Arcangelo D'Errico

Speckle-Tracking Echocardiography A New Technique for Assessing Myocardial Function

Speckle‐tracking echocardiography has recently emerged as a quantitative ultrasound technique for accurately evaluating myocardial function by analyzing the motion of speckles identified on routine 2‐dimensional sonograms. It provides non‐Doppler, angle‐independent, and objective quantification of myocardial deformation and left ventricular systolic and diastolic dynamics. By tracking the displacement of the speckles during the cardiac cycle, strain and the strain rate can be rapidly measured offline after adequate image acquisition. Data regarding the feasibility, accuracy, and clinical applications of speckle‐tracking echocardiography are rapidly accumulating. This review describes the fundamental concepts of speckle‐tracking echocardiography, illustrates how to obtain strain measurements using this technique, and discusses their recognized and developing clinical applications.

Nebivolol improves coronary flow reserve in hypertensive patients without coronary heart disease.

Objective To examine the effects of nebivolol, a β-blocker with nitroxide-mediated vasodilating properties, on coronary flow reserve (CFR) in patients with uncomplicated arterial hypertension. Design, setting and patients Fourteen newly diagnosed, never-treated, World Health Organization grade I–II hypertensive patients (male/female, 10/4; mean age, 47 years), free of coronary heart disease, underwent standard Doppler echocardiography and determination of CFR in the distal left anterior descending artery by low-dose dipyridamole (0.56 mg/kg intravenously in 4 min) at baseline and after 4 weeks of treatment with 5 mg nebivolol once daily. Results At baseline, nine patients had left ventricular (LV) hypertrophy (LV mass index ⩾ 51 g/m2.7). After 4 weeks of therapy, the blood pressure was decreased from 148 ± 8.1/101.4 ± 4.6 mmHg to 140.7 ± 7.0/91.1 ± 7.4 mmHg and end-systolic stress was also significantly reduced. Heart rate was reduced (P < 0.01), whereas LV end-diastolic diameter and stroke volume tended to increase (P = 0.07 and P = 0.09, respectively). No changes were detected in the LV mass index, relative wall thickness, fractional shortening and LV diastolic properties. Both resting and dipyridamole rate–pressure products were lower after nebivolol but dipyridamole-induced changes were not influenced by the therapy. In contrast, nebivolol therapy did not alter coronary velocities at rest, but caused a greater increase in coronary velocities after dipyridamole (P < 0.03), leading to a greater CFR (2.12 ± 0.33 versus 1.89 ± 0.31, P < 0.0001). Nebivolol induced an absolute increase of 8% in the CFR in nine of 14 patients (64.3%). Conclusions In hypertensive patients free of coronary artery disease, 4-week nebivolol therapy induces a significant increase of the CFR. Nebivolol preserves coronary flow at rest despite the reduction of metabolic (O2 consumption) and hemodynamic (diastolic blood pressure) determinants. The increase of hyperemic coronary velocities appears due to the reduction of coronary resistance.

Echocardiography in patients with hypertrophic cardiomyopathy: usefulness of old and new techniques in the diagnosis and pathophysiological assessment

Hypertrophic cardiomyopathy (HCM) is one of the most common inherited cardiomyopathy. The identification of patients with HCM is sometimes still a challenge. Moreover, the pathophysiology of the disease is complex because of left ventricular hyper-contractile state, diastolic dysfunction, ischemia and obstruction which can be coexistent in the same patient. In this review, we discuss the current and emerging echocardiographic methodology that can help physicians in the correct diagnostic and pathophysiological assessment of patients with HCM.

Plasma leptin concentration, insulin sensitivity, and 24-hour ambulatory blood pressure and left ventricular geometry

Left ventricular (LV) hypertrophy is an important predictor of cardiovascular morbidity and mortality. Hemodynamic factors, such as 24-h blood pressure (BP) values, are responsible for left ventricular hypertrophy in hypertensives. On the other hand, some metabolic factors have also been suggested to affect LV mass and geometry. In particular, plasma leptin concentrations have been found associated to LV myocardial growth. Because chronic leptin infusion stimulates sympathetic nervous system activity and increases BP levels, the role of 24-h BP values on leptin-related changes in myocardial wall geometry cannot be ruled out. Thus, the aim of our study was to evaluate whether the relationship between plasma leptin levels and LV wall thickness is mediated by 24-h BP values in hypertensive male patients. Thirty-six newly diagnosed hypertensive patients underwent Doppler echocardiographic examination, 24-h ambulatory BP recording, and metabolic (euglycemic hyperinsulinemic glucose clamp and fasting plasma leptin levels) measurements. Left ventricular mass correlated positively only with ambulatory diastolic BP (DBP) values, whereas the indices of myocardial wall growth such as interventricular septum thickness and sum of wall thickness (ie, septal + posterior wall thickness) correlated either with 24 h, daytime, or nighttime DBP, as well as with fasting plasma glucose, fasting plasma leptin, and insulin action after adjustment for age, body mass index (BMI), and waist/hip ratio (WHR). In contrast, plasma leptin concentration did not correlate with clinical and ambulatory BP values. A multiple linear regression analysis allowed to investigate the independent role of main anthropometric and cardiovascular covariates on the sum of wall thickness variability. A model that includes age, BMI, WHR, fasting plasma leptin concentration, plasma Na+ concentration, insulin action, and nighttime DBP explained 68% of the sum of wall thickness variability. In such a model, plasma leptin concentration (P < .001), insulin action (P < .029), and nighttime DBP (P < .002) were significantly and independently associated with myocardial wall thickness. In conclusion, our study demonstrates that in hypertensive men fasting plasma leptin levels are determinant of myocardial wall thickness independently of 24-h BP values.

Cardiovascular Complications in Acromegaly: Methods of Assessment

Cardiac involvement is common in acromegaly. Evidence for cardiac hypertrophy, dilation and diastolic filling abnormalities has been widely reported in literature. Generally, ventricular hypertrophy is revealed by echocardiography but early data referred increased cardiac size by standard X-ray. Besides, echocardiography investigates cardiac function and value disease. There are new technologic advances in ultrasonic imaging. Pulsed Tissue Doppler is a new non-invasive ultrasound tool which extends Doppler applications beyond the analysis of intra-cardiac flow velocities until the quantitative assessment of the regional myocardial left ventricular wall motion, measuring directly velocities and time intervals of myocardium. The radionuclide techniques permit to study better the cardiac performance. In fact, diastolic as well as systolic function can be assessed at rest and at peak exercise by equilibrium radionuclide angiography. This method has a main advantage of providing direct evaluation of ventricular function, being operator independent. Coronary artery disease has been poorly studied mainly because of the necessity to perform invasive procedures. Only a few cases have been reported with heart failure study by coronarography and having alterations of perfusion which ameliorated after somatostatin analog treatment. More recently, a few data have been presented using perfusional scintigraphy in acromegaly, even if coronary artery disease does not seem very frequent in acromegaly. Doppler analysis of carotid arteries can be also performed to investigate atherosclerosis: however, patients with active acromegaly have endothelial dysfunction more than clear-cut atherosclerotic plaques. In conclusion, careful assessments of cardiac function, morphology and activity need in patients with acromegaly.

Independent association of plasma leptin levels and left ventricular isovolumic relaxation in uncomplicated hypertension.

BACKGROUND On the basis of evidence of plasma leptin (LE) effects on cardiovascular system, we assessed possible association of LE and Doppler-derived left ventricular (LV) diastolic function in arterial hypertension. METHODS Doppler echocardiography, blood sample for fasting plasma LE levels, and euglycemic hyperinsulinemic glucose clamp were performed on 15 healthy insulin-sensitive men and 40 newly diagnosed hypertensive men, who were divided into two groups according to insulin sensitivity degree: 15 insulin sensitive (IS) and 25 insulin resistant (IR) individuals (whole body glucose disposal >33.3 and <33.3 micromol/kg, respectively). RESULTS The IR hypertensives had significantly higher body mass index (BMI), waist/hip ratio, LE and LV mass index than the other two groups. IR hypertensives had lower LE (even after adjusting for BMI and waist/hip ratio) and among LV diastolic indexes, lower E peak velocity (P < .05) and longer isovolumic relaxation time (IVRT) (P < .001) in comparison to IR hypertensives. IR hypertensives had the lowest E/A ratio (0.88 +/- 0.2) compared to IS patients (1.03 +/- 0.1 P < .05) and controls (1.31 +/- 10.2 P < .001). By multiple linear regression analyses performed both in the overall population and hypertensives, LV mass index and LE were independently associated to IVRT (R2 = 0.41 in overall population, R2 = 0.42 in hypertensives, both P < .0001), whereas age, heart rate, diastolic and systolic blood pressure (BP), BMI, waist/hip ratio, and insulin action were not significant. CONCLUSIONS Our study underscores an independent association of increased plasma LE and lengthening of isovolumic relaxation in uncomplicated hypertension. Further studies will need to understand the conditions underlying both these phenomena.

Transthoracic coronary flow reserve and dobutamine derived myocardial function: a 6-month evaluation after successful coronary angioplasty

After percutaneous transluminal coronary angioplasty (PTCA), stress-echocardiography and gated single photon emission computerized tomography (g-SPECT) are usually performed but both tools have technical limitations. The present study evaluated results of PTCA of left anterior descending artery (LAD) six months after PTCA, by combining transthoracic Doppler coronary flow reserve (CFR) and color Tissue Doppler (C-TD) dobutamine stress.Six months after PTCA of LAD, 24 men, free of angiographic evidence of restenosis, underwent standard Doppler-echocardiography, transthoracic CFR of distal LAD (hyperemic to basal diastolic coronary flow ratio) and C-TD at rest and during dobutamine stress to quantify myocardial systolic (Sm) and diastolic (Em and Am, Em/Am ratio) peak velocities in middle posterior septum. Patients with myocardial infarction, coronary stenosis of non-LAD territory and heart failure were excluded. According to dipyridamole g-SPECT, 13 patients had normal perfusion and 11 with perfusion defects. The 2 groups were comparable for age, wall motion score index (WMSI) and C-TD at rest. However, patients with perfusion defects had lower CFR (2.11 ± 0.4 versus 2.87 ± 0.6, p < 0.002) and septal Sm at high-dose dobutamine (p < 0.01), with higher WMSI (p < 0.05) and stress-echo positivity of LAD territory in 5/11 patients. In the overall population, CFR was related negatively to high-dobutamine WMSI (r = -0.50, p < 0.01) and positively to high-dobutamine Sm of middle septum (r = 0.55, p < 0.005).In conclusion, even in absence of epicardial coronary restenosis, stress perfusion imaging reflects a physiologic impairment in coronary microcirculation function whose magnitude is associated with the degree of regional functional impairment detectable by C-TD.

Coronary vasoreactivity is not altered in young people with type 1 diabetes

BACKGROUND AND AIM Abnormal coronary microvascular circulation has been demonstrated in diabetes and is associated with increased rate of cardiovascular events. Our objective was to evaluate coronary vasoreactivity in young people with type 1 diabetes with and without microvascular complications. METHODS AND RESULTS Twenty-five type 1 diabetic patients without microvascular complications (DC-), 23 with microvascular complications (DC+), and 18 control subjects (C) were studied. Coronary vasoreactivity was assessed by means of coronary flow reserve (CFR). Blood flow velocity in the left anterior descending coronary artery was measured at rest and after high-dose dipyridamole using transthoracic color-guided pulsed Doppler echocardiography. CFR was defined as the ratio of hyperaemic to resting diastolic peak flow velocities. The three groups had similar cardiac function parameters, and also systolic and diastolic blood pressure at rest, which remained unchanged during dipyridamole infusion. Resting coronary flow velocity was comparable in C, DC-, and DC+ (p=ns). Dipyridamole infusion produced a threefold increase in coronary diastolic peak velocity, which reached similar values in C (0.69±0.16 m/s), DC- (0.69±0.18 m/s), and DC+ (0.66±0.11 m/s). Mean CFR ratio was similar in C (3.33±0.66), DC- (3.30±0.51), and DC+ (3.24±0.60). At multiple linear regression analysis, no association was found between CFR and age, sex, HbA(1c), duration of diabetes, and complications. CONCLUSION Coronary vasodilatory function is preserved in young D patients, even those with early microvascular complications, suggesting that coronary vasoreactivity deteriorates at more advanced stages of microvascular complications and/or in the presence of other cardiovascular risk factors.

383 The impact of cholesterol on coronary flow reserve in hypertensive patients without evidence of coronary heart disease

Background: It has been demonstrated that the maximal oxygen uptake (VO2max) is strictly related to functional status (NYHA Class) in patients with idiopathic dilative cardiomyopathy (IDC) and therefore represents an important clinical predictor. The VO2max is the physiological trigger to increase the coronary flow reserve (CFR). At present it is possible noninvasively evaluate the CFR by transthoracic echocardiography on left anterior descending (LAD) coronary artery. Methods: We have consecutively enrolled 26 patients (pts), 16 Male mean age 64±b12 years, all affected with IDC confirmed by normal coronary artery with angiography. Each of them underwent TTE, evaluating the standard parameters such as LVEDV, LVESV (ml), EF (%) and Stress-Echo with Dipirydamole (0,84 mg/Kg over 6 m’) evaluating the LV contractility (WMSI) and simultaneously the CFR on LAD, calculated as the maximum peak-rest diastolic flow velocity (LADDFVDp-r) ratio, using a high frequency probe in 2ˆ harmonic (7 MHz). We utilized an off axis apical approach under the guide of color-Doppler and when necessary we injected a contrast agent (Sonovue 2ml in bolus) to improve the signal-noise coronary flow ratio. All pts underwent within 24 hour the effort test (treadmill) with gas analysis evaluating particularly the VO2max (ml/kg/m’) and anaerobic threshold. We considered as clinical parameter the NYHA Class. Results: We found the following mean values: EDV = 226 ± 63ml, ESV = 144 ± 52ml, EF = 36 ± 6%, WMSIb = 1,8 ± 0,3, LADDFVr 31 ± 4cm/s, LADDFVp = 59 ± O8cm/s, CFR = 1,9 ± 0,2, VO2max = 19 ± O6, NYHA Class = 2,3 ± 0,8 The parameters that demonstrated a significance linear statistical relationship were: NYHA Class vs MVO2: r = 0,70 p = 0.002 NYHA Class vs RC: r = 0.92 p = 0.001 VO2max vs CFR: r = 0.60 p = 0.016 VO2max vs LADDFVDr: r = 0.60 p = 0.020 The feasibility of CFR study in pts affected with IDC was excellent: 27/27 pts (100%) Conclusion: The excellent relationship between the NYHA Class and VO2max and between CFR and VO2max suggest us to consider the CFR of LAD in daily practice as an important functional predictor: this, in the next future could have a relevant therapeutic and prognostic impact in pts with IDC.