Objective: Early detection of LV mechanical abnormalities in patients with cardiac syndrome X (CSX) by speckle tracking echocardiography (STE). Background: Cardiac syndrome X is a triad of angina pectoris, positive st...Objective: Early detection of LV mechanical abnormalities in patients with cardiac syndrome X (CSX) by speckle tracking echocardiography (STE). Background: Cardiac syndrome X is a triad of angina pectoris, positive stress test for myocardial ischemia and angiographically free coronary arteries. Two dimensional speckle tracking?echocardiography (2D-STE) provides a more sensitive method for evaluation of global and segmental LV function than conventional two dimensional echocardiographic parameters. Subjects and Methods: Seventy patients proved to have CSX and 20 healthy control volunteers were included with a mean age of 49.43 ± 5.92 vs. 49.40 ±6.27 years respectively with no difference regarding sex for both patients and controls. Patients with hypertension, diabetes mellitus, valvular heart disease, cardiomyopathies, inflammatory diseases, myocarditis and arrhythmias were excluded. All included individuals were subjected to complete conventional echocardiographic assessment and left ventricular global and segmental mechanical function was assessed using 2D based strain and strain rate (longitudinal, radial and circumferential) imaging. Results: There was no statistically significant difference in LV conventional echo parameters between patients and controls. However, global mean longitudinal strain was significantly lower in patients than controls (-15.05 ± 3.28 vs. -20.22 ± 2.49;p 0.001). For radial and circumferential strain stain, there was no significant changes between patients vs. controls (29.75 ± 18.26 vs. 28.09 ± 15.48;p = 0.74) and (-19.88 ± 8.63 vs. -21.93 ± 5.69;p 0.05) respectively. Conclusion: In spite of normal conventional echo parameters among patients and controls, LV longitudinal strain and strain rate by 2D speckle tracking imaging were lower in the patients denoting subclinical left ventricular mechanical dysfunction in patients with CSX.展开更多
Annually, an estimated 1,285,000 in-patient angioplasty procedures, 1,471,000 inpatient diagnostic cardiac catheteri-zations and 68,000 inpatient defibrillator implantations are performed. The direct and indirect cost...Annually, an estimated 1,285,000 in-patient angioplasty procedures, 1,471,000 inpatient diagnostic cardiac catheteri-zations and 68,000 inpatient defibrillator implantations are performed. The direct and indirect cost of cardiovascular diseases for 2007 is approximately $431.8 billion. The occurrence of plaque rupture with subsequent microemboli of atherosclerotic and thrombolytic debris into small coronary vessels has been confirmed. Microinfarction results from microemboli that are shed following coronary interventions. The aims of this review are to: 1) detect heterogeneous microinfarction using viability imaging, 2) characterize the consequences of distal coronary microembolization on left ventricle function and perfusion and 3) illustrate the progress of non-invasive imaging modalities in assessing distal coronary microembolization.展开更多
The present study investigated the role of cardiac nerves on homeometric autoregulation in anesthetized dogs during acute volume loading. Ventricular pressure-volume loops (conductance catheter method) were constructe...The present study investigated the role of cardiac nerves on homeometric autoregulation in anesthetized dogs during acute volume loading. Ventricular pressure-volume loops (conductance catheter method) were constructed during acute volume loading with intact cardiac nerves (ICN) and after cardiac decentralization (DCN;bilateral ablation of thoracic vagosympathetic complexes, stellate ganglia and anterior and posterior ansae subclavia). Arterial pressure increased as expected after volume loading but no significant changes were observed for heart rate and other hemodynamic parameters. Coronary sinus venous oxygen content was also higher regardless of nerve status in response to the overall increase in cardiac work. Pressure-volume catheter data showed markedly higher end-systolic volumes after volume loading under ICN and DCN conditions;stroke volume (mL/beat) and stroke work (mL/mm Hg) were not changed but LV ejection fraction was significantly lower. End-diastolic volume and cardiac output did not change. In addition, systemic vascular resistance and tau were higher with volume loading but no differences between ICN and DCN were observed. These findings show that acute volume loading produces an immediate influence on LV function independent of cardiac nerve status.展开更多
文摘Objective: Early detection of LV mechanical abnormalities in patients with cardiac syndrome X (CSX) by speckle tracking echocardiography (STE). Background: Cardiac syndrome X is a triad of angina pectoris, positive stress test for myocardial ischemia and angiographically free coronary arteries. Two dimensional speckle tracking?echocardiography (2D-STE) provides a more sensitive method for evaluation of global and segmental LV function than conventional two dimensional echocardiographic parameters. Subjects and Methods: Seventy patients proved to have CSX and 20 healthy control volunteers were included with a mean age of 49.43 ± 5.92 vs. 49.40 ±6.27 years respectively with no difference regarding sex for both patients and controls. Patients with hypertension, diabetes mellitus, valvular heart disease, cardiomyopathies, inflammatory diseases, myocarditis and arrhythmias were excluded. All included individuals were subjected to complete conventional echocardiographic assessment and left ventricular global and segmental mechanical function was assessed using 2D based strain and strain rate (longitudinal, radial and circumferential) imaging. Results: There was no statistically significant difference in LV conventional echo parameters between patients and controls. However, global mean longitudinal strain was significantly lower in patients than controls (-15.05 ± 3.28 vs. -20.22 ± 2.49;p 0.001). For radial and circumferential strain stain, there was no significant changes between patients vs. controls (29.75 ± 18.26 vs. 28.09 ± 15.48;p = 0.74) and (-19.88 ± 8.63 vs. -21.93 ± 5.69;p 0.05) respectively. Conclusion: In spite of normal conventional echo parameters among patients and controls, LV longitudinal strain and strain rate by 2D speckle tracking imaging were lower in the patients denoting subclinical left ventricular mechanical dysfunction in patients with CSX.
文摘Annually, an estimated 1,285,000 in-patient angioplasty procedures, 1,471,000 inpatient diagnostic cardiac catheteri-zations and 68,000 inpatient defibrillator implantations are performed. The direct and indirect cost of cardiovascular diseases for 2007 is approximately $431.8 billion. The occurrence of plaque rupture with subsequent microemboli of atherosclerotic and thrombolytic debris into small coronary vessels has been confirmed. Microinfarction results from microemboli that are shed following coronary interventions. The aims of this review are to: 1) detect heterogeneous microinfarction using viability imaging, 2) characterize the consequences of distal coronary microembolization on left ventricle function and perfusion and 3) illustrate the progress of non-invasive imaging modalities in assessing distal coronary microembolization.
文摘The present study investigated the role of cardiac nerves on homeometric autoregulation in anesthetized dogs during acute volume loading. Ventricular pressure-volume loops (conductance catheter method) were constructed during acute volume loading with intact cardiac nerves (ICN) and after cardiac decentralization (DCN;bilateral ablation of thoracic vagosympathetic complexes, stellate ganglia and anterior and posterior ansae subclavia). Arterial pressure increased as expected after volume loading but no significant changes were observed for heart rate and other hemodynamic parameters. Coronary sinus venous oxygen content was also higher regardless of nerve status in response to the overall increase in cardiac work. Pressure-volume catheter data showed markedly higher end-systolic volumes after volume loading under ICN and DCN conditions;stroke volume (mL/beat) and stroke work (mL/mm Hg) were not changed but LV ejection fraction was significantly lower. End-diastolic volume and cardiac output did not change. In addition, systemic vascular resistance and tau were higher with volume loading but no differences between ICN and DCN were observed. These findings show that acute volume loading produces an immediate influence on LV function independent of cardiac nerve status.
