Thomas Cognet

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.

AimsAlthough 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.MethodsSeventy-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.ResultsMean 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).ConclusionLSR 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.

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.

Cardiovascular effects of low-dose spinal anaesthesia as a function of age: An observational study using echocardiography

BACKGROUND Spinal anaesthesia (SA) is a widely used technique of regional anaesthesia but hypotension is an adverse effect commonly observed, especially in elderly patients. OBJECTIVE The objective of this study was to assess the cardiovascular effects induced by a single injection of a low-dose SA during elective surgery by using transthoracic echocardiography (TTE) and to compare these effects in patients older and younger than 70 years of age. DESIGN Observational study. SETTING Single centre university hospital. PATIENTS OR OTHER PARTICIPANTS Forty-six patients scheduled for surgery under SA were included in the study (25 patients<70 years and 21 patients ≥ 70 years). INTERVENTION(S) A cardiologist, blinded to all clinical parameters, interpreted the TTE. MAIN OUTCOME MEASURES Two TTEs were performed for each patient: one at baseline before and the second 20 minutes after the placement of the SA. RESULTS Sixty-six percent of patients became hypotensive in the ≥ 70 years group whereas no episode of hypotension occurred in the<70 years group (P<0.0001). At baseline (i.e. prior to SA), when compared to younger patients, elderly patients had both a lower E/A ratio (0.8 [0.5-2.1] vs. 1.4 [0.7-1.6], P=0.001) as well as a lower LVEF (50.4% [37.7-72.3] vs. 60.9% [44.8-69.8], P<0.0001). SA in the elderly induced a larger decrease in the cardiac index (CI) (-0.5 L·min(-1)·m(-2) [-0.8 to -0.3] vs. -0.2 L·min(-1)·m(-2) [-0.8-0.1], P<0.0001), LV stroke volume (-8mL [-13-4] vs. -2mL [-14 to -1], P<0.0001) and systemic vascular resistances (SVR) (-2.2 WU [-6.7-0.3] vs. -0.8 WU [-2.3-0.1], P<0.0001). CONCLUSIONS Hypotension is more frequent among elderly patients, even after low-dose SA. Known age-related changes in cardiovascular performance, such as impaired myocardial relaxation and decreased systolic function could be responsible for the decrease in cardiac output (CO) and SVR seen in these patients.

Relation between left ventricular outflow tract obstruction and left ventricular shape in patients with hypertrophic cardiomyopathy: A cardiac magnetic resonance imaging study

BACKGROUND Hypertrophic cardiomyopathies (HCM) are often associated with left ventricular (LV) outflow tract obstruction, which can explain symptoms and impact prognosis. AIMS To better understand the mechanisms that link obstruction and LV shape in HCM. METHODS Patients with HCM who underwent cardiac magnetic resonance (CMR) imaging were included retrospectively. Obstructive HCM was defined as LV outflow gradient more than 30 mm Hg at rest by transthoracic echocardiography. The LV shape and mitral angle were assessed by CMR. Results were compared with control subjects. RESULTS Mean LV-mitral angle was smaller in patients with obstructive HCM (n=29) than in patients with non-obstructive HCM (n=15) or control subjects (n=15) (80 ± 5° vs 87 ± 7° [P=0.0002] and 89 ± 2° [P<0.0001]). Mean mitral papillary muscles angle was greater in patients with non-obstructive HCM than in patients with obstructive HCM or control subjects (136 ± 17° vs 123 ± 16° [P=0.007] and 118 ± 10° [P=0.002]). Patients with non-obstructive HCM had a greater mean LV-aortic root angle than patients with obstructive HCM or control subjects (139 ± 6° vs 135 ± 7° [P=0.04] and 133 ± 7° [P=0.03]). CONCLUSION There is a relation between morphological and functional parameters in HCM within which the mitral valve is probably part of pathophysiogenesis.

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.

Myocardial multilayer strain does not provide additional value for detection of myocardial viability assessed by SPECT imaging over and beyond standard strain

The aim of this study was to evaluate the value of multilayer strain analysis to the assessment of myocardial viability (MV) through the comparison of both speckle tracking echocardiography and single‐photon emission computed tomography (SPECT) imaging. We also intended to determine which segmental longitudinal strain (LS) cutoff value would be optimal to discriminate viable myocardium.