Recommendations for chamber quantification: a report from the American Society of Echocardiography's Guidelines and Standards Committee and the Chamber Quantification Writing Group, developed in conjunction with the European Association of Echocardiography, a branch of the European Society of Cardiology

Masked Nocturnal Hypertension and Target Organ Damage in Hypertensives with Well-Controlled Self-Measured Home Blood Pressure

It has been reported that masked hypertension, a state in which patients show normal clinic blood pressure (BP) but elevated out-of-clinic BP by self-measured home BP, is a predictor of cardiovascular morbidity much like sustained hypertension. In addition, nocturnal BP is closely associated with cardiovascular disease. This might mean that ambulatory and self-measured home BP monitoring each provide independent information. We performed ambulatory BP monitoring, self-measured home BP monitoring, echocardiography and carotid ultrasonography in 165 community-dwelling subjects. We subclassified the patients according to the ambulatory and self-measured home BP levels as follows: in the masked nocturnal hypertension group, the self-measured home BP level was <135/85 mmHg and the ambulatory nocturnal BP level was >or=120/75 mmHg; in the normotensive group, the self-measured home BP level was <135/85 mmHg and the ambulatory nocturnal BP level was <120/75 mmHg. The intima-media thickness (IMT) and relative wall thickness (RWT) were greater in the masked nocturnal hypertension group than in the normotensive group (IMT: 0.76+/-0.20 vs. 0.64+/-0.14 mm, p<0.05; RWT: 0.50+/-0.14 vs. 0.41+/-0.10, p<0.05). Even in hypertensives with well-controlled self-measured home BP, elevated ambulatory nocturnal BP might promote target organ damage. We must rule out masked hypertension using self-measured home BP monitoring, and we might also need to rule out nocturnal masked hypertension using ambulatory BP monitoring.

A Novel Two-Dimensional Echocardiographic Image Analysis System Using Artificial Intelligence-Learned Pattern Recognition for Rapid Automated Ejection Fraction

OBJECTIVES

We sought to test the hypothesis that a novel 2-dimensional echocardiographic image analysis system using artificial intelligence-learned pattern recognition can rapidly and reproducibly calculate ejection fraction (EF).

BACKGROUND

Echocardiographic EF by manual tracing is time consuming, and visual assessment is inherently subjective.

METHODS

We studied 218 patients (72 female), including 165 with abnormal left ventricular (LV) function. Auto EF incorporated a database trained on >10,000 human EF tracings to automatically locate and track the LV endocardium from routine grayscale digital cineloops and calculate EF in 15 s. Auto EF results were independently compared with manually traced biplane Simpson's rule, visual EF, and magnetic resonance imaging (MRI) in a subset.

RESULTS

Auto EF was possible in 200 (92%) of consecutive patients, of which 77% were completely automated and 23% required manual editing. Auto EF correlated well with manual EF (r = 0.98; 6% limits of agreement) and required less time per patient (48 +/- 26 s vs. 102 +/- 21 s; p < 0.01). Auto EF correlated well with visual EF by expert readers (r = 0.96; p < 0.001), but interobserver variability was greater (3.4 +/- 2.9% vs. 9.8 +/- 5.7%, respectively; p < 0.001). Visual EF was less accurate by novice readers (r = 0.82; 19% limits of agreement) and improved with trainee-operated Auto EF (r = 0.96; 7% limits of agreement). Auto EF also correlated with MRI EF (n = 21) (r = 0.95; 12% limits of agreement), but underestimated absolute volumes (r = 0.95; bias of -36 +/- 27 ml overall).

CONCLUSIONS

Auto EF can automatically calculate EF similarly to results by manual biplane Simpson's rule and MRI, with less variability than visual EF, and has clinical potential.

Circulating heat shock proteins and inflammatory markers in patients with idiopathic left ventricular dysfunction: their relationships with myocardial and microvascular impairment

Little information is available on peripheral levels of Hsp72, Hsp60, and anti-Hsp60 antibodies in patients with left ventricular (LV) dysfunction due to non-atherosclerotic cardiac disease. In this study, serum Hsp72, Hsp60 and anti-Hsp60 antibodies, IL-6, and C-reactive protein (CRP) were measured in 44 healthy controls and in 82 patients with angiographically normal coronary arteries (LV ejection fraction [EF] > or = 50%, n=22; -35% to <50%, n=32; <35%, n=28). Patients with more severe disease (more depressed myocardial blood flow at rest and during dipyridamole, indicative of coronary microvascular impairment) showed more elevated circulating Hsp60 and auto-antibodies, Hsp72, and CRP levels. IL-6 was increased progressively as a function of severity of LV dysfunction. Anti-Hsp60 antibodies, Hsp72, and IL-6 were significantly correlated with brain natriuretic peptide (BNP) levels and LV end-diastolic dimensions (LVEDD) values. IL-6 tended to be related with Hsp72 in particular in patients with more severe disease (r = 0.45, P = 0.021). Hsp60 and Hsp72 activation and inflammatory markers were correlated with the extent of cardiac and microvascular dysfunction in patients with angiographycally normal coronary arteries. These results suggest a pathogenic role of infective-metabolic insult and inflammatory reaction in the development of vascular and myocardial damage in patients with heart failure even in the absence of overt coronary artery disease.

Left ventricular hypertrophy in severe obesity: interactions among blood pressure, nocturnal hypoxemia, and body mass

Obese subjects have a high prevalence of left ventricular (LV) hypertrophy. It is unclear to what extent LV hypertrophy results directly from obesity or from associated conditions, such as hypertension, impaired glucose homeostasis, or obstructive sleep apnea. We tested the hypothesis that LV hypertrophy in severe obesity is associated with additive effects from each of the major comorbidities. Echocardiography and laboratory testing were performed in 455 severely obese subjects with body mass index 35 to 92 kg/m(2) and 59 nonobese reference subjects. LV hypertrophy, defined by allometrically corrected (LV mass/height(2.7)), gender-specific criteria, was present in 78% of the obese subjects. Multivariable regression analyses showed that average nocturnal oxygen saturation <85% was the strongest independent predictor of LV hypertrophy (P<0.001), followed by systolic blood pressure (P<0.015) and then body mass index (P<0.05). With regard to LV mass, there were synergistic effects between hypertension and body mass index (P interaction <0.001) and between hypertension and reduced nocturnal oxygen saturation. Severely obese subjects had normal LV endocardial fractional shortening (35+/-6% versus 35+/-6%) but mildly decreased midwall fractional shortening (15+/-2% versus 17+/-2%; P<0.001), indicating subtle myocardial dysfunction. In conclusion, more severe nocturnal hypoxemia, increasing systolic blood pressure, and body mass index are all independently associated with increased LV mass. The effects of increased blood pressure seem to amplify those of sleep apnea and more severe obesity.

Exercise performance during losartan- or atenolol-based treatment in hypertensive patients with electrocardiographic left ventricular hypertrophy (a LIFE substudy)

The objective of the study was to assess the influence of left ventricular (LV) hypertrophy regression on exercise capacity in hypertensive patients. Doppler echocardiography was performed at rest and during exercise in 51 patients with electrocardiographic LV hypertrophy before and after 1 year of randomized blinded losartan- or atenolol-based antihypertensive treatment. After 1 year, blood pressure was comparably reduced by 32/14 and 27/13 mmHg, respectively, in the losartan and atenolol groups, but the atenolol group had higher mean LV mass index (118 vs 103 g/m2) and lower LV ejection fraction (61% vs 67%) and midwall shortening (15.8% vs 16.8%) (all p<0.05). Resting diastolic Doppler indices remained unchanged and did not differ between the groups. Peak oxygen uptake during exercise was virtually unchanged after 1 year and did not differ between the groups in spite of a lower peak exercise heart rate in atenolol-treated patients. In multivariate analysis, higher peak oxygen uptake at 1 year was associated with lower body mass index, and higher systolic blood pressure and shorter isovolumic relaxation time at peak exercise (multiple R2 = 0.51, p<0.01), while age, gender, heart rate increase during exercise, reduction in LV mass and study treatment did not enter. In conclusion, reduction in blood pressure and LV mass induced by losartan or atenolol treatment was not accompanied by improved exercise capacity after 1 year. The results may be explained by persistent impairment of myocardial relaxation influencing exercise capacity.

Relation of arterial stiffness to left ventricular diastolic function and cardiovascular risk prediction in patients > or =65 years of age

There is a paucity of data regarding the relation between the various noninvasive indexes of arterial stiffness and left ventricular diastolic function. In 188 subjects aged > or =65 years (mean 75 +/- 5; 71% men), the concordance and strength of the association between measures of arterial stiffness and left ventricular diastolic function were evaluated. Indexes of arterial stiffness (brachial and aortic pulse pressure [PP], carotid-femoral pulse-wave velocity [PWV], and augmentation pressure [AP]) were measured using applanation tonometry. Diastolic function was classified in terms of instantaneous diastolic function grade and quantitated as left atrial volume, a measure of chronic diastolic burden. Risk for new cardiovascular events was estimated using a validated clinical echocardiographic risk algorithm. Aortic and brachial PP, PWV, and AP were correlated positively with left atrial volume and diastolic function grade. After adjusting for age, gender, and clinical and echocardiographic covariates, 1-SD increases in aortic PP, brachial PP, PWV, and AP were associated with 6%, 6%, 4%, and 4% increases in indexed left atrial volume, respectively. Similarly, 1-SD increases in aortic PP, brachial PP, and AP were associated with 84%, 81%, and 83% increased risk for diastolic dysfunction, respectively (all p <0.04). PWV and aortic and brachial PP were superior to AP in discriminating subjects with the highest risk of having new cardiovascular events (5-year risk >50%; area under receiver-operating characteristic curve 0.67, 0.67, 0.70, and 0.56, respectively; p <0.05). In conclusion, increased arterial stiffness was associated with more severe left ventricular diastolic dysfunction, although the strength of the association varied according to the specific measure used. Aortic PP, brachial PP, and PWV appeared superior to AP in risk discrimination in this elderly cohort.

Prognostic importance of wall motion abnormalities in patients with ischemic cardiomyopathy and an implantable cardioverter-defibrillator

Patients with extensive regional wall motion abnormalities are predisposed to development of ventricular tachyarrhythmia. The prognostic effect of this in patients with an implantable cardioverter-defibrillator (ICD) and coronary artery disease (CAD) is not known. Echocardiographic left ventricular systolic indexes, wall motion score index (WMSI), and extent of regional akinesia in 140 patients (65 +/- 10 years old; 92% men) with an ICD and CAD were studied. Arrhythmic events requiring ICD therapy and causing death (n = 41, 29%) were recorded over a mean follow-up of 1.4 +/- 0.8 years. Left ventricular basal fractional shortening, ejection fraction, global WMSI, and extent of akinesia, especially in the inferoposterior regions of a right coronary artery territory, were univariate predictors (all p values <0.05). Global WMSI (hazard ratio 2.18, 95% confidence interval 1.03 to 4.65, p = 0.04) and fractional shortening (hazard ratio 0.93, 95% confidence interval 0.88 to 1.00, p = 0.04) were multivariate predictors. Global WMSI (p = 0.04) and > or =2 right coronary region akinetic segments (p = 0.05) provided incremental risk prediction to left ventricular ejection fraction in a global risk-assessment model (chi-square p = 0.001). Presence of right coronary region akinesia better identified those at increased risk of events (p = 0.02) compared with the presence of left anterior descending region akinesia (p = 0.2), independent of systolic function. In conclusion, global WMSI and left ventricular basal fractional shortening were important additional risk predictors of ICD events in CAD. Global WMSI and right coronary region inferoposterior akinesia provided independent and incremental risk assessment to left ventricular ejection fraction and improved identification of those at increased risk of ICD-related events in patients with ischemic cardiomyopathy.

Right ventricular dysfunction and adverse outcome in patients with advanced heart failure

BACKGROUND

In patients with heart failure (HF) from left ventricular systolic dysfunction, the presence of coexistent right ventricular (RV) dysfunction is associated with poor exercise capacity and reduced survival. We sought to determine whether a simple measure of RV function, the RV myocardial performance index (RV MPI), is associated with adverse outcome in a population of advanced heart failure patients selected to receive cardiac resynchronization therapy (CRT).

METHODS AND RESULTS

The RV MPI was measured on 77 consecutive preimplantation echocardiograms. The relationship between RV MPI and the end point of all-cause mortality, transplantation, or ventricular assist device placement was evaluated. The end point occurred in 28 patients (36%) during a median follow-up of 21 months. The median RV MPI was 0.73 (interquartile range 0.51-0.89). Worse RV function, as demonstrated by a higher RV MPI, was seen in those patients who reached the end point compared with those who did not (0.83 vs. 0.69, P = .004). The highest tercile of RV MPI was associated with a 3.3-fold increased risk of poor outcome (95% CI 1.3-8.5). Each 0.1 unit increase in RV MPI was associated with a 16% increased risk (95% CI 8-26). After adjusting for other echocardiographic variables, RV MPI remained significantly associated with the outcome.

CONCLUSION

In a population of advanced HF patients selected to receive CRT, RV dysfunction, as assessed by the RV MPI, is associated with adverse outcome. Wider use of this simple nongeometric parameter may help to identify patients for whom options for further intervention should be carefully evaluated.

Longitudinal left ventricular contractile dysfunction after exercise in aortic stenosis

OBJECTIVE

To determine whether longitudinal left ventricular systolic function measured by Doppler tissue imaging (DTI) after exercise can identify early left ventricular dysfunction in asymptomatic patients with moderate-severe aortic stenosis.

DESIGN

Case-control study.

SETTING

Outpatient cardiology departments.

PATIENTS

20 patients with aortic stenosis, with or without equivocal symptoms, a peak aortic valve velocity > or =3 m/s, and left ventricular ejection fraction >50% and 15 aged-matched normal controls.

INTERVENTIONS

Echocardiogram performed at rest and immediately after treadmill exercise.

MAIN OUTCOME MEASURES

The peak systolic velocity of the lateral mitral annulus (S') by DTI at rest and immediately after exercise, exercise capacity, exercise systolic blood pressure and the plasma level of B-type natriuretic peptide (BNP).

RESULTS

For patients with aortic stenosis, mean (SD) aortic valve area was 0.95 (0.3) cm(2). At rest, S' was similar for patients with aortic stenosis and controls, respectively (8.5 (1.5) vs 9.1 (1.8) cm/s, p = 0.15). However, after exercise, S' (12.2 (3.2) vs 17 (2.8) cm/s, p<0.001) and the increase in S' between rest and exercise (4 (3) vs 7.9 (1.5) cm/s, p<0.001) were lower in patients with aortic stenosis. In patients with aortic stenosis, a smaller increase in S' after exercise was associated with lower exercise capacity (r = 0.5, p = 0.02), a smaller increase in exercise systolic blood pressure (r = 0.6, p = 0.005) and higher plasma level of BNP (r = 0.66, p = 0.002).

CONCLUSION

In asymptomatic patients with moderate-severe aortic stenosis a lower than normal increase in peak systolic mitral annular velocity after treadmill exercise is a marker of early left ventricular systolic dysfunction.

Real-time three-dimensional dobutamine stress echocardiography for coronary artery disease diagnosis: validation with coronary angiography

OBJECTIVE

To compare real-time three-dimensional echocardiography (RT3DE) with two-dimensional dobutamine stress echocardiography (2DE) for the detection of myocardial ischaemia, with angiographic validation of the results.

METHODS

56 patients (mean (SD) age 64.5 (6.2) years, 38 males), referred for coronary angiography, were examined by 2DE and RT3DE during the same dobutamine stress protocol.

RESULTS

All 56 patients completed the stress protocol uneventfully. The mean (SD) acquisition time for the necessary views to evaluate all segments was 26.3 (2.5) s for RT3DE and 58.8 (3.7) s for 2DE (p<0.001). At peak stress, RT3DE had a higher wall-motion score index (1.25 (0.24) by 2DE, 1.30 (0.27) by RT3DE; p = 0.014). The regional wall-motion score for the four apical segments at peak stress was compared; it was 1.35 (0.55) by 2DE and 1.52 (0.69) by RT3DE (p = 0.003). The diagnostic parameters of 2DE versus RT3DE were: sensitivity 73% vs 78%, specificity 93% vs 89% and overall accuracy 86% vs 85%, respectively. In the left anterior descending artery territory, in particular, where RT3DE had higher regional wall-motion scores, it showed a tendency towards higher sensitivity (85% vs 78%), although this difference did not achieve statistical significance.

CONCLUSION

RT3DE identifies wall-motion abnormalities more readily in the apical region than 2DE, which may explain the tendency towards higher sensitivity in the left anterior descending artery territory. RT3DE results were validated using angiography as reference and findings indicate diagnostic equivalence to 2DE, with the advantage of considerable shorter acquisition times.

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.

Assessment of left ventricular function by cardiac ultrasound

Our understanding of the physical underpinnings of the assessment of cardiac function is becoming increasingly sophisticated. Recent developments in cardiac ultrasound permit exploitation of many of these newer physical concepts with current echocardiographic machines. This review will first focus on the current approach to the assessment of cardiovascular hemodynamics by cardiac ultrasound. The next focus will be the assessment of global cardiac mechanics in systole and diastole. Finally, relationships between the cardiac structure and regional myocardial function, and the way regional function can be quantified by ultrasound, will be presented. This review also discusses the clinical impact of echocardiography and its future directions and developments.

Hyperuricaemia and long-term outcome after hospital discharge in acute heart failure patients

BACKGROUND

Uric acid (UA) may be involved in chronic heart failure (HF) pathogenesis, entailing a worse outcome. The purpose of this study was to examine the role of hyperuricaemia as a prognostic marker after hospital discharge in acute HF patients.

METHODS

We studied 212 patients consecutively discharged after an episode of acute HF with LVEF<40%. Blood samples for UA measurement were extracted in the morning prior to discharge. The evaluated endpoints were death and new HF hospitalization.

RESULTS

Mean UA levels were 7.4+/-2.4 mg/dl (range 1.6 to 16 mg/dl), with 127 (60%) of patients being within the range of hyperuricaemia. Hyperuricaemia was associated with a higher risk of death (n=48) (HR 2.0, 95% CI 1.1-3.9, p=0.028), new HF readmission (n=67) (HR 1.8, 95% CI 1.1-3.1, p=0.023) and the combined event (n=100) (HR 1.9, 95% CI 1.2-2.9, p=0.004). At 24 months, cumulative event-free survival was lower in the two higher UA quartiles (36.9% and 40.7% vs. 63.5% and 59.5%, log rank=0.006). After adjustment for potential confounders, hyperuricaemia remains an independent risk factor for adverse outcomes (HR 1.6, 95% CI 1.1-2.6, p=0.02).

CONCLUSIONS

In hospitalized patients with acute HF and LV systolic dysfunction, hyperuricaemia is a long-term prognostic marker for death and/or new HF readmission.

Contrast administration reduces interobserver variability in determination of left ventricular ejection fraction in patients with left ventricular dysfunction and good baseline endocardial border delineation

Echocardiographic contrast agents improve endocardial border delineation in patients with technically difficult baseline studies. With medical and device therapy for heart failure increasingly based on left ventricular (LV) ejection fraction (EF) partition values, the accurate and reproducible assessment of LV function is necessary. It was hypothesized that routine contrast enhancement would significantly reduce interobserver variability in the determination of LVEFs in a cohort of patients with LV dysfunction and good baseline endocardial delineation. All patients underwent baseline noncontrast studies followed by contrast-enhanced imaging using Definity. Two experienced echocardiographers, blinded to the clinical data, determined LVEFs using 4 different techniques: noncontrast estimated (NCE), noncontrast calculated (NCC), contrast estimated (CE), and contrast calculated (CC). Using a mixed-model procedure that allows for fixed and random events, the variance due to error and that due to the patient was obtained (interclass correlation). The proportion of variation due to the reader was calculated as 1--interclass correlation. Mean standardized percentage differences ([reader 1 EF--reader 2 EF]/mean EF) were also calculated for each method. The proportion of variation due to the reader was smallest in the CC group and largest in the NCC group (NCE = 0.21, NCC = 0.33, CE = 0.25, CC = 0.11). The results were similar when only patients with NCE EFs >or=20% and <or=50% were analyzed (NCE = 0.29, NCC = 0.47, CE = 0.33, CC = 0.15). The mean standardized percentage difference between readers was smallest in the CC group for all patients and for those with NCE EFs >or=20% and <or=50%. In conclusion, contrast administration reduces interobserver variability in LVEF assessment, even in patients with good baseline endocardial border delineation, and should be used routinely regardless of the perceived adequacy of baseline images, especially if the LVEF is >or=20% and <or=50%.

Differences of lateral and septal mitral annulus velocity by tissue Doppler imaging in the evaluation of left ventricular diastolic function

Left ventricular diastolic dysfunction (LVDD) was investigated in 276 outpatients at a university cardiology practice by tissue Doppler imaging of mitral valve annular velocity. The well-investigated parameters of mitral inflow were used as the standard. Using septal E/Ea ratios, 62 patients (22%) had no LVDD, 44 patients (16%) had mild LVDD, 126 patients (46%) had moderate LVDD, 25 patients (9%) had severe LVDD, and 19 patients (7%) had indeterminate LVDD. Using lateral E/Ea ratios, 131 patients (48%) had no LVDD, 40 patients (14%) had mild LVDD, 62 patients (22%) had moderate LVDD, 9 patients (3%) had severe LVDD, and 12 patients (13%) had indeterminate LVDD. In conclusion, the use of septal tissue Doppler imaging tends to overestimate the severity of LVDD compared with the use of lateral tissue Doppler imaging.

Prescription Patterns of Pharmacological Agents for Left Ventricular Systolic Dysfunction Among Hemodialysis Patients

BACKGROUND

Recommendations for the management of left ventricular (LV) systolic dysfunction in the general population and patients with end-stage renal disease (ESRD) include the use of angiotensin-converting enzyme (ACE) inhibitors and beta-blockers. Limited data from the literature suggest that these pharmacological agents may be underused in patients with ESRD. The goal of this study is to describe the use of these medications and investigate barriers to their use in dialysis patients.

METHODS

We prospectively studied 420 hemodialysis patients. Diagnosis of systolic dysfunction was based on echocardiogram results. Use of cardiac medication was recorded for all patients with systolic dysfunction, and a questionnaire was administered to nephrologists to determine the basis for decisions concerning ACE-inhibitors and beta-blockers use/nonuse.

RESULTS

Forty-seven patients (11%) were found to have an LV ejection fraction of 40% or less. Of those, 72% were administered a beta-blocker and 36% were administered an ACE inhibitor. Only 12 patients (25.5%) were administered a combination of beta-blocker and ACE inhibitor. Reasons indicated by nephrologists for not prescribing these medications were "concern about adverse reactions (eg, hypotension, hyperkalemia)" in 88% of cases, "adequate control of symptoms with ultrafiltration" in 38%, "unproven benefit" in 25%, and "unfavorable risk-benefit ratio" in 17%. Medication costs and concern about patient compliance were not identified as significant concerns by physicians.

CONCLUSION

Only 25.5% of patients with ESRD with LV systolic dysfunction receive appropriate treatment. Concern regarding adverse reactions was the most frequent reason indicated by nephrologists for not prescribing ACE inhibitors and beta-blockers.

Beta-adrenergic receptor desensitization in man: insight into post-exercise attenuation of cardiac function

Desensitization of the beta-adrenoreceptors (beta-AR) may contribute to a post-exercise reduction in left ventricular (LV) function. However, attenuation of the chronotropic and inotropic responses to a beta-AR agonist may depend upon alterations in parasympathetic tone. Furthermore, changes in cardiac output and LV diastolic function in response to a beta-AR agonist, pre- to post-prolonged exercise, remain unclear. Seven trained males (mean+/-s.d., age 27+/-6 years) performed 4 h of ergometer rowing. Peak heart rate (HR) and LV systolic and diastolic functional responses to incremental isoproterenol (isoprenaline) infusion (2, 4 and 6 microg kg min-1) were assessed after vagal blockade (glycopyrrolate, 1.2 mg). LV systolic function was assessed by the pressure/volume ratio (systolic blood pressure/end systolic volume) and , whilst diastolic function was evaluated as peak early and late transmitral filling velocities. Following exercise, the pressure/volume ratio decreased by 25% (P<0.05), whereas was unchanged (P>0.05). The early/late filling ratio was reduced by 36% after exercise, due to an elevation in late LV filling (P<0.01). The increase in HR response to isoproterenol infusion was blunted post-exercise at both 4 and 6 microg kg min-1 (127+/-7 and 132+/-6 beats min-1) compared with pre-exercise (138+/-8 and 141+/-12 beats min-1, P<0.05). Additionally, the pressure/volume ratio and were blunted post-exercise in response to isoproterenol (P<0.05). In contrast, diastolic function was similar before and after exercise during isoproterenol infusion (P>0.05). Desensitization of the beta-AR contributes to an attenuated left ventricular systolic but not diastolic function following prolonged exercise.

Assessment of pulmonary valve and right ventricular outflow tract with real-time three-dimensional echocardiography

AIM

Assessment of pulmonary valve (PV) and right ventricular outflow tract (RVOT) using real-time 3-dimensional echocardiography (RT3DE).

METHODS

Two-dimensional echocardiography (2DE) and RT3DE were performed in 50 patients with congenital heart disease (mean age 32 +/- 9.5 years, 60% female). Measurements were obtained at parasternal views: short axis (PSAX) at aortic valve level and long axis (PLAX) with superior tilting. RT3DE visualization was evaluated by 4-point score (1: not visualized, 2: inadequate, 3: sufficient, and 4: excellent). Diameters of PV annulus (PVAD), and RVOT (RVOTD) were measured by both 2DE and RT3DE, while areas (PVAA) and (RVOTA) by RT3DE only.

RESULTS

By RT3DE, PV was visualized sufficiently in 68% and RVOT excellently in 40%. PVAD and PVAA were measured in 88%. RVOTD and PVAD by 2DE at PLAX were significantly higher than PSAX (P < 0.0001) and lower than that by RT3DE (P < 0.001).

CONCLUSION

RT3DE helps in RVOT and PV assessment adding more details supplemental to 2DE.

Rationale and design: the VALsartan In Diastolic Dysfunction (VALIDD) Trial: evolving the management of diastolic dysfunction in hypertension

BACKGROUND

Although 50% of hypertensive patients in the community are estimated to have diastolic dysfunction, there is no specific guideline for diastolic dysfunction therapy at present despite the condition's clear association with increased cardiovascular risk. Although the efficacy of angiotensin II receptor blockers (ARBs) in hypertension and left ventricular hypertrophy regression has been established, the effect of angiotensin II receptor blockade on intrinsic parameters of diastolic function has not been evaluated in large-scale studies.

METHODS

The VALIDD Trial is an investigator-initiated randomized, controlled, double-blind clinical trial on approximately 350 patients designed to explore whether antihypertensive therapy with the ARB valsartan, in addition to standard therapy, would improve intrinsic diastolic properties of the myocardium in patients with hypertension and evidence of diastolic dysfunction. The result of such therapy will be compared with placebo after 38 weeks of treatment. The primary efficacy variable is change in early diastolic lateral mitral annular relaxation velocity measured by tissue Doppler imaging on week 38.

CONCLUSIONS

We expect the VALIDD Trial to provide novel insights into the specific effects of ARBs on diastolic dysfunction, as assessed by tissue Doppler imaging, in hypertensive patients. The trial may provide clinically useful data on whether such therapy can directly improve diastolic function in patients with hypertension.

Left Atrial Size

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.

Effects of childhood primary hypertension on carotid intima media thickness: a matched controlled study

To determine whether carotid intima media thickness is increased in children with primary hypertension, the current study compared carotid intima media thickness in hypertensive children with that of normotensive control subjects matched closely for body mass index and determined the relationship between carotid intima media thickness and hypertension severity determined by ambulatory blood pressure monitoring. Children with newly diagnosed office hypertension (n=28) had carotid intima media thickness, left ventricular mass index, and ambulatory blood pressure monitoring performed. Carotid intima media thickness was performed in normotensive control subjects (n=28) matched pairwise to hypertensive subjects for age (+/-1 year), gender, and body mass index (+/-10%). Eighty-two percent of subjects were overweight or obese (body mass index > or =85th percentile). The median carotid intima media thickness of hypertensive subjects was greater than that of matched controls (0.67 versus 0.63 mm; P=0.045). In the hypertensive subjects, carotid intima media thickness correlated strongly with several ambulatory blood pressure monitoring parameters, with the strongest correlation for daytime systolic blood pressure index (r=0.57; P=0.003). In the hypertensive group, the prevalence of left ventricular hypertrophy was 32%, but unlike carotid intima media thickness, left ventricular mass index did not correlate with ambulatory blood pressure monitoring. Together, the findings that hypertensive subjects had increased carotid intima media thickness compared with matched controls and that higher carotid intima media thickness correlated with more severe hypertension by ambulatory blood pressure monitoring provide strong evidence that carotid intima media thickness is increased in childhood primary hypertension, independent of the effects of obesity.

Prediction of Cardiovascular Outcomes With Left Atrial Size

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.

Exploring oligodendrocyte guidance: 'to boldly go where no cell has gone before'

Oligodendrocytes, the myelinating cells of the central nervous system (CNS), originate early in the formation of the brain in specific foci, and migrate throughout the parenchyma. The instructional cues guiding the migration of these progenitor cells must be encoded into their developing environment. Soluble factors as well as membrane-bound cues most likely synergize to create a complex thoroughfare needed to sculpt and organize the brain into a functional organ with white and gray matter. Classically, the focus of many guidance related studies in the CNS has been limited to neuron physiology. However, It is becoming increasingly clear that their lifelong partners, oligodendrocytes, express both ligands and receptors able to both present and respond to these classical cues. In this short review, some recent findings in the Semaphorin and Eph fields will be presented with respect to oligodendrocyte expression and function.

Hcc-1 is a novel component of the nuclear matrix with growth inhibitory function

Hcc-1 is a novel nuclear protein containing the SAF-box DNA-binding domain. It binds to both double-stranded and single-stranded DNA with higher affinity for the single-stranded form. In addition, it also binds specifically to scaffold/matrix attachment region DNA. These nucleic acid-binding characteristics suggest a potential function for Hcc-1 as a component of the heterogeneous ribonucleoprotein complex. Using a yeast two-hybrid screen, two DEAD-box RNA helicases, BAT1 and DDX39, were identified as proteins that interact with Hcc-1. Interactions with these RNA helicases suggested a role for Hcc-1 in nucleic acid biogenesis. Expression of Hcc-1 in the HEK293 cell line resulted in a slower growth rate compared to controls (p = 0.0173) and an accumulation of cells at the G2/M phase (p = 0.0276 compared to control HEK293 cells). Taken together, these results suggest a role for Hcc-1 in growth regulation and nucleic acids metabolism.