage, other than left ventricular (LV) hypertrophy (LVH), has been described: in particular, concentric remodeling, LV diastolic dysfunction (DD), and left atrial (LA) enlargement are significantly associated with cardiovascular morbility and mortality in different populations. This study evaluated the prevalence of these latter morphofunctional abnormalities, in never-treated essential hypertensive patients and the role of such a serial assessment of hypertensive cardiac damage in improving cardiovascular risk stratification in these patients. A total of 100 never-treated essential hypertensive subjects underwent a complete clinical and echocardiographic evaluation. Left ventricular morphology, systolic and diastolic function, and LA dimension (linear and volume) were evaluated by echocardiography. Left ventricular hypertrophy was present in 14% of the patients, whereas concentric remodeling was present in 25% of the subjects. Among patients free from LV morphology abnormalities, the most frequent abnormality was LA enlargement (global prevalence 57%); the percentage of patients with at least one parameter consistent with DD was 22% in the entire population, but DD was present as the only cardiac abnormality in 1% of our patient. Left atrial volume indexed for body surface area was the most sensitive parameter in identifying hypertension-related cardiac modification. The global prevalence of cardiac alteration reached 73% in never-treated hypertensive patients. Left ventricular remodeling and LA enlargement evaluation may grant a better assessment of cardiac organ damage and cardiovascular risk stratification of hypertensive patients without evidence of LVH after routine examination.     

Clinical implications of enlargement of left atrium

Enlargement of left atrium (LA) has been shown to be a barometer of diastolic burden and a predictor of common cardiovascular outcomes such as atrial fibrillation, stroke, congestive heart failure, and cardiovascular death. Different methods exist for the assessment of LA size. The American Society of Echocardiography recommended LA volume and its indexed value assessed by 2-dimensional echocardiography, to measure LA size. Current findings suggest that echocardiographically determined LA size may become an important clinical risk identifier in preclinical cardiovascular disease and should be assessed as a part of routine echocardiographic evaluation.     

Comparison of heart rate reserve versus 85% of age-predicted maximum heart rate as a measure of chronotropic response in patients undergoing dobutamine stress echocardiography

The role of heart rate (HR) reserve (HRR) in the risk stratification of patients who undergo dobutamine stress echocardiography is not well defined. This study evaluated 1,323 patients (mean age 63 +/- 13 years, 47% men) who underwent dobutamine stress echocardiography. Abnormal stress echocardiographic results were defined as those with stress-induced ischemia. HRR was defined as [(peak HR - HR at rest)/(220 - age - HR at rest)] x 100, with HRR <70% defined as low. Follow-up data (2.7 +/- 1.1 years) for confirmed myocardial infarction (n = 16) and cardiac death (n = 58) were obtained. HRR risk stratified patients into normal and abnormal subgroups (event rate 1.1%/year vs 4.2%/year, p <0.0001) and further risk stratified patients into normal (adjusted HR 1 [reference] vs 2.88, p = 0.04) and abnormal (adjusted HR 4.17 vs 10.09, p <0.0001) stress echocardiography groups. Low HRR (relative risk [RR] 2.15, 95% confidence interval [CI] 1.23 to 4.01, p = 0.013) was an independent predictor of cardiac event even after controlling for standard cardiovascular risk factors, other stress electrocardiographic variables, and stress echocardiographic variables. Low HRR (chi-square 32) was superior to 85% maximum predicted HR (MPHR; chi-square 18) and provided incremental value over stress echocardiography and 85% MPHR (global chi-square increased from 48.3 to 54 to 61.3, p <0.0001) in a model consisting of stress echocardiography, MPHR, and HRR. In conclusion, HRR can further risk stratify patients who undergo dobutamine stress echocardiography and provides independent and incremental prognostic value over standard cardiovascular risk factors and also independent of echocardiographic myocardial ischemia and left ventricular dysfunction and is superior to 85% MPHR. In the setting of low HRR, normal stress echocardiographic results are prognostically less benign, whereas abnormal stress echocardiographic results are prognostically more malignant.     

Left atrial size: physiologic determinants and clinical applications.

Left atrial (LA) enlargement has been proposed as a barometer of diastolic burden and a predictor of common cardiovascular outcomes such as atrial fibrillation, stroke, congestive heart failure, and cardiovascular death. It has been shown that advancing age alone does not independently contribute to LA enlargement, and the impact of gender on LA volume can largely be accounted for by the differences in body surface area between men and women. Therefore, enlargement of the left atrium reflects remodeling associated with pathophysiologic processes. In this review, we discuss the normal size and phasic function of the left atrium. Further, we outline the clinically important aspects and pitfalls of evaluating LA size, and the methods for assessing LA function using echocardiography. Finally, we review the determinants of LA size and remodeling, and we describe the evidence regarding the prognostic value of LA size. The use of LA volume for risk stratification is an evolving science. More data are required with respect to the natural history of LA remodeling in disease, the degree of LA modifiability with therapy, and whether regression of LA size translates into improved cardiovascular outcomes.     

Left atrial size: physiologic determinants and clinical applications

Left atrial (LA) enlargement has been proposed as a barometer of diastolic burden and a predictor of common cardiovascular outcomes such as atrial fibrillation, stroke, congestive heart failure, and cardiovascular death. It has been shown that advancing age alone does not independently contribute to LA enlargement, and the impact of gender on LA volume can largely be accounted for by the differences in body surface area between men and women. Therefore, enlargement of the left atrium reflects remodeling associated with pathophysiologic processes. In this review, we discuss the normal size and phasic function of the left atrium. Further, we outline the clinically important aspects and pitfalls of evaluating LA size, and the methods for assessing LA function using echocardiography. Finally, we review the determinants of LA size and remodeling, and we describe the evidence regarding the prognostic value of LA size. The use of LA volume for risk stratification is an evolving science. More data are required with respect to the natural history of LA remodeling in disease, the degree of LA modifiability with therapy, and whether regression of LA size translates into improved cardiovascular outcomes.     

Risk of ventricular arrhythmias in hypertensive men with left ventricular hypertrophy

The echocardiographic predictors of ventricular arrhythmias are reported for the Hypertension Arrhythmia Reduction Trial. Men with mild hypertension were withdrawn from their diuretic therapy and repleted with 40 mEq/day of oral potassium and 20 mEq/day of oral magnesium for 1 month. M-mode echocardiography and 24-hour continuous ambulatory electrocardiography were performed on 123 men, mean age 62 years. Forty-eight men (39%) had echocardiographic evidence of left ventricular (LV) hypertrophy defined as an LV mass index greater than 134 g/m2 and this finding was not related to the presence of LV hypertrophy on electrocardiogram or to age. Men who had echocardiographic LV hypertrophy were more likely than men without echocardiographic LV hypertrophy to have greater than or equal to 30 ventricular premature complexes (VPCs)/hr (odds ratio = 2.7; 95% confidence interval = 0.9, 8.0), multiform extrasystoles (odds ratio = 1.7; confidence interval = 0.8, 3.7), episodes of ventricular tachycardia (odds ratio = 2.3; confidence interval = 0.7, 7.1) and the combination of frequent (greater than or equal to 30 VPCs/hr) or complex (ventricular couplets, multiform extrasystoles or episodes of ventricular tachycardia) ventricular arrhythmia (odds ratio = 1.7; confidence interval = 0.8, 3.5). Similar associations between echocardiographic LV hypertrophy and ventricular arrhythmias were observed on 24-hour tracings obtained on entry to the study (before electrolyte repletion) in the 96 men who were taking diuretics at this time. The combination of a frequent or complex arrhythmia was also more common in men aged 60 to 70 compared to men aged 35 to 59 (odds ratio = 3.4; confidence interval = 1.4, 8.2).(ABSTRACT TRUNCATED AT 250 WORDS)     

Prevalence and correlates of echocardiographic left atrial enlargement in hypertensive outpatients in clinical practice

Prevalence of left atrial enlargement (LAE) in hypertension has been mostly assessed in population-based samples and selected hypertensive groups. A few data are available in clinical practice. We examined LAE prevalence and severity in a cohort of hypertensive patients referred by general practitioners to a routine echocardiographic examination. A total of 2170 hypertensive individuals (mean age 62 years, 53% men) referred by practitioners to 17 outpatient echocardiographic laboratories across Italy for detection of hypertensive cardiac disease were included in the study. LAE was defined as: A) absolute LA diameter >4.0 cm in men and >3.8 cm in women; B) LA diameter normalized to body surface area (BSA) >2.3 cm/m(2) in both sexes. Left atrial enlargement was graded as mild, moderate, and severe according to Lang's report. Patients with LAE were 38% by criterion A, and 20% by criterion B. A moderate/severe increase in LA size was present in 34% (A) and 32% (B) of patients with LAE. Severe LAE was 3.3-fold (A) and 2.6-fold (B) more frequent in women than in men. Left ventricular mass was the strongest correlate of absolute LA diameter as well as of normalized LA diameter, after age. Left atrial enlargement defined either by absolute or normalized LA diameter is a frequent cardiac phenotype in hypertensive patients referred to echo-labs in clinical practice. This cardiac parameter is closely related to LV mass and its severity is highly prevalent in women.     

Usefulness of stress echocardiography for risk stratification and prognosis of patients with left ventricular hypertrophy

The purpose of this study was to evaluate the role of stress echocardiography in the risk stratification and prognosis of patients with left ventricular (LV) hypertrophy. One thousand two patients (mean age 62 +/- 13 years, 35% men) with LV hypertrophy (defined by LV mass index >115 g/m(2) for men and >95 g/m(2) for women) were evaluated. LV mass was calculated using the linear dimension method, as recommended by the American Society of Echocardiography. The calculation of relative wall thickness was performed using the formula (2 x posterior wall thickness)/LV internal diameter. Concentric and eccentric LV hypertrophy were defined as relative wall thicknesses > or =0.42 and <0.42 cm, respectively. Follow-up (2.6 +/- 1.1 years) for confirmed myocardial infarction and cardiac death (n = 71) was obtained. Four hundred seventy-three patients (47%) had concentric hypertrophy, and 529 patients (53%) had eccentric hypertrophy. In patients with either concentric or eccentric LV hypertrophy, stress echocardiography was able to effectively risk-stratify normal versus abnormal subgroups (event rate 1.1% vs 4.9% per year, p <0.0001), whereas stress electrocardiography was unable to do so. In the cohort with normal stress echocardiographic results, patients with concentric LV hypertrophy had an event rate 5 times higher than those with eccentric LV hypertrophy (event rate 1.7% vs 0.3% per year, p = 0.007). In conclusion, stress echocardiography effectively risk-stratifies patients with LV hypertrophy compared with stress electrocardiography. Normal stress echocardiographic results in patients with concentric LV hypertrophy indicate a worse prognosis than in patients with eccentric LV hypertrophy, probably reflecting decreased sensitivity in this cohort. However, abnormal stress echocardiographic results portend a worse prognosis in patients with either concentric or eccentric LV hypertrophy.     

Prediction of cardiovascular outcomes with left atrial size: is volume superior to area or diameter?

OBJECTIVES: We sought to compare left atrial (LA) volume to LA area and diameter for the prediction of adverse cardiovascular outcomes. BACKGROUND: The incremental value of LA volume compared with LA area or diameter as a cardiovascular risk marker has not been evaluated prospectively for patients with sinus rhythm or atrial fibrillation (AF). METHODS: Left atrial size was assessed with biplane LA volume, four-chamber LA area, and M-mode dimension for 423 patients (mean age 71 +/- 8 years, 56% men) who were prospectively followed for development of first AF, congestive heart failure, stroke, transient ischemic attack, myocardial infarction, coronary revascularization, and cardiovascular death. RESULTS: Of the 317 subjects in sinus rhythm at baseline, 62 had 90 new events during a mean follow-up of 3.5 +/- 2.3 years. All three LA size parameters were independently predictive of combined outcomes (all p < 0.0001). The overall performance for the prediction of cardiovascular events was greatest for LA volume (area under the receiver operator characteristic curve: indexed LA volume 0.71; LA area 0.64; LA diameter 0.59). A graded association between the degree of LA enlargement and risk of cardiovascular events was only evident for indexed LA volume. For subjects with AF, there was no association between LA size and cardiovascular events. CONCLUSIONS: Left atrial volume is a more robust marker of cardiovascular events than LA area or diameter in subjects with sinus rhythm. The predictive utility of LA size for cardiovascular events in AF was poor, irrespective of the method of LA size quantitation.     

Neuropeptide Y,left ventricular mass and function in patients with end stage renal disease

OBJECTIVE: Neuropeptide Y (NPY) is released during sympathetic stimulation and mediates the central effects of the adipostatic hormone leptin. The plasma concentration of NPY and leptin is increased in patients with end stage renal disease (ESRD), but it is unknown whether these substances are related to biochemical markers of sympathetic activity and to alterations in left ventricular (LV) mass and function in these patients. DESIGN: We investigated the relationship between NPY, norepinephrine (NE), leptin and echocardiographic measurements in a cross-sectional study in 198 patients with ESRD. RESULTS: NPY was directly related to plasma NE and heart rate but it was largely independent of arterial pressure and of retention of metabolic waste products. NPY was significantly higher in patients with LV hypertrophy and in those with LV systolic dysfunction than in those without these alterations. Of note, NPY emerged as an independent correlate of LV mass index and of LV ejection fraction (LVEF) (both P 相似文献   

Left atrial deformation analysis by speckle tracking echocardiography for prediction of cardiovascular outcomes

The incremental value of left atrial (LA) deformation analysis by speckle tracking echocardiography compared with LA volume or LA ejection fraction as a cardiovascular risk marker has not been evaluated prospectively. We sought to compare LA function by speckle tracking echocardiography to other conventional LA parameters for prediction of adverse cardiovascular outcomes. This prospective study included 312 adults (mean age 71 ± 6 years, 56% men) in sinus rhythm who were followed for development of first atrial fibrillation, congestive heart failure, stroke, transient ischemic attack, myocardial infarction, coronary revascularization, and cardiovascular death. Global peak atrial longitudinal strain (PALS) by speckle tracking echocardiography was measured in all subjects by averaging all atrial segments. Left atrium was assessed with biplane LA volume, LA ejection fraction, 4-chamber LA area, and M-mode dimension. Of 312 subjects at baseline, 43 had 61 new events during a mean follow-up of 3.1 ± 1.4 years. All LA parameters, traditional parameters, and parameters derived by speckle tracking echocardiography were independently predictive of combined outcomes (p <0.0001 for all comparisons). Overall performance for prediction of cardiovascular events was greatest for global PALS (area under receiver operator characteristic curve: global PALS 0.83, indexed LA volume 0.71, LA ejection fraction 0.69, LA area 0.64, LA diameter 0.59). A graded association between degree of LA enlargement and risk of cardiovascular events was evident only for global PALS and indexed LA volume. In conclusion, global PALS is a strong and independent predictor of cardiovascular events and appears to be superior to conventional parameters of LA analysis.     

Arrhythmia risk stratification in idiopathic dilated cardiomyopathy based on echocardiography and 12-lead, signal-averaged, and 24-hour holter electrocardiography

BACKGROUND: To date, considerable controversy exists regarding noninvasive arrhythmia risk stratification in idiopathic dilated cardiomyopathy (IDC).Methods and Results Between 1992 and 1997, 202 patients with IDC without a history of sustained ventricular tachycardia (VT) underwent echocardiography, signal-averaged electrocardiogram (ECG), and 24-hour Holter ECG in the absence of antiarrhythmic drugs. During 32 +/- 15 months of prospective follow-up, major arrhythmic events, including sustained VT, ventricular fibrillation, or sudden death, occurred in 32 (16%) of 202 patients. After adjusting for baseline medical therapy and antiarrhythmic therapy during follow-up, multivariate Cox regression analysis identified a left ventricular (LV) end-diastolic diameter >/=70 mm and nonsustained VT on Holter as the only independent arrhythmia risk predictors. The combination of an LV end-diastolic diameter >/=70 mm and nonsustained VT was associated with a 14. 3-fold risk for future arrhythmic events (95% confidence interval 2. 3-90). To further elucidate the prognostic value of LV ejection fraction, multivariate Cox analysis was repeated with ejection fraction forced to remain in the model. In the latter model, an ejection fraction /=70 mm and nonsustained VT on Holter, and the combination of LV ejection fraction 相似文献   

Echocardiographic determinants of clinical outcome in subjects with coronary artery disease (the Framingham Heart Study).

Echocardiographic predictors of clinical outcome were examined in subjects from the Framingham Heart Study with overt coronary artery disease. The study population consisted of 185 men and 147 women with coronary artery disease who underwent M-mode echocardiography and were followed for a mean of 3.90 years. At baseline, 37 men (18.4%) and 16 women (10.9%) had reduced fractional shortening, 43 men (23.2%) and 28 women (19%) had left ventricular (LV) dilatation, and 76 men (41%) and 76 women (51.7%) had LV hypertrophy. During the follow-up period new cardiovascular disease events (coronary disease, stroke, transient ischemic attack, claudication, heart failure and deaths from cardiovascular disease) occurred in 60 men (32%) and 58 women (39%). With use of age-adjusted proportional hazards analyses, LV mass/height in men (relative risk [RR] = 1.25/50 g/m increment, 95% confidence interval [CI] 1.01 to 1.55) and LV end-diastolic diameter in women (RR = 1.36/5 mm increment, 95% CI 1.05 to 1.76) were predictors of new cardiovascular disease events. Cardiovascular risk was also associated with LV end-systolic diameter in both sexes (in men RR = 1.28/1 SD increment, 95% CI 1.02 to 1.63; in women RR = 1.40/1 standard deviation increment, 95% CI 1.09 to 1.82). Reduced fractional shortening alone (RR = 1.91, 95% CI 1.11 to 3.31) and in combination with LV dilatation (RR = 2.13, 95% CI 1.13 to 4.02) was associated with the incidence of new cardiovascular disease outcomes in men.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prognostic implications of subclinical left ventricular dilatation and systolic dysfunction in men free of overt cardiovascular disease (the Framingham Heart Study).

To determine the prognostic significance of asymptomatic left ventricular (LV) dilatation and LV systolic dysfunction, 1,493 men who were free of symptomatic cardiovascular disease underwent M-mode echocardiography and were then followed for a mean of 4.15 years. At baseline examination, 170 men (11.4%) had an abnormally high end-diastolic LV internal dimension (> or = 56 mm) and 76 (5.1%) had an abnormally low fractional shortening (< or = 30%). During the follow-up period, 68 men experienced 92 cardiovascular disease events. After adjusting for age and traditional cardiovascular disease risk factors in proportional-hazards analyses, fractional shortening was a significant independent predictor of cardiovascular risk (relative risk [RR] = 1.42, 95% confidence interval [CI] 1.12 to 1.81, for decrease of fractional shortening by 4%). Increased risk was also associated with combinations of low fractional shortening and high end-diastolic internal dimension (RR = 3.77, 95% CI 1.59 to 8.93) and with low percent fractional shortening with LV hypertrophy (RR = 5.93, 95% CI 1.97 to 17.85). In conclusion, subclinical LV dilatation and LV systolic dysfunction, although uncommon in men free of overt cardiovascular disease, are associated with increased risk for new cardiovascular disease events.     

Prolonged QTc interval and risk of sudden cardiac death in a population of older adults.

OBJECTIVES: This study sought to investigate whether prolongation of the heart rate-corrected QT (QTc) interval is a risk factor for sudden cardiac death in the general population. BACKGROUND: In developed countries, sudden cardiac death is a major cause of cardiovascular mortality. Prolongation of the QTc interval has been associated with ventricular arrhythmias, but in most population-based studies no consistent association was found between QTc prolongation and total or cardiovascular mortality. Only very few of these studies specifically addressed sudden cardiac death. METHODS: This study was conducted as part of the Rotterdam Study, a prospective population-based cohort study that comprises 3,105 men and 4,878 women aged 55 years and older. The QTc interval on the electrocardiogram was determined during the baseline visit (1990 to 1993) and the first follow-up examination (1993 to 1995). The association between a prolonged QTc interval and sudden cardiac death was estimated using Cox proportional hazards analysis. RESULTS: During an average follow-up period of 6.7 years (standard deviation, 2.3 years) 125 patients died of sudden cardiac death. An abnormally prolonged QTc interval (>450 ms in men, >470 ms in women) was associated with a three-fold increased risk of sudden cardiac death (hazard ratio, 2.5; 95% confidence interval, 1.3 to 4.7), after adjustment for age, gender, body mass index, hypertension, cholesterol/high-density lipoprotein ratio, diabetes mellitus, myocardial infarction, heart failure, and heart rate. In patients with an age below the median of 68 years, the corresponding relative risk was 8.0 (95% confidence interval 2.1 to 31.3). CONCLUSIONS: Abnormal QTc prolongation on the electrocardiogram should be viewed as an independent risk factor for sudden cardiac death.     

Left atrial physiology and pathophysiology: Role of deformation imaging

The left atrium (LA) acts as a modulator of left ventricular (LV) filling. Although there is considerable evidence to support the use of LA maximum and minimum volumes for disease prediction, theoretical considerations and a growing body of literature suggest to focus on the quantification of the three basic LA functions: (1) Reservoir function: collection of pulmonary venous return during LV systole; (2) Conduit function: passage of blood to the left ventricle during early LV diastole; and (3) Contractile booster pump function (augmentation of ventricular filling during late LV diastole. Tremendous advances in our ability to non-invasively characterize all three elements of atrial function include speckle tracking echocardiography (STE), and more recently cardiovascular magnetic resonance myocardial feature tracking (CMR-FT). Corresponding imaging biomarkers are increasingly recognized to have incremental roles in determining prognosis and risk stratification in cardiac dysfunction of different origins. The current editorial introduces the role of STE and CMR-FT for the functional assessment of LA deformation as determined by strain and strain rate imaging and provides an outlook of how this exciting field may develop in the future.