Critical finger ischemia and myocardial fibrosis development after sudden interruption of sildenafil treatment in a systemic sclerosis patient.

Systemic sclerosis (SSc) is a connective tissue disease frequently associated with Raynaud's Phenomenon (RP). Among possible pharmacological treatments, phosphodiesterase 5 inhibitors are considered in cases of severe non -responsive RP. We present the case of a male SSc patient wh presented with critical finger ischemia and concomitant appearance of myocardial fibrosis after sudden interruption of sildenafil treatment.

Minimal changes of thyroid axis activity influence brain functions in young females affected by subclinical hypothyroidism.

There is evidence of an association between thyroid hormones (TH) alterations and mental dysfunctions related to procedural and working memory functions, but the physiological link between these domains is still under debate, also for the presence of age as a confounding factor. Thus, we investigated the TH tuning of cerebral functions in young females affected by the borderline condition of subclinical hypothyroidism (SH) and in euthyroid females of the same age. The experiment consisted in the characterization of the affective state and cognitive abilities of the subjects by means of specific neuropsychological questionnaires, and of brain activity (EEG) in resting state and during the passive viewing of emotional video-clips. We found that SH had i) increased anxiety for Physical Danger; ii) better scores for both Mental Control and no-working-memory-related functions; iii) association between anxiety for Physical Danger and fT4 levels. Thus, in young adults, SH increases inward attention and paradoxically improves some cognitive functions. In addition, self-assessed questionnaires showed that SH had a greater susceptibility to unpleasant emotional stimulation. As for EEG data, SH compared to controls showed: i) reduction of alpha activity and of gamma left lateralization in resting state; ii) increased, and lateralized to the right, beta2 activity during stimulations. Both results indicated that SH have higher levels of arousal and greater susceptibility to negative emotion than controls. In conclusion, our study indicates that minimal changes in TH levels produce subtle but well-defined mental changes, thus encouraging further studies for the prediction of pathology evolution.

Thyroid hormone, amiodarone therapy, and prognosis in left ventricular systolic dysfunction.

BACKGROUND: Amiodarone protects patients with left ventricular systolic dysfunction (LVSD) against serious arrhythmias, but it also has numerous side effects on non-cardiac organs, such as the thyroid. Indeed, amiodarone may inhibit the peripheral conversion of T4 into T3. Pathologically reduced serum levels of T3 - the so-called "low T3 syndrome" (LOWT3) - increase mortality in patients with LVSD and not on amiodarone. AIM: The aim of the study was to examine the relationship between thyroid hormone status, amiodarone therapy, and outcome in a population with LVSD. MATERIAL/ SUBJECTS AND METHODS: A total of 2344 patients with LVSD and free of overt hyper- and hypothyroidism were enrolled. The population was divided into 4 groups: group 1 (LOWT3 and amiodarone therapy, no.=126), group 2 (isolated amiodarone therapy, no.=74), group 3 (isolated LOWT3, no.=682), group 4 (controls, no.=1462). RESULTS: Kaplan-Meier curves showed, after a mean follow-up of 31 months, increased total and cardiac mortality in groups 1 (30% and 20%, respectively), 2 (23%, 11%), and 3 (22%, 12%) compared to group 4 (total mortality log-rank 82.8, p<0.0001; cardiac mortality log-rank 63.1, p<0.0001). At Cox analysis, adjusted for several clinical variables, survival was reduced in groups 1 and 3 compared to group 4. Group 2 had a similar mortality to group 4, although the number of patients was too limited to accurately assess the effect of amiodarone on long-term prognosis. CONCLUSIONS: LOWT3 exerts an adverse impact on prognosis in LVSD, which is not influenced by concomitant amiodarone therapy.

Influence of all-trans-retinoic acid on oxoglutarate carrier via retinoylation reaction.

All-trans-retinoic acid (atRA), an activated metabolite of vitamin A, is incorporated covalently into proteins both invivo and invitro. AtRA reduced the transport activity of the oxoglutarate carrier (OGC) isolated from testes mitochondria to 58% of control via retinoylation reaction. Labeling of testes mitochondrial proteins with (3)HatRA demonstrated the binding of atRA to a 31.5 KDa protein. This protein was identified as OGC due to the competition for the labeling reaction with 2-oxoglutarate, the specific OGC substrate. The role of retinoylated proteins is currently being explored and here we have the first evidence that retinoic acids bind directly to OGC and inhibit its activity in rat testes mitochondria via retinoylation reaction. This study indicates the evidence of a specific interaction between atRA and OGC and establishes a novel mechanism for atRA action, which could influence the physiological biosynthesis of testosterone in situations such as retinoic acid treatment.

The role of thyroid hormone in the pathophysiology of heart failure: clinical evidence.

Thyroid hormone (TH) has a fundamental role in cardiovascular homeostasis in both physiological and pathological conditions, influencing cardiac contractility, heart rate (HR), diastolic function and systemic vascular resistance (SVR) through genomic and non-genomic mediated effects. In heart failure (HF) the main alteration of thyroid function is referred to as "low-triiodothyronine (T3) syndrome" (LT3S) characterized by decreased total serum T3 and free T3 (fT3) with normal levels of thyroxine (T4) and thyrotropin (TSH). Even if commonly interpreted as an adaptive factor, LT3S may have potential negative effects, contributing to the progressive deterioration of cardiac function and myocardial remodeling in HF and representing a powerful predictor of mortality in HF patients. All these observations, together with the early evidence of the benefits of T3 administration in HF patients indicate that placebo-controlled prospective studies are now needed to better define the safety and prognostic effects of chronic treatment with synthetic TH in HF.

Antioxidants in the Diet and Cognitive Function: Which Role for the Mediterranean Life-style?

This review aims to focus on main antioxidants- abundantly contained in the diet- as well as of the whole Mediterranean diet and life-style and their relationship with cognitive function, especially critical in two phases of life, in children until adolescence and oldness. The role of emerging biochemical and molecular biomarkers as opportunity to estimate more accurately nutritional assumption and requirement, in terms of cognitive preservation and disease risk, will be also discussed. The cluster of factors within the Mediterranean pattern -which include not only nutritional, but also physical, social, and stimulating aspects- is still largely understudied as a whole, but it is proposed as attractive research area and tool for public health planning of prevention and intervention.

The monounsaturated fatty acid oleate is the major physiological toxic free fatty acid for human beta cells.

Free fatty acids (FFAs) can cause glucose intolerance and diabetes. Lipotoxicity to the pancreatic beta cells is considered to be a major underlying cause for this phenomenon. The aim of this study was to analyse the toxicity profile of FFAs in the human EndoC-ßH1 beta-cell line and to compare the results with isolated rat and human islets with special reference to the physiologically most prevalent FFAs palmitic acid (PA) and oleic acid (OA). Toxicity after a 2-day incubation with the different FFAs was analysed by the caspase-3 assay and confirmed by the propidium iodide and annexin V staining tests. The long-chain saturated PA (C16:0) and the monounsaturated OA (C18:1) were both toxic to human EndoC-ßH1 beta cells and pseudoislets, as well as to rat islets, and, as confirmed in a pilot experiment, also to human islets. Furthermore, OA provided no protection against the toxicity of PA. Likewise, elaidic acid (EA, the trans isomer of OA; trans-OA) was significantly toxic, in contrast to the non-metabolisable analogues methylated PA (MePA) and methylated OA (MeOA). Fatty acids with a chain length < C16 were not toxic in EndoC-ßH1 beta cells. Caspase-3 was also activated by linoleic acid (LA)(C18:2) but not by γ-linolenic acid (γ-LNA)(C18:3). Overall, only long-chain FFAs with chain lengths > C14, which generate hydrogen peroxide in the peroxisomal beta-oxidation, were toxic. This conclusion is also supported by the toxicity of the branched-chain FFA pristanic acid, which is exclusively metabolised in the peroxisomal beta-oxidation. The lack of a protective effect of the monounsaturated fatty acid OA has important consequences for a beta-cell protective lipid composition of a diet. A cardioprotective diet with a high OA content does not fulfil this requirement.

Analysis of interinstitutional observer agreement in interpretation of dobutamine stress echocardiograms.

OBJECTIVES: This study sought to determine the degree of interinstitutional agreement in the interpretation of dobutamine stress echocardiograms. BACKGROUND: Dobutamine stress echocardiography involves subjective interpretation. Consistent methods for acquisition and interpretation are of critical importance for obtaining high interobserver agreement and for facilitating communication of test results. METHODS: Five experienced centers were each asked to submit 30 dobutamine stress echocardiograms (dobutamine up to 40 micrograms/kg body weight per min and atropine up to 1 mg) obtained in patients undergoing coronary angiography. Thus, a total of 150 dobutamine stress echocardiograms were interpreted by each center without knowledge of any other patient data. Left ventricular wall motion was assessed using a 16-segment model but was otherwise not standardized. No patient was excluded because of poor image quality or inadequate stress level. Echocardiographic image quality was assessed using a five-point scale. RESULTS: Angiographically significant coronary artery disease (> or = 50% diameter stenosis) was present in 95 patients (63%). By a majority decision (three or more centers), the sensitivity, specificity and accuracy of dobutamine echocardiography were 76%, 87% and 80%, respectively. Abnormal or normal results of stress echocardiography were agreed on by four or all five of the centers in 73% of patients (mean kappa value 0.37, fair agreement only). Agreement on the left anterior descending artery territory (78%) was similar to that for the combined right coronary artery/left circumflex artery territory (74%), and for specific segments the agreement ranged from 84% to 97% and was highest for the basal anterior segment and lowest for the basal inferior segment. Agreement was higher in patients with no (82%) or three-vessel coronary artery disease (100%) and lower in patients with one- or two-vessel disease (61% and 68%, respectively). Agreement on positivity or negativity of stress test results was 100% for patients with the highest image quality but only 43% for those with the lowest image quality (p = 0.003). CONCLUSIONS: The current heterogeneity in data acquisition and assessment criteria among different centers results in low interinstitutional agreement in interpretation of stress echocardiograms. Agreement is higher in patients with no or advanced coronary artery disease and substantially lower in those with limited echocardiographic image quality. To increase interinstitutional agreement, better standardization of image acquisition and reading criteria of stress echocardiography is recommended.

Prognostic value of pharmacological stress echocardiography in patients with known or suspected coronary artery disease: a prospective, large-scale, multicenter, head-to-head comparison between dipyridamole and dobutamine test. Echo-Persantine International Cooperative (EPIC) and Echo-Dobutamine International Cooperative (EDIC) Study Groups.

OBJECTIVES: The study compared the prognostic value of dipyridamole and dobutamine stress echocardiography in patients with known or suspected coronary artery disease. BACKGROUND: Extensive information is available on the relative diagnostic accuracy of the two tests assessed in a head-to-head fashion, whereas comparative data on their prognostic yield are largely preliminary to date. METHODS: Dipyridamole (up to 0.84 mg/kg over 10 min) atropine (up to 1 mg over 4 min) (DIP) and dobutamine (up to 40 microg/kg/min)-atropine (1 mg over 4 min) (DOB) stress tests were performed in 460 patients with known or suspected coronary artery disease. Patients were followed up for 38+/-21 months. RESULTS: The DIP was negative in 253 and positive in 207 patients. The DOB was negative in 242 and positive in 218 patients. During the follow-up, there were 80 cardiac events. For all cardiac events, the negative and positive predictive value were 83% and 17% for DOB, 84% and 19% for DIP, respectively (p = NS). Considering only cardiac death, by univariate analysis Wall-Motion Score Index (WMSI) at DIP peak dose (chi-square 13.80, p<0.0002) was the strongest predictor, followed by WMSI DOB (chi2 = 8.02, p<0.004) and WMSI at rest (chi2 = 6.85, p<0.008). By stepwise analysis, WMSI at DIP peak dose was the most important predictor (RR [relative risk] 7.4, p<0.0001). CONCLUSIONS: In patients at low-to-moderate risk of cardiac events, pharmacological stress echocardiography with either dobutamine or dipyridamole allows effective and grossly comparable, risk stratification on the basis of the presence, severity and extension of the induced ischemia.

Stress echocardiographic results predict risk of reinfarction early after uncomplicated acute myocardial infarction: large-scale multicenter study. Echo Persantine International Cooperative (EPIC) Study Group.

OBJECTIVES: This study sought to assess the value of dipyridamole echocardiography in predicting reinfarction in patients evaluated early after uncomplicated acute myocardial infarction. BACKGROUND: The identification of future nonfatal reinfarction seems an elusive target for physiologic testing. However, a large sample population is needed to detect minor differences in phenomena with a low event rate. METHODS: We assessed the value of dipyridamole echocardiography in predicting reinfarction in 1,080 patients (mean [+/- SD] age 56 +/- 9 years; 926 men, 154 women) evaluated early (10 +/- 5 days) after uncomplicated acute myocardial infarction and followed up for 14 +/- 10 months. RESULTS: Submaximal studies due to limiting side effects occurred in 14 patients (1.3%); these test results were included in the analysis. Results of dipyridamole echocardiography were positive in 475 patients (44%). During follow-up, there were 50 reinfarctions: 45 nonfatal, 5 fatal (followed by cardiac death < or = 4 days after reinfarction). Reinfarction (either nonfatal or fatal) occurred in 30 patients with positive and 20 with negative results (6.3% vs. 3.3%, p < 0.01). Nonfatal reinfarction occurred in 25 patients with positive and 20 with negative results (5% vs. 3.3%, p < 0.05). Reinfarction was fatal in 5 of 30 patients with positive and in none of 20 with negative results (16.6% vs. 0%, p = 0.07). The relative risk of reinfarction was 1.9. CONCLUSIONS: Dipyridamole echocardiographic positivity identifies patients evaluated early after uncomplicated acute myocardial infarction at higher risk of reinfarction, especially fatal reinfarction.

Prognostic value of dipyridamole echocardiography early after myocardial infarction in elderly patients. Echo Persantine Italian Cooperative (EPIC) Study Group.

OBJECTIVES: This study was conducted to assess the feasibility, safety and prognostic value of dipyridamole echocardiography in elderly patients recovering from an uncomplicated acute myocardial infarction in a subset analysis performed on the patients entered in the subproject "residual ischemia" of the Echo Persantine Italian Cooperative Study (EPIC). BACKGROUND: Coronary heart disease accounts for two thirds of all deaths in the age group > 65 years, and > 50% of all patients admitted to the hospital with acute myocardial infarction are > 65 years old. The prognostic value of dipyridamole-induced left ventricular dysfunction was clearly established in patients evaluated early after acute infarction. METHODS: In a subgroup analysis of the Echo Persantine Italian Cooperative Study (EPIC), we assessed the value of dipyridamole echocardiography in predicting cardiac events in 190 elderly (> or = 65 years) patients (age 68.4 +/- 3.3 years, range 65 to 78; 147 men and 43 women) evaluated early (mean 10 days) after uncomplicated acute myocardial infarction and followed up for 14 +/- 9.8 months. RESULTS: There was no major side effect during dipyridamole echocardiography. A positive test result occurred in 85 patients (44.7%). During follow-up, there were 62 events (14 cardiac deaths, 7 nonfatal reinfarctions, 21 cases of class III or IV angina and 20 revascularization procedures). Of these 62 events, 44 occurred among 85 patients with positive dipyridamole echocardiography and 18 among 105 patients with negative dipyridamole echocardiography (52% vs. 17%, p < 0.001). Spontaneous events (death, reinfarction, angina) occurred in 31 patients with positive and in 11 with negative dipyridamole echocardiography (36% vs. 10%, p < 0.001). Hard events (myocardial infarction or death) occurred in 14 patients with positive and 7 with negative dipyridamole echocardiography (16% vs. 6%, p < 0.05). Death occurred in 11 patients with positive and in 3 with negative dipyridamole echocardiography (13% vs. 3%, p < 0.01). The positive predictive value of positive dipyridamole echocardiography and negative predictive value of negative dipyridamole echocardiography as related to the occurrence of all events in the follow-up period (death, reinfarction, angina, revascularization procedures) were 52% and 83%, respectively. The relative risk (that is, the relative risk of occurrence of future cardiac events in the group with positive dipyridamole echocardiography compared with that in those with negative dipyridamole echocardiography) was 3 for all events and 4.4 for death. CONCLUSIONS: Dipyridamole echocardiography was well tolerated by elderly patients and proved to be very effective in prognostic stratification early after uncomplicated acute myocardial infarction, even when only survival was considered.

Does stress echocardiography predict the site of future myocardial infarction? A large-scale multicenter study. EPIC (Echo Persantine International Cooperative) and EDIC (Echo Dobutamine International Cooperative) study groups.

OBJECTIVES: We sought to assess whether the site of future myocardial infarction can be predicted on the basis of induced dyssynergy ("area at risk") recognized by stress echocardiography. BACKGROUND: The severity and extent of stress-induced dyssynergy are strong predictors of subsequent major cardiac events. However, high grade stenotic lesions are not strictly associated with the site of future coronary occlusions. METHODS: From the stress echocardiography multicenter trials data bank, we selected 70 patients (56 men; mean age +/- SD 58 +/- 11 years) meeting the following inclusion criteria: 1) dipyridamole (n = 53) or dobutamine (n = 17) stress echocardiography; 2) a spontaneously occurring infarction, with no intercurrent revascularization procedure between the initial study and the infarction; and 3) a follow-up rest echocardiogram obtained 41 +/- 90 days after the infarction. RESULTS: A complete ischemia-infarction mismatch (infarct-related dysfunction in a patient with negative stress test results) occurred in 29 patients (41%). A partial mismatch (ischemic dysfunction in a territory different from the infarct area) occurred in nine patients (13%). A match (ischemia-related and infarction-related dyssynergy involving the same region) occurred in 32 patients (46%). The average time interval between the stress examination and the occurrence of infarction or reinfarction was 144 +/- 160 days in patients with a match and 439 +/- 622 days in patients with a mismatch (p < 0.05). CONCLUSIONS: Induced ischemia (imaged as transient dyssynergy by pharmacologic stress echocardiography) inconsistently identifies the site of future infarction. The majority of spontaneous coronary occlusions leading to infarction are unheralded by induced ischemia. However, most infarctions occurring within 1 year of stress testing are in the area identified as ischemic during testing.

Prognostic value of dobutamine-atropine stress echocardiography early after acute myocardial infarction. Echo Dobutamine International Cooperative (EDIC) Study.

OBJECTIVES: The aim of this multicenter, multinational, prospective, observational study was to assess the relative value of myocardial viability and induced ischemia early after uncomplicated myocardial infarction. BACKGROUND: Dobutamine-atropine stress echocardiography allows evaluation of rest function (at baseline), myocardial viability (at low dose) and residual ischemia (peak dose, up to 40 micrograms with atropine up to 1 mg) in one test. METHODS: Dobutamine-atropine stress echocardiography was performed 12 +/- 5 days (mean +/- SD) after a first uncomplicated acute myocardial infarction in 778 patients (677 men; mean age 58 +/- 10 years) with technically satisfactory rest echocardiographic study results. Patients were followed-up for 9 +/- 7 months. RESULTS: Dobutamine-atropine stress echocardiographic findings were positive for myocardial ischemia in 436 of patients (56%) and negative in 342 (44%). During follow-up, there were 14 cardiac-related deaths (1.8% of the total cohort), 24 (2.9%) nonfatal myocardial infarctions and 63 (8%) hospital readmissions for unstable angina. One hundred seventy-four patients (22%) underwent coronary revascularization (bypass surgery or coronary angioplasty). Spontaneous events occurred in 61 of 436 patients with positive and 40 of 342 patients with negative findings on dobutamine-atropine stress echocardiography (14% vs. 12%, p = 0.3). When only spontaneously occurring events were considered, the most important predictor was myocardial viability (chi-square 9.7). Using the Cox proportional hazards model, only the presence of myocardial viability (hazard ratio [HR] 2.0, p < 0.002) and age (HR 1.03, p < 0.001) were predictive of spontaneously occurring events. When only hard cardiac events were considered, age was the strongest predictor (chi-square 3.6, p = 0.056), followed by wall motion score index (WMSI) at peak dose (chi-square 3.3, p = 0.06) and remote ischemia (chi-square 2.25, p = 0.1). When cardiac death was considered, WMSI at peak dose was the best predictor (HR 9.2, p < 0.0001). CONCLUSIONS: During dobutamine stress, echocardiographic recognition of myocardial viability is more prognostically important than echocardiographic recognition of myocardial ischemia for predicting unstable angina, whereas WMSI at peak stress was the best predictor of cardiac-related death. Different events can be recognized with different efficiency by various stress echocardiographic variables.

The atropine factor in pharmacologic stress echocardiography. Echo Persantine (EPIC) and Echo Dobutamine International Cooperative (EDIC) Study Groups.

OBJECTIVES: This study sought to compare, head to head, the two most popular pharmacologic stress echocardiographic tests--dipyridamole and dobutamine--with state of the art protocols in a large multicenter prospective study. BACKGROUND: In the continuing quest for ideal diagnostic accuracy, pharmacologic stress echocardiography has quickly moved over the years from low to high dose regimens and is currently performed with atropine coadministration. METHODS: Dobutamine (up to 40 microgram/kg body weight per min) plus atropine (up to 1 mg over 4 h) and dipyridamole (up to 0.84 mg/kg per min over 10 h) plus atropine (up to 1 mg over 4 h) stress echocardiography was performed on different days, in random order and within 1 week in 360 patients with chest pain syndrome. Thirteen different echocardiographic laboratories, all fulfilling quality control criteria for stress echocardiographic reading, contributed to the study. RESULTS: No major complications occurred during either test. The test was interrupted before achievement of predetermined end points for limiting side effects in 37 dobutamine-atropine and 7 dipyridamole-atropine stress echocardiographic studies (feasibility 90% vs. 98%, p < 0.01). Diagnostic accuracy was assessed in a subset of 110 patients with no obvious rest dyssynergy (akinesia or dyskinesia) who underwent coronary angiography independently of test results and within 1 week of testing. Significant coronary artery disease (> or = 50% diameter reduction in at least one major coronary vessel by quantitative coronary angiography) was found in 92 patients. Sensitivity for detection of coronary artery disease was 84% (77 of 92) for dobutamine-atropine and 82% (75 of 92) for dipyridamole-atropine stress echocardiography (p = NS), with a specificity of 89% (16 of 18) for dobutamine-atropine and 94% (17 of 18) for dipyridamole-atropine stress echocardiography (p = NS). A significant correlation was present between peak wall motion score index during dipyridamole-atropine and dobutamine-atropine stress echocardiography (r = 0.83, p < 0.0001). CONCLUSIONS: Dobutamine-atropine and dipyridamole-atropine stress echocardiography are safe and feasible, although submaximal studies are more frequent with dobutamine. The two stresses have comparable accuracy in the detection of angiographically assessed coronary artery disease, although dobutamine is marginally more sensitive and dipyridamole marginally more specific. Stratification of the ischemic response in the space domain is also comparable with the two stresses.

Dipyridamole stress echocardiography in patients with severe left main coronary artery narrowing. Echo Persantine International Cooperative (EPIC) Study Group--Subproject "Left Main Detection".

From a population of 2,698 patients (579 evaluated early after an uncomplicated acute myocardial infarction) who underwent dipyridamole echocardiography testing (DET) and subsequent coronary angiography, left main (LM) stenosis > or = 50% was present in 73 (61 men and 12 women, mean age 62 +/- 8 years). These 73 patients were compared with a control group comprising 100 consecutive coronary patients without LM disease. Both groups were similar regarding mean age, sex, incidence of previous myocardial infarction, left ventricular function at rest, and severity of coronary artery disease by the number of diseased vessels excluding the LM. The proportion of patients receiving antianginal therapy during DET was higher in the LM than in the non-LM group (32 vs 14%; p < 0.01). No major complication (severe hypotension, sustained arrhythmia, myocardial infarction or death) occurred during DET. Of 73 patients with LM disease, 68 had positive DET (sensitivity 93%), dipyridamole time was 7.1 +/- 3.8 minutes, and the rest-peak stress variation in dipyridamole wall motion score index (1 = normal to 4 = dyskinesia, in an 11-segment model) was 0.37 +/- 0.23; 14 patients (19%) were resistant to aminophylline and needed nitrates to resolve ischemia. In the non-LM group, DET was positive in 72% (p < 0.001 vs LM), with a longer dipyridamole time (9.6 +/- 5.2 minutes; p < 0.001 vs LM), lower rest-peak stress wall motion score index variation (0.29 +/- 0.25; p < 0.05 vs LM), and less frequent antidote resistance (1%; p < 0.001 vs LM).(ABSTRACT TRUNCATED AT 250 WORDS)

Angiographically assessed coronary collateral circulation increases vulnerability to myocardial ischemia during vasodilator stress testing.

In patients with a major coronary vessel occluded, the presence of good coronary collateral circulation increases vulnerability to myocardial ischemia induced by pharmacologic coronary vasodilation. The presence of good collaterals results in a greater frequency, severity, and extent of dipyridamole-induced regional left ventricular dysfunction, consistent with the hypothesis of angiographically assessed collaterals facilitating "steal phenomena" during dipyridamole-induced coronary vasodilation.

A videodensitometric study of transmural heterogeneity of cyclic echo amplitude variation in human myocardium.

The aims of this study were: (1) to assess whether variations in cyclic echo amplitude might be detected across the human myocardium by videodensitometric analysis of images obtained with epicardial echocardiography; and (2) to explore the possible relation between cyclic gray level variation and left ventricular (LV) hypertrophy and function. Experimental studies show that transmural differences in contractile performance across the normal myocardium are paralleled by differences in the cyclic (diastolic-to-systolic) variation of myocardial echo amplitude. Thirty-three patients (aged 60 +/- 11 years) undergoing cardiac surgery were studied by intraoperative epicardial echocardiography. LV mass index as normal (<110 g/m2 in women, <131 g/m2 in men) in 10 patients and increased in 22. Two-dimensional echocardiographic images were obtained with a 5 MHz transducer and digitized off-line. Videodensitometric analysis was performed at end-diastole and end-systole with regions of interest across the septal and posterior wall. The cyclic variation was more pronounced in the left than in the right septal subendocardium (31% +/- 14% vs 16% +/- 14% <0.01) and higher in the subendocardial than in the subepicardial layer of the posterior wall (30% +/- 21% vs 23 +/- 18%, p <0.01). Cyclic variation of the left septal subendocardium was higher in 11 patients with nonhypertrophic ventricles than in 22 with hypertrophic left ventricles (42% +/- 15% vs 27% +/- 12%; p <0.01). The percent cyclic variation of the left septal subendocardium appeared to be much more tightly related to percent systolic thickening in patients with eccentric LV hypertrophy (r=0.80 p <0.01) than in patients with concentric LV hypertrophy (r=0.27, p=0.9) or normal LV mass (r=0.43, p=0.2). A cyclic gray level variation can be consistently detected in different human myocardial regions and layers. It is more obvious in the subendocardial than in the subepicardial layer, and in nonhypertrophic than hypertrophic ventricles. The cyclic subendocardial variation is tightly related to regional systolic thickening in patients with eccentric LV hypertrophy.

Standardized guidelines for the interpretation of dobutamine echocardiography reduce interinstitutional variance in interpretation.

Subjective interpretation of dobutamine echocardiograms provides only moderate interinstitutional observer agreement if nonunified data acquisition and assessment criteria are applied. The present study was undertaken to evaluate parameters associated with low interinstitutional observer agreement in the interpretation of dobutamine echocardiograms and to analyze whether standardized interpretation criteria improve interinstitutional observer agreement. One hundred fifty dobutamine echocardiograms (dobutamine up to 40 microg/kg/min body weight and atropine up to 1 mg) were evaluated at 5 centers. Clinical, procedural, and echocardiographic parameters were included in the analysis of variables with significant impact on interinstitutional agreement. Standardized interpretative criteria were established, and 90 dobutamine echocardiograms were reanalyzed by 3 observers using a standardized image display. Multivariate analysis demonstrated low image quality (odds ratio [OR] 0.19, 95% confidence interval [CI] 0.08 to 0.45, p=0.0002), low severity of induced wall motion abnormality (OR 0.17, 95% CI 0.07 to 0.40, p <0.0001), and a low peak rate-pressure product (OR 0.93, 95% CI 0.43 to 2.27, p=0.0382) to result in a low interinstitutional agreement. Standardization of image display in cine loop format and of dobutamine stress echo interpretation criteria resulted in improvement in test result categorization as normal or abnormal, with a kappa value of 0.50, compared with 0.39 using the original subjective interpretation. In conclusion, image quality, the severity of induced wall motion abnormalities, and the obtained rate-pressure product have a significant impact on the interpretation homogeneity of dobutamine echocardiograms. Standardization of image display in cine loop format and of reading criteria results in improved interinstitutional agreement in interpretation of stress echocardiograms.