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.

[Transthoracic real-time three-dimensional echocardiography: clinical role, value and limitations in assessing heart valves]. / Ecocardiografia tridimensionale transtoracica in tempo reale. Applicazioni, vantaggi e limiti per lo studio delle valvulopatie.

The introduction of three-dimensional echocardiography and its evolution from time-consuming and cumbersome off-line reconstruction to real-time volumetric technique (real-time three-dimensional echocardiography) are one of the most significant advances in ultrasound imaging of the heart of the past decade. This imaging modality currently provides realistic views of cardiac valves capable of demonstrating the anatomy of various heart valve diseases in a unique, noninvasive manner. In addition, real-time three-dimensional echocardiography offers completely new views of the valves and surrounding structures, and allows accurate quantification of severity of valve disease. This article reviews the advantages of real-time three-dimensional echocardiography in assessing heart valves and shows also technological limitations in order to provide the scientific basis for its clinical use.

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.

[Real-time multiplane echocardiography. Current applications, limits and perspectives]. / Ecocardiografia multiplanare in tempo reale. Applicazioni attuali, limiti e prospettive.

Echocardiography is the most commonly used imaging technique in current clinical cardiology practice and is usually performed using a monoplane approach. In recent years new matrix-array transducers have become available that allow the real-time simultaneous display of two or more echocardiographic scanning planes from the same acoustic window. This multiplane approach is particularly interesting as it may reduce, during the examination, the number of probe movements and consequently facilitate image acquisition. In some clinical applications, moreover, the multiplane approach improves both accuracy and reproducibility of echocardiography. This review evaluates the state of the art of multiplane echocardiography and discusses possible clinical applications, advantages and limitations of this technique.

[Real-time three-dimensional echocardiography: current applications, advantages and limits for the evaluation of the left ventricle]. / Ecocardiografia tridimensionale in tempo reale. Attuali applicazioni, vantaggi e limiti per lo studio del ventricolo sinistro.

In the last decades the introduction and development of echocardiography allowed a significant improvement in the diagnosis as well as in the morphological and functional evaluation of several heart diseases, and today many therapeutic decisions are taken based on the results of the echocardiographic examination. One of the most important development in the field of echocardiography is three-dimensional imaging, which has evolved from the slow and labor-intense off-line reconstruction techniques to the faster and simpler real-time volumetric imaging, which has the potential to be integrated in routine clinical practice. One of the major proven advantages of real-time three-dimensional echocardiography is the evaluation of left ventricular volume, mass and function, which is achieved by eliminating the need for geometric modeling and the errors caused by foreshortened views. In this review we discuss the state-of-the-art and anticipate future developments of real-time three-dimensional echocardiography that are relevant to its application to the left ventricle.

[Echocardiographic evaluation of the athlete's heart: from morphological adaptations to myocardial function]. / Lo studio ecocardiografico del cuore d'atleta: dagli adattamenti morfologici alla funzione miocardica.

The definition of the athlete's heart includes the mechanisms of cardiac adaptation to training, characterized by the increase of internal chamber dimensions, ventricular wall thickness, and atrial chambers. The morphology of the athlete's heart is intermediate between concentric and eccentric left ventricular hypertrophy (LVH), in relation to the large prevalence of mixed sports activities and training protocols (including both aerobic and anaerobic exercise). Echocardiography is the tool of choice for the assessment of the athlete's heart and also for the differentiation of physiologic and pathologic LVH (hypertrophic cardiomyopathy and LVH due to arterial hypertension). The initial echocardiographic approach includes the quantitative analysis of the left ventricle, in order to calculate left ventricular mass, left ventricular mass index and relative wall thickness for diagnosing concentric or eccentric LVH. Tissue Doppler (pulsed or color modality) and strain rate imaging (Doppler or two-dimensional modality) may give additional information to the standard indices of systolic function. Diastolic function can be evaluated not only by standard Doppler transmitral inflow measurements but also using pulsed tissue Doppler, which may allow to distinguish the athlete's LVH from diastolic impairment of hypertensive patients or hypertrophic cardiomyopathy by the simple determination of myocardial early diastolic velocity. Also the morphological and functional features of the left atrium and of the right ventricle can be assessed in the athlete's heart by combining standard echocardiography with new echocardiographic technologies.

[B-type natriuretic peptide and Doppler echocardiography in the diagnosis of heart failure: alternative or complementary tools?]. / Peptide natriuretico di tipo B ed ecocardiografia Doppler nella diagnosi di scompenso cardiaco: metodiche alternative o complementari?

Several studies have demonstrated the usefulness of B-type natriuretic peptide (BNP) dosage in patients referring for acute dyspnea in the emergency department. BNP is strongly associated not only with the evidence but even with the degree of heart failure, and BNP values are particularly increased in the advanced NYHA classes and in patients with poor prognosis. High BNP levels correlate with echocardiographic indexes of left ventricular and right ventricular systolic dysfunction but even better with diastolic dysfunction and degree of left ventricular filling pressure. However, in presence of some clinical confounders, such as obesity, renal insufficiency and anemia, BNP dosage itself cannot be interpretable. Under these circumstances, Doppler echocardiography is able to identify with better accuracy patients affected by heart failure. Algorithms built taking into account clinical and echocardiographic parameters as well as BNP measurements are already available in the guidelines of the European Society of Cardiology on heart failure with normal ejection fraction. They will lead to a better and earlier identification, better risk stratification and management of patients referring for heart failure.

Nebivolol induces parallel improvement of left ventricular filling pressure and coronary flow reserve in uncomplicated arterial hypertension.

PURPOSE: Our aim was to analyze the effects of 3-month antihypertensive therapy by nebivolol, a beta-blocking agent with nitric oxide-mediated vasodilatory properties, on coronary flow reserve (CFR) and left ventricular filling pressure (LVFP) in uncomplicated arterial hypertension. METHODS: Twenty newly diagnosed, never treated, uncomplicated hypertensive patients (14 male and six female patients, mean age = 49 years), I-II WHO grade, underwent single-blind nebivolol treatment. At baseline and at 3-month follow-up, patients underwent Doppler echocardiography including pulsed Tissue Doppler of septal mitral annulus: the ratio between transmitral E velocity and myocardial early diastolic velocity (E/Em ratio) was calculated as an index of LVFP degree. Transthoracic Doppler-derived CFR (high-dose dipyridamole coronary diastolic peak flow velocity to resting coronary peak flow velocity ratio) of distal left anterior descending artery was also determined. RESULTS: After 3-month nebivolol therapy, rate-pressure product decreased (P < 0.0001). No significant change of left ventricular mass index, relative wall thickness and midwall shortening was detected. Left ventricular end-diastolic diameter and stroke volume were both marginally increased. Nebivolol increased Em (P < 0.0001), reduced E/Em ratio (from 9.0 +/- 1.6 to 8.2 +/- 1.1, P < 0.0001) and enhanced CFR (from 2.07 +/- 0.2 to 2.20 +/- 0.2, P = 0.003), because of increased hyperemic coronary flow velocity (P < 0.001). CFR increase remained significant (P < 0.001) after normalizing resting and dipyridamole coronary velocities for the respective rate-pressure product. The increase of normalized CFR induced by nebivolol was related with E/Em ratio decrease (r = -0.65, P < 0.002). CONCLUSION: Nebivolol improves LVFP as well as CFR in uncomplicated hypertension. The association between changes of CFR and those of LVFP indicates a possible common denominator between improvement of coronary microvascular function and myocardial stimulation of nitric oxide release induced by the drug.

Endothelial-mediated coronary flow reserve in patients with mild thyroid hormone deficiency.

CONTEXT: Although coronary flow reserve (CFR) is reduced in patients with subclinical hypothyroidism (SHypo), the endothelial response of coronary vasomotion has never been explored in this clinical setting. OBJECTIVE: To investigate the endothelial response of coronary flow in young and middle-aged patients with SHypo, without associated cardiovascular risk factors compared with healthy control subjects. PATIENTS AND METHODS: The study population consisted of 20 women (mean age 38.4+12.1 years) with newly diagnosed, untreated and persistent SHypo due to Hashimoto's thyroiditis. A total of 15 volunteers served as controls. Age, gender, body surface area, glucose, insulin levels, heart rate, systolic, diastolic, and mean blood pressure were similar in patients and controls. Body mass index was significantly higher in SHypo patients. Total cholesterol and low-density lipoprotein cholesterol, despite not significant, tended to be higher, and high-density lipoprotein cholesterol to be lower in SHypo. Coronary blood flow velocities were recorded in patients at rest and after the cold pressor test (CPT), a stimulus that can be considered totally endothelium-dependent. CFR was calculated as the ratio of hyperemic-to-resting diastolic peak velocities. RESULTS: Coronary diastolic peak velocities at rest did not differ between the two groups but were significantly lower after CPT in patients with SHypo, thereby resulting in a lower CFR. The difference remained significant after adjusting resting and CPT velocities for the respective mean blood pressures. TSH was inversely correlated with CFR in the pooled population. CONCLUSION: Patients with SHypo without associated cardiovascular risk factors have a coronary endothelial dysfunction that appears in response to a physiological stimulus (the CPT).

Independent association of coronary flow reserve with left ventricular relaxation and filling pressure in arterial hypertension.

BACKGROUND: It has been recognized that "cross-talk" occurs between coronary flow and left ventricular (LV) function. This study tested the hypothesis that impairment of coronary flow reserve (CFR) in arterial hypertension is associated with LV systolic and diastolic dysfunction, independent of abnormalities in LV geometry. METHODS: We studied 59 newly diagnosed, never-treated hypertensive patients, using transthoracic Doppler echocardiography including pulsed Tissue Doppler of mitral annulus and CFR on left anterior descending artery (low-dose dipyridamole). The study population was divided into two groups on the basis of age-normalized relative wall thickness (RWTn): 36 patients with normal LV geometry (RWTn < or = 0.41) and 23 patients with LV concentric geometry (RWTn > 0.41). RESULTS: Patients with LV concentric geometry (RWTn > 0.41) had significantly lower values of midwall shortening (but not of endocardial shortening), longer isovolumic relaxation time (IVRT), lower Tissue Doppler-derived early diastolic velocity (Em), higher ratio of transmitral E velocity to Em, and lower CFR as compared to patients with normal LV geometry (RWTn < or = 0.41). In the whole population, a lower CFR was significantly associated with lower values of midwall shortening and Em, longer IVRT, and higher E/Em ratio. After controlling for heart rate, mean blood pressure, and RWTn, only the relation of CFR with IVRT, Em, and E/Em ratio remained significant. CONCLUSIONS: Reduced midwall mechanics is associated with lower CFR, a relationship that depends on LV concentric geometry. A reduced CFR is associated with both impaired relaxation and increased filling pressure, a relation that is independent of LV geometry and pressure load.

Beta-blockers and coronary flow reserve: the importance of a vasodilatory action.

Coronary flow reserve (CFR) is the maximal increase in coronary blood flow (CBF) above its resting level for a given perfusion pressure when coronary vasculature is maximally dilated. Normally, hyperaemic CBF reaches values at least 2- to 3-fold greater than resting CBF. Reduction of CFR is mainly due to epicardial coronary artery stenosis or to coronary microvascular dysfunction. CFR can be determined by several techniques that measure CBF itself (e.g. positron emission tomography) or CBF velocities (Doppler methods) from which coronary flow velocity reserve is calculated. Hyperaemic coronary vasodilation can be obtained by pharmacological agents (e.g. adenosine and dipyridamole), but also by the cold pressure test. Long-term antihypertensive treatment induces significant improvement of CFR, which is parallel to the regression of left ventricular (LV) hypertrophy. First- and second-generation beta-adrenergic receptor antagonists (beta-blockers) have shown contradictory influences on CFR. This can be explained by the interaction of the effects on CBF at rest, generally reduced by these drugs, and after hyperaemia, when minimal coronary resistance appears to be either increased or reduced. Third-generation beta-blockers (e.g. carvedilol and nebivolol), which have vasodilating capacity, improve hyperaemic CBF. This occurs as a result of a reduction in minimal resistance, which can be attributed to alpha-adrenergic blockade and/or to a nitric oxide-mediated effect. This improvement is clearly beneficial in patients with coronary artery disease and indicates an improved coronary microvascular function. Changes of CFR due to vasodilating beta-blockers improve microvascular angina pectoris or silent ischaemia in patients without epicardial artery stenosis, and are also helpful in predicting the response or the further improvement of LV function to treatment.

Determinants of reduction of coronary flow reserve in patients with type 2 diabetes mellitus or arterial hypertension without angiographically determined epicardial coronary stenosis.

BACKGROUND: Coronary flow reserve (CFR) may be reduced even in the absence of coronary artery disease. We investigated the determinants of CFR impairment in Type 2 diabetes mellitus (DM2) and in arterial hypertension (HTN) without epicardial coronary artery stenosis. METHODS: Twenty-eight patients with DM2 and 27 with HTN, both with normal coronary angiography, and 18 healthy controls underwent transthoracic echocardiography, including Doppler recording of the distal left anterior descending artery, at rest as well as after high-dose dipyridamole. Coronary flow reserve was calculated as the hyperemic to resting coronary diastolic peak velocities ratio. RESULTS: The three groups were comparable for sex, age, and heart rate. Systolic and mean blood pressures were higher in DM2 and HTN patients than in control subjects. Diabetic and hypertensive patients had a higher left-ventricular mass index (LVMi) and relative wall thickness, impaired diastolic indexes, and lower CFR compared with control subjects (P = .02 and P = .03, respectively) because of lower hyperemic coronary velocity (P = .005 and P = .004, respectively). After a multilinear regression analysis (using age, sex, HTN status, DM2 status, smoking, total cholesterol/HDL-cholesterol ratio, and LVMi as potential determinants), the LVMi increase was the main predictor of the reduction of CFR, adjusted for mean BP (P < .0001), in the pooled population, with a minor contribution of age (P = .03), HTN status (P = .02), and DM2 status (P = .03). CONCLUSIONS: In Type 2 DM and HTN without epicardial coronary stenosis, an impairment of CFR is demonstrable. This is partly explained by an increased left-ventricular mass, able to condition the hyperemic stimulation of myocardial blood flow.

Coronary flow reserve in hypertensive patients with hypercholesterolemia and without coronary heart disease.

BACKGROUND: Coronary flow reserve (CFR) may be reduced both in arterial hypertension and in hypercholesterolemia. The aim of the study was to assess an association between CFR and levels of plasma total cholesterol (TC) in untreated arterial hypertension. METHODS: We studied 54 consecutive, untreated hypertensive outpatients free of coronary heart disease. Twenty of them had normal TC and 34 high TC (>/=200 mg/dL). Standard echocardiograms and transthoracic Doppler interrogation of the distal left anterior descending artery were obtained. Coronary diastolic peak velocities were measured both at rest and after low-dose dipyridamole. The CFR was calculated as dipyridamole/resting velocities ratio. RESULTS: The two groups had similar age, body mass index, heart rate, and diastolic blood pressure (BP). Patients with high TC had higher systolic BP (P < .05), triglycerides (P < .02), LDL-cholesterol, and TC/HDL-cholesterol ratio (both P < .0001) than controls. Left ventricular (LV) mass index, relative wall thickness, and fractional shortening did not differ between the two groups. Coronary diastolic peak velocities were similar at rest but lower after dipyridamole in patients with high TC (P < .02). As a consequence, CFR was reduced (P < .002). In multiple linear regression analyses, adjusting for age, heart rate, systolic BP, smoking, and relative wall thickness, TC (beta = -0.338) or high LDL-cholesterol (beta = -0.301) (both P < .001) were predictors of lower CFR independently of the concomitant effect of potential confounders. CONCLUSIONS: In hypertensive patients free of coronary artery disease, the degree of impairment in coronary vasodilator capacity is independently associated with plasma cholesterol and LDL-cholesterol.

Treatment with growth hormone receptor antagonist in acromegaly: effect on cardiac structure and performance.

AIM: The aim of the current study was to evaluate the effect of short-term (6 months) and long-term (18 months) treatment with pegvisomant on cardiac structure and performance in patients with acromegaly. PATIENTS: Seventeen patients (nine women, eight men, 27-61 yr) with active acromegaly entered and 12 completed the long-term study. After a baseline evaluation, including measurement of hemodynamic, biochemical, and hormonal parameters, and a standard Doppler echocardiography, treatment with pegvisomant was started at the initial dose of 10 mg/d, increasing by 5 mg/d every 6 wk on the basis of IGF-I levels until normalization or the achievement of a maximal dose of 40 mg/d. RESULTS: After short-term treatment, IGF-I levels were normalized in 10 of the 17 (59%) patients. Left ventricular mass index (LVMi) was significantly decreased without changes in diastolic and systolic performance. After long-term treatment, IGF-I levels were normalized in 10 of the 12 (83%) patients. Blood glucose and serum insulin levels were decreased compared with baseline. LVMi was further decreased compared with short-term treatment, so that the prevalence of left ventricle hypertrophy decreased from 50% at baseline to 17% after 18 months of treatment. Moreover, ejection fraction as well as early to late (atrial) peak velocity ratio (E/A) were significantly increased, whereas isovolumic relaxation time was significantly decreased compared with baseline, demonstrating an improvement of both diastolic and systolic function. A significant correlation was found between the change in IGF-I levels and that of left ventricular ejection fraction. In general, the prevalence of cardiac insufficiency was present in 13 of the 17 (76%) patients at baseline and in one (8%) patient after 18 months of treatment. CONCLUSIONS: Long-term treatment with the GH receptor antagonist improves acromegalic cardiomyopathy by decreasing cardiac hypertrophy and enhancing diastolic and systolic function, and consequently partially or completely reverting the cardiac insufficiency.

Early detection of biventricular involvement in myotonic dystrophy by tissue Doppler.

BACKGROUND: Myotonic dystrophy is associated with arrhythmias and risk of sudden death but also with symptoms of heart failure. Our study aimed to identify early biventricular dysfunction in asymptomatic patients with myotonic dystrophy by tissue Doppler. METHODS: Thirty-six patients with myotonic dystrophy (M/F=20/16, mean age=36.4 years), asymptomatic for heart failure, and 36 age- and sex-matched healthy controls underwent Doppler echocardiography and pulsed tissue Doppler of lateral mitral annulus and of tricuspid annulus. RESULTS: The two groups had similar body mass index, blood pressure, heart rate, cardiac mass and endocardial shortening. Standard Doppler showed significantly lower transmitral early (E) diastolic peak velocity, longer transmitral deceleration and isovolumic relaxation times and higher tricuspid inflow atrial peak velocity in myotonic dystrophy than in controls. Tissue Doppler of mitral annulus showed lower myocardial systolic velocity (p<0.02), lower early diastolic velocity (E(m)) (p<0.05) and atrial velocity (A(m)) (p<0.005), but no difference of E(m)/A(m) ratio. At tricuspid annulus, E(m) and E(m)/A(m) ratio were lower (p<0.02 and p<0.005, respectively). The ratio between tricuspid inflow E velocity and E(m), index of the degree of right ventricular filling pressure, was higher (p<0.001) than in controls. Tissue Doppler derived left ventricular and right ventricular measurements were all associated with the disease condition, independent of age and heart rate. CONCLUSIONS: Tissue Doppler identifies subclinical biventricular involvement in myotonic dystrophy. Early left ventricular myocardial systolic and diastolic changes are evident. Right ventricular dysfunction, involving myocardial relaxation and right ventricular filling pressure, might be the arrhythmogenic substratum of these patients.

Currently available technology for echocardiographic assessment of left ventricular function.

New ultrasound technology is mainly represented by tissue Doppler (TD), which allows the quantitative analysis of myocardial function and includes two modalies: pulsed-wave TD and color TD. Strain rate imaging (SRI) is an implementation of color TD. Pulsed-wave TD, performed and analyzed in real time, instantaneously measures myocardial velocities. Color TD, performed offline on digitally stored images, allows the quantification of mean myocardial velocities. The advantage of color TD compared with pulsed TD is the ability to simultaneously analyze multiple myocardial segments. The limit of both these methodologies consists of the myocardial velocity dependence by the base-apex myocardial gradient. SRI measures the rate and percentage of myocardial wall deformation. From digitally recorded color TD cine loops containing velocity data from the entire myocardium, SRI can be derived from regional Doppler velocity gradients. Strain rate is relatively load dependent, and, therefore, can be considered a strong index of myocardial contractility. Due to these favorable characteristics, SRI may potentially overcome the limitations of color TD, discriminating between active and merely passive wall motion. A novel technique is the implementation of 2D SRI, which is not angle dependent, and therefore potentially more feasible and reliable.

Acute hyperglycemia does not affect the reactivity of coronary microcirculation in humans.

OBJECTIVE: There is some evidence that acute hyperglycemia (H) may cause vascular dysfunction in normal subjects. This study investigates whether acute, short-term H affects coronary vasodilatory function in healthy subjects. DESIGN: Diastolic peak flow velocity in the left anterior descending coronary artery was measured at rest and after dipyridamole (0.56 mg/kg over 4 min) using transthoracic color Doppler echocardiography in 13 healthy men. Coronary flow reserve (CFR) was defined as the ratio of dipyridamole-induced coronary peak diastolic to resting peak diastolic flow velocity. CFR was measured both in euglycemia (E) and after 3 h H ( approximately 14 mmol/liter) by a variable infusion of glucose and octreotide (0.4 mg/h) to prevent increase in insulin concentration. RESULTS: Fasting plasma glucose increased to 14.3 +/- 0.33 mmol/liter during the study and maintained variability within less than 10%. Plasma insulin remained nearly stable during H. Resting diastolic flow velocity was 18.5 +/- 0.6 cm/sec in E and increased to 20.0 +/- 0.7 cm/sec during H (P < 0.005). Dipyridamole infusion produced a marked increase in coronary flow velocity, which reached values of 50.8 +/- 2.9 cm/sec in E and 51.8 +/- 2.1 cm/sec in H (P = not significant). CFR was 2.78 +/- 0.16 in E and 2.59 +/- 0.12 in H (P = not significant). CONCLUSION: Our study indicates that short-term hyperglycemia does not affect the vasodilatory response of coronary microcirculation in healthy subjects.

Rapid reversion of Loeffler's endocarditis by imatinib in early stage clonal hypereosinophilic syndrome.

Endomyocardial fibrosis (Loeffler's endocarditis) is the main cause of poor outcome in Hyper Eosinophilic Syndrome (HES) and Eosinophilic Leukemia (EL). Reversion of the cardiac damage has been seldom reported, and thrombi can superimpose on infiltrated walls, originating oembolic complications. The tyrosine kynase inhibitor imatinib has been recently employed in patients affected by HES or EL, with impressive results. We have treated with imatinib a young patient affected by Loeffler's endocarditis during EL. Loeffler's endocarditis was studied by transthoracic Doppler echocardiography with and without the contrast agent SonoVue. Cytogenetics, FISH and molecular analysis showed the presence of the FIP1L1/PDGFRA fusion gene, recently detected in a majority of HES patients. Standard echocardiography revealed a large infiltration of the apical region, with apparently pedunculate corpora floating in the LV chamber; after SonoVue injection, a thick endo-myocardial infiltration involving papillary muscles and tendinous chords appeared, which simulated mobile thrombi at standard echography. Treatment with low dose imatinib caused rapid regression of both eosinophilic proliferation and endomyocardiopathy. The fusion gene FIP1L1-PDGFRA was found significantly decreased after a few months of treatment. Using a contrast echocardiographic approach, we demonstrated the non-thrombotic origin of the "in plus" image in our patient and its rapid resolution following imatinib treatment. Imatinib is an excellent candidate for first line treatment of Loeffler's endocarditis, especially when the FIP1L1/PDGFA fusion gene is detected.

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.

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

OBJECTIVE: To examine the effects of nebivolol, a beta-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 > or = 51 g/m). 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.