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Giuseppe Limongelli

Publications and source records attributed to Giuseppe Limongelli.

23 records · Page 2Linked to original sources
PubMed2003

Left ventricular remodeling, mechanics, and tissue characterization in congenital aortic stenosis.

BACKGROUND: As the response of the myocardium to pressure overload is age-dependent, this study was designed to examine left ventricular (LV) remodeling, mechanics, and tissue characterization in children with moderate congenital aortic stenosis. METHODS: We studied by echocardiography Doppler 22 patients (mean age 12.4 +/- 5.6 years) with peak and mean transvalvular gradient of 63 +/- 6 and 32 +/- 4 mm Hg, respectively. In addition, 30 age- and body surface area-matched participants with structurally normal hearts were used as a control group. Sex- and age-specific cut-off levels for LV mass/height(2.7) and relative wall thickness were defined to assess LV geometry. As a load-independent index of myocardial contractility, the relation between the rate-corrected velocity of circumferential fiber shortening both at endocardium and midwall, and meridional end-systolic stress was assessed. In addition, LV diastolic function was also evaluated by the mitral flow indexes. Finally, ultrasonic tissue characterization of the LV myocardium was performed by calculating the magnitude of cyclic variation, which reflects the intramural contractile function, and the averaged myocardial intensity of integrated backscatter, which is directly related to the myocardium collagen content. RESULTS: The endocardial velocity of circumferential fiber shortening endocardium and meridional end-systolic stress relationship was within the normal range (mean +/- 2SD) in 18 of 22 patients (81.8%), and midwall velocity of circumferential fiber shortening at endocardium and meridional end-systolic stress was normal in all 22 patients. No mitral flow index of LV diastolic function was significantly different between aortic stenosis group and normal participants. In our study population, 16 of 22 patients (72.7%) showed normal LV geometry, 3 (13.6%) had a pattern of concentric remodeling, and 3 (13.6%) concentric hypertrophy. LV hypertrophy was not marked (left ventricular mass index [LVMI] < 51 g/m(2.7)) in any patient. Finally, compared with control participants our study population showed, both at interventricular septum and posterior wall, comparable values of cyclic variation integrated backscatter, but significantly higher values of averaged myocardial integrated backscatter intensity (P <.01). CONCLUSIONS: In children with moderate congenital aortic stenosis, the total amount of myocardial collagen was increased despite normal LV myocardial contractility and diastolic function. Furthermore, LV remodeling was abnormal in only about a quarter of our patients and none had more than mild hypertrophy. Although the majority of these patients do not have markers now recognized to predict higher risk of cardiovascular events, the long-term significance of myocardial fibrosis and its response to treatment remain to be investigated.

Adolescent↗
PubMed2003

Myocardial ultrasound tissue characterization in patients with hypertrophic cardiomyopathy: noninvasive evidence of electrical and textural substrate for ventricular arrhythmias.

BACKGROUND: Although in patients with hypertrophic cardiomyopathy (HCM) pathologic studies seem to suggest a correlation between morphologic findings and arrhythmias, it has never been confirmed in the clinical setting. OBJECTIVE: We sought to noninvasively assess the electrical and textural properties of the myocardium and to define their potential relationship in patients with HCM. METHODS: We studied 48 patients: 22 with HCM (mean age: 22 +/- 5.1 years) and 26 age- and body surface area-matched healthy patients. They underwent a standard echocardiographic examination to assess left ventricular size and thickness. In addition, by integrated backscatter analysis, we assessed textural properties of left ventricular myocardium with calibrated averaged intensity (IB) and to assess functional properties of the myocardium with cyclic variation, both at the interventricular septum (IVS) and posterior wall. Finally, we studied ventricular late potentials (VLPs) by signal-averaged electrocardiography and performed a 24-hour electrocardiography Holter monitoring to respectively define electrical instability and ventricular arrhythmias. RESULTS: Compared with control patients, patients with HCM had, both at IVS and posterior wall, increased IB (-28.8 +/- 10 vs -35 +/- 4 dB [P =.007] and -29 +/- 8 vs -33 +/- 5 dB [P <.035], respectively) and decreased cyclic variation (6.8 +/- 2.7 vs 10.3 +/- 2.3 dB [P <.001] and 8.2 +/- 2.9 vs 11.4 +/- 2.1 dB [P <.001], respectively). In all, 5 patients with HCM had positivity of VLPs, and 4 of them showed nonsustained ventricular tachycardia (nsVT) on the Holter monitoring. Compared with patients who had HCM without VLPs and nsVT, patients with positivity of VLPs and nsVT showed higher IB both at IVS (-15.8 +/- 8.4 vs -32.6 +/- 5.9 dB [P <.001] and -16.6 +/- 9.5 vs -31.5 +/- 7.5 dB [P =.002], respectively) and at posterior wall (-19.08 +/- 8.42 vs -32.5 +/- 4.2 dB [P <.001] and -22.4 +/- 4.6 vs -31 +/- 7.5 [P =.04], respectively). A multivariate analysis showed IB at IVS (P =.042; odds ratio = 1.19) and positivity of VLPs (P =.026; odds ratio = 3.67) as independent predictors of nsVT. CONCLUSION: Patients with HCM showed abnormal morphologic and electrical properties of the myocardium. The correlation between VLPs and IB at IVS and their relationship with nsVT suggests a link between textural and electrical nonhomogeneity of myocardial fibers, a potential substrate of nsVT in patients with HCM.

Adolescent↗
PubMed2002

Association between left ventricular structure and cardiac performance during effort in two morphological forms of athlete's heart.

AIM: The aim of the study was to evaluate in 263 competitive athletes possible correlations between changes induced by different sport activities in left ventricular (LV) structure and cardiac response during maximal physical effort. METHODS: A total of 160 top-level endurance athletes (ATE; swimmers, runners; 28+/-4 years; 98 male) and 103 strength-trained athletes (ATS; weight-lifters, body-builders; 27+/-5 years; male), selected on the basis of training protocol (dynamic vs. static exercise), underwent standard Doppler echocardiography, heart rate variability analysis and maximal exercise stress test by bicycle ergometry. M- and B-mode echocardiographic LV measurements were determined at rest, while the following functional indexes were assessed during effort: maximal heart rate (HR), maximal systolic blood pressure (SBP) and maximal workload (Watts reached by bicycle test). RESULTS: The two groups were comparable for age and sex, but ATS at rest showed higher HR, SBP, and body surface area (BSA). By echo analysis, LV mass index and ejection fraction did not significantly differ between the two groups. However, ATS showed increased sum of wall thickness (septum+posterior wall), relative wall thickness and LV end-systolic stress, while LV stroke volume and LV end-diastolic diameter (P<0.01) were greater in ATE. HR variability analysis underlined in ATE increased indexes of vagal tone (P<0.01). During maximal physical effort, ATE showed a better functional capacity, with greater maximal workload (P<0.001) reached with lower maximal HR and SBP. After adjusting for HR, age, sex, BSA and SBP, distinct multiple linear regression models evidenced in ATE independent associations of maximal effort workload with LV end-diastolic diameter (P<0.001), HR (P<0.001) at rest and LV end-systolic stress (P<0.01) were found in ATE. On the other hand, independent direct correlation of SBP max during effort with sum of wall thickness (P<0.001), BSA (P<0.05) and LV end-systolic stress (P<0.001) was evidenced in ATS. CONCLUSIONS: LV structural changes in competitive athletes represent adaptation to hemodynamic overload induced by training and are consistent with different kinds of sport activity. Work capacity during exercise is positively influenced by preload increase in ATE, while increased afterload due to isometric training in ATS determines higher systemic resistance during physical effort.

Adult↗
PubMed2002

Effects of different training protocols on left ventricular myocardial function in competitive athletes: a Doppler tissue imaging study.

BACKGROUND: The aim of the study was to analyze the differences in myocardial function in case of left ventricular (LV) hypertrophy induced by either endurance or strength training in top-level athletes. METHODS: Standard Doppler echo and pulsed Doppler tissue imaging (DTI) of the interventricular septum and of the LV inferior wall were performed in 26 competitive endurance athletes (long-distance swimmers) (group A) and in 20 strength-trained athletes (short-distance swimmers) (group B). By means of DTI, the following parameters of myocardial function were assessed: the systolic peak velocities (Sm), the pre-contraction time, the contraction time, the early (Em) and late (Am) diastolic velocities, the Em/Am ratio and the relaxation time. RESULTS: The two groups were comparable for age and sex, but at rest group B showed a higher heart rate, systolic blood pressure and body surface area. The LV mass index and fractional shortening did not significantly differ between the two groups. However, group B showed an increased sum of the wall thicknesses (septum + posterior wall) (p < 0.001) and of the relative wall thickness, while the LV stroke volume and LV end-diastolic diameter (p < 0.001) were greater in group A. All transmitral Doppler indexes were higher in group A, with an increased E/A ratio. DTI analysis showed, in group A, a higher Em and Em/Am ratio as well as a longer relaxation time both at the septal and at the inferior wall levels, with comparable Sm, pre-contraction and contraction times. Distinct multiple linear regression models revealed an independent positive association between the inferior peak Em velocity and the LV end-diastolic diameter (p < 0.001) in group A, and an independent direct correlation of the inferior peak Sm velocity with the sum of the wall thicknesses (p < 0.001) and with the end-systolic stress in group B. CONCLUSIONS: The early diastolic myocardial function is positively influenced by the preload increase in group A, while an increased afterload and LV wall thickness in group B mainly seem to induce an enhancement of the regional myocardial systolic function.

Adaptation, Physiological↗