Novel wall motion score-based method for estimating global left ventricular ejection fraction: validation by real-time 3D echocardiography and global longitudinal strain.

AIMS: To evaluate the reliability of a regional wall motion score index (WMSI)-based method for assessment of left ventricular (LV) ejection fraction (EF). METHODS AND RESULTS: Two-dimensional (2D) echocardiography was used to assess a LV 16-segment-based regional wall motion. Each segment received a score based on contractility status: 4, normal kinesis; 3, mild; 2.5, moderate; and 1.5, severe hypo-kinesis; 0, akinesis; -1, dyskinesis; 3.5 and 4.5 were used for low-normal and high-normal kinesis; 5 for hyper-kinesis. Hence, WMSI-based EF was derived by summing the score assigned to each segment. Contextually, EF was evaluated by real-time three-dimensional (3D) echocardiography and by traditional Simpson's method (2D). Global longitudinal strain (GLS) by speckle-tracking method was derived as a volume-independent indicator of LV chamber contractility sensitive to regional wall motion abnormalities. In 40 subjects with 3D-EF ranging from 14 to 80%, including clinically healthy hypertensive and patients with Stage B-D congestive heart failure with global or segmental wall motion abnormalities, on average, WMSI-EF did not differ from EF measured by 3D or 2D (all P > 0.5). By intraclass correlation coefficients, reliability of WMSI-EF vs. 3D method was as good as the reliability of 2D method vs. 3D method. GLS correlated with WMSI-EF as strongly as with 3D-EF (both r(2) = 0.90). Moderate-severe mitral regurgitation was associated with increased difference between WMSI-EF and 3D-EF, independent to potential confounders. Intra-observer and inter-observer reproducibility of WMSI-EF was comparable to the reproducibility of EF estimated by 3D echocardiography. Feasibility (WMSI, 3D, 2D, and GLS all available) was 78%; however, feasibility of WMSI per se was approximately 92% in clinical series. CONCLUSION: Trained readers may rapidly estimate EF by a novel WMSI system, which was found to be accurate compared with 3D method and GLS.

UbcH10 expression in human lymphomas.

AIMS: The UbcH10 ubiquitin-conjugating enzyme plays a key role in regulating mitosis completion. We have previously reported that UbcH10 overexpression is associated with aggressive thyroid, ovarian and breast carcinomas. The aim of this study was to investigate UbcH10 expression in human lymphomas. METHODS AND RESULTS: Cell lines and tissue samples of Hodgkin's lymphoma (HL) and of non-Hodgkin's lymphoma (NHL) were screened for UbcH10 expression at transcriptional and translational levels. UbcH10 expression was related to the grade of malignancy. In fact, it was low in indolent tumours and high in a variety of HL and NHL cell lines and in aggressive lymphomas. It was highest in Burkitt's lymphoma, as shown by quantitative real-time polymerase chain reaction and by tissue microarray immunohistochemistry. Flow cytometry of cell lines confirmed that UbcH10 expression is cell-cycle dependent, steadily increasing in S phase, peaking in G(2)/M phase and dramatically decreasing in G(0)/G(1) phases. We also showed that UbcH10 plays a relevant role in lymphoid cell proliferation, since blocking of its synthesis by RNA interference inhibited cell growth. CONCLUSIONS: Taken together, these results indicate that UbcH10 is a novel lymphoid proliferation marker encompassing the cell cycle window associated with exit from mitosis. Its overexpression in aggressive lymphomas suggests that UbcH10 could be a therapeutic target in this setting.

Changes in components of left ventricular mechanics under selective beta-1 blockade: insight from traditional and new technologies in echocardiography.

AIMS: Myocardial inotropism is considered to be reduced under beta-1 adrenoreceptor blockage (beta1-block). However, relationships between components of left ventricular (LV) systolic mechanics under beta1-block accounting for physiological correlates are only partially explored. METHODS AND RESULTS: Hypertensive outpatient without previous cardiovascular events and with normal LV ejection fraction (EF) at rest underwent echocardiographic evaluations of LV size and systolic function by standard, tissue-Doppler, and speckle-tracking methods before and after 2 weeks of treatment with bisoprolol to obtain change in LV systolic mechanics at a stable heart rate reduction (-20 +/- 10% from baseline) without significant change in LV mass. In the study sample (n = 26, 62% women, mean age 52 +/- 10 years), under bisoprolol, afterload [i.e. circumferential (CESS) and meridional (MESS) end-systolic stress], LV mass, left atrial volume, and EF did not change significantly; LV chamber contractility [i.e. CESS/LV end-systolic volume index (CESS/ESVi) as well as MESS/ESVi] and relative wall thickness (RWT) decreased; stroke volume increased (all P < 0.05). Circumferential LV contractility (i.e. stress-corrected midwall shortening) increased, whereas regional longitudinal strain and strain rate, and global longitudinal strain decreased (all P < 0.05). Peak velocities of the systolic displacement of the lateral and medial mitral anulus did not change under bisoprolol. Parameters of longitudinal LV systolic function did not correlate with preload, afterload, RWT, or with stoke volume. CONCLUSION: In hypertensive subjects with preserved LV EF, parameters of longitudinal LV systolic mechanics may not reflect the LV myocardial contractility status in steady-state conditions under short-term treatment with beta1-block.

Effects of growth hormone on exercise capacity and cardiopulmonary performance in patients with chronic heart failure.

BACKGROUND: Because GH exerted beneficial effects in various experimental models of heart failure, we investigated the effects of GH on physical exercise capacity and cardiopulmonary performance in patients with dilated cardiomyopathy and chronic heart failure (CHF). METHODS: Twenty-two patients with CHF (New York Heart Association functional class II-III) underwent spirometry and a symptom-limited, cardiopulmonary exercise testing before and after 3 months of GH (n = 11; seven males; seven idiopathic; 57 +/- 11 yr; 4 IU sc every other day) or placebo (n = 11; eight males; six idiopathic; 54 +/- 10 yr) administration, in a randomized, double-blind trial. Background CHF therapy remained unchanged. RESULTS: GH, but not placebo, increased IGF-I serum concentration (from 144 +/- 35 to 293 +/- 58 ng/ml; P < 0.005) and improved New York Heart Association functional class (from 2.4 +/- 0.5 to 1.8 +/- 0.4; P < 0.005), exercise duration (from 831 +/- 273 to 925 +/- 266 sec; P < 0.005), peak power output (from 245 +/- 127 to 280 +/- 132 W; P < 0.05), peak minute ventilation (from 52.5 +/- 16.1 to 61.3 +/- 17.3 liters/min; P < 0.05), peak oxygen consumption (from 19.8 +/- 5.6 to 25.1 +/- 5.6 ml/kg.min; P < 0.005), and anaerobic threshold (from 14.9 +/- 4.8 to 20.0 +/- 4.5 ml/kg.min; P < 0.005) without affecting lung function parameters. Furthermore, the slope of the relationship between minute ventilation and pulmonary carbon dioxide production (ventilatory efficiency) decreased from 34.7 +/- 5.1 to 31.7 +/- 5.3 (P < 0.005), whereas the slope of the relation between percent predicted heart rate reserve used and percent observed metabolic reserve used (chronotropic index) rose from 0.57 +/- 0.20 to 0.69 +/- 0.18 (P < 0.005). CONCLUSION: Given the predictive value of physical exercise capacity and cardiopulmonary performance in CHF progression, these data provide additional insights into the mechanisms by which GH may potentially benefit CHF patients.

Growth hormone- and pressure overload-induced cardiac hypertrophy evoke different responses to ischemia-reperfusion and mechanical stretch.

OBJECTIVE: To compare the molecular, histological, and functional characteristics of growth hormone (GH)- and pressure overload-induced cardiac hypertrophy, and their responses to ischemia-reperfusion and mechanical stretch. DESIGN: Four groups of male Wistar rats were studied: aortic banding (n=24, AB) or sham (n=24, controls) for 10 weeks, and GH treatment (n=24; 3.5mg/kg/day, GH) or placebo (n=24, controls) for 4 weeks. At 13 weeks, the rats were randomly subjected to: (i) assessment of basal left ventricular mRNA expression of sarcoplasmic reticulum calcium-ATPase (SERCA-2), phospholamban (PLB), and Na(+)-Ca(2+) exchanger (NCX) and collagen volume fraction (CVF) (Protocol A, 8 rats in each group); (ii) left ventricular no-flow ischemia with simultaneous evaluation of intracellular Ca(2+) handling and ATP, phosphocreatine (PCr) and inorganic phosphate (Pi) content (Protocol B, 12 rats in each group); or (iii) left ventricular mechanical stretch for 40 min with assessment of tumor necrosis-alpha (TNF-alpha) mRNA (Protocol C, 4 rats in each group). Protocol B and C were carried out in a Langendorff apparatus. RESULTS: In Protocol A, no difference was found as to myocardial mRNA content of Ca(2+) regulating proteins and CVF in GH animals vs controls. In contrast, in the AB group, myocardial mRNA expression of SERCA-2 and PLB was downregulated while that of NCX and CVF were increased vs. controls (p<0.05). In Protocol B, recovery of left ventricular function was significantly decreased in AB vs GH groups and controls and this was associated with 1.6-fold increase in intracellular Ca(2+) overload during reperfusion (p<0.05). Baseline ATP content was similar in the four study groups, whereas PCr and Pi was lower in AB vs GH rats and controls. However, the time courses of high-energy phosphate metabolic changes did not differ during ischemia and reperfusion in the four study groups. In Protocol C, no detectable TNF-alpha mRNA level was found in the left ventricular myocardium of GH treated rats and controls at baseline, while a modest expression was noted in AB animals. Mechanical stretch resulted in de novo myocardial TNF-alpha mRNA expression in GH group and controls, which was dramatically increased in AB animals ( approximately 5-fold above baseline, p<0.001). CONCLUSIONS: The data show that cardiac hypertrophy activated by short-term GH treatment confers cardioprotection compared with pressure overload with regard to molecular and histological characteristics, and responses to ischemia-reperfusion and mechanical stretch.

Growth hormone corrects vascular dysfunction in patients with chronic heart failure.

OBJECTIVES: The goal of this study was to test the hypothesis that growth hormone (GH) administration to patients with chronic heart failure (CHF) corrects their vascular dysfunction. BACKGROUND: Endothelial dysfunction is a prominent feature of CHF. Recent evidence indicates that GH plays a role in vascular reactivity. METHODS: We studied vascular reactivity in 16 patients with CHF (New York Heart Association class II to III) before and after three months of GH (4 IU subcutaneously every other day) or placebo administration in a randomized, double-blind trial. We measured forearm blood flow (FBF) by strain-gauge plethysmography during intrabrachial, graded infusion of acetylcholine (ACh) and sodium nitroprusside (NP). We also measured the forearm balance of nitrite and cyclic guanosine monophosphate (cGMP) before and during ACh infusion. Maximal oxygen uptake (VO2max) was measured by breath-to-breath respiratory gas analysis. RESULTS: Before treatment, the response of FBF to ACh was flat (p = NS). Growth hormone, but not placebo, greatly improved this response (p = 0.03) and, concomitantly, increased the forearm release of nitrite and cGMP (p < 0.05). Growth hormone also potentiated the FBF response to NP (p = 0.013). Growth hormone interacted with ACh response (p = 0.01) but not with the response to NP (p = NS). Accordingly, GH enhanced the slope of the dose-response curve to ACh (p < 0.05) but not to NP. The VO2max increased significantly after GH treatment (20 +/- 2 and 26 +/- 2 ml x Kg(-1) x min(-1) before and after GH treatment, respectively, p < 0.05) but not after placebo. CONCLUSIONS: A three-month treatment with GH corrected endothelial dysfunction and improved non-endothelium-dependent vasodilation in patients with CHF. The data highlight the potential role of GH in the progression of congestive heart failure.

HMGA1 protein overexpression in human breast carcinomas: correlation with ErbB2 expression.

We measured, by immunohistochemistry, HMGA1 protein expression in 212 breast tissue specimens: 6 normal samples, 28 hyperplastic lesions (13 with cellular atypia), 11 fibroadenomas, 10 in situ ductal carcinomas, 144 ductal carcinomas, and 13 lobular carcinomas. HMGA1 was not expressed in normal breast tissue; HMGA1 staining was intense in 40% of hyperplastic lesions with cellular atypia and in 60% of ductal carcinomas and weak in fibroadenomas and in hyperplastic lesions without cellular atypia. Because HMGA1 expression was similar among ductal breast carcinomas with different histologic grading, we evaluated the association between HMGA1 expression and that of other markers of breast carcinoma invasion (estrogen and progesterone receptors, Ki-67 antigen, and ErbB2) in 21 cases of grade 3 breast ductal carcinomas and 7 cases of breast lobular carcinomas. We found that HMGA1 expression tended to be associated only with c-erbB-2 expression (Spearman rho: 0.36; P=0.065). Taken together, these results suggest that HMGA1 expression might be a novel indicator for the diagnosis and prognosis of human breast cancer.

p27Kip1 is expressed in proliferating cells in its form phosphorylated on threonine 187.

BACKGROUND: G1/S cell cycle progression requires p27Kip1 (p27) proteolysis, which is triggered by its phosphorylation on threonine (Thr) 187. Since its levels are abundant in quiescent and scarce in cycling cells, p27 is an approved marker for quiescent cells, extensively used in histopathology and cancer research. METHODS: However here we showed that by using a specific phosphorylation site (pThr187) antibody, p27 is detectable also in proliferative compartments of normal, dysplastic and neoplastic tissues. RESULTS: In fact, whereas un-phosphorylated p27 and MIB-1 showed a significant inverse correlation (Spearman R = -0.55; p < 0,001), pThr187-p27 was positively and significantly correlated with MIB-1 expression (Spearman R = 0.88; p < 0,001). Thus proliferating cells only stain for pThr187-p27, whereas they are un-reactive with the regular p27 antibodies. However increasing the sensitivity of the immunocytochemistry (ICH) by the use of an ultra sensitive detection system based on tiramide signal amplification, simultaneous expression and colocalisation of both forms of p27 was shown in proliferating compartments nuclei by double immunofluorescence and laser scanning confocal microscopy studies. CONCLUSION: Overall, our data suggest that p27 expression also occurs in proliferating cells compartments and the combined use of both regular and phospho- p27 antibodies is suggested.

Effects of subclinical thyroid dysfunction on the heart.

BACKGROUND: Mounting evidence indicates that subclinical thyroid dysfunction has important clinical effects and prognostic implications, supporting the view that it is not a compensated biochemical change sensu strictu. PURPOSE: To review clinical information on the effects of subclinical thyroid dysfunction on the heart. DATA SOURCES: English-language articles identified from files and a MEDLINE search (1970-September 2001), references of relevant articles, textbooks, and meeting abstracts. STUDY SELECTION: Reports on the effects of subclinical hypothyroidism and subclinical hyperthyroidism on the cardiovascular system in humans. DATA EXTRACTION: Data on cardiac structure and performance, arrhythmias, and risk for coronary artery disease were independently assessed by all authors and summarized. DATA SYNTHESIS: Subclinical hypothyroidism is associated with impaired left ventricular diastolic function at rest, systolic dysfunction on effort, and enhanced risk for atherosclerosis and myocardial infarction. Subclinical hyperthyroidism is associated with increased heart rate, atrial arrhythmias, increased left ventricular mass with marginal concentric remodeling, impaired ventricular relaxation, reduced exercise performance, and increased risk for cardiovascular death. All abnormalities were reversed by restoration of euthyroidism (subclinical hypothyroidism) or were blunted by beta-blockade and tailoring of the l -thyroxine dose (subclinical hyperthyroidism). CONCLUSION: The heart responds to the minimal but persistent changes in circulating thyroid hormone levels typical of subclinical thyroid dysfunction. Thus, the condition is not a compensated biochemical change sensu strictu, and timely treatment should be considered in an attempt to avoid adverse cardiovascular effects.

Cardiovascular safety of acute recombinant human thyrotropin administration to patients monitored for differentiated thyroid cancer.

Eleven patients who had undergone total thyroidectomy for differentiated thyroid cancer and who were on chronic TSH-suppressive therapy with levothyroxine (L-T4), underwent 24-h Holter electrocardiogram and Doppler-echocardiography before and after acute recombinant human TSH (rhTSH) administration for disease staging. The treatment, which was generally well tolerated, did not affect circulating thyroid hormones levels, nor did it have measurable effects on heart rate, rhythm, left ventricular morphology, or systo-diastolic function. Notably, arterial blood pressure tended to be slightly reduced after rhTSH administration, although in no instance did the patients become frankly symptomatic. Our data demonstrate that rhTSH does not alter cardiovascular function acutely. Consequently, it can safely be used in the routine staging of patients affected by differentiated thyroid cancer.

Subclinical hypothyroidism and cardiac function.

The cardiovascular system is sensitive to the action of thyroid hormone. However, although a wide spectrum of cardiac abnormalities has long been recognized in patients with overt thyroid dysfunction, the question of cardiac involvement in patients with subclinical thyroid dysfunction has been investigated only in the last two to three decades. Most clinical studies have shown that subclinical hypothyroidism or hyperthyroidism is associated with changes in several cardiac parameters. More specifically, the literature on cardiac involvement in subclinical hypothyroidism consistently shows that patients have resting left ventricular diastolic dysfunction evidenced by delayed relaxation, and impaired systolic dysfunction on effort that results in poor exercise capacity. Whether or not subclinical hypothyroidism also affects left ventricular systolic function at rest remains controversial. Studies of subclinical hypothyroid patients before and after euthyroidism was achieved with levothyroxine replacement provided evidence of impaired resting left ventricular systolic function. Indeed, at-rest left ventricular systolic function was substantially normal in most studies of subclinical hypothyroid patients compared to normal control subjects. Drawing on these data, it appears that subclinical hypothyroidism should be considered a mild form of thyroid failure, associated with initial signs of cardiovascular hypothyroidism. Therefore, it would seem appropriate to initiate timely treatment of patients with mild thyroid failure to prevent cardiac involvement.

Subclinical hypothyroidism and cardiovascular risk: a reason to treat?

Subclinical hypothyroidism (SH), defined by elevated serum levels of thyroid stimulating hormone (TSH) with normal levels of free thyroid hormones, is common in adults, especially in women over 60 years of age. Among individuals with this condition, up to two-thirds have serum TSH levels between 5-10 mU/L and thyroid autoantibodies; almost half of them may progress to overt thyroid failure, the annual percent risk increasing with serum TSH level. There is evidence that elevated TSH levels in patients with SH do not reflect pituitary compensation to maintain euthyroidism, but a mild tissue hypothyroidism sensu strictu. When lasting more than 6-12 months, SH may be associated with an atherogenic lipid profile, a hypercoagulable state, a subtle cardiac defect with mainly diastolic dysfunction, impaired vascular function, and reduced submaximal exercise capacity. The deviation from normality usually increases with serum TSH level ('dosage effect' phenomenon). Restoration of euthyroidism by levothyroxine (LT4) treatment may correct the lipid profile and cardiac abnormalities, especially in patients with an initially higher deviation from normality and higher serum TSH levels. Importantly, a strong association between SH and atherosclerotic cardiovascular disease, independent of the traditional risk factors, has been recently reported in a large cross-sectional survey (the Rotterdam Study). However, whether SH confers a high risk for cardiovascular disease, and whether LT4 therapy has a long-term benefit that clearly outweighs the risks of overzealous treatment in these individuals, remain topics of controversy. Therefore, until randomized, controlled, prospective, and adequately powered trials provide unequivocal answers to these critical questions, it is advisable to prescribe LT4 therapy on a case-by-case basis, taking into account the risk of progressive thyroid failure and the risk of cardiovascular events.

p27(Kip1) expression and grading of breast cancer diagnosed on cytological samples.

The progressive reduction in p27(Kip1) (p27) protein immunohistochemical staining with increasing histological grading is a well-established finding occurring in breast cancer, and its role as diagnostic complement and prognostic marker has been thoroughly evaluated. To clarify whether this test may be applied to breast cytopathology, we performed p27 immunostaining on fresh fine-needle cytology (FNC) samples from 10 benign and 40 malignant breast lesions. On average, p27 immunostaining was significantly lower in carcinomas than in benign lesions (P < 0.005). In particular, among carcinomas, p27 immunostaining progressively reduced from well-to poorly differentiated lesions (G1 vs. G2, P < 0.05; G1 vs. G3, P < 0.001; G2 vs. G3; P < 0.001). A similar trend was noted in a subgroup of 20 matched FNCs and histological samples of breast carcinomas, when p27 immunostaining on FNCs was stratified according to the histological grading (G1 vs. G2, P = 0.18; G1 vs. G3, P < 0.05; G2 vs. G3, P < 0.05). In addition, p27 immunostaining on FNCs showed a good positive correlation with that on histology (Spearman R = 0.58; P < 0.01), with a diagnostic concordance between samples of 85%, by using the standard 50% positive cell cutoff. Taken in concert, our data suggest that p27 immunostaining is a reliable marker of tumor cell differentiation in breast cytopathology as well as in histopathology. Accordingly, staining FNCs for p27 may be an useful complement in addition to cytological grading in the preoperative assessment of breast cancer.

Lytic failure in the current pharmacointensive ST-elevated acute myocardial infarction care: insights from a pilot real-world study.

BACKGROUND: Thrombolysis remains a very acceptable reperfusion option for ST-elevated acute myocardial infarction (STEMI); however, it fails relatively frequently and unpredictably. AIM AND METHODS: To investigate correlates of lytic failure (according to the standard ST resolution criterion) in current pharmacointensive STEMI care (dual antiplatelets with antithrombin), we analyzed retrospectively clinical data and echocardiographic left ventricular systolic function before initiation of reperfusion treatment in Killip I-III STEMI patients admitted to our 'spoke' intensive cardiac care unit between 1 January and 31 December 2010. RESULTS: Of the 53 STEMI patients enrolled, 28% failed thrombolysis. Patients who did not reperfuse were less frequently active smokers (P < 0.05, odds ratio 4.33) and had a higher prevalence of hemodynamic instability [heart rate/SBP (i.e. shock index) >0.75; P < 0.05, odds ratio 13.45) and left ventricular systolic dysfunction (ejection fraction <45%; P < 0.005, odds ratio 11.14). In an exploratory multivariable logistic regression analysis, those variables were the only discriminators independently associated with lytic failure (adjusted odds ratio 8.74, 230.10, and 18.22, respectively, all P < 0.05). Moreover, the combined variables had a high accuracy for prediction of failed thrombolysis (all discriminators positive, 99% specificity and 83% positive predictive value). CONCLUSION: Our pilot study indicates that thrombolysis still fails in about one-third of STEMI patients despite the current pharmacointensive approach and suggests that failed ST resolution might be independently associated with nonsmoking habit and pretreatment hemodynamic instability and left ventricular systolic dysfunction. Larger trials are needed to verify the potential clinical implications of our preliminary observation.

Cyclin D1 and D3 overexpression predicts malignant behavior in thyroid fine-needle aspirates suspicious for Hurthle cell neoplasms.

BACKGROUND: Thyroid fine-needle aspiration (FNA) samples that feature a follicular-patterned, monotonous Hurthle (oncocytic) cell population cannot be diagnosed reliably. The authors of this report recently identified cyclin D3 overexpression on histologic sections of Hurthle cell carcinoma. In this study, they assessed the diagnostic value of cyclin D3 immunohistochemistry added to routine cytology. METHODS: Fifty-one FNA samples that were suspicious for Hurtle cell neoplasia and that had histologic follow-up (19 malignant cases) were examined. Cyclin D3 expression levels were evaluated in cell block preparations and were compared with levels of the closely related cyclin D1 protein. RESULTS: Greater than 25% positive cells were used as the cutoff point, as suggested by previous studies. Cyclin D1 and cyclin D3 were highly specific (100% for both) and fairly accurate (75% and 92%, respectively) in distinguishing between benign and malignant oncocytic lesions; the positive predictive value (PPV) for each was 100%. However, both cyclins D1 and D3 had low sensitivity (32% and 79%, respectively) and low negative predictive value (NPV) (71% and 89%, respectively). In contrast, by adopting balanced receiver operating characteristic-derived positive cutoff values, cyclin D1 (>or=6.5%) and cyclin D3 (>or=7.5%) were found to be highly sensitive (100% for both) and accurate (90% and 94%, respectively); and the NPV was 100% for both. In contrast, cyclins D1 and D3 had low specificity (84% and 91%, respectively) and a low PPV (79% and 86%, respectively); however, these values improved in samples that were positive for both cyclins (sensitivity, 100%; specificity, 94%; PPV, 90%; NPV, 100%; and accuracy, 96%). CONCLUSIONS: Cyclin D3 increased the suspicion of malignancy in indeterminate oncocytic lesions; its diagnostic performance depended on the cutoff point used and was enhanced further when combined with cyclin D1.

Isolated left ventricular diastolic dysfunction: implications for exercise left ventricular performance in patients without congestive heart failure.

OBJECTIVE: Clinical relevance of left ventricular (LV) diastolic dysfunction in the absence of congestive heart failure (CHF) and LV systolic dysfunction is not fully established. METHODS: Asymptomatic outpatients, sedentary, with cardiovascular risk factors but no history of cardiovascular events, underwent echocardiographic evaluation of LV structure and function by standard Doppler, color M-mode, and Doppler tissue methods, and exercise testing with simultaneous noninvasive assessment of LV stroke index and cardiac index. LV ejection fraction less than 50% and significant valvular disease or stress test suggestive of coronary disease were additional exclusion criteria. RESULTS: In 70 patients selected (40 +/- 10 years old, 63% men, 34% hypertensive, 34% diabetic, 4% diabetic and hypertensive, 11% with LV hypertrophy), LV diastolic dysfunction was detected in 26%, which was associated with hypertension, higher LV mass index, lower systolic function, lower peak exercise heart rate, and chronotropic reserve (all P < .05), and with lower peak exercise stroke index and cardiac index (both covariates adjusted P < .05), but not with lower peak exercise metabolic equivalents (P > .5). Abnormal LV relaxation was independently correlated with lower peak exercise cardiac index and stroke index (both P < .05). Peak exercise systolic and cardiac indices were comparable between patients with CHF risk factors (74%) versus those without. CONCLUSIONS: Isolated LV diastolic dysfunction was independently associated with lower peak exercise LV systolic performance in patients without CHF. Its diagnosis may provide a target for aggressive CHF risk management.

Effects of thyroid hormone on the cardiovascular system.

Increased or reduced action of thyroid hormone on certain molecular pathways in the heart and vasculature causes relevant cardiovascular derangements. It is well established that overt hyperthyroidism induces a hyperdynamic cardiovascular state (high cardiac output with low systemic vascular resistance), which is associated with a faster heart rate, enhanced left ventricular (LV) systolic and diastolic function, and increased prevalence of supraventricular tachyarrhythmias - namely, atrial fibrillation - whereas overt hypothyroidism is characterized by the opposite changes. However, whether changes in cardiac performance associated with overt thyroid dysfunction are due mainly to alterations of myocardial contractility or to loading conditions remains unclear. Extensive evidence indicates that the cardiovascular system responds to the minimal but persistent changes in circulating thyroid hormone levels, which are typical of individuals with subclinical thyroid dysfunction. Subclinical hyperthyroidism is associated with increased heart rate, atrial arrhythmias, increased LV mass, impaired ventricular relaxation, reduced exercise performance, and increased risk of cardiovascular mortality. Subclinical hypothyroidism is associated with impaired LV diastolic function and subtle systolic dysfunction and an enhanced risk for atherosclerosis and myocardial infarction. Because all cardiovascular abnormalities are reversed by restoration of euthyroidism ("subclinical hypothyroidism") or blunted by beta-blockade and L-thyroxine (L-T4) dose tailoring ("subclinical hyperthyroidism"), timely treatment is advisable in an attempt to avoid adverse cardiovascular effects. Interestingly, some data indicate that patients with acute and chronic cardiovascular disorders and those undergoing cardiac surgery may have altered peripheral thyroid hormone metabolism that, in turn, may contribute to altered cardiac function. Preliminary clinical investigations suggest that administration of thyroid hormone or its analogue 3,5-diiodothyropropionic acid greatly benefits these patients, highlighting the potential role of thyroid hormone treatment in patients with acute and chronic cardiovascular disease.