Showing papers by "Sverre E. Kjeldsen published in 1992"

The sympathetic nervous system may modulate the metabolic cardiovascular syndrome in essential hypertension.

Abstract: The association between blood pressure and coronary artery disease may be caused by a concurrence of atherogenic biochemical abnormalities in hypertensive patients, i.e., the metabolic cardiovascular syndrome (increased total cholesterol, triglycerides, and insulin; decreased high-density lipoprotein (HDL) cholesterol; and insulin resistance, glucose intolerance, and blood platelet dysfunction). There are numerous reports of sympathetic nervous system overactivity in hypertensive subjects that could be of importance for the pathophysiology of the high blood pressure. Plasma catecholamines have metabolic hormonal effects at concentrations slightly above low normal resting levels. Even transiently and certainly chronically raised plasma catecholamine levels may cause biochemical abnormalities. Catecholamines may raise total cholesterol, triglycerides, and insulin, decrease HDL cholesterol, and cause insulin resistance and glucose intolerance, and recent evidence supports an in vivo influence of epinephrine on blood platelets, causing dysfunction in hypertensive subjects. Thus, the sympathetic nervous system may modulate the metabolic cardiovascular syndrome in essential hypertension. Hypertensive subjects may respond to environmental stimuli with larger sympathoadrenal responses than normal subjects. Furthermore, emotional stress has been associated with coronary artery disease. Thus, the metabolic hormonal effects of catecholamines, by causing the metabolic cardiovascular syndrome, may be the crucial link between "stress" and cardiovascular disease.

Haemodynamic and neurohumoral effects of cold pressor test in severe heart failure.

Abstract: The effect of a cold pressor test (CPT) on haemodynamics in relation to general and regional sympathetic activity and arginin vasopressin (AVP), was studied in eleven patients with severe congestive heart failure (CHF). Compared to an age-matched control group (C), resting arterial plasma noradrenaline (NA) (419 +/- 77 vs. 182 +/- 15 pg ml-1), and adrenaline (A) (142 +/- 28 vs 54 +/- 10 pg ml-1) were higher (P less than 0.05) in CHF. AVP showed no significant difference (14 +/- 4 vs. 9 +/- 4 pg ml-1). During CPT systolic and diastolic blood pressure and systemic vascular resistance increased (P less than 0.01), as did NA (delta 114 +/- 39 pg ml-1, P less than 0.01), A (delta 33 +/- 10 pg ml-1, P less than 0.01) and heart rate (delta 10 beats min-1, P less than 0.01). The myocardial v-a difference of NA decreased (P less than 0.05), but was unchanged across the renal vascular bed during CPT. The a-v difference of NA in the hepatic vascular bed, and fractional extraction of A in the coronary sinus, renal and hepatic vascular beds remained unchanged during CPT. AVP did not change significantly and no change in cardiac index or left ventricular filling pressure was observed during CPT. These data suggest that despite an increased activation of the sympathetic nervous system at rest, a further increase in blood pressure and catecholamines took place during CPT. Thus, the effect of a CPT which activates the central sympathetic system seems not to be altered in patients with severe CHF.