New concept of myocardial longitudinal strain reserve assessed by a dipyridamole infusion using 2D-strain echocardiography: the impact of diabetes and age, and the prognostic value.

AIMS: Although dipyridamole is a widely used pharmacological stress agent, the direct effects on myocardium are not entirely known. Diabetic cardiomyopathy can be investigated by 2D-strain echocardiography. The aim of this study was to assess myocardial functional reserve after dipyridamole infusion using speckle-tracking echocardiography. METHODS: Seventy-five patients referred for dipyridamole stress myocardial perfusion gated SPECT (MPGS) were examined by echocardiography to assess a new concept of longitudinal strain reserve (LSR) and longitudinal strain rate reserve (LSRR) respectively defined by the differences of global longitudinal strain (GLS) and longitudinal strain rate between peak stress after dipyridamole and rest. Twelve patients with myocardial ischemia were excluded on the basis of MPGS as gold standard. RESULTS: Mean LSR was -2.28±2.19% and was more important in the 28 (44%) diabetic patients (-3.27±1.93%; p=0.001). After multivariate analyses, only diabetes improved LSR (p=0.011) after dipyridamole infusion and was not associated with glycaemic control (p=0.21), insulin therapy (p=0.46) or duration of the disease (p=0.80). Conversely, age (p=0.002) remained associated with a decrease in LSR. LSSR was also correlated to age (p=0.005). Patients with a LSR<0% have a better survival after 15 months (log-rank p=0.0012). CONCLUSION: LSR explored by 2D speckle-tracking echocardiography after dipyridamole infusion is a simple and new concept that provides new insights into the impact of diabetes and age on the myocardium with a potential prognostic value.

The relation between atrial septal defect shape, diameter, and area using three-dimensional transoesophageal echocardiography and balloon sizing during percutaneous closure in children.

BACKGROUND: A trans-catheter closure of an atrial septal defect (ASD) is efficient. Balloon sizing (BS) during the catheterization leads to an overestimation of ASD size. Three-dimensional transoesophageal echocardiography (3D-TEE) allows the ASD morphology to be assessed comprehensively. The aim of this study was to assess the relationships between the shape and the measurements of ASDs by 2D-, 3D-TEE, and BS in children. METHODS AND RESULTS: Thirty children who underwent percutaneous closures of a single ASD were enrolled. ASD diameters were measured by 2D-transthoracic echocardiography (TTE), 2D-TEE, 3D-TEE and compared with BS. The ASD area was measured on 3D-TEE images after multi-planar reconstruction. ASD was estimated as round or oval on 3D-TEE 'en-face' view. 2D-TTE, 2D-TEE, and 3D-TEE(max) ASD diameters were well correlated with BS (r = 0.75; 0.80, and 0.85, respectively). Mean diameters were all significantly smaller than the mean BS. The mean difference between the balloon area and 3D-TEE area was 1.6 ± 1.4 cm(2) (P < 0.0001). The mean difference between BS and 3D-TEE(max) diameters was higher in round ASDs than in oval ASDs (4.0 ± 3.3 vs. 1.1 ± 3.3, P = 0.02). With multivariate linear regression analysis, two formulas were built to predict BS. The first model was BS = 1.07 × 3D-TEE(max)- 3.1 × ASDshape + 3. The ASD shape was 0 for round and 1 for oval ASDs. A second model was BS = 4.5 × ASDarea + 11.5. CONCLUSION: The ASD shape is accurately estimated by 3D-TEE and influences the relationship between echocardiographic measurements and BS. The ASD shape, its maximal diameter and the area assessed by 3D-TEE may be sufficient to determine the device size without BS in children.

Anesthetic regimen for cardiac function evaluation by echocardiography in mice: comparison between ketamine, etomidate and isoflurane versus conscious state.

Mice with genetic alterations are used in heart research for the extrapolation of human diseases. Echocardiography is an essential tool for evaluating cardiac and hemodynamic functions in small animals. The purpose of this study was to compare the effect of different anesthetic regimens and the conscious state on the evaluation of cardiac function by echocardiography. Mice were examined in the conscious state after three days of training, and then for a 7 min period after a single intraperitoneal injection of ketamine at 100 mg/kg, etomidate at 10, 20 or 30 mg/kg, or after inhalation of isoflurane at 1.5% with or without a short period of induction with isoflurane 3%. Intra- and inter-observer variabilities were assessed. The operator's comfort was also assessed. Heart rate, left ventricular end diastolic diameter, fraction shortening and cardiac output were measured using echocardiography. Ketamine at 5 and 7 min after induction and isoflurane at 3, 5 and 7 min after induction provided good anesthetic conditions and a quick awakening time, and did not influence cardiac performance, whereas the conscious state was associated with a non-physiological sympathetic activation and other anesthetic drugs induced a significant decrease in heart rate. Etomidate 10 mg/kg and 20 mg/kg were not enough to provide adequate anesthesia. Etomidate 30 mg/kg induced a good anesthetic condition but influenced cardiac performance and had a long awakening time. Our results indicate that ketamine and isoflurane with a short induction period are better anesthetic drugs than isoflurane without induction or etomidate for evaluating cardiac function in healthy mice.

Relationship between left ventricular sphericity and trabeculation indexes in patients with dilated cardiomyopathy: a cardiac magnetic resonance study.

AIMS: To study the relationship between left ventricular (LV) trabeculations, volume, and sphericity in patients with dilated cardiomyopathy (DCM) by cardiac magnetic resonance imaging (CMR). METHODS AND RESULTS: Eighty-two patients with DCM were prospectively explored by CMR. The segmental trabeculation index (STI) was defined by the ratio of trabeculated layer thickness on compacted layer thickness per segment. The global trabeculation index (GTI) was defined by the ratio of the sum of the total trabeculated layer thickness to the sum of the total compacted layer thickness. The apex was excluded from the analysis. The mean number of segments with trabeculation per patient was 10 ± 2 with a mean GTI of 0.68 ± 0.32. The LV sphericity index was inversely correlated with LV ejection fraction (R = -0.42, P = 0.0002) and positively with the brain natriuretic peptide (BNP) level (R = 0.34, P = 0.003). The maximal STI was positively correlated with the indexed LV end-diastolic volume (R = 0.32, P = 0.004) and the LV sphericity index (R = 0.25, P = 0.02), but not with the BNP level or LV ejection fraction. The GTI was positively correlated with the LV sphericity index (R = 0.27, P = 0.016) but not with indexed LV end-diastolic volume, BNP levels, or LV ejection fraction. CONCLUSION: Trabeculation indexes depend on LV shape and are positively correlated with LV sphericity. These results encourage interpreting LV trabeculation with caution in patients with DCM, considering additional morphologic criteria such as LV geometry.

A family history of dilated cardiomyopathy induced by viral myocarditis.

Myocarditis can lead to acute heart failure, cardiogenic shock, or sudden death and later, dilated cardiomyopathy (DCM) with chronic heart failure. We report the cases of two DCM induced by acute and past myocarditis in the same family and expressed by its two main complications within few weeks: an hemodynamic presentation as a fulminant myocarditis rapidly leading to cardiac tranplantation and a rythmologic presentation as an electrical storm leading to catheter ablation of ventricular tachycardia. These cases ask the question of the family predisposition to viral myocarditis leading to DCM.

Early triage of emergency department patients with acute coronary syndrome: contribution of 64-slice computed tomography angiography.

BACKGROUND: Multislice computed tomography coronary angiography (MSCT-CA) is feasible in the emergency department (ED) for ruling out obstructive coronary artery disease (CAD). AIM: To investigate a diagnostic strategy using MSCT-CA for the early triage of patients presenting to the ED with acute chest pain suggestive of acute coronary syndrome (ACS), according to the medium-term incidence of clinical events. METHODS: We conducted a single-centre, prospective, observational cohort study in 123 patients with low-risk to intermediate-risk acute chest pain suggestive of ACS. MSCT-CA was performed using dual-source 64-slice computed tomography with retrospective electrocardiographic gating. Patients without coronary artery lesions were discharged from the ED. The incidences of death, myocardial infarction and myocardial revascularization were collected during a mid-term follow-up. RESULTS: According to MSCT-CA, 93 patients (75.6%) had no CAD or coronary artery stenosis less or equal to 50% and 28 patients (22.8%) had stenosis more or equal to 50%. Invasive coronary angiography was performed in 29 patients (23.6%). MSCT-CA accurately identified ten patients (8.13%) with obstructive CAD requiring myocardial revascularization; all had a low TIMI score (0-2) and eight had a low GRACE score. The mean estimated effective dose of MSCT-CA was 16.3±6.4 mSv. Median follow-up was 15 months. No patient (95% CI 0-3.0%) had major adverse cardiovascular events during follow-up. CONCLUSION: MSCT-CA appears to be a useful initial triage tool in the ED. When the MSCT-CA result is negative, it allows safe early discharge because of its high negative predictive value. In a significant number of cases of low-risk ACS, MSCT-CA detects severe coronary lesions and allows further dedicated diagnostic and therapeutic intervention. Reduction of radiation exposure would help acceptance in clinical practice.