Is insulin action a determinant of left ventricular relaxation in uncomplicated essential hypertension?

Predicting hospitalization by TAPSE/SPAP and the role of spironolactone in asymptomatic heart failure patients

Aim: To appraise the prediction of tricuspid annular plane systolic excursion (TAPSE)/systolic pulmonary artery pressure (SPAP) with regard to hospitalization and the effect of spironolactone use. Materials & methods: A total of 245 patients were evaluated for the study. Patients were followed for 1 year and cardiovascular outcomes were determined. Results: It was determined that TAPSE/SPAP was an independent predictor of hospitalization. A 0.1-mmHg decrease in TAPSE/SPAP was associated with a 9% increase in relative risk. No event was observed above the 0.47 level. Negative correlation with TAPSE (uncoupling) began in the spironolactone group when SPAP was ≥43 and in nonusers when SPAP was 38 (Pearson's correlation coefficient: -,731 vs -,383; p < 0.001 vs p = 0.037). Conclusion: TAPSE/SPAP measurement may be useful in predicting 1-year hospitalization in asymptomatic heart failure patients. This ratio was also found to be higher in patients who used spironolactone.

Recombinant Human Thyrotropin Improves Endothelial Coronary Flow Reserve in Thyroidectomized Patients with Differentiated Thyroid Cancer

BACKGROUND

The role of thyrotropin (TSH) on the cardiovascular system has been poorly investigated. It is unknown whether the changes in the vasculature associated with thyroid diseases result from altered thyroid hormone action or whether they are a consequence of a direct effect of TSH on endothelial cells. The present study was designed to evaluate the endothelial response of coronary flow to TSH in patients with differentiated thyroid cancer (DTC) without cardiovascular risk factors.

METHODS

The study population consisted of three men and seven women (M_age = 32.6 ± 8 years) who underwent total thyroidectomy for DTC. All were receiving therapy with L-thyroxine to maintain TSH within the reference range. No patient was obese, or had hypertension, diabetes, or dyslipidemia. Patients underwent standard echo-Doppler examination with evaluation of the coronary flow reserve (CFR) of the distal left anterior descending artery obtained by cold pressure test (CPT) before and 24 h after the second recombinant human TSH (rhTSH) injection.

RESULTS

Left ventricular morphology and systolic and diastolic function were normal in all patients. Levels of thyroid hormones and thyroglobulin and antithyroglobulin antibodies did not differ significantly pre- versus post-rhTSH treatment, whereas TSH levels were higher after rhTSH administration. Blood pressure and heart rate were not affected by rhTSH. Coronary flow peak velocity at rest (22.3 ± 6 vs 23.2 ± 8.7; p = 0.66) did not differ between baseline and 24 h after rhTSH, while post-CPT velocity (29.3 ± 6.8 vs 34.4 ± 10.9; p < 0.05) and the CFR were higher after rhTSH administration (1.32 ± 0.2 vs. 1.53 ± 0.2; p < 0.01).

CONCLUSIONS

rhTSH administration may improve the CFR after the non-pharmacological stressor CPT in DTC patients. The increase of coronary blood flow after rhTSH suggests that TSH may exert a protective effect on the coronary endothelium.

Diabetic cardiomyopathy: understanding the molecular and cellular basis to progress in diagnosis and treatment

Diabetes mellitus is an important and prevalent risk factor for congestive heart failure. Diabetic cardiomyopathy has been defined as ventricular dysfunction that occurs in diabetic patients independent of a recognized cause such as coronary artery disease or hypertension. The disease course consists of a hidden subclinical period, during which cellular structural insults and abnormalities lead initially to diastolic dysfunction, later to systolic dysfunction, and eventually to heart failure. Left ventricular hypertrophy, metabolic abnormalities, extracellular matrix changes, small vessel disease, cardiac autonomic neuropathy, insulin resistance, oxidative stress, and apoptosis are the most important contributors to diabetic cardiomyopathy onset and progression. Hyperglycemia is a major etiological factor in the development of diabetic cardiomyopathy. It increases the levels of free fatty acids and growth factors and causes abnormalities in substrate supply and utilization, calcium homeostasis, and lipid metabolism. Furthermore, it promotes excessive production and release of reactive oxygen species, which induces oxidative stress leading to abnormal gene expression, faulty signal transduction, and cardiomyocytes apoptosis. Stimulation of connective tissue growth factor, fibrosis, and the formation of advanced glycation end-products increase the stiffness of the diabetic hearts. Despite all the current information on diabetic cardiomyopathy, translational research is still scarce due to limited human myocardial tissue and most of our knowledge is extrapolated from animals. This paper aims to elucidate some of the molecular and cellular pathophysiologic mechanisms, structural changes, and therapeutic strategies that may help struggle against diabetic cardiomyopathy.

Non-alcoholic fatty liver disease is associated with left ventricular diastolic dysfunction in essential hypertension

BACKGROUND AND AIM

Insulin resistance is recognized as the pathophysiological hallmark of non-alcoholic fatty liver disease (NAFLD). A relation between insulin sensitivity and left ventricular morphology and function has been reported in essential hypertension, where a high prevalence of NAFLD has been recently found. We investigated the inter-relationship between left ventricular morphology/function, metabolic parameters and NAFLD in 86 never-treated essential hypertensive patients subdivided in two subgroups according to the presence (n = 48) or absence (n = 38) of NAFLD at ultrasonography.

METHODS AND RESULTS

The two groups were similar as to sex, age and blood pressure levels. No patient had diabetes mellitus, obesity, hyperlipidemia, or other risk factors for liver disease. Body mass index, waist circumference, triglycerides, glucose, insulin, homeostasis model of assessment index for insulin resistance (HOMA-IR), aspartate aminotransferase and alanine aminotransferase were higher and adiponectin levels were lower in patients with NAFLD than in patients without NAFLD, and were associated with NAFLD at univariate analysis. Patients with NAFLD had similar prevalence of left ventricular hypertrophy compared to patients without NAFLD, but a higher prevalence of diastolic dysfunction (62.5 vs 21.1%, P < 0.001), as defined by E/A ratio <1 and E-wave deceleration time >220 ms. Diastolic dysfunction (P = 0.040) and HOMA-IR (P = 0.012) remained independently associated with NAFLD at backward multivariate analysis.

CONCLUSIONS

Non-alcoholic fatty liver disease was associated with insulin resistance and abnormalities of left ventricular diastolic function in a cohort of patients with essential hypertension, suggesting a concomitant increase of metabolic and cardiac risk in this condition.

Detection of increased left ventricular filling pressure by pulsed tissue Doppler in cardiac amyloidosis

OBJECTIVE

The aim of this study was to evaluate the incremental diagnostic role of tissue Doppler in primary cardiac amyloidosis (CA).

METHODS

Eleven patients with CA at diagnosis and 11 healthy controls, matched for sex and age, underwent standard Doppler echocardiography and pulsed tissue Doppler of the left ventricular (LV) lateral annulus, in the apical four-chamber view. The ratio of early transmitral flow velocity to early diastolic mitral annular velocity (E/E(m) ratio) was derived as an index of LV filling pressure.

RESULTS

The two groups were comparable for body mass index, blood pressure, heart rate and standard Doppler diastolic measurements. Patients with CA had a significantly higher sum of wall thickness (SWT) and LV mass, a lower E(m) peak velocity (P < 0.002) and a higher E/E(m) ratio (P < 0.001) than controls. By dividing CA patients according to the transmitral E/A ratio, patients with an E/A ratio < 1 (abnormal relaxation) (n = 5) and patients with an E/A ratio > 1 (likely pseudonormal/restrictive pattern) (n = 6) did not show any difference in the E/E(m) ratio (14.5 + or - 7.1 vs. 15.1 + or - 6.4, P = NS). In the overall population, the E/E(m) ratio was related to SWT (r = 0.84, P < 0.0001) and LV mass index (r = 0.72, P < 0.0001). After adjusting for age and heart rate by separate multivariate models, SWT (beta = 0.78, P < 0.0001; cumulative r(2) = 0.63, SE = 3.38, P < 0.0001) and LV mass index (beta = 0.71, P < 0.0001; cumulative r(2) = 0.53, SE = 3.80, P < 0.002) were both independently associated with the E/E(m) ratio.

CONCLUSIONS

Pulsed tissue Doppler is able to detect early myocardial diastolic impairment in CA. The E/E(m) ratio is very useful in diagnosing increased LV filling pressure, regardless of the transmitral pattern, and may, therefore, be helpful in the clinical management of these patients.

Left ventricular systolic and diastolic function after anthracycline chemotherapy in childhood

BACKGROUND

In childhood, late cardiotoxicity is characterized by inappropriately thin wall and consequent increased end-systolic wall stress, but the associations of impaired left ventricular geometry and function occurring under these circumstances need further investigation.

HYPOTHESIS

The purpose of this study was to assess anthracycline late effects on the relationships occurring between increased end-systolic stress (ESS) and changes in both M-mode systolic measurements (i.e., endocardial and midwall fractional shortening) and Doppler diastolic indices in the pediatric age.

METHODS

The population consisted of 101 children treated with anthracyclines for at least 12 months and 91 healthy children. Using M-mode echocardiography, end-systolic wall stress was calculated as index of afterload, and endocardial and midwall fractional shortening as systolic indices. Doppler transmitral measurements were made as diastolic indices.

RESULTS

Patients treated with anthracyclines showed significantly lower relative wall thickness and left ventricular mass index, greater end-systolic wall stress, reduced endocardial and midwall fractional shortening and peak E/A ratio, prolonged deceleration, and isovolumic relaxation times. Direct relationships were found between end-systolic wall stress and both endocardial and midwall shortening. The use of midwall shortening in the relation showed a greater, but not significant increase (from 3 to 6%) in the proportion of patients with depressed systolic function than did endocardial shortening. In the anthracycline group, end-systolic wall stress was also inversely related to relative wall thickness and directly to isovolumic relaxation time.

CONCLUSIONS

In childhood, reduced myocardial thickness and increased afterload explain much of systolic and diastolic dysfunction of late anthracycline toxicity. Midwall fractional shortening does not seem to add useful information for identifying subsets of children more prone to the development of heart failure.

Increased prevalence of tricuspid regurgitation in patients with prolactinomas chronically treated with cabergoline

BACKGROUND

Cabergoline, a dopamine receptor-2 agonist used to treat prolactinomas, was associated with increased risk of cardiac valve disease in Parkinson's disease.

OBJECTIVE

Our objective was to evaluate prevalence of cardiac valve regurgitation in cabergoline-treated patients with prolactinomas.

DESIGN AND SETTING

An observational, case-control study was conducted at a university hospital.

PATIENTS

Fifty treated patients (44 women and six men) and 50 sex- and age-matched control subjects participated; 20 de novo patients were also studied.

INTERVENTION

In the treated patients, the last cabergoline dose was 1.3 +/- 1.3 mg/wk (<1 mg/wk in 44%, 1-3 mg/wk in 46%, and >3 mg/wk in 10%). Treatment duration was 12-60 months in 32% and more than 60 months in 68%. The cumulative (milligrams x months of treatment) dose of cabergoline ranged from 32-1938 mg (median 280 mg).

MEASUREMENTS

Valve regurgitation was assessed according to the recommendations of the American Society of Echocardiography.

RESULTS

In de novo patients, treated patients, and controls, the prevalence of mild regurgitation of mitral (35, 22, and 12%, P = 0.085), aortic (0, 4, and 2%, P = 0.59), tricuspid (55, 30, and 42%, P = 0.13) or pulmonic (20, 12, and 6%, P = 0.22) valves was similar. Conversely, the prevalence of moderate tricuspid regurgitation was higher in the treated patients (54%) than in de novo patients (0%) and controls (18%, P < 0.0001). Moderate tricuspid regurgitation was more frequent in patients receiving a cumulative dose above the median (72%) than in those receiving a lower dose (36%, P = 0.023). A higher systolic (P = 0.03) and diastolic blood pressure (P < 0.0001) was found in patients with than in those without moderate tricuspid regurgitation.

CONCLUSION

Moderate tricuspid regurgitation is more frequent in patients taking cabergoline (at higher cumulative doses) than in de novo patients and control subjects, but the clinical significance of this finding has not been established. A complete echocardiographic assessment is indicated in patients treated long term with cabergoline, particularly in those requiring elevated doses.

Circulating IGF-I levels are associated with increased biventricular contractility in top-level rowers

BACKGROUND

The intensive physical activity is often associated with cardiac changes.

OBJECTIVES

(i) To evaluate the IGF-I system and myocardial structure and function by standard Doppler echocardiography and Tissue Doppler in athletes and sedentary controls; and (ii) to determine any relationship between IGF-I system and echocardiographic parameters.

METHODS

Nineteen male top-level rowers and 19 age-matched healthy sedentary male controls underwent blood determination of fasting serum IGF-I, IGFBP-3 and acid-labile subunit levels and standard Doppler echocardiography combined with pulsed Tissue Doppler of posterior septal wall, left ventricular (LV) lateral mitral annulus and right ventricular (RV) tricuspid annulus. Myocardial presystolic (PS(m)), systolic (S(m)), the ratio of early diastolic (E(m)) to atrial (A(m)) velocities as well as myocardial time intervals were calculated.

RESULTS

Rowers had higher serum IGF-I levels (P = 0.04), higher biventricular cavity dimensions and wall thicknesses compared to controls. They also had better LV and RV myocardial function than controls. In the rowers, IGF-I was associated with LV ejection fraction (r = 0.50, P = 0.03), RV PS(m) velocity (r = 0.55, P = 0.01) and with RV myocardial precontraction time (r = -0.57, P = 0.01). These associations remained significant after adjusting for age and heart rate.

CONCLUSIONS

Top-level athletes showed higher IGF-I levels and a better myocardial performance than controls, particularly for the RV systolic activity. The independent correlations between IGF-I and systolic parameters of the left (ejection fraction) and right (PS(m) velocity and precontraction time) ventricles may possibly indicate a role of IGF-I system in the modulation of myocardial inotropism in athletes. Further studies are needed to confirm this hypothesis.

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.

Role of Exercise and Metabolism in Heart Failure with Normal Ejection fraction

Left ventricular dysfunction associated with metabolic disorders has a number of features that might shed light on the integrity of heart failure with normal ejection fraction. First, although these patients may be dyspneic and have a normal ejection fraction, their diastolic dysfunction is not isolated. Both experimental models and sensitive new parameters in humans have shown abnormal systolic function, even though the less sensitive parameters (such as ejection fraction) become abnormal only with stress. Moreover, the mechanistic contributors to myocardial dysfunction, including structural changes and metabolic influences on the cardiac myocyte, interstitial fibrosis, vascular disease, and altered loading, are likely to influence systolic as much as diastolic function. The responses of systolic and diastolic heart failure to exercise training show analogies, particularly with respect to the importance of peripheral adaptation, as well as a similar training response. Together, these features are more supportive of a continuum of pathophysiology between systolic and diastolic heart failure, rather than the 2 representing discreet phenomena.

Pulsed tissue Doppler identifies subclinical myocardial biventricular dysfunction in active acromegaly

OBJECTIVE

The aim of this study was to assess the role of pulsed tissue Doppler (TD) to identify left (LV) and right ventricular (RV) myocardial regional involvement in acromegaly.

PATIENTS AND MEASUREMENTS

Thirty active acromegaly patients, free of diabetes mellitus, thyroid dysfunction, valvular and coronary heart disease, clinically overt heart failure, and 30 sex- and age-matched healthy controls underwent standard Doppler echocardiography and pulsed TD, by placing the sample volume at the level of basal posterior septum, LV lateral mitral annulus and RV lateral tricuspid annulus. Myocardial systolic (S(m)) and diastolic velocities (E(m)/A(m) ratio) and time-intervals of relaxation (RT(m)), precontraction (PCT(m)) and contraction (CT(m)) and the PCT(m)/CT(m) ratio were measured at each level.

RESULTS

The two groups had similar heart rate, whereas acromegaly patients had higher body mass index, systolic and diastolic blood pressure, LV mass and impaired Doppler indexes of LV and RV diastolic function, without any difference in the global systolic function. At TD, acromegaly patients showed significantly delayed RT(m) and PCT(m,) reduced E(m)/A(m), S(m) and increased PCT(m)/CT(m) of posterior septum, mitral annulus and tricuspid annulus in comparison with controls. By separate multilinear regression analyses, after adjusting for body mass index, heart rate, diastolic blood pressure and LV mass index, age was the main independent determinant of tissue Doppler diastolic but not of systolic indexes.

CONCLUSIONS

In active acromegaly, pulsed TD confirms LV and RV diastolic abnormalities detectable by standard Doppler, additionally identifying subclinical biventricular impairment of systolic function.

Myocardial collagen turnover in normotensive obese patients: relation to insulin resistance

OBJECTIVES

The present study was undertaken to assess the differential impact of insulin resistance, leptin and body composition on myocardial mass and serum markers of cardiac fibrosis in obese subjects, within a small range of elevated BMI (30-40 kg/m(2)), without pulmonary disease, cardiovascular disease, hypertension, cardiac hypertrophy or other cardiovascular disease.

BACKGROUND

Obesity is an independent predictor of left ventricular mass (LVM) and is associated with disturbances in cardiac structure. The extent of the interstitial fibrosis in obese patients is not known, especially in the absence of cardiac hypertrophy.

METHODS AND RESULTS

We included 160 obese subjects. The LVM was obtained using the Devereux formula. Body composition was estimated from a total body scan. Insulin sensitivity was assessed by homeostasis model assessment (HOMA), and cardiac collagen turnover by measurement of procollagen type III aminopeptide (PIIINP). PIIINP was correlated to the E/A ratio (r=0.24; P=0.012), a marker of ventricular function. PIIINP was independently correlated with glucose concentration (r=0.27; P=0.004), indexes of insulin resistance (HOMA (r=0.27; P=0.003), insulin (r=0.24; P=0.008)), and parameters associated with the insulin-resistance syndrome (HDL-cholesterol r=-0.27; P=0.004) and fat trunk/fat leg ratio (r=0.24; P=0.053)). The variable most correlated with PIIINP was HDL-cholesterol, followed by HOMA (r (2)=0.13). When HOMA was substituted for blood glucose concentration and insulinemia (Model 2), HDL-cholesterol was strongly related to lower PIIINP levels, followed by higher glucose concentration (r (2)=0.21). Regression analyses showed that LVM had the strongest independent positive correlation with fat-free mass (FFM) (r=0.39; P=0.0002), followed by systolic blood pressure (r=0.19; P=0.034). Neither adipose mass nor height independently added information to multivariate models. The ratio leptin/fat mass was correlated with LVM (r=-0.27; P=0.004), but not independently of the FFM. Markers for fibrosis were not significantly correlated with LVM. As a result, FFM was the most predictive factor of LVM in obese subjects.

CONCLUSION

We found that serum levels of markers of cardiac collagen synthesis were significantly associated with insulin resistance in normotensive, nondiabetic obese subjects, and not related to the LVM. As a result, PIIINP could be a very early marker of ventricular dysfunction in these patients. Furthermore, we suggest that, for better detection of left ventricle hypertrophy in obese subjects, LVM should be indexed to FFM rather than to body surface area, or height.

Insulin resistance, dietary fat intake and blood pressure predict left ventricular diastolic function 20 years later

BACKGROUND AND AIMS

Our knowledge on the development of left ventricular diastolic dysfunction is scarce. Thus, we aimed to investigate the relationship between left ventricular diastolic function and a wide variety of cardiovascular risk factors, including dietary factors using both cross-sectional and longitudinal data with 20 years follow-up.

METHOD AND RESULTS

A population-based cohort of 505 50-year-old men was examined with determinations of blood pressure, insulin, glucose and fatty acid composition of serum cholesterol esters. A reinvestigation 20 years later also included hyperinsulinaemic euglycaemic clamp, 7-day diet record and Doppler echocardiography with determination of left ventricular diastolic function (early (E) and late (A) peak mitral velocities and left atrial diameter). Blood pressure both at age 50 and 70 was negatively correlated to the E/A ratio (r=-0.15, p<0.001 and r=-0.23, p<0.001) at age 70. Insulin resistance at age 50 and 70 were negatively correlated to the A-wave and left atrial diameter at follow-up. A fatty acid profile indicating a diet high in saturated fats at age 50 was correlated to an increased left atrial diameter 20 years later and the dietary intake of fat was negatively correlated to the E/A ratio (r=-0.09, p<0.05) at age 70. All findings were independent of myocardial infarction and cardiovascular medication.

CONCLUSION

Apart from blood pressure, insulin resistance and dietary fat intake predicted left ventricular diastolic function after 20 years. These findings suggest that both hemodynamic and metabolic factors may play a role for left ventricular diastolic function and disclose new possibilities for prevention of left ventricular diastolic dysfunction.

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.

Diastolic dysfunction and diastolic heart failure: diagnostic, prognostic and therapeutic aspects

Left ventricular (LV) diastolic dysfunction (DD) and diastolic heart failure (HF), that is symptomatic DD, are due to alterations of myocardial diastolic properties. These alterations involve relaxation and/or filling and/or distensibility. Arterial hypertension associated to LV concentric remodelling is the main determinant of DD but several other cardiac diseases, including myocardial ischemia, and extra-cardiac pathologies involving the heart are other possible causes. In the majority of the studies, isolated diastolic HF has been made equal to HF with preserved systolic function (= normal ejection fraction) but the true definition of this condition needs a quantitative estimation of LV diastolic properties. According to the position of the European Society of Cardiology and subsequent research refinements the use of Doppler echocardiography (transmitral inflow and pulmonary venous flow) and the new ultrasound tools has to be encouraged for diagnosis of DD. In relation to uncertain definitions, both prevalence and prognosis of diastolic heart failure are very variable. Despite an apparent lower death rate in comparison with LV systolic HF, long-term follow-up (more than 5 years) show similar mortality between the two kinds of HF. Recent studies performed by Doppler diastolic indexes have identified the prognostic power of both transmitral E/A ratio < 1 (pattern of abnormal relaxation) and > 1.5 (restrictive patterns). The therapy of LV DD and HF is not well established but ACE-inhibitors, angiotensin inhibitors, aldosterone antagonists and β-blockers show potential beneficial effect on diastolic properties. Several trials, completed or ongoing, have been planned to treat DD and diastolic HF.

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.

Diabetic cardiomyopathy: evidence, mechanisms, and therapeutic implications

The presence of a diabetic cardiomyopathy, independent of hypertension and coronary artery disease, is still controversial. This systematic review seeks to evaluate the evidence for the existence of this condition, to clarify the possible mechanisms responsible, and to consider possible therapeutic implications. The existence of a diabetic cardiomyopathy is supported by epidemiological findings showing the association of diabetes with heart failure; clinical studies confirming the association of diabetes with left ventricular dysfunction independent of hypertension, coronary artery disease, and other heart disease; and experimental evidence of myocardial structural and functional changes. The most important mechanisms of diabetic cardiomyopathy are metabolic disturbances (depletion of glucose transporter 4, increased free fatty acids, carnitine deficiency, changes in calcium homeostasis), myocardial fibrosis (association with increases in angiotensin II, IGF-I, and inflammatory cytokines), small vessel disease (microangiopathy, impaired coronary flow reserve, and endothelial dysfunction), cardiac autonomic neuropathy (denervation and alterations in myocardial catecholamine levels), and insulin resistance (hyperinsulinemia and reduced insulin sensitivity). This review presents evidence that diabetes is associated with a cardiomyopathy, independent of comorbid conditions, and that metabolic disturbances, myocardial fibrosis, small vessel disease, cardiac autonomic neuropathy, and insulin resistance may all contribute to the development of diabetic heart disease.

Right ventricular myocardial dysfunction in adult patients late after repair of tetralogy of fallot

AIM OF THE STUDY

To detect in adult patients late after repair of Tetralogy of Fallot (TOF) possible correlation between myocardial parameters assessed at rest by Tissue Doppler (TD) and cardiac performance during physical effort.

METHODS

Doppler echo, treadmill test and pulsed TD of both mitral and tricuspid annulus were performed in 25 healthy subjects and in 40 adult patients who had undergone surgery for TOF at a mean age of 1.4+/-0.5 years. Exclusion criteria were echocardiographic evidence of residual pulmonary, either stenosis or regurgitation. By use of TD, the following parameters were assessed: systolic peak velocities (Sm), pre-contraction time, contraction time, early (E(m)) and late (A(m)) diastolic velocities, E(m)/A(m) ratio, relaxation time. By treadmill test, we measured: maximal heart rate (HR), systolic blood pressure (SBP), rate-pressure product, maximal workload, time duration of the exercise.

RESULTS

the two groups were comparable for left ventricular measurements and for all transmitral and transtricuspid Doppler indexes, while tricuspid ring diameter was increased in TOF. TD analysis showed in TOF lower S(m), E(m) and E(m)/A(m) ratio and prolonged PCT(m) and Rt(m) at tricuspid annulus level, despite comparable TD mitral annulus indexes. By treadmill test, TOF showed reduced time of exercise, number of METS reached and rate-pressure product. Multiple linear regression models evidenced in TOF independent positive association between tricuspid Em velocity and time of exercise (p<0.0001), achieved METS at peak effort (p<0.001) and rate-pressure product (p<0.001). An E(m) peak velocity of tricuspid annulus lower than 0.13 m/s showed 90% sensitivity and 93% specificity in identifying TOF patients unable to perform maximal exercise test.

CONCLUSIONS

despite normal Doppler parameters, adult patients late after correction of TOF showed impaired right ventricular myocardial function. In these patients pulsed TD may be taken into account as a valuable supporting tool to predict the effort response and possibly to assess long-term follow-up of cardiac functional reserve.

Coronary flow reserve in hypertensive patients with appropriate or inappropriate left ventricular mass

OBJECTIVE

To assess the association between coronary flow reserve (CFR) and levels of left ventricular mass (LVM) exceeding the compensatory needs in arterial hypertension. DESIGN, SETTINGS AND PATIENTS: The association between the excess of LV mass and CFR was assessed in a population of 40 consecutive hypertensive outpatients free of coronary heart disease, 22 with appropriate and 17 with inappropriately high LVM (i.e. LVM exceeding 128% of the value predicted by sex, stroke work and height in m(2.7)). The CFR (the ratio between dipyridamole and basal diastolic peak velocity) of the distal left anterior descending artery was measured by transthoracic Doppler echocardiography.

RESULTS

Patients with inappropriate LVM had similar age, body mass index (BMI), baseline blood pressure (BP) and coronary velocities, but lower LV systolic function, post-dipyridamole diastolic peak velocities (P < 0.05) and lower CFR (P < 0.002) than patients with appropriate LVM. CFR was negatively related to the extent of the excess of LVM (beta = -0.44, P < 0.005), independently of potential combined effect of age, BMI and post-dipyridamole diastolic BP. Impairment of CFR (i.e. < 2) was better discriminated by identification of clear-cut inappropriate LVM (P < 0.004) than by the presence of LV hypertrophy (i.e. LV mass index > or = 51 g/m(2.7); P = 0.057).

CONCLUSIONS

In hypertensive patients free of coronary artery disease, the degree of reduction in CFR is associated with the excess of LVM beyond the values compensatory for individual haemodynamic load. This relation is also independent of the presence of LV hypertrophy.

Different involvement of right ventricular myocardial function in either physiologic or pathologic left ventricular hypertrophy: a Doppler tissue study

The aim of the study was to analyze right ventricular (RV) myocardial function in patients with left ventricular (LV) hypertrophy secondary to either hypertrophic cardiomyopathy (HC) or athletic endurance training. Doppler echocardiography and pulsed Doppler tissue imaging of the posterior septal wall, and mitral and tricuspid annulus were performed in 32 top-level endurance athletes (AT) and in 27 patients with HC, all men. LV mass index was comparable between the 2 groups. All transmitral Doppler indexes were higher in AT, whereas only tricuspid inflow peak E and E/A ratio were slightly decreased in the HC group. In the HC group, Doppler tissue analysis showed lower myocardial systolic and early-diastolic (Em) peak velocities, and longer time intervals at the level of all the analyzed segments, even after correction for age, heart rate, and LV mass index. Distinct multiple linear regression models revealed an independent positive association between RV peak Em velocity and LV end-diastolic diameter (beta coefficient = 0.72, P <.0001) in AT, and an independent inverse correlation of the same peak Em velocity of tricuspid annulus with septal thickness (beta = - 0.65, P <.001) in the HC group. Of interest, a RV Em peak velocity < 0.16 m/s differentiated AT and HC groups better than tricuspid Doppler (89% sensitivity and 93% specificity). In conclusion, Em RV myocardial function is positively influenced by preload increase in AT and negatively associated to increased septal thickness in patients with HC. Therefore, Doppler tissue imaging may represent a useful tool in the differential diagnosis between athlete's heart and HC, underlining the different involvement of RV myocardial function in either physiologic or pathologic LV hypertrophy.

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.

Left ventricular myocardial impairment in subclinical hypothyroidism assessed by a new ultrasound tool: pulsed tissue Doppler

Pulsed tissue Doppler (TD) is a new ultrasound tool that allows quantification of myocardial regional wall motion. To investigate the cardiac effects of subclinical hypothyroidism (SH), the present study assessed left ventricular (LV) myocardial regional function in SH by pulsed TD. Twenty women with SH and 20 healthy women underwent standard Doppler echocardiograms and pulsed TD, placing a sample volume at the level of posterior septum and LV mitral annulus. Myocardial systolic and diastolic velocities and time intervals were determined for both levels. Doppler-echocardiographic and TD measurements were adjusted for body surface area and heart rate. Standard Doppler showed an increases in LV preejection period, preejection period/LV ejection time ratio, and isovolumic relaxation time (IVRT) in SH. By TD analysis, myocardial precontraction time (PCT(m)), PCT(m)/myocardial contraction time ratio, and myocardial relaxation time (RT(m)) were prolonged at the level of both posterior septum and mitral annulus in SH. In the whole population, IVRT, PCT(m), and RT(m) were negatively related to FT(4), whereas IVRT, PCT(m)/myocardial contraction time ratio, and RT(m) were positively correlated to TSH. In conclusion, this study underscores the usefulness of TD to detect cardiac functional abnormalities due to stable SH, mainly by changes in myocardial time intervals in several LV segments.

Fasting plasma glucose is an independent determinant of left ventricular diastolic dysfunction in nondiabetic patients with treated essential hypertension

Left ventricular (LV) hypertrophy and LV diastolic dysfunction are common cardiac changes in hypertensive patients, and these changes are modified by various factors other than blood pressure. The present study was conducted to investigate the influence of mild abnormalities in glucose metabolism on LV structure and function in essential hypertension. In 193 nondiabetic patients with treated essential hypertension, two-dimensional and Doppler echocardiographic examinations were performed, and relative wall thickness (RWT), LV mass index (LVMI), fractional shortening, and the ratio of the peak velocity of atrial filling to early diastolic filling (A/E) were calculated. Fasting plasma glucose (FPG) and HbA1c levels were positively correlated with the A/E ratio and the deceleration time of the E wave. However, these plasma levels had no correlation with RWT, LVMI, or fractional shortening. Peak A wave velocity and the A/E ratio were significantly higher in patients who had FPG of > or = 100 mg/dl (and <126 mg/dl) than those who had FPG of <100 mg/dl, although age, blood pressure, RWT, LVMI, and fractional shortening did not differ between the two groups. In a multiple regression analysis of all subjects, only FPG and age were independent determinants of the A/E ratio. These observations suggest that FPG is a sensitive predictor for LV diastolic dysfunction in nondiabetic patients with treated hypertension. Since a slight increase in plasma glucose levels is associated with abnormalities in diastolic function independent of LV hypertrophy, an early stage of impaired glucose metabolism in hypertensive patients may specifically deteriorate cardiac diastolic function.

Left ventricular hypertrophy in hypertension as a predictor of coronary events: relation to geometry

The present review examines epidemiological evidence for a relation of left ventricular hypertrophy with coronary heart disease, and mechanisms that may represent pathophysiological links between left ventricular hypertrophy and coronary events. Left ventricular hypertrophy has been demonstrated to be a powerful predictor of coronary heart disease, and when geometry is concentric the relation is even stronger. In addition to its association with risk factors for atherosclerosis and mechanisms that precipitate acute heart attacks, left ventricular hypertrophy also directly predisposes to and aggravates clinical presentation of coronary heart disease through a number of biological mechanisms. These include the following: increase in oxygen requirement related to left ventricular geometry; coronary hypertension, with endothelial dysfunction and reduced coronary reserve; diastolic dysfunction; and structural remodelling of myocardium and vascular bed. Some of these alterations are also worsened by underlying coronary heart disease, and can potentially be maintained by loop mechanisms. A recognizable stage of abnormal coronary haemodynamics in the context of left ventricular hypertrophy is probably that at which coronary reserve is impaired in the absence of any other sign of heart disease; in many circumstances, this may occur early in the disease process.

Inverse association between free insulin-like growth factor-1 and isovolumic relaxation in arterial systemic hypertension

Several trials have suggested that insulin-like growth factor-1 (IGF-1) may have a pathophysiological role in the development of arterial essential hypertension. To verify the possible association of IGF-1 with left ventricular morphological and functional echocardiographic parameters in hypertension, we studied 40 male patients with newly diagnosed hypertension and 15 normotensive control subjects. Doppler echocardiography was performed and circulating free IGF-1 levels were determined in all subjects. Circulating free IGF-1 levels were higher in hypertensives than in control subjects (P<0.01). A significant inverse correlation was observed between free IGF-1 and isovolumic relaxation time in the overall population (r=-0.37, P<0.01) and in hypertensives (r=-0.57, P<0.0001), whereas this relation disappears in normotensives. These results were confirmed by multivariate analysis. The present study confirms that arterial essential hypertension represents a clinical condition associated with an increased synthesis of IGF-1. The observation of an inverse, independent association between free IGF-1 and isovolumic relaxation time suggests 2 alternative hypotheses: a possible beneficial effect of IGF-1 to diastolic relaxation or a resistance to IGF-1 in hypertension.

Pulsed Doppler tissue imaging in endurance athletes: relation between left ventricular preload and myocardial regional diastolic function

The aim of this study was to assess the effects of endurance training on myocardial regional systolic and diastolic function by pulsed Doppler tissue imaging (DTI). Twenty male water polo players and 20 male control subjects underwent standard Doppler echocardiography and pulsed DTI, performed in apical views by placing a sample volume on left ventricular (LV) basal septal and inferior walls. Age, body surface area, and blood pressure were comparable between the 2 groups, with lower heart rate in athletes (p <0.001). They had significantly increased LV mass index (due to both higher wall thickness and end-diastolic diameter), greater endocardial fractional shortening, higher transmitral early/atrial (E/A) peak velocities ratio. In athletes, DTI analysis showed significantly prolonged myocardial deceleration time and greater myocardial E/A peak velocity ratio of septal and inferior walls, whereas myocardial early peak velocity was increased (p <0.01) only at the inferior wall. In the overall group, we found univariate relations of septal and inferior E/A peak velocity ratio and myocardial deceleration time with LV mass levels, and, in particular, with the sum of wall thickness. By separate multivariate analyses, however, these relations disappeared, being dependent on heart rate degree. Another association found between LV end-diastolic diameter and myocardial early diastolic wave peak velocity of the inferior wall (r = 0.68, p <0.0001) remained significant (standardized beta coefficient 0.60, p <0.00001), even after adjusting for heart rate, body surface area, age, and stroke volume (R(2) = 0.71, p <0.00001). In conclusion, DTI is a useful tool for detecting regional changes in myocardial function induced by training, because athletes present with an improvement in diastolic passive properties of myocardium. The higher early diastolic velocity of the inferior wall and its relation to increased preload may represent an indicator of aerobic training, allowing quantification of the degree of LV adaptation to endurance exercise.

Myocardial diastolic impairment caused by left ventricular hypertrophy involves basal septum more than other walls: analysis by pulsed Doppler tissue imaging

OBJECTIVE

To assess regional diastolic function in patients with hypertension with or without left ventricular hypertrophy using Doppler tissue imaging, a new tool that analyzes myocardial wall motion 'on-line'.

METHODS

Ten normotensive subjects, 20 hypertensive patients without hypertrophy and 20 with hypertrophy (left ventricular mass index >50 g/m2.7), all men, underwent Doppler echocardiography and Doppler tissue imaging, which was performed in apical view by placing pulsed sample volume at the level of the basal and middle septum, basal and middle lateral wall, and infero-posterior wall. Peak velocities and time-velocity integrals of myocardial early (Em) and late (Am) waves and their ratios, regional deceleration time and regional relaxation time were measured in each segment.

RESULTS

Transmitral peak E/A ratio was 1.37 in normotensive subjects, 1.01 in hypertensive patients without hypertrophy and 0.77 in those with hypertrophy (P < 0.00001). The myocardial diastolic indexes derived by Doppler tissue imaging worsened at all levels in hypertensive patients without hypertrophy compared with normotensive subjects. In hypertensive patients with hypertrophy, the majority of myocardial diastolic indexes were further impaired at the basal septal level, but only marginal differences were found in other regions, compared with indexes in hypertensive patients without hypertrophy. The main diastolic indexes were found, using separate intra-group analyses, to be more compromised at the basal septum than at other levels only in hypertrophic hypertensive patients. The prevalence of regions having peak Em/Am ratios < 1 increased significantly from normotensive subjects to hypertensive patients without hypertrophy, but not significantly from these to the hypertrophic group. Among pooled hypertensive patients, after adjusting for heart rate and diastolic blood pressure using multivariate models, the septal wall thickness was shown to be an independent determinant of the diastolic indexes of the basal and middle septum.

CONCLUSIONS

In hypertensive patients without hypertrophy, diastolic dysfunction is uniform along the ventricular walls, whereas in those with hypertrophy it is more evident at the basal septal level than in other walls. Overall among hypertensive patients, the diastolic properties of the interventricular septum worsen as the thickness of the septal wall increases, in the presence and in the absence of hypertrophy.

Use of pulsed Doppler tissue imaging to assess regional left ventricular diastolic dysfunction in hypertrophic cardiomyopathy

In this study, regional diastolic patterns and their relations with transmitral Doppler inflow were investigated in hypertrophic cardiomyopathy (HC) by pulsed Doppler tissue imaging (DTI). Doppler echocardiography and DTI of basal septum and lateral wall (apical 4-chamber view) were performed in 20 patients (15 men and 5 women) with HC and in 10 healthy subjects (7 men and 3 women). Diabetes, hypertension, coronary artery and valvular disease, mitral regurgitation, New York Heart Association functional classes III to IV, sinus tachycardia, atrial fibrillation, and inadequate echocardiograms were exclusion criteria. Peak velocity and time-velocity integral of early and late waves and their ratios, and deceleration and isovolumic relaxation times were determined by standard Doppler and by DTI at the septal and lateral wall levels. The 2 groups were comparable for age, heart rate, blood pressure, and ejection fraction. Transmitral peak velocity and time-velocity integral E/A ratios were reduced (both p <0.05) and deceleration and isovolumic relaxation times prolonged (both p <0.00001) in HC. Septal DTI showed lower peak velocity and time-velocity integral e/a ratios (p <0.00001 and p <0.001, respectively) and lengthened regional deceleration (p <0.01) and isovolumic (p <0.001) relaxation times. DTI of the lateral wall showed a prolongation of deceleration and isovolumic relaxation times (both p <0.01). By dividing HC according to transmitral E/A, 8 patients with E/A <1 had lower DTI septal e/a ratio (p <0.01) and prolonged septal deceleration and isovolumic relaxation times (both p <0.01) but no changes in DTI pattern of lateral wall than 12 patients with E/A > 1. In conclusion, DTI is useful and complementary to standard Doppler imaging to characterize diastolic properties in HC, reflecting a typical pattern of intramyocardial impaired relaxation at the level of hypertrophied septum and also providing information about the degree of this regional impairment. The lateral wall presents minor changes in diastolic times, which indicate how diastolic asynchrony is not confined to the hypertrophied segment in HC.

Diastolic function and insulin resistance in essential hypertension

We studied the relationship of insulin metabolism to diastolic function in 41 hypertensive patients and 24 healthy subjects. They underwent a 75-g oral glucose tolerance test. Integrated response of insulin to the glucose load was calculated as the area under the curve of insulin (AUC-I) and glucose (AUC-G). The ratio AUC-I/AUC-G was taken as an index of insulin resistance. Echocardiographic examination was performed to measure left ventricular mass. We used pulsed Doppler technique to assess the ratio of early to late transmitral peak velocity (E/A). The hypertensives had higher fasting insulin concentrations, insulin levels at 60 min and at 120 min after oral glucose load. They had higher AUC-I and higher index of insulin resistance compared to normotensives. Patients with hypertension had a lower E/A ratio in comparison to normotensive volunteers. In all subjects, the E/A ratio was negatively correlated with fasting insulin and insulin concentrations at 30, at 60 and at 120 min, AUC-I and insulin resistance index. Multiple regression analysis was performed to evaluate the above relationships, when the effects of confounding factors such as age, heart rate and systolic blood pressure were taken into account. We found that E/A ratio is negatively correlated to insulin concentrations at 120 min and to AUC-I in hyperinsulinemic subgroup of subjects (fasting insulin> 10). We conclude, that insulin metabolism and E/A ratio, which reflects diastolic function of the left ventricle, are related in hypertension.

Impact of heart rate and atrioventricular delay on left ventricular diastolic filling in patients with dual-chamber pacing for sick sinus syndrome or atrioventricular block

We examined the effect of left ventricular filling on different combinations of programmable heart rate and atrioventricular delay in patients with dual-chamber pacemakers. Pacing mode with heart rates of 60 beats/min and 156 ms of atrioventricular delay induced a diastolic pattern that resembles more than others the one observed in healthy subjects in sinus rhythm.