RESUMEN Introduccion Estudios previos han publicado la correlacion entre defectos de perfusion miocardica (PM)SPECT durante la prueba de frio (PF) y la acetilcolina intracoronaria y su utilidad comomarcador independiente de disfuncion endotelial (DE). Objetivo Analizar la incidencia de positivizacion de los estudios de PM de esfuerzo en el seguimiento depacientes asintomaticos con riesgo cardiovascular (CV) moderado y DE detectada con la PF. Material y metodos De 301 pacientes del Registro PARADIGMA (PM SPECT esfuerzo normal y probabilidadclinica < 20% de eventos a 10 anos [riesgo moderado por indice de Framingham]), 55 tuvie-ron PF positiva (+) (18,3%). Se analizaron en forma prospectiva y consecutiva 15 pacientesasintomaticos con PF (+) y un grupo control (GC) de 15 pacientes con PF negativa (-), conapareamiento de sexo, edad y factores de riesgo coronario (FRC), que cumplieron un segui-miento de 12 ± 2 meses, en quienes se realizo una nueva PM SPECT de reposo y esfuerzo.Se utilizo un

The ejection fraction (LVEF) is a commonly used marker of left ventricular function. However, because it is strongly influenced by loading conditions, it can be inaccurate in representing cardiac contractility. We therefore evaluated a gated SPECT based tool to simultaneously assess preload, afterload, and contractility. Using gated SPECT-determined ventricular volumes and arterial tension measurements, we calculated ventricular and arterial elastance (Ev and Ea), as well as end-diastolic volumes, which are surrogates for contractility, afterload, and preload, respectively. We applied this protocol to 1462 consecutive patients and assessed the ventricular function in patients with and without myocardial infarction. The median LVEF was 68% (IQR 62–74%). Patients with infarction exhibited decreased contractility (ventricular elastance of 3 mmHg/ml vs. 6 mmHg/ml), compensated by an increase of preload (end-diastolic volume of 100 ml vs. 78 ml) and a decrease in afterload (arterial elastance of 1.8 mmHg/ml vs. 2.2 ml/mmHg). These interactions yielded a preserved ejection fraction in both groups. Gated SPECT-measured volumes were consistent with values reported in the literature. In addition, the combination of nuclear imaging and arterial tension measurement accounted for not only the ejection fraction but also the loading context, providing a more accurate representation of cardiac contractility.

espanolIntroduccion: El score de calcio (SC) es una prueba utilizada en la estratificacion de riesgo de pacientes asintomaticos. Aunque la enfermedad coronaria puede ocurrir en ausencia de calcificaciones, no se han descripto afecciones asociadas a la presencia de placa blanda (PB) en este contexto, mas alla de la presencia de sintomas. Objetivos: determinar predictores clinicos de PB y su eventual precision diagnostica en pacientes con un SC de cero. Materiales y metodos: Se incluyeron pacientes consecutivos con un SC de 0 Unidades Agatston que se hubieran realizado ademas una angiotomografia coronaria. Se determinaron predictores a partir de tres modelos de analisis multivariado. Se calculo la sensibilidad, especificidad, VPN, VPP, + LR y - LR. Resultados: Se incluyeron 93 pacientes. El 10% (n = 9) presentaron PB. La ergometria positiva fue predictor independiente de placas de cualquier severidad (OR 6.5; IC del 95%: 1.3-33, p = 0.02). El poder predictivo persistio para placas no severas cuando se combino la ergometria con perfusion miocardica SPECT o ecocardiograma estres negativos para isquemia (OR 12.4 IC 95% 1.5 - 101, p = 0.02). La sensibilidad y la especificidad del infradesnivel del ST para placa blanda de cualquier grado de severidad fue 44.4% y 86%, respectivamente. El VPN fue del 94% y el VPP del 25%, + LR fue de 3.11 y -LR fue de 0.65. Conclusiones: El infradesnivel del ST podria ser predictor de PB en pacientes sin calcificaciones coronarias, incluso en contexto de perfusion miocardica o ecocardiograma estres normales (enfermedad no obstructiva). EnglishBackground: The coronary artery calcium score is used for risk stratification in asymptomatic patients. Although coronary arterydisease can occur in the absence of coronary artery calcifications, no conditions associated with the presence of soft non-calcifiedplaques have been described in this scenario, beyond the presence of symptoms.Objectives: The aim of this study was to determine the associations between non-calcified plaques and independent variables inpatients with coronary artery calcium score of zero.Methods: Consecutive patients with coronary artery score of zero Agatston units who also underwent computed tomography coronaryangiography were included in the study. Univariate logistic regression analysis was used to find associations. (15) Sensitivity,specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LH+) and negative likelihoodratio (LH-) were calculated.Results: Among a total of 93 patients, 10% (n = 9) presented non-calcified plaque. A positive exercise stress test was associated withplaques of any degree of severity (OR 6.5; 95% CI, 1.3-33, p = 0.02). This association persisted for non-severe plaques when the positiveexercise stress test was combined with a negative myocardial perfusion SPECT or stress echocardiography for ischemia (OR,12.4; 95% CI 1.5-101, p = 0.02). Sensitivity and specificity of ST-segment depression for non-calcified plaque of any degree of severitywas 44.4% and 86%, respectively, with NPV of 94%, PPV of 25%, LR+ of 3.11 and LR– of 0.65.Conclusions: ST-segment depression could be associated with non-calcified plaques in patients without coronary artery calcifications,even with normal exercise stress myocardial perfusion or wall motion (non-obstructive disease).

Background: The coronary artery calcium score is used for risk stratification in asymptomatic patients. Although coronary arterydisease can occur in the absence of coronary artery calcifications, no conditions associated with the presence of soft non-calcifiedplaques have been described in this scenario, beyond the presence of symptoms.Objectives: The aim of this study was to determine the associations between non-calcified plaques and independent variables inpatients with coronary artery calcium score of zero.Methods: Consecutive patients with coronary artery score of zero Agatston units who also underwent computed tomography coronaryangiography were included in the study. Univariate logistic regression analysis was used to find associations. (15) Sensitivity,specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LH+) and negative likelihoodratio (LH-) were calculated.Results: Among a total of 93 patients, 10% (n = 9) presented non-calcified plaque. A positive exercise stress test was associated withplaques of any degree of severity (OR 6.5; 95% CI, 1.3-33, p = 0.02). This association persisted for non-severe plaques when the positiveexercise stress test was combined with a negative myocardial perfusion SPECT or stress echocardiography for ischemia (OR,12.4; 95% CI 1.5-101, p = 0.02). Sensitivity and specificity of ST-segment depression for non-calcified plaque of any degree of severitywas 44.4% and 86%, respectively, with NPV of 94%, PPV of 25%, LR+ of 3.11 and LR– of 0.65.Conclusions: ST-segment depression could be associated with non-calcified plaques in patients without coronary artery calcifications,even with normal exercise stress myocardial perfusion or wall motion (non-obstructive disease).

AimsIn patients with normal myocardial perfusion, ST-segment depression and reserve pulse pressure (rPP) can identify patients at higher risk of cardiovascular events. We aimed to explore the prevalence of impaired ventricular-arterial coupling (VAc) in patients with normal myocardial perfusion imaging and its relationship with ST-segment depression and rPP.Methods and resultsThe present study included consecutive patients with normal myocardial perfusion imaging by single-photon emission computed tomography and ST-segment depression. Stroke volume, end-systolic pressure, arterial elastance (E-a), ventricular elastance (E-v), and VAc (E-a/E-v) were estimated both at rest and during stress. The difference between stress and rest (VAc) was calculated. A positive VAc was considered an impaired VAc (iVAc).ResultsA total of 92 patients were prospectively included. iVAc was identified in 44 (59%) patients with ST-segment depression compared with 3 (16%) patients with normal repolarization (P=0.001). A higher incidence of abnormal rPP was identified in patients with ST-segment depression compared with the control group (61 vs. 16%, P=0.0001). ST-segment depression was identified as the only independent predictor of iVAc (adjusted OR 7.5; 95% CI 1.9-30.0, P=0.004).ConclusionNoninvasive assessment of VAc is feasible with gated single-photon emission computed tomography and appears to be related to ST-segment depression and reserve rPP.

Introduction. Knowledge on dietary habits, tobacco and alcohol consumption in adolescents is crucial to plan early preventive programs. The objective was to assess the eating habits, physical activity and tobacco and alcohol consumption in adolescents of Buenos Aires, in order to get information on cardiovascular risk factors. Material and methods. Cross-sectional observational study in adolescents aged 11-16 years of 12 urban and rural, public and private schools of the province of Buenos Aires. An anonymous survey was carried out including demographical data, eating habits, physical activity, smoking and alcohol consumption. Results. 1230 adolescents were surveyed, 46% of rural zones, Of them, 42.5% restrained food intake to control weight; 92% performed physical activity at least 1 h a week; 29.3% were smokers and 38.4% drank alcoholic beverages. Females restrained more food intake (46.3% vs. 37.7%; p=0.003) and were heavier smokers (32.6% vs. 25.2%; p=0.005). Alcohol consumption and smoking were associated (OR 8.27; p < 0.001). Having a smoker friend increased almost 4 times the chance of smoking. Alcohol consumption by the best friend (OR 10.0; p < 0.001), father o brother also increased chance in the adolescent. Adolescents of rural zones performed less physical activity (89.6% vs. 94.2%; p=0.003) and smoked more cigarettes (32.1% vs. 26.8%; p=0.04). Conclusions. 42% restrained food intake to control weight, and almost all performed physical activity. Rates of smoking and alcohol consumptions were 29.3% and 38.4%, and were strongly associated. Smoking was more common in females and in rural zones, and more associated to alcohol and a smoker friend.

Apical hypertrophy cardiomyopathy (ACM) is a rare condition characterized by asymmetric myocardial hypertrophy of the apex of the left ventricle. When two-dimensional echocardiography is limited by a poor acoustic window, patients are often referred for MRI. Our hypothesis is that a cheaper and more widely available diagnostic modality like myocardial perfusion single photon emission computed tomography (SPECT) may be helpful in the diagnosis of ACM.

Background: Several methods are available for the assessment of coronary endothelial function, but there are no reports to date regarding the usefulness of cold pressor stress echocardiography (CPSE). Objective: To assess regional systolic and diastolic left ventricular function using CPSE in patients with endothelial dysfunction. Methods: We studied 24 patients, of whom 10 were men, aged 27 to 68 years, who had coronary risk factors and a normal exercise MP‐SPECT test. They were compared with 10 normal subjects (6 men), aged 21 to 44 years. All patients underwent a CPSE. Results: The cold pressor‐MP‐SPECT revealed myocardial ischemia in 10 patients (Group I) and was normal in 14 patients (Group II). All normal subjects (Group III) had normal cold pressor‐MP‐SPECT. The cold pressor test caused a significant increase in systolic BP in the three groups (baseline 117 ± 17 mmHg vs. postcold test 137 ± 16 mmHg, P < 0.05), without changes in heart rate, PR interval, or the corrected QT interval. During the CPSE, no patient developed WMA in 2D echo or changes in regional systolic or diastolic LV function in the pulsed Doppler tissue imaging. Conclusions: In patients with endothelial dysfunction and no known coronary artery disease, the ischemic response to the cold pressor‐MP‐SPECT is not accompanied by WMA or changes in regional systolic or diastolic LV function during CPSE. Such negative findings indicate that the amount of ischemia that occurs secondarily to endothelial dysfunction does not involve sufficient myocardial mass to cause contractile dysfunction.

This aim of this study was to evaluate the presence of endothelial dysfunction in patients with primary hypertension and to determine the usefulness of nebivolol, a selective β-adrenoceptor blocking agent, as a potential treatment for endothelial dysfunction. Of 176 patients with stage I hypertension, 36 patients (20%), the majority of whom were overweight/obese, were found to have abnormal results with myocardial perfusion single-photon emission computed tomography (MP-SPECT) under cold pressor test conditions. These 36 patients were treated for 28 days with 5 mg/d nebivolol, after which only 3 (8.3%) still had abnormal MP-SPECT results. The mean ischemia score was consistent with moderate risk and decreased significantly after treatment with nebivolol. All hemodynamic variables measured (systolic and diastolic blood pressure and heart rate) were also reduced significantly by treatment with nebivolol. Endothelial dysfunction plays a key role in the pathogenesis of atherosclerosis and its reversal has considerable implications for clinical outcomes in affected patients. The cold pressor testing results of this study suggest that nebivolol may have beneficial anti-ischemic effects in the coronary arteries of patients with hypertension. However, these findings need to be confirmed in larger randomized controlled trials, ideally comparing nebivolol with other blood pressure lowering agents or NO synthase inhibitors.

Resumen es: Introduccion En la Argentina, las enfermedades cardiovasculares producen, junto con el cancer, mas del 50% de las muertes anuales. En contraposicion a la...

Correlation between Cold Pressure Testing (CPT)/ 99 Tc MIBI-SPECT defects and intracoronary acetylcholine (ACH) paradoxical constriction was published by our group.The usefulness of CPT non -invasive diagnosis of dysfunction (ED) was demonstrated by our observation in coincidence with other authors.There is little information on ED incidence on moderate risk asymptomatic (MRA) patients according to ATP III/Framingham index.Objective: This study is aimed at analyzing the incidence and localization of 99 Tc MIBI/ SPECT myocardial perfusion (MP) defects during CPT as indicator of ED on MRA patients.Methods: 124 patients (78 female) currently compounding PARADIGMA Study Register were analyzed.PARADIGMA is a prospective multicenter study that will include once completed a total number of 450 MRA patients according to ATP III/ Framingham index (Ͻ 20% events at 10 years ), with normal exercise MP and no cardiovascular disease history.CPT-MP imaging was obtained in all these patients.MP extension score was used in a 17 segment model , reported by two observers on consensus.Mann-Whitney U Test statistical analysis was performed.l Results: positive CPT 25/113 patients (22,12 %).CPT extension perfusion score positive 5,77Ϯ2,38(pϽ0.0001).CPT was positive in 30,76 % men and 17,56 % women (pϽ0.001).Localization : anterior wall 4 3%,i n ferior wall 47 %, lateral wall 4,5% and anterior with inferior walls 4,5 %.Conclusion: These results suggest high incidence of ED on MRA patients, who are also free from exercise --related ischemia.There were no significant differences in clinical data and defects localization.Further studies will indicate whether this positive CPT population would have higher risk of cardiovascular events during follow-up Age, Bood Pressure and Cholesterol pns (*) AGE SBP DBP CHOLEST.HDL LDL TRIGL.CPT ( ϩ ) 55.