Arterial Blood-Flow Acceleration Time on Doppler Ultrasound Waveforms: What Are We Talking About?

In recent years, the assessment of systolic acceleration in lower-extremity peripheral artery disease (PAD) has been brought back into the spotlight, whatever measure is used: time (in s) or acceleration (in cm.s-2). Acceleration time (also called systolic rise time) and maximal acceleration are two different but very useful measurements of growing interest in PAD. A background of the historical development, physics rationale, semantics, and methods of measurement, as well as their strengths and weaknesses, are discussed herein. Acceleration time is a powerful tool for predicting significant arterial stenosis or for estimating the overall impact of PAD as it is highly correlated to the ankle or toe pressure indexes. It could even become a new diagnostic criterion for critical limb ischemia. Similarly, maximal systolic acceleration ratios are highly predictive of carotid or renal stenosis. However, the literature lacks reference standards or guidelines for the assessment of such variables, and their measurement techniques seem to differ between authors. We propose herein a semantic and measurement statement order to clarify and help standardize future research.

Direct Determination rather than Oscillometric Estimation of Systolic Blood Pressure in Patients with Severe Chronic Kidney Disease.

INTRODUCTION: Although arterial hypertension is a major concern in patients with chronic kidney disease (CKD), obtaining accurate systolic blood pressure (SBP) measurement is challenging in this population for whom automatic oscillometric devices may yield erroneous results. METHODS: This cross-sectional study was conducted in 89 patients with stages 4, 5, and 5D CKD, for whom we compared SBP values obtained by the recently described systolic foot-to-apex time interval (SFATI) technique which provides direct SBP determination, the standard technique (Korotkoff sounds), and oscillometry. We investigated the effects of age, sex, diabetes, CKD stage, and pulse pressure to explain measurement errors defined as biases or misclassification relative to the SBP thresholds of 110-130-mm Hg. RESULTS: All 3 techniques showed satisfactory reproducibility for SBP measurement (CCC > 0.84 and >0.91, respectively, in dialyzed and nondialyzed patients). The mean ± SD from SBP as determined via Korotkoff sounds was 1.7 ± 4.6 mm Hg for SFATI (CCC = 0.98) and 5.9 ± 9.3 mm Hg for oscillometry (CCC = 0.88). Referring to the 110-130-mm Hg SBP range outside which treatment prescription or adaptation is recommended for CKD patients, SFATI underestimated SBP in 3 patients and overestimated it in 1, whereas oscillometry underestimated SBP in 12 patients and overestimated it in 3. Higher pulse pressure was the main explanatory factor for measurement and classification errors. DISCUSSION/CONCLUSION: SFATI provides accurate SBP measurements in patients with severe CKD and paves the way for the standardization of automated noninvasive blood pressure measurement devices. Before prescribing or adjusting antihypertensive therapy, physicians should be aware of the risk of misclassification when using oscillometry.

Acute effects of graduated and progressive compression stockings on leg vein cross-sectional area and viscoelasticity in patients with chronic venous disease.

OBJECTIVE: To determine the effects of graduated and progressive elastic compression stockings (ECS) on postural diameter changes and viscoelasticity of leg veins in healthy controls and in limbs with chronic venous disease (CVD). METHODS: In 57 patients whose legs presented with C1s, C3, or C5 CEAP classes of chronic venous disease and were treated primarily with compression, and 54 healthy controls matched for age and body mass index, we recorded interface pressures (IFP) at 9 reference leg levels. Cross-sectional areas of the small saphenous vein (SSV) and a deep calf vein (DCV) were measured with B-mode ultrasound with patients supine and standing, recording the force (PF) applied on the ultrasound probe to collapse each vein with progressive ECS, and with and without graduated 15 to 20 mm Hg and 20 to 36 mm Hg elastic stockings. We chose these veins because they were free of detectable lesion and could be investigated at the same level (mid-height of the calf), and their compression by the ultrasound probe was not hampered by bone structures. RESULTS: IFP decreased from ankle to knee with graduated 15 to 20 and 20 to 36 mm Hg, but increased with progressive ECS, and were 8.4 to 13.8 mm Hg lower for C1s than for control or C3 and C5 limbs. Without ECS, the SSV median [lower-upper quartile] cross-sectional area was 4.9 mm2 [3.6-7.1 mm2] and 7.1 mm2 [3.0-9.9 mm2] in C3 and C5 limbs versus 2.9 mm2 [1.8-5.2 mm2] and 3.8 mm2 [2.1-5.4 mm2] in controls (P < .01), respectively, while supine and standing. It remained greater in C3 and C5 than in C1s and control limbs wearing any ESC. Wearing compression, especially with progressive ECS, decreased the SSV and DCV cross-sectional area only with patients supine, thus decreasing postural changes, which remained highly diverse between individuals. The SSV cross-sectional area versus PF function traced a hysteresis loop of which the area, related to viscosity, was greater in C3 and C5 limbs than controls, even with graduated 15 to 20 or 20 to 36 mm Hg ECS. Progressive ECS decreased vein viscosity in the supine position, whereas 20 to 36 mm Hg and progressive ECS increased distensibility in the standing position. CONCLUSIONS: ECS decrease the cross-sectional area of SSV and DCV with patients supine, but not upright. C1s limbs show distinctive features, especially regarding IFP. Graduated 20 to 36 mm Hg and progressive stockings lower viscosity and increase distensibility of the SSV.

Skin Layer Thickness and Shear Wave Elastography Changes Induced by Intensive Decongestive Treatment of Lower Limb Lymphedema.

Background: A detailed quantitative evaluation would be beneficial for management of patients with limb lymphedema. Methods and Results: In 47 patients with lower limb lymphedema at International Society of Lymphology clinical stage 2A (18 limbs), 2B (41 limbs), and 3 (13 limbs), we measured the limb circumference and thickness of epidermis, dermis, and subcutis layers with B-mode ultrasonography and subcutis elastic modulus with ultrafast shear wave velocity (ultrasound elastography) at 5 anatomical levels (M1 to M5) before and after a 3- to 5-day intensive decongestive therapy (IDT) session. Limb circumference and thickness of the epidermis, dermis, and subcutis were greater in the 72 limbs with lymphedema than in the 22 unaffected limbs before and after IDT. The affected limb volume was 10,980 [8458-13,960] mL before and 9607 [7720-11,830] mL after IDT (p < 0.0001). The IDT-induced change in subcutis thickness was -9 [-25 to 13]% (NS), -11 [-26 to 3]% (p = 0.001), -18 [-40 to -1]% (p < 0.0001), -15 [-35 to 3]% (p = 0.0003), and -25 [-45 to -4]% (p < 0.0001) and significantly correlated with the change in elastic modulus, which was 13 [-21 to 90]% (p = 0.004), 33 [-27 to 115]% (p = 0.0002), 40[-13 to 169]% (p < 0.0001), 9 [-36 to 157]% (p = 0.024), and -13 [-40 to 97]% (NS), respectively, at the M1, M2, M3, M4, and M5 levels. Intraobserver reproducibility was satisfactory for skin thickness and fairly good for elastography, but interobserver reproducibility was poor or unacceptable. Conclusions: IDT reduced the circumference and subcutis thickness of lower limbs with lymphedema and increased their elastic modulus, implying greater tissue stiffness probably due to fluid evacuation. Although subcutis thickness measurement proved to be reliable, technological and methodological improvements are required before ultrasonographic elastography can be used in clinical practice.

Noninvasive measurement of venous wall deformation induced by changes in transmural pressure shows altered viscoelasticity in patients with chronic venous disease.

OBJECTIVE: The noninvasive measurement of venous wall deformation induced by changes in transmural pressure could allow for the assessment of viscoelasticity and differentiating normal from diseased veins. METHODS: In 57 patients with limbs in the C1s (telangiectasia or reticular veins and symptoms), C3 (edema), or C5 (healed venous ulcer) CEAP (clinical, etiologic, anatomic, pathophysiologic) category of chronic venous disease and 54 matched healthy controls, we measured the changes in the cross-sectional area of the small saphenous vein and a deep calf vein in the supine and standing positions and under compression with an ultrasound probe using ultrasonography. RESULTS: The small saphenous vein, but not the deep calf vein, cross-sectional area was smaller in the limbs of the controls than in the limbs with C3 or C5 disease but was not different from that in C1s limbs. When changing from the supine to the standing position, a greater force was required to collapse the leg veins. Their cross-sectional area increased in most subjects but decreased in 31.5% of them as for the small saphenous veins and 40.5% for the deep calf vein. The small saphenous vein area vs compression force function followed a hysteresis loop, demonstrating viscoelastic features. Its area, which represents the viscosity component, was greater (P < .001) in the pooled C3 and C5 limbs (median, 2.40 N⋅mm2; lower quartile [Q1] to upper quartile [Q3], 1.65-3.88 N⋅mm2) than in the controls (median, 1.24 N⋅mm2; Q1-Q3, 0.64-2.14 N⋅mm2) and C1s limbs (median, 1.15 N⋅mm2; Q1-Q3, 0.71-2.97 N⋅mm2). The area increased (P < .0001) in the standing position in all groups. CONCLUSIONS: Postural changes in the cross-sectional area of the leg veins were highly diverse among patients with chronic venous disease and among healthy subjects and appear unsuitable for pathophysiologic characterization. In contrast, small saphenous vein viscoelasticity increased consistently in the standing position and the viscosity was greater in limbs with C3 and C5 CEAP disease than in controls.

Systolic peak foot-to-apex time interval, a novel oscillometric technique for systolic blood pressure measurement.

BACKGROUND: Noninvasive blood pressure (BP) measurement is essential for the study of human physiology but automatic oscillometric devices only estimate SBP and DBP using various, undisclosed algorithms, precluding standardization and interchangeability. We propose a novel approach by tracking, during pneumatic cuff deflation, the time interval from the foot to the apex of the systolic peak of the oscillometric signal, which reaches a maximum concomitant with the first Korotkoff sound. METHOD: In 145 study participants and patients (group 1), we measured the systolic brachial artery blood pressure by Korotkoff sound recording, conventional oscillometry, and our fully automated systolic peak foot-to-apex time interval (SFATI) technique. In 35 other patients (group 2), we compared SFATI with intra-arterial measurement. RESULTS: In group 1, the concordance correlation coefficient was 0.989 and 0.984 between SFATI and Korotkoff sounds, 0.884 and 0.917 between oscillometry and Korotkoff sounds, and 0.882 and 0.919 between SFATI and oscillometry, respectively, on the left and right arm. In group 2, it was 0.72 between SFATI and intra-arterial measurement, 0.67 between oscillometry and intra-arterial measurement, and 0.92 between SFATI and Korotkoff sounds. In 40 study participants, the reproducibility study yielded a concordance coefficient of 0.95 for SFATI and 0.94 for Korotkoff sounds. CONCLUSION: SFATI BP measurement shows an excellent concordance with the auscultatory technique, offering a major improvement over current oscillometric techniques and allowing standardization.

An ultrasound look at Korotkoff sounds: the role of pulse wave velocity and flow turbulence.

AIMS: The aim of this study was to analyze the temporal relationships between pressure, flow, and Korotkoff sounds, providing clues for their comprehensive interpretation. MATERIALS AND METHODS: When measuring blood pressure in a group of 23 volunteers, we used duplex Doppler ultrasonography to assess, under the arm-cuff, the brachial artery flow, diameter changes, and local pulse wave velocity (PWV), while recording Korotkoff sounds 10 cm downstream together with cuff pressure and ECG. RESULTS: The systolic (SBP) and diastolic (DBP) blood pressures were 118.8±17.7 and 65.4±10.4 mmHg, respectively (n=23). The brachial artery lumen started opening when cuff pressure decreased below the SBP and opened for an increasing length of time until cuff pressure reached the DBP, and then remained open but pulsatile. A high-energy low-frequency Doppler signal, starting a few milliseconds before flow, appeared and disappeared together with Korotkoff sounds at the SBP and DBP, respectively. Its median duration was 42.7 versus 41.1 ms for Korotkoff sounds (P=0.54; n=17). There was a 2.20±1.54 ms/mmHg decrement in the time delay between the ECG R-wave and the Korotkoff sounds during cuff deflation (n=18). The PWV was 10±4.48 m/s at null cuff pressure and showed a 0.62% decrement per mmHg when cuff pressure increased (n=13). CONCLUSION: Korotkoff sounds are associated with a high-energy low-frequency Doppler signal of identical duration, typically resulting from wall vibrations, followed by flow turbulence. Local arterial PWV decreases when cuff pressure increases. Exploiting these changes may help improve SBP assessment, which remains a challenge for oscillometric techniques.

Endurance training minimizes age-related changes of left ventricular twist-untwist mechanics.

BACKGROUND: The aim of this study was to test the effect of endurance training on the age-related changes of left ventricular (LV) twist-untwist mechanics. Aging has been shown to induce a decline of diastolic function and more recently an impairment of twist-untwist mechanics, which constitutes an important factor for early diastolic suction and filling. On the other hand, endurance training has been shown to improve cardiac function. METHODS: Speckle-tracking echocardiography was performed in 106 endurance-trained male athletes and 75 controls (age range 18-70 years), divided into three groups according to age. RESULTS: From the younger to older age groups, progressive increases in LV apical rotation and twist angle and a decrease in LV untwisting rate during isovolumic relaxation time were observed. Athletes had lower systolic twist angles (P < .01) but higher untwist/twist ratios and LV untwisting rate during isovolumic relaxation time compared with controls, with the largest difference between senior groups (51 ± 24% vs 42 ± 22% in the young and 42 ± 29% vs 24 ± 25% in seniors, P < .001, respectively). The normal timing of untwisting rate occurring before radial displacement was preserved in athletes with increasing age, whereas it was blunted in controls. CONCLUSIONS: Endurance training does not prevent but minimizes changes in LV twist-untwist mechanics from young subjects to seniors. Athletes showed smaller increases of twist angle with age and smaller declines of LV untwisting rate during isovolumic relaxation time and untwist/twist ratio compared with controls. This training-improved preservation of LV twist-untwist mechanics is likely to play a key role for systolic-diastolic coupling and diastolic filling, particularly during exercise.

Systems medicine approaches for the definition of complex phenotypes in chronic diseases and ageing. From concept to implementation and policies.

Chronic diseases are diseases of long duration and slow progression. Major NCDs (cardiovascular diseases, cancer, chronic respiratory diseases, diabetes, rheumatologic diseases and mental health) represent the predominant health problem of the Century. The prevention and control of NCDs are the priority of the World Health Organization 2008 Action Plan, the United Nations 2010 Resolution and the European Union 2010 Council. The novel trend for the management of NCDs is evolving towards integrative, holistic approaches. NCDs are intertwined with ageing. The European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) has prioritised NCDs. To tackle them in their totality in order to reduce their burden and societal impact, it is proposed that NCDs should be considered as a single expression of disease with different risk factors and entities. An innovative integrated health system built around systems medicine and strategic partnerships is proposed to combat NCDs. It includes (i) understanding the social, economic, environmental, genetic determinants, as well as the molecular and cellular mechanisms underlying NCDs; (ii) primary care and practice-based interprofessional collaboration; (iii) carefully phenotyped patients; (iv) development of unbiased and accurate biomarkers for comorbidities, severity and follow up of patients; (v) socio-economic science; (vi) development of guidelines; (vii) training; and (viii) policy decisions. The results could be applicable to all countries and adapted to local needs, economy and health systems. This paper reviews the complexity of NCDs intertwined with ageing. It gives an overview of the problem and proposes two practical examples of systems medicine (MeDALL) applied to allergy and to NCD co-morbidities (MACVIA-LR, Reference Site of the European Innovation Partnership on Active and Healthy Ageing).

Specific left ventricular twist-untwist mechanics during exercise in children.

BACKGROUND: In adults, left ventricular (LV) systolic twist is an important factor that determines LV filling, both at rest and during exercise. In children, lower LV twist has been demonstrated at rest, but its adaptation during exercise and its functional consequences on LV filling are unknown. METHODS: Using speckle-tracking echocardiography, LV twist-untwist mechanics were studied in 25 children (aged 10-12 years) and 20 young adults (aged 18-44 years) at rest and during three exercise workloads performed at 20%, 30%, and 40% of their maximal aerobic power. RESULTS: At rest, LV twist was lower in children, because of a higher temporal dispersion of peak rotation between base and apex. During exercise, the increase of basal rotation was blunted in children compared with adults (-6.7 ± 2.7° vs -9.0 ± 2.0° at 40% of maximal aerobic power, P < .05). Consequently, LV twist increased to a lesser extent (13.0 ± 5.0° vs 15.8 ± 4.5° at 40% of maximal aerobic power, P < .05). The increase in LV untwisting rates during exercise was also lower in children, leading to a lower percentage of untwisting during early diastole (8 ± 8% vs 29 ± 20% at 40% of maximal aerobic power, P < .001). Consequently, during early diastole, the normal timing of diastolic events observed in young adults, with untwist occurring before radial displacement, was blunted in children. Nevertheless, children exhibited normal LV filling due to higher diastolic radial and longitudinal strain rates. CONCLUSIONS: Twist-untwist mechanics may evolve with advancing age. In children, early diastolic LV untwisting appears to be less important than in adults. Their better LV intrinsic myocardial relaxation may ensure adequate LV filling during exercise without dependence on the additional effect of suction resulting from LV energy recoil.

Diastolic dysfunction and intraventricular dyssynchrony are restored by low intensity exercise training in obese men.

The aim of this study was to evaluate the impact of a low-intensity training program on subclinical cardiac dysfunction and on dyssynchrony in moderately obese middle aged men. Ten obese and 14 age-matched normal-weight men (BMI: 33.6 ± 1.0 and 24.2 ± 0.5 kg/m(2)) were included. Obese men participated in an 8-week low-intensity training program without concomitant diet. Cardiac function and myocardial synchrony were assessed by echocardiography with tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE). At baseline, obese men showed diastolic dysfunction on standard echocardiography, lower strain values (systolic strain: 15.9 ± 0.9 vs. 18.8 ± 0.3%, diastolic strain rate: 0.81 ± 0.09 vs. 1.05 ± 0.06 s(-1)), and significant intraventricular dyssynchrony (systolic: 13.3 ± 2.1 vs. 5.4 ± 2.1 ms, diastolic: 17.4 ± 3.2 vs. 9.1 ± 2.1 ms) (P < 0.05 vs. controls for all variables). Training improved aerobic fitness, decreased systolic blood pressure and heart rate, and reduced fat mass without weight loss. Diastolic function, strain values (systolic strain: 17.4 ± 0.9%, diastolic strain rate: 0.96 ± 0.12 s(-1)) and intraventricular dyssynchrony (systolic: 3.3 ± 1.7 ms, diastolic: 5.5 ± 3.4 ms) improved significantly after training (P < 0.05 vs. baseline values for all variables), reaching levels similar to those of normal-weight men. In conclusion, in obese men, a short and easy-to-perform low intensity training program restored diastolic function and cardiac synchrony and improved body composition without weight loss.

Comparative incidence of a first thrombotic event in purely obstetric antiphospholipid syndrome with pregnancy loss: the NOH-APS observational study.

The incidence of thrombosis in the purely obstetric form of antiphospholipid syndrome is uncertain. We performed a 10-year observational study of 1592 nonthrombotic women who had experienced 3 consecutive spontaneous abortions before the 10th week of gestation or 1 fetal death at or beyond the 10th week of gestation. We compared the frequencies of thrombotic events among women positive for antiphospholipid Abs (n = 517), women carrying the F5 6025 or F2 rs1799963 polymorphism (n = 279), and women with negative thrombophilia screening results (n = 796). The annual rates of deep vein thrombosis (1.46%; range, 1.15%-1.82%), pulmonary embolism (0.43%; range, 0.26%-0.66%), superficial vein thrombosis (0.44%; range, 0.28%-0.68%), and cerebrovascular events (0.32%; range, 0.18%-0.53%) were significantly higher in aPLAbs women than in the other groups despite low-dose aspirin primary prophylaxis. Women carrying 1 of the 2 polymorphisms did not experience more thrombotic events than women who screened negative for thrombophilia. Lupus anticoagulant was a risk factor for unprovoked proximal and distal deep and superficial vein thrombosis and women in the upper quartile of lupus anticoagulant activity had the highest risk. Despite data suggesting that aPLAbs may induce pregnancy loss through nonthrombotic mechanisms, women with purely obstetric antiphospholipid syndrome are at risk for thrombotic complications.

Addition of enoxaparin to aspirin for the secondary prevention of placental vascular complications in women with severe pre-eclampsia. The pilot randomised controlled NOH-PE trial.

Administration of heparin in the secondary prevention of placental vascular complications is still experimental. In women with a previous severe pre-eclampsia, we investigated the effectiveness of enoxaparin, a low-molecular-weight heparin, in preventing these complications. Between January 2000 and January 2010, 224 women from the NOHA First cohort, with previous severe pre-eclampsia but no foetal loss during their first pregnancy and negative for antiphospholipid antibodies, were randomised to either a prophylactic daily dose of enoxaparin starting from the positive pregnancy test (n=112), or no enoxaparin (n=112). The primary outcome was a composite of at least one of the following: pre-eclampsia, abruptio placentae, birthweight ≤ 5th percentile, or foetal loss after 20 weeks. Enoxaparin was associated with a lower frequency of primary outcome: 8.9% (n=10/112) vs. 25 % (28/112), p=0.004, hazard ratio = 0.32, 95% confidence interval (0.16-0.66), p=0.002. Enoxaparin was safe, with no obvious side-effect, no thrombocytopenia nor major bleeding event excess. This pilot study shows that enoxaparin given early during the second pregnancy decreases the occurrence of placental vascular complications in women with a previous severe pre-eclampsia during their first pregnancy.

Systems medicine and integrated care to combat chronic noncommunicable diseases.

We propose an innovative, integrated, cost-effective health system to combat major non-communicable diseases (NCDs), including cardiovascular, chronic respiratory, metabolic, rheumatologic and neurologic disorders and cancers, which together are the predominant health problem of the 21st century. This proposed holistic strategy involves comprehensive patient-centered integrated care and multi-scale, multi-modal and multi-level systems approaches to tackle NCDs as a common group of diseases. Rather than studying each disease individually, it will take into account their intertwined gene-environment, socio-economic interactions and co-morbidities that lead to individual-specific complex phenotypes. It will implement a road map for predictive, preventive, personalized and participatory (P4) medicine based on a robust and extensive knowledge management infrastructure that contains individual patient information. It will be supported by strategic partnerships involving all stakeholders, including general practitioners associated with patient-centered care. This systems medicine strategy, which will take a holistic approach to disease, is designed to allow the results to be used globally, taking into account the needs and specificities of local economies and health systems.

Enoxaparin for the secondary prevention of placental vascular complications in women with abruptio placentae. The pilot randomised controlled NOH-AP trial.

Administration of heparin in the secondary prevention of placental vascular complications is still experimental. In women with a previous placental abruption, we investigated the effectiveness of enoxaparin, a low-molecular-weight heparin, in preventing these complications. Between January 2000 and January 2009, 160 women from the NOHA First cohort, with previous abruptio placentae but no foetal loss during their first pregnancy and negative for antiphospholipid antibodies, were randomised to either a prophylactic daily dose of enoxaparin starting from the positive pregnancy test (n=80), or no enoxaparin (n=80). The primary outcome was a composite of at least one of the following: abruptio placentae, preeclampsia, birthweight < 5th percentile, or foetal loss after 20 weeks. Enoxaparin was associated with a lower frequency of primary outcome: 12.5% (n=10/80) vs. 31.3 % (25/80), p=0.004, adjusted hazard ratio = 0.37, 95% confidence interval (0.18-0.77), p=0.011. Enoxaparin was safe, with no obvious side-effect, no thrombocytopenia nor major bleeding event excess. This pilot study shows that enoxaparin given early during the second pregnancy decreases the occurrence of placental vascular complications in women with a previous placental abruption during their first pregnancy.

Kinetics of left ventricular strains and torsion during incremental exercise in healthy subjects: the key role of torsional mechanics for systolic-diastolic coupling.

BACKGROUND: The dynamics of systolic and diastolic strains and torsional mechanics of the left ventricle (LV) and their relation to diastolic filling never have been evaluated at various exercise intensities. METHODS AND RESULTS: Speckle tracking echocardiography was performed in 20 healthy sedentary subjects at rest and during a progressive submaximal exercise test at 20%, 30%, and 40% of maximal aerobic power. LV twist increased progressively with exercise intensity (10.5 ± 3.2 to 15.8 ± 4.5°; P<0.001), whereas longitudinal strain remained unchanged after the first workload, underlining the key role of torsional reserve in systolic-diastolic coupling during exercise. The increase in diastolic untwisting (-88.7 ± 34.2 to -182.9 ± 53.5 deg · s(-1); P<0.01) was correlated to enhanced systolic twist (R=0.61; P<0.001), and its magnitude of increase was significantly higher compared to diastolic longitudinal and circumferential strain rates (119 ± 64% versus 65 ± 44% and 57 ± 24%, respectively), emphasizing its contribution to diastolic filling. The timing of peak untwisting and the chronology of diastolic mechanical events were unchanged during effort. Untwisting was driven mainly by apical rotation and determined mitral opening and isovolumic relaxation time (R=0.47 and 0.61, respectively; P<0.001), whereas basal rotation and longitudinal and circumferential diastolic strain rates were major determinants of increased early diastolic filling (R=0.64, 0.79, and 0.81, respectively; P<0.001). CONCLUSIONS: The use of speckle tracking echocardiography gives new insights into physiological adaptive LV mechanics during incremental exercise in healthy subjects, underlining the key role of torsional mechanics. It might be useful to better understand the mechanisms of diastolic dysfunction and exercise intolerance in various pathological conditions.

Alteration in left ventricular strains and torsional mechanics after ultralong duration exercise in athletes.

BACKGROUND: Numerous studies have reported evidence of cardiac injury associated with transient left ventricular (LV) systolic and diastolic dysfunction after prolonged and strenuous exercise. We used 2D ultrasound speckle tracking imaging to evaluate the effect of an ultralong-duration exercise on LV regional strains and torsion. We speculated that systolic dysfunction after exercise is associated with depressed LV strains and torsion, and diastolic dysfunction results from decreased and delayed untwisting, a key factor of LV suction and early filling. METHODS AND RESULTS: Twenty-three triathletes underwent conventional and speckle tracking imaging echocardiography at rest before and immediately after an ultralong distance triathlon. Measurements included LV longitudinal, circumferential and radial strains, LV rotations, and LV torsion. After the race, LV systolic dysfunction was characterized by a decrease in LV longitudinal, radial, and circumferential strains, especially for apical radial strains (44.6+/-15.1% versus 31.1+/-13.8%, P<0.001). Peak torsion was slightly decreased (8.3+/-5.1 degrees versus 6.4+/-3.9 degrees , respectively, P=0.09) and significantly delayed (91+/-18% versus 128+/-31% of systolic duration, P<0.001) beside end-ejection. Peak untwisting was also depressed and delayed beside isovolumic relaxation. CONCLUSIONS: This study documented major alterations in cardiac strains and torsion after an ultralong distance triathlon. LV systolic strains were depressed but not delayed, whereas twisting was decreased and delayed. This altered pattern hampered the rapid untwisting during isovolumic relaxation phase, reducing LV diastolic suction and early filling.

Silent cardiac dysfunction and exercise intolerance in HIV+ men receiving combined antiretroviral therapies.

Resting and exercise cardiac function, skeletal muscle oxygenation and whole-body aerobic exercise capacities were evaluated prospectively in cardiac symptom-free HIV men receiving antiretroviral therapies and in healthy controls matched for age, physical activity, smoking and body surface area. HIV patients showed resting cardiac dysfunction, altered cardiac responses to exercise and depressed exercise tolerance. Exercise stroke volume kinetics and muscle oxygenation were impaired in HIV patients, especially in those with resting diastolic dysfunction.