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Haemodynamic and neurohumoral effects of cold pressor test in severe heart failure
1Department of Internal Medicine, Ullevaal Hospital, University of Oslo, Norway.
Insights
Patients with severe congestive heart failure (CHF) show heightened sympathetic nervous system activity at rest. A cold pressor test (CPT) further increases blood pressure and catecholamines, indicating preserved sympathetic response in CHF.
Area of Science:
- Cardiology
- Physiology
- Neuroscience
Background:
- Patients with severe congestive heart failure (CHF) exhibit elevated sympathetic nervous system (SNS) activity at rest.
- Arginine vasopressin (AVP) levels are not significantly different in severe CHF patients compared to controls.
Purpose of the Study:
- To investigate the hemodynamic and sympathetic responses to a cold pressor test (CPT) in patients with severe CHF.
- To assess regional sympathetic activity and arginine vasopressin (AVP) levels during CPT in severe CHF.
Main Methods:
- Eleven patients with severe CHF and an age-matched control group underwent a cold pressor test (CPT).
- Measurements included arterial plasma catecholamines (noradrenaline and adrenaline), arginine vasopressin (AVP), and hemodynamic parameters.
- Regional sympathetic activity was assessed via arteriovenous differences across vascular beds.
Main Results:
- Severe CHF patients had higher resting noradrenaline and adrenaline levels than controls.
- CPT significantly increased blood pressure, systemic vascular resistance, heart rate, noradrenaline, and adrenaline in CHF patients.
- Myocardial noradrenaline extraction decreased during CPT, while renal and hepatic vascular beds showed no significant changes in catecholamine or AVP handling.
Conclusions:
- Despite elevated resting sympathetic tone, patients with severe CHF demonstrate a preserved and augmented sympathetic response to CPT.
- The CPT's effect on central sympathetic activation appears unaltered in severe CHF.
- Regional sympathetic responses, particularly myocardial, are affected during CPT in severe CHF.
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.