Simultaneous measurement of serum cTnT and NT-proBNP allows for precise APE prognosis. Normotensive patients on admission with cTnT> or =0.07 microg/L and NT-proBNP> or =600 ng/L are at high risk of APE mortality, whereas NTproBNP<600 ng/L indicates excellent prognosis.
Recent case reports provided alarming signals that treatment with bortezomib might be associated with cardiac events. In all reported cases, patients experiencing cardiac problems were previously or concomitantly treated with other chemotherapeutics including cardiotoxic anthracyclines. Therefore, it is difficult to distinguish which components of the therapeutic regimens contribute to cardiotoxicity. Here, we addressed the influence of bortezomib on cardiac function in rats that were not treated with other drugs. Rats were treated with bortezomib at a dose of 0.2 mg/kg thrice weekly. Echocardiography, histopathology, and electron microscopy were used to evaluate cardiac function and structural changes. Respiration of the rat heart mitochondria was measured polarographically. Cell culture experiments were used to determine the influence of bortezomib on cardiomyocyte survival, contractility,
Carotid chemoreceptors provoke an increase in muscle sympathetic nerve activation (MSNA) in response to hypoxia; they are also tonically active during normoxic breathing. The contribution of peripheral chemoreceptors to sympathetic activation in hypertension is incompletely understood. The aim of our study was to investigate the effect of chemoreceptor deactivation on sympathetic activity in untreated patients with hypertension. A total of 12 untreated hypertensive males and 11 male controls participated in this randomized, crossover, placebo-controlled study. MSNA, systolic blood pressure(BP), diastolic BP, heart rate (HR), electrocardiogram, hemoglobin oxygen saturation (Sat%) and respiratory movements were measured during repeated 10-min periods of respiration with 100% oxygen or 21% oxygen in a blinded fashion. Compared with controls, hypertensives had higher resting MSNA (38±10 vs. 29±0.9 burst per min, Po0.05), systolic BP (150±12 vs. 124±10 mm Hg, Po 0.001) and diastolic BP (92 ± 10 vs. 77 ± 9 mm Hg, Po0.005). Breathing 100% oxygen caused significant decrease in MSNA in hypertensive patients (38 ± 10 vs. 26 ± 8 burst per min and 100 ± 0 vs. 90 ± 10 arbitrary units, Po0.05) and no change in controls (29±9 vs. 27±7 burst per min and 100±0 vs. 96±11 arbitrary units). BP, respiratory frequency and end tidal CO 2 did not change during chemoreceptor deactivation with hyperoxia. HR decreased and Sat% increased in both the study groups. These results confirm the role of tonic chemoreceptor drive in the development of sympathetic overactivity in hypertension.
Previous studies have shown that hyperoxia-induced deactivation of carotid body chemoreceptors reduces sympathetic activity in hypertensive patients but it does not affect blood pressure. The maintenance of blood pressure can be explained by the direct, vasoconstrictive effect of hyperoxia, which offsets diminished sympathetic activity. This study compares the effect of acute hyperoxia on hemodynamic parameters between hypertensive and normotensive subjects. Twelve males with hypertension (age 39.4±2.4 years; body mass index 27.4±1.1 kg m(-2)) and 11 normotensive males (age 39.9±2.7 years; body mass index 25.4±0.7 kg m(-2)) received, via non-rebreathing mask ventilation, ambient air, followed by 100% oxygen for 20 min. The stroke volume, heart rate, cardiac output, blood pressure, total peripheral resistance, respiratory rate, baroreceptor control of heart rate and oxygen saturation were recorded continuously. Several 30 s periods were analyzed before, during and after inducing hyperoxia. At baseline, the hypertensive subject's blood pressure was higher and their baroreflex control of heart rate was lower when compared with the normotensive control group. After the first 30 s of hyperoxia, systolic, diastolic and mean blood pressures, as well as the total peripheral resistance, decreased significantly in hypertensives but not in normotensives. After 20 min of 100% oxygen ventilation, systolic and mean blood pressures and total peripheral resistance was increased in hypertensive patients, and the cardiac output and stroke volume had decreased in both groups. The results of this study confirm that deactivation of carotid body chemoreceptors can acutely decrease blood pressure in humans.
Beyond their hypolipidemic effect, statins reduce cardiovascular risk in hypertensive subjects via various mechanisms; one suggested mechanism is that they reduce sympathetic activity. We investigated the hypothesis that simvastatin decreased muscle sympathetic nerve activity (MSNA) in 31 hypertensive subjects with hypercholesterolemia (aged 38.7±10 years). In this randomized, placebocontrolled, double-blinded study, patients were treated with simvastatin (40 mg day À1 ; n¼15) or placebo (n¼16) for 8 weeks. Before and after treatment, we measured MSNA, blood pressure and heart rate. Baroreceptor control of the heart rate, or baroreceptor sensitivity (BRS), was computed by the sequence method, a cross-analysis of systolic blood pressure and the electrocardiogram R-R interval. Blood samples were tested for plasma levels of catecholamines, neuropeptide Y, aldosterone, endothelin and renin activity. Simvastatin significantly reduced MSNA (from 36.5 ± 5 to 27.8 ± 6 bursts per min, P¼0.001), heart rate (from 77 ± 6.7 to 71 ± 6.1 beats per min, P¼0.01) and both total and low-density lipoprotein cholesterol (from 249±30.6 to 184±28.3 mg dl À1 , P¼0.001 and from 169±30.6 to 117±31.2 mg dl À1 , P¼0.01, respectively). Simvastatin also improved BRS (from 10.3 ± 4.1 to 17.1 ± 4.3 ms per mm Hg, P¼0.04). No changes were observed in systolic or diastolic blood pressures, or in plasma levels of catecholamines, neuropeptide Y, endothelin, aldosterone and renin activity. After simvastatin therapy, MSNA and BRS were inversely related (r¼À0.94, Po0.05). In conclusion, we found that, in patients with hypertension and hypercholesterolemia, simvastatin reduced MSNA, and this was related to increased baroreceptor sensitivity.
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