Hypertension research : official journal of the Japanese Society of Hypertension
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Although right ventricular (RV) function is an important determinant of morbidity and mortality in patients with primary pulmonary hypertension (PPH), there have been no clinically validated quantification methods to date. The first derivative of RV pressure (dP/dt) is a good index of contractility, but it depends on preload. dP/dt divided by end-diastolic volume (EDV), that is, dP/dt/EDV, on the other hand, is an index of contractility relatively independent of preload. However, the measurement of accurate RV EDV is difficult because of RV complex geometry. ⋯ EDV(3D) showed better correlations than EDV(2D) with the invasive and non-invasive parameters of RV function, suggesting the validity of volume measurement by 3D echocardiography. RV dP/dt/EDV(3D) correlated well with disease severity, whereas dP/dt and dP/dt/EDV(2D) did not. In patients with PPH, 3D-echocardiography-determined RV dP/dt/EDV and EDV seem to be potential markers of disease severity.
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Takotsubo cardiomyopathy, alternatively known as stress cardiomyopathy, is an increasingly recognized clinical syndrome characterized by acute reversible apical ventricular dysfunction. To elucidate the mechanism, we tried to make a new model of takotsubo-like cardiomyopathy in non-human primates. Echocardiography revealed that repeated intravenous infusion of epinephrine overdose in cynomolgus monkeys induced takotsubo-like cardiomyopathy, which is characterized by progressive left ventricle and depressed systolic function with severe hypokinesis in apical regions and hyperkinesis in the basal region. ⋯ Heart failure-related genes, such as brain natriuretic peptide, connective tissue growth factor and osteopontin; calcium signaling-related genes, such as ryanodine receptor 2, sarcoendoplasmic reticulum Ca(2+)-ATPase 2A2 and adenylate cyclase 7; renin-angiotensin system-related genes, such as angiotensinogen, angiotensin II receptor, type 1 and type 2; and mitochondria-related genes, such as peroxisome proliferator-activated receptor-gamma co-activator-1alpha, cytochrome c and transcription factor A mitochondrial, were significantly changed at the apical ventricle rather than at the basal ventricle. The changes of some genes improved with metoprolol treatment. These results indicate that this model is valuable in understanding the pathogenesis of takotsubo cardiomyopathy and the effectivity of beta-blockers.