Differences in myocardial velocity gradient measured throughout the cardiac cycle in patients with hypertrophic cardiomyopathy, athletes and patients with left ventricular hypertrophy due to hypertension

Characteristics of the athlete's heart in aged hypertensive and normotensive subjects

BACKGROUND

Both hypertension and age-related impairment of the cardiac condition are known to be improved by regular physical training. As relatively few studies have been reported about the older, hypertensive patients, the aim of this study was to establish cardiac benefits of active lifestyle in these subjects.

METHODS

Two-dimensionally guided M-mode, Doppler- and tissue Doppler echocardiography was performed in 199 normo- and hypertensive, active and sedentary older (age>60 yrs.) men (111) and women (88). Results were compared either by ANOVA, or by Kruskall-Wallis test.

RESULTS

The left ventricular muscle index (LVMI), which is higher in young active than in sedentary persons, proved to be smaller in the active than sedentary older subjects: men normotensives: actives 83 vs. sedentary ones 98, hypertensives: actives 88 vs. sedentary ones 107, women normotensives: actives 77 vs. sedentary ones 89 g/m3. Diastolic function was better in the active groups demonstrated both by the ratio of the early to atrial peak blood flow velocities (men: normotensives: actives 1.03 vs. sedentary ones 0.76, women normotensives: actives 1.21 vs. sedentary ones 0.9, hypertensives: actives 1.04 vs. sedentary ones 0.88). The tissue Doppler results were also better in the active groups; the difference between the active and sedentary groups was more marked in the normotensive male groups than in the hypertensive ones.

CONCLUSIONS

Active lifestyle prevents age-related pathological LV hypertrophy, and attenuates the LV diastolic dysfunction.

Analysis of three-chamber view conventional and tagged cine MRI in patients with suspected hypertrophic cardiomyopathy

OBJECTIVES

To investigate the potential value of adding a tagged three-chamber (3Ch) cine to clinical hypertrophic cardiomyopathy (HCM) magnetic resonance imaging (MRI) protocols, including to help distinguish HCM patients with regionally impaired cardiac function.

METHODS

Forty-eight HCM patients, five patients with "septal knuckle" (SK), and 20 healthy volunteers underwent MRI at 1.5T; a tagged 3Ch cine was added to the protocol. Regional strain, myocardial wall thickness, and mitral valve leaflet lengths were measured in the 3Ch view.

RESULTS

In HCM, we found a reduced tangential strain with decreased diastolic relaxation in both hypertrophied (p = 0.003) and remote segments (p = 0.035). Strain in the basal septum correlated with the length of the coaptation zone + residual leaflet (r = 0.48, p < 0.001). In the basal free wall, patients with SK had faster relaxation compared to HCM patients with septal hypertrophy.

DISCUSSION

The 3Ch tagged MRI sequence provides useful information for the examination of suspected HCM patients, with minimal additional time cost. Local wall function is closely associated with morphological changes of the mitral apparatus measured in the same plane and may provide insights into mechanisms of obstruction. The additional strain information may be helpful when analyzing local myocardial wall motion patterns in the presence of SK.

Strain Imaging: From Physiology to Practical Applications in Daily Practice

Non-Doppler, 2-dimensional strain imaging is a new echocardiographic technique for obtaining strain and strain rate measurements, which serves as a major advancement in understanding myocardial deformation. It analyzes motion in ultrasound imaging by tracking speckles in 2 dimensions. There are a lot of data emerging with multiple applications of strain imaging in the clinical practice of echocardiography. As incorporation of strain imaging in daily practice has been challenging, we intend to systematically highlight the top 10 applications of speckle-tracking echocardiography, which every cardiologist should be aware of: chemotherapy cardiotoxicity, left ventricular assessment, cardiac amyloidosis, hypertrophic obstructive cardiomyopathy, right ventricular dysfunction, valvular heart diseases (aortic stenosis and mitral regurgitation), cardiac sarcoidosis, athlete heart, left atrial assessment, and cardiac dyssynchrony.

Cardiovascular magnetic resonance for amyloidosis

Cardiac involvement drives the prognosis and treatment in systemic amyloid. Echocardiography, the mainstay of current cardiac imaging, defines cardiac structure and function. Echocardiography, in conjunction with clinical phenotype, electrocardiogram and biomarkers (brain natriuretic peptide and troponin), provides an assessment of the likelihood and extent of cardiac involvement. Two tests are transforming our understanding of cardiac amyloidosis, bone tracer scanning and cardiovascular magnetic resonance (CMR). CMR provides a "second opinion" on the heart's structure and systolic function with better accuracy and more precision than echocardiography but is unable to assess diastolic function and is not as widely available. Where CMR adds unique advantages is in evaluating myocardial tissue characterisation. With administration of contrast, the latest type of late gadolinium enhancement imaging (phase-sensitive inversion recovery sequence) is highly sensitive and specific with images virtually pathognomonic for amyloidosis. CMR is also demonstrating that the range of structural and functional changes in cardiac amyloid is broader than traditionally thought. CMR with T1 mapping, a relatively new CMR technique, can measure the amyloid burden and the myocyte response to infiltration (hypertrophy/cell loss) with advantages for tracking change (e.g. the wall thickness can stay the same but the composition can change) over time or during therapy. Such techniques hold great promise for advancing drug development in this arena and providing new prognostic insights. CMR with tissue characterisation is rewriting our understanding of cardiac amyloidosis and may lead to the development of new classification, therapies and prognostic systems.

The Effect of Chronic Anabolic-Androgenic Steroid Use on Tp-E Interval, Tp-E/Qt Ratio, and Tp-E/Qtc Ratio in Male Bodybuilders

BACKGROUND

The chronic consumption of androgenic anabolic steroids has shown to cause atrial arrhythmias. Several studies have suggested that the interval from the peak to the end of the electrocardiographic T wave (Tp-e) may correspond to the transmural dispersion of repolarization and that increased Tp-e interval and Tp-e/QT ratio are associated with malignant ventricular arrhythmias. The aim of this study was to evaluate repolarization dispersion measured from the 12-lead surface electrocardiogram (including Tp-e interval, Tp-e/QT ratio, and Tp-e/cQT ratio) in bodybuilders who are using anabolic androgenic steroids (AAS).

METHODS

We selected a population of 33 competitive bodybuilders, including 15 actively using AAS for ≥ 2 years (users) and 18 who had never used AAS (nonusers), all men.

RESULTS

QT, cQT, QTd, cQTd, JT, and cJT were significantly increased in AAS users bodybulders compared to the nonusers (all P < 0.001). Tp-e interval, Tp-e/QT ratio, and Tp-e/cQT ratio were also significantly higher in AAS user group compared to the nonuser group (all P < 0.001). QRS duration was not different between the groups. There were negative correlation between E(m) and Tp-e, Tp-e/QT ratio, Tp-e/cQT ration (r = -0.657, P < 0.01; r = -0.607, P = 0.02; r = -0.583, P = 0.02; respectively).There were also negative correlation between S(m) and Tp-e, Tp-e/QT ratio, Tp-e/cQT ration (r = -0.681, P < 0.01; r = -0.549, P = 0.03; r = -0.544, P = 0.023; respectively).

CONCLUSION

In conclusion, we have presented a strong evidence suggesting that Tp-e interval, Tp-e/QT ratio, and Tp-e/QTc ratio were increased in AAS users, which suggest that there might be a link between AAS use and ventricular arrthymias and sudden death.

Passive ventricular remodeling in cardiac disease: focus on heterogeneity

Passive ventricular remodeling is defined by the process of molecular ventricular adaptation to different forms of cardiac pathophysiology. It includes changes in tissue architecture, such as hypertrophy, fiber disarray, alterations in cell size and fibrosis. Besides that, it also includes molecular remodeling of gap junctions, especially those composed by Connexin43 proteins (Cx43) in the ventricles that affect cell-to-cell propagation of the electrical impulse, and changes in the sodium channels that modify excitability. All those alterations appear mainly in a heterogeneous manner, creating irregular and inhomogeneous electrical and mechanical coupling throughout the heart. This can predispose to reentry arrhythmias and adds to a further deterioration into heart failure. In this review, passive ventricular remodeling is described in Hypertrophic Cardiomyopathy (HCM), Dilated Cardiomyopathy (DCM), Ischemic Cardiomyopathy (ICM), and Arrhythmogenic Cardiomyopathy (ACM), with a main focus on the heterogeneity of those alterations mentioned above.

Brain natriuretic peptide predicts forced vital capacity of the lungs, oxygen pulse and peak oxygen consumption in physiological condition

Brain natriuretic peptide (NT-pro-BNP) is used as marker of cardiac and pulmonary diseases. However, the predictive value of circulating NT-pro-BNP for cardiac and pulmonary performance is unclear in physiological conditions. Standard echocardiography, tissue Doppler and forced spirometry at rest were used to assess cardiac parameters and forced vital capacity (FVC) in two groups of athletes (16 elite male wrestlers (W), 21 water polo player (WP)), as different stress adaptation models, and 20 sedentary subjects (C) matched for age. Cardiopulmonary test on treadmill (CPET), as acute stress model, was used to measure peak oxygen consumption (peak VO2), maximal heart rate (HRmax) and peak oxygen pulse (peak VO2/HR). NT-pro-BNP was measured by immunoassey sandwich technique 10min before the test - at rest, at the beginning of the test, at maximal effort, at third minute of recovery. FVC was higher in athletes and the highest in W (WP 5.60±0.29 l; W 6.57±1.00 l; C 5.41±0.29 l; p<0.01). Peak VO2 and peak VO2/HR were higher in athletes and the highest in WP. HRmax was not different among groups. In all groups, NT-pro-BNP decreased from rest to the beginning phase, increased in maximal effort and stayed unchanged in recovery. NT-pro-BNP was higher in C than W in all phases; WP had similar values as W and C. On multiple regression analysis, in all three groups together, ΔNT-pro-BNP from rest to the beginning phase independently predicted both peak VO2 and peak VO2/HR (r=0.38, 0.35; B=37.40, 0.19; p=0.007, 0.000, respectively). NT-pro-BNP at rest predicted HRmax (r=-0.32, B=-0.22, p=0.02). Maximal NT-pro-BNP predicted FVC (r=-0.22, B=-0.07, p=0.02). These results show noticeable predictive value of NT-pro-BNP for both cardiac and pulmonary performance in physiological conditions suggesting that NT-pro-BNP could be a common regulatory factor coordinating adaptation of heart and lungs to stress condition.

Comprehensive assessment of biventricular function and aortic stiffness in athletes with different forms of training by three-dimensional echocardiography and strain imaging

AIMS

Previous studies have shown distinct models of cardiac adaptations to the training in master athletes and different effects of endurance and strength-training on cardiovascular function. We attempted to assess left-ventricular (LV) function, aortic (Ao) function, and right-ventricular (RV) function in athletes with different forms of training by using three-dimensional (3D) echocardiography, tissue Doppler imaging (TDI) and speckle-tracking imaging (STI).

METHODS AND RESULTS

We examined 35 male marathon runners (endurance-trained athletes, ETA), 35 powerlifting athletes (strength-trained athletes, STA), 35 martial arts athletes (mixed-trained athletes, MTA), and 35 sedentary untrained healthy men (controls, CTR). Two-dimensional and three-dimensional echocardiography were performed for the assessment of LV and RV systolic/diastolic function. LV and RV longitudinal strain (LS) and LV torsion (LVtor) were determined using STI (EchoPAC BT11, GE-Ultrasound). Maximum velocity of systolic wall expansion peaks (AoSvel) was determined using TDI. ETA experienced LV eccentric hypertrophy with increased 3D LV end-diastolic volume and mass and significant increase in peak systolic apical rotation and LVtor. In all groups of athletes, RV-LS was reduced at rest and improved after exercise. AoSvel was significantly increased in ETA and MTA and significantly decreased in STA compared with CTR. There were good correlations between LV remodelling and aortic stiffness values. Multivariate analysis showed aortic wall velocities to be independently related to LV mass index.

CONCLUSION

In strength-trained, endurance-trained, and mixed-trained athletes, ventricular and vascular response assessed by 3DE, TDI, and STI underlies different adaptations of LV, RV, and aortic indexes.

Advanced echocardiographic techniques

Echocardiography has advanced significantly since its first clinical use. The move towards more accurate imaging and quantification has driven this advancement. In this review, we will briefly focus on three distinct but important recent advances, three‐dimensional (3D) echocardiography, contrast echocardiography and myocardial tissue imaging. The basic principles of these techniques will be discussed as well as current and future clinical applications.

Tissue Doppler Imaging: a promising technique for quantifying regional myocardial function

Tissue Doppler Imaging (TDI) is a recent ultrasound technique that enables the quantification of regional myocardial function by measuring myocardial velocities. Three TDI modes are available: pulsed wave mode, 2D color mode and color M-mode. Each of them allows the specific analysis of radial and longitudinal myocardial motion. Both phase and amplitude of regional myocardial motion may be analyzed by TDI. Therefore, TDI appears to be a precise non-invasive method for assessing myocardial dysfunction: several studies have already shown that TDI is a more sensitive technique than conventional echocardiography for detecting mild myocardial alterations in human heart diseases as well as in animal models.

[The various forms of left ventricular hypertrophy: diagnostic value of echocardiography]

Left ventricular hypertrophy is a non-specific physiological or maladaptive cardiac response to a large array of stimuli mediated by exercise and numerous cardiac and systemic diseases. The precise characterization and quantification of left ventricular hypertrophy may allow a more timely diagnosis of the underlying condition. The clinical reference standard to assess left ventricular hypertrophy is echocardiography, but a comprehensive description of how to approach this frequent finding in clinical practice is lacking. The current review systematically describes the typical echocardiographic patterns of important types of cardiac hypertrophy using both established and advanced imaging modalities. In hypertrophic obstructive cardiomyopathy a markedly reduced regional systolic function is found in the prominent thickened septum, whereas in essential arterial hypertension a typical concentric left ventricular hypertrophy with a less prominent basal septal bulge is present. The echocardiographic characteristics of cardiac amyloidosis are ventricular hypertrophy with sparkling granular myocardial texture and a small epicardial effusion. In addition, the strain rate curve for longitudinal function shows a typically reduced function which reaches maximum already in early systole. The typical feature of Friedreich cardiomyopathy is concentric left ventricular hypertrophy and sparkling granular texture with preserved regional systolic function. In Fabry cardiomyopathy a prominent papillary muscle is presented and a typical strain rate curve can be extracted from the basal lateral wall, indicating replacement fibrosis. Prominent hypertrabecularisation (ratio of non-compacted to compacted myocardium >2) in the apical and mid left ventricular segments is typical for non-compaction cardiomyopathy. Knowledge of these typical echocardiographic features enables the cardiologist to distinguish between the different hypertrophic entities, thus paving the way to early diagnosis.

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is a fascinating disease of marked heterogeneity. Hypertrophic cardiomyopathy was originally characterized by massive myocardial hypertrophy in the absence of known etiology, a dynamic left ventricular outflow obstruction, and increased risk of sudden death. It is now well accepted that multiple mutations in genes encoding for the cardiac sarcomere are responsible for the disease. Complex morphologic and pathophysiologic differences, disparate natural history studies, and novel treatment strategies underscore the challenge to the practicing cardiologist when faced with the management of the hypertrophic cardiomyopathy patient.

Echocardiographic assessment of myocardial strain

Echocardiographic strain imaging, also known as deformation imaging, has been developed as a means to objectively quantify regional myocardial function. First introduced as post-processing of tissue Doppler imaging velocity converted to strain and strain rate, strain imaging has more recently also been derived from digital speckle tracking analysis. Strain imaging has been used to gain greater understanding into the pathophysiology of cardiac ischemia and infarction, primary diseases of the myocardium, and the effects of valvular disease on myocardial function, and to advance our understanding of diastolic function. Strain imaging has also been used to quantify abnormalities in the timing of mechanical activation for heart failure patients undergoing cardiac resynchronization pacing therapy. Further advances, such as 3-dimensional speckle tracking strain imaging, have emerged to provide even greater insight. Strain imaging has become established as a robust research tool and has great potential to play many roles in routine clinical practice to advance the care of the cardiovascular patient. This perspective reviews the physiology of myocardial strain, the technical features of strain imaging using tissue Doppler imaging and speckle tracking, their strengths and weaknesses, and the state-of-the-art present and potential future clinical applications.

[The "athlete's heart": structure, function and differential diagnosis]

Long-term, intense sport activity induces morphologic and functional adaptations on cardiovascular system. The magnitude of these changes is determined by various factors, creating a specific condition: the "Athlete's Heart" (AH). It is important to distinguish this entity from other cardiomyopathies, taking into account that the differential diagnosis can be challenging. There has been an increase in the number of people practicing sports, which goes in parallel with the increase in the prevalence of AH. However, the proportion of asymptomatic subjects affected by cardiovascular diseases taking part on competitive sports, is also growing. We revise the main characteristics of AH, as well as the key points to distinguish AH from pathologic conditions. A delicate characterization as AH or cardiomyopathy would help to settle appropriate measures to lower the risk of sports-related sudden cardiac death.

The effect of exercise training on left ventricular function in young elite athletes

BACKGROUND

Regular training, in particular endurance exercise, induces structural myocardial adaptation, so-called "athlete's heart". In addition to the 2D standard echo parameters, assessment of myocardial function is currently possible by deformation parameters (strain, rotation and twist). Aim of study is to assess the role of rotation and twist parameters for better characterize the heart performance in trained elite young athletes from different kind of sports. Eventually, verify early on any possible impact due to the regular sport activity not revealed by the standard parameters.

METHODS

50 young athletes (16 cyclists, 17 soccer players, 17 basket players) regularly trained at least three times a week for at least 9 months a year and 10 young controls (mean age 18.5 ± 0.5 years) were evaluated either by to 2D echocardiography or by a Speckle Tracking (ST) multi-layer approach to calculate Left Ventricle (LV) endocardial and epicardial rotation, twist, circumferential strain (CS) and longitudinal strain (LS). Data were compared by ANOVA test.

RESULTS

All the found values were within the normal range. Left Ventricle Diastolic Diameter (LVDD 51.7 ± 2.6 mm), Cardiac Mass index (CMi 114.5 ± 18.5 g/m²), epi-CS, epi-LS, epicardial apex rotation and the Endo/Epi twist were significantly higher only in cyclists. In all the groups, a physiological difference of the Endo/Epi basal circumferential strain and twist values have been found. A weak but not significant relationship between the Endo and twist values and LVDD (r² = 0.44, p = .005) and CMi was also reported in cyclists.

CONCLUSIONS

Progressive increase of apical LV twist may represent an important component of myocardial remodelling. This aspect is particularly evident in the young cyclists group where the CMi and the LVDD are higher. ST multilayer approach completes the LV performance evaluation in young trained athletes showing values similar to adults.

Prevalence of suspected hypertrophic cardiomyopathy or left ventricular hypertrophy based on race and gender in teenagers using screening echocardiography

BACKGROUND

The goal of this study was to evaluate the prevalence of suspected hypertrophic cardiomyopathy (HCM) in a population of teenagers undergoing screening echocardiography for the detection of HCM.

METHOD

The Anthony Bates Foundation performs screening echocardiography for the prevention of sudden death. A total of 2,066 students were studied between the ages of 13 to 19 years. Suspected HCM was defined as any wall thickness ≥ 15 mm. LVH was defined as wall thickness ≥ 13 mm

RESULTS

Prevalence of suspected HCM was 0.7% (14/2066). After adjusting for hypertension (HTN), the total prevalence was 0.5% (8/1457). In a subgroup analysis, 551 teenagers with documented race and LV wall thickness were identified between the ages of 13-19 years. African American teenagers [6% (3/50)] had higher prevalence of suspected HCM [0.8% (4/501), OR 7.93, CI 1.72-36.49, p = 0.002]. After multivariate adjustment for age, gender, BMI and HTN (systolic BP >140 and diastolic BP of > 90), African American race remained independently associated with suspected HCM (OR 4.89, CI 1.24-39.62, p = 0.02).

CONCLUSION

The prevalence of suspected HCM in young teenagers is approximately 0.2%. This prevalence appears to be higher in African Americans. However, due to small number of African Americans in our population, our result needs to be confirmed in larger trials.

Early myocardial dysfunction after chronic use of anabolic androgenic steroids: combined pulsed-wave tissue Doppler imaging and ultrasonic integrated backscatter cyclic variations analysis

BACKGROUND

The chronic consumption of androgenic anabolic steroids (AAS) has shown to cause subclinical impairment of myocardial function. Pulsed-wave Doppler tissue imaging (PWDTI) detects early regional alterations of ventricular function, whereas integrated backscatter cyclic variations (IBScv) are tightly related to the contractile efficiency of the left ventricular wall. The aim of this study was to identify the effects of chronic AAS misuse on myocardial function using both PWDTI and IBScv.

METHODS

Twenty-eight male bodybuilders (11 AAS users, 17 AAS nonusers) and 20 healthy sedentary subjects (controls), matched according to age, were studied. To assess left ventricular function, each subject underwent standard Doppler echocardiography, PWDTI, and IBScv analyses.

RESULTS

Left ventricular mass was significantly higher in AAS users than in AAS nonusers and controls. Global systolic function (assessed by determining the ejection fraction) was similar in all subjects, but isovolumetric relaxation time was significantly higher in AAS users than in controls. On PWDTI analysis, AAS users showed regional systolic and diastolic dysfunction (evaluated by measuring s', e', and a') not detectable in the other two groups. IBScv identified regional systolic impairment only in AAS users at the level of the left ventricular inferior wall.

CONCLUSIONS

The present study confirms that in AAS users, PWDTI and IBScv are effective and reliable noninvasive diagnostic tools for detecting early abnormalities of the systolic and diastolic longitudinal myocardial function, probably related to an increase in myocardial collagen content, interpretable as a repair process against the direct cellular injury produced by AAS.

Evaluation of left atrial function in physiological and pathological left ventricular myocardial hypertrophy by real-time tri-plane strain rate imaging

BACKGROUND

We investigated the difference between left ventricular (LV) hypertrophy caused by primary hypertension and physiological LV hypertrophy in athletes as seen in left atrial (LA) function by real-time tri-plane strain rate imaging.

HYPOTHESIS

A real-time tri-plane imaging technique using the same phase of the same cardiac circle was used to synchronously demonstrate the section of apical 4-chamber, 2-chamber, and apical left ventricle long axis.

METHODS

We measured standard Doppler echocardiographic quantitative analysis and the strain rate peak values of each LA wall in the systolic phase, in the early stage of diastole, and in the advanced stage of diastole and made a comparison of these values.

RESULTS

The alteration of configuration and function of the left atrium in hypertensive patients is an early sign of the myocardial damage caused by hypertension. Strain rate imaging could sensitively reflect LA function changes in the early stages of hypertension. While physiological, myocardial hypertrophy is a benign reaction, LA function is significantly different from that of hypertension.

CONCLUSIONS

Real-time tri-plane strain rate imaging techniques could simultaneously analyze 3 sections, which shortens scanning time and depletes the influence of variations of different cardiac cycles on quantitative analysis of local myocardial segments of the left atrium. This would improve the comparability of myocardial movement of different segments so that we could more comprehensively and accurately evaluate the systolic and diastolic function of the left atrium in primary hypertension and physiological LV hypertrophy in athletes.

Preoperative systolic strain rate predicts postoperative left ventricular dysfunction in patients with chronic aortic regurgitation

BACKGROUND

The best predictor for postoperative left ventricular (LV) systolic dysfunction in patients with chronic aortic regurgitation is still a matter of debate. The aim of this study was to assess the clinical significance of preoperative systolic radial strain rate (Ssr) derived from tissue Doppler echocardiography as a predictor of postoperative LV systolic dysfunction in patients with chronic aortic regurgitation.

METHODS AND RESULTS

In 52 patients (mean age, 58 years; 13 women) with isolated chronic aortic regurgitation, we performed standard and tissue Doppler echocardiography before and after operation, obtained echocardiographic parameters such as LV dimensions and LV ejection fraction, and measured Ssr in 4 walls of the LV. Linear regression analysis determined correlations between preoperative parameters and postoperative LV ejection fraction. Receiver-operating characteristic curve analysis assessed the optimal cutoff values of parameters that predicted postoperative LV systolic dysfunction (ejection fraction <50%). The operation caused significant decreases in LV dimensions and volumes and significant increases in Ssr (1.94+/-0.64 to 2.39+/-0.83 per second; P<0.001) and ejection fraction (53.0+/-8.7 to 59.0+/-8.8%; P<0.001). Multiple regression analysis demonstrated that averaged Ssr was the only independent predictor of postoperative LV systolic dysfunction among the covariates examined (P<0.001). Using receiver-operating characteristic curve analysis, averaged Ssr yielded the greatest area under the curve among preoperative parameters (0.80) and was indicated to be a good predictor of postoperative LV dysfunction, with 90.9% sensitivity and 73.2% specificity (cutoff value, 1.82 per second).

CONCLUSIONS

Measurement of preoperative averaged Ssr is useful in predicting postoperative LV systolic dysfunction and optimizing surgical timing in patients with isolated chronic aortic regurgitation.

Phase rotation methods in filtering correlation coefficients for ultrasound speckle tracking

In speckle-tracking-based myocardial strain imaging, large interframe/volume peak-systolic strains cause peak hopping artifacts separating the highest correlation coefficient peak from the true peak. A correlation coefficient filter was previously designed to minimize peak hopping artifacts. For large strains, however, the correlation coefficient filter must follow the strain distribution to remove peak hopping effectively. This processing usually means interpolation and high computational load. To reduce the computational burden, a narrow band approximation using phase rotation is developed in this paper to facilitate correlation coefficient filtering. Correlation coefficients are first phase rotated to increase coherence, then filtered. Rotated phase angles are determined by the local strain and spatial position. This form of correlation coefficient filtering enhances true correlation coefficient peaks in large strain applications if decorrelation due to deformation does not completely destroy the coherence among neighboring correlation coefficients. The assumed strain used in the filter can also deviate from the true strain and still be effective. Further improvement in displacement estimation can be expected by combining correlation coefficient filtering with a new Viterbi-based displacement estimator.

[Correlation between atrial function and functional capacity in highly trained subjects]

AIM

The aim of the study is to show the relationship existing between tissular Doppler imaging (TDI) parameters and functional capacity in highly trained subjects.

METHODS AND PATIENTS

We therefore studied 46 patients including 22 untrained and 24 trained subjects. Each subject had pulsed TDI recording of systolic (S) and diastolic (E and A) longitudinal myocardial velocities in the basal portion of the RV free wall (RV), the septum (sep) and the LV free wall (LV) from apical 4C view. Athletes underwent the same day a cardiopulmonary test during which we measured peak V(O)2 (ml/kg/min) and anaerobic threshold (AT, ml/kg/min) and calculated VE/V(CO)2 slope. We studied differences between echocardiographic parameters in the two groups using Student test. Coefficients of correlations were calculated using the Spearman method.

RESULTS

Differences between two groups concerned Tei index of right (RV) and left ventricle (LV), telediastolic diameter of LV, and A waves on each wall. In athletes RV, sep and LV S waves did not correlate with V(O)2, AT or VE/V(CO)2 RV, sep and LV A waves correlated significantly and negatively with V(O)2, RV and sep A waves negatively with AT, and sep and LV A waves positively with VE/V(CO)2.

CONCLUSION

In athletes, atrial function shows a negative relationship with cardiopulmonary exercise parameters: the lower the proportion of LV filling due to atrial contraction, the better the level of functional capacity. This is probably due to myocardial structure, which allows more efficient early filling in hypertrophic athlete's heart.

Left ventricular hypertrophy in athletes

Participation in regular intensive exercise is associated with a modest increase in left ventricular wall thickness (LVWT) and cavity size. The magnitude of these physiological changes is predominantly determined by a variety of demographic factors which include age, gender, size, ethnicity, and sporting discipline. A small minority of male athletes participating in sporting disciplines involving intensive isotonic and isometric exercise may exhibit substantial increases in cardiac size that overlap with the phenotypic manifestation of the cardiomyopathies. The most challenging clinical dilemma incorporates the differentiation between physiological left ventricular hypertrophy (LVH) (athlete's heart) and hypertrophic cardiomyopathy (HCM), which is recognized as the commonest cause of non-traumatic exercise related sudden cardiac death in young (<35 years old) athletes. This review aims to highlight the distribution and physiological upper limits of LVWT in athletes, determinants of LVH in athletes, and echocardiographic methods of differentiating athlete's heart from HCM.

Hypertension and heart failure: a dysfunction of systole, diastole or both?

The pathological myocardial hypertrophy associated with hypertension contains the seed for further maladaptive development. Increased myocardial oxygen consumption, impaired epicardial coronary perfusion, ventricular fibrosis and remodelling, abnormalities in long-axis function and torsion, cause, to a varying degree, a mixture of systolic and diastolic abnormalities. In addition, chronotropic incompetence and peripheral factors such as lack of vasodilator reserve and reduced arterial compliance further affect cardiac output particularly on exercise. Many of these factors are common to hypertensive heart failure with a normal ejection fraction as well as systolic heart failure. There is increasing evidence that these apparently separate phenotypes are part of a spectrum of heart failure differing only in the degree of ventricular remodelling and volume changes. Furthermore, dichotomizing heart failure into systolic and diastolic clinical entities has led to a paucity of clinical trials of therapies for heart failure with a normal ejection fraction. Therapies aimed at reversing myocardial fibrosis, and targets outside the heart such as enhancing vasodilator reserve and improving chronotropic incompetence deserve further study and may improve the exercise capacity of hypertensive heart failure patients. Hypertension heart disease with heart failure is simply not a dysfunction of systole and diastole. Other peripheral factors including heart rate and vasodilator response with exercise may deserve equal attention in an attempt to develop more effective treatments for this disorder.

Evidence of left ventricular systolic and diastolic dysfunction by color tissue Doppler imaging despite normal ejection fraction in patients on chronic hemodialysis program

BACKGROUND

Cardiovascular diseases are responsible for about half of deaths and are the major cause of mortality in hemodialysis patients. The aim of this study is to assess left ventricular (LV) longitudinal myocardial functions by color tissue Doppler imaging (TDI) in patients with chronic renal failure on a regular hemodialysis program.

METHODS

Thirty-one patients on a regular hemodialysis program (mean age 47 +/- 12 years; 17 males, 14 females) were included into the study. Twenty-three healthy subjects (mean age 44 +/- 8 years; 15 males, 8 females) were studied as a control group. The patients had been on maintenance hemodialysis for at least 1 month and hemodialysis sessions were three times per week. For color TDI, apical two- and four-chamber views of left ventricle were used. Sample volumes were placed on the mid-left ventricle in the inner half of the myocardium at the septum, lateral, inferior, and anterior walls. Peak LV strain, peak systolic strain rate, peak early diastolic strain rate, peak late diastolic strain rate, peak systolic tissue velocity, peak early diastolic tissue velocity, and peak late diastolic tissue velocity values were measured.

RESULTS

Mean peak LV strain, mean peak systolic strain rate, and mean peak systolic tissue velocity values were all lower in the hemodialysis group. Although mean peak late diastolic strain rate and mean peak late diastolic tissue velocity values were similar between the groups, mean peak early diastolic strain rate and mean peak early diastolic tissue velocity values were lower in the hemodialysis group.

CONCLUSION

Patients with chronic renal failure on regular hemodialysis program show significant alterations at LV longitudinal myocardial function parameters assessed by color TDI.

Hypertrophic cardiomyopathy: etiology, diagnosis, and treatment

Hypertrophic cardiomyopathy (HCM) is a disease characterized by primary hypertrophy of the left (and sometimes right) ventricle. The clinical manifestations of the disease are dyspnea, angina, and a continuum encompassing lightheadedness, presyncope, syncope, and sudden death. Although HCM is often caused by an identifiable mutation in a gene coding for a sarcomeric protein and inherited in an autosomal-dominant pattern, many patients do not have any relatives in whom the disease is manifest. The prevalence of HCM is estimated to be 0.2%, with nearly 600,000 Americans affected. This limited exposure of clinicians to HCM understandably accounts for the uncertainty that prevails regarding this disease and its management.

Longitudinal plane colour tissue-Doppler myocardial velocities and their association with left ventricular length, volume, and mass in humans

AIMS

We investigated the relationships between colour tissue-Doppler parameters of left ventricular (LV) function and indices of LV morphology.

METHODS AND RESULTS

LV length, end-diastolic volume, and mass were assessed in 40 healthy adult subjects. Further, colour tissue-Doppler scans assessed peak myocardial velocities during systole (S') and early diastole (E') as well as acceleration during isovolumic contraction (IVCa) at the mitral annulus. Non-linear allometric relationships (Y = aX(b)) were calculated to provide size exponents (b), with 95% confidence intervals, for tissue-Doppler variables (Y) and LV morphology parameters (X). The b exponents for LV length with Peaks S' and E' were not substantially different from unity (b = 0.87 and 0.95, respectively, P > 0.05). Peak E' was also associated with LV volume (b = 0.39, r = 0.53, P < 0.05). IVCa was not related to any LV morphology parameter.

CONCLUSION

Peak S' or E' divided by LV length was confirmed as a valid size-independent scaling index. Conversely, IVCa is seemingly size independent.

Assessment of regional atrial function in patients with hypertrophic cardiomyopathies using tissue Doppler imaging

BACKGROUND

This study applied tissue Doppler imaging and color tissue Doppler imaging to study atrial function changes in patients with hypertrophic cardiomyopathy (HCM). The profile of the segmental atrial velocities and the strain rate were determined and compared with those of normal matched control subjects.

METHODS

This study investigated 20 patients with HCM and 20 age-matched healthy control subjects. In a four-chamber apical view, tissue Doppler imaging was used to measure the lateral left and right atrial (LA and RA) and interatrial septal (IAS) wall systolic, early, and late diastolic velocities. Similarly, the atrial strain rate during ventricular systole (SR(S)) and the early (SR(E)) and late (SR(A)) diastolic phases in patients and control subjects were measured. The interventricular septal tissue Doppler-derived isovolumic relaxation time was calculated.

RESULTS

Only the IAS annular and middle segments showed a significant reduction in the early diastolic velocity (mean, 4.01 +/- 2.2 vs 8.7 +/- 1.1, p = 0.001; 3.23 +/- 2 vs 6.01 +/- 1.9, p = 0.001, respectively) for the patients with HCM in comparison with the control subjects. Generally, the atrial strain rate was clearly reduced. The systolic strain rate (SR(S)) was significantly reduced in the LA wall in the annular (p = 0.007) and middle (p = 0.001) segments and in the IAS middle segment (p = 0.007). Similarly, there was a reduction of the early diastolic strain rate (SR(E)) in the LA annular (p = 0.001) and middle (p = 0.01) segments and in the IAS annular (p = 0.05) and middle (p = 0.001) segments, as well as in the RA annular segment (p = 0.02). The RA middle segments showed insignificant changes.

CONCLUSION

Atrial function may be affected by HCM due to impairment of myocardial diastolic function. Strain rate imaging is reproducible, yields readily obtained parameters that provide unique data about global and longitudinal segmental atrial contraction, and can quantify the atrial dysfunction in patients with HCM.

Detection of myocardial dysfunction in the presence of normal ejection fraction

Detection of subclinical myocardial involvement is of utmost importance in risk stratification and prognosis; the role of ejection fraction in the detection of subclinical disease may be unhelpful. Our aim was to evaluate the methodology and importance of early detection of myocardial involvement in the presence of normal ejection fraction. Most of the pertinent English and non-English articles published from 1980 to 2006 in Medline, Scopus, and EBSCO Host research databases have been reviewed. Serial assessment of systolic function with different techniques should be avoided, since imaging modalities and ejection fraction measurements are not interchangeable. Additional non-invasive tools still are needed for the identification of subclinical left ventricular dysfunction in certain diseases. The recognition of subclinical involvement will prompt initiation of specific therapy to prevent the development of overt left ventricular dysfunction. This also is needed for determining the best timing for intervention in asymptomatic patients with metabolic and valvular disorders.

An ultrasound speckle tracking (two-dimensional strain) analysis of myocardial deformation in professional soccer players compared with healthy subjects and hypertrophic cardiomyopathy

Deformation analysis using 2-dimensional strain echocardiography can detect early systolic function abnormalities in patients with left ventricular hypertrophy. This study was designed to characterize global and regional myocardial deformation using 2-dimensional strain in professional soccer players (PSPs) compared with control subjects and patients with hypertrophic cardiomyopathy (HC). Twenty nine PSPs, 26 patients with HC, and 17 controls were investigated at rest using transthoracic echocardiography with 2-dimensional strain analysis. Radial and transverse strains were significantly higher in PSPs compared with controls, whereas longitudinal strain was lower. Compared with patients with HC, athletes had higher values for transverse, radial, and circumferential strains. In pathologic hypertrophic segments, longitudinal strain was lower in patients with HC than in PSPs. In conclusion, 2-dimensional strain can identify specific patterns of myocardial deformation in PSPs, controls, and patients with HC. It has the potential to become a routinely used method for the differentiation of athlete's heart and HC.

Strain rate and tissue tracking imaging in quantitation of left ventricular systolic function in endurance and strength athletes

AIM

The aim of this study was to assess the impact of long-term physical training on left ventricular longitudinal contraction by strain rate analysis and tissue tracking imaging.

METHODS AND RESULTS

The study population comprised 17 male elite endurance and 15 male elite strength athletes and 12 male control subjects of similar age. Tissue Doppler imaging was recorded in the apical views and used for analysis of the longitudinal systolic myocardial velocity, annular diastolic velocities, strain rate and tissue tracking. Left ventricular mass index was significantly increased in both endurance athletes (209+/-40 g/m(2)) and strength athletes (138+/-38 g/m(2)) compared with normal subjects (96+/-20 g/m(2), P<0.001). Tissue tracking score index and mean strain rate of the 16 segments were significantly increased in strength athletes (7.9+/-1.1 mm and -1.4+/-0.3 s(-1), respectively) compared with endurance athletes (7.5+/-0.9 mm and -1.0+/-0.4 s(-1), P<0.01 for both) and normal subjects (7.4+/-1.0 mm and -1.0+/-0.3 s(-1), P<0.01 for both).

CONCLUSION

Despite significant left ventricular hypertrophy and extensive training in elite athletes, we found normal longitudinal left ventricular systolic function, and in strength athletes performing isometric exercise even increased function.