BACKGROUND: No method exists to assess human splanchnic venous function, the most important region in terms of vascular capacity. METHODS AND RESULTS: We studied 25 stable patients without heart failure or hypertension to develop a method to assess thesplanchnic venous volume-pressure (V-P) relation and to determine the effect of nitroglycerin (GTN). We used blood pool scintigraphy to assess changes in regional splanchnic vascular volume (SVV) and low levels of continuous positive airway pressure (CPAP) to passively alter venous pressure and thus, SVV. We postulated that the relation between SVV and the CPAP used would reflect the capacitance of the splanchnic venous bed and that changes in the position of this relation would provide a relative measurement of any change in capacitance. In 12 patients (group 1), the splanchnic vascular V-P curves were recorded before and 2, 9, and 20 minutes after 0.6 mg sublingual GTN; in eight patients (group 2), recordings were made at similar times before and after sublingual administration of placebo; in five patients (group 3), the hemodynamic effects of CPAP were assessed by means of right and left cardiac catheterization. Right atrial and femoral venous pressures increased (p < 0.001) and cardiac output fell (p < 0.05) during CPAP. There was an apparently linear relation between CPAP and SVV (r = 0.74-0.98); SVV increased an average of 7.4 +/- 2.2% (p < 0.001) by 12 cm H2O CPAP: The splanchnic vascular V-P curves were reproducible with minimal variability in SVV (+/- 2%, p > 0.2) in group 2. After administration of GTN, the splanchnic vascular V-P curve shifted away from the pressure axis in a parallel fashion by an average of 9.4 +/- 5.4% (p < 0.001). CONCLUSIONS: We have developed a reproducible noninvasive technique that may be used to assess human splanchnic venous V-P relations. We have demonstrated for the first time in humans that GTN exerts its dilatory effect by increasing the unstressed splanchnic venous volume.
RCT Entities:
BACKGROUND: No method exists to assess human splanchnic venous function, the most important region in terms of vascular capacity. METHODS AND RESULTS: We studied 25 stable patients without heart failure or hypertension to develop a method to assess the splanchnic venous volume-pressure (V-P) relation and to determine the effect of nitroglycerin (GTN). We used blood pool scintigraphy to assess changes in regional splanchnic vascular volume (SVV) and low levels of continuous positive airway pressure (CPAP) to passively alter venous pressure and thus, SVV. We postulated that the relation between SVV and the CPAP used would reflect the capacitance of the splanchnic venous bed and that changes in the position of this relation would provide a relative measurement of any change in capacitance. In 12 patients (group 1), the splanchnic vascular V-P curves were recorded before and 2, 9, and 20 minutes after 0.6 mg sublingual GTN; in eight patients (group 2), recordings were made at similar times before and after sublingual administration of placebo; in five patients (group 3), the hemodynamic effects of CPAP were assessed by means of right and left cardiac catheterization. Right atrial and femoral venous pressures increased (p < 0.001) and cardiac output fell (p < 0.05) during CPAP. There was an apparently linear relation between CPAP and SVV (r = 0.74-0.98); SVV increased an average of 7.4 +/- 2.2% (p < 0.001) by 12 cm H2O CPAP: The splanchnic vascular V-P curves were reproducible with minimal variability in SVV (+/- 2%, p > 0.2) in group 2. After administration of GTN, the splanchnic vascular V-P curve shifted away from the pressure axis in a parallel fashion by an average of 9.4 +/- 5.4% (p < 0.001). CONCLUSIONS: We have developed a reproducible noninvasive technique that may be used to assess humansplanchnic venous V-P relations. We have demonstrated for the first time in humans that GTN exerts its dilatory effect by increasing the unstressed splanchnic venous volume.
Authors: Matthias Schmitt; Daniel J Blackman; Gordon W Middleton; John R Cockcroft; Michael P Frenneaux Journal: Br J Clin Pharmacol Date: 2002-12 Impact factor: 4.335
Authors: Marat Fudim; David M Kaye; Barry A Borlaug; Sanjiv J Shah; Stuart Rich; Navin K Kapur; Maria Rosa Costanzo; Michael I Brener; Kenji Sunagawa; Daniel Burkhoff Journal: J Am Coll Cardiol Date: 2022-05-10 Impact factor: 27.203
Authors: Abdul R Maher; Sayqa Arif; Melanie Madhani; Khalid Abozguia; Ibrar Ahmed; Bernadette O Fernandez; Martin Feelisch; A G O'Sullivan; Arthur Christopoulos; Aaron L Sverdlov; Doan Ngo; Rustem Dautov; Philip E James; John D Horowitz; Michael P Frenneaux Journal: Br J Pharmacol Date: 2013-06 Impact factor: 8.739
Authors: Marat Fudim; Piotr P Ponikowski; Daniel Burkhoff; Mark E Dunlap; Paul A Sobotka; Jeroen Molinger; Manesh R Patel; G Michael Felker; Adrian F Hernandez; Sheldon E Litwin; Barry A Borlaug; Anisha Bapna; Horst Sievert; Vivek Y Reddy; Zoar J Engelman; Sanjiv J Shah Journal: Eur J Heart Fail Date: 2021-05-09 Impact factor: 17.349
Authors: Julian O M Ormerod; Sayqa Arif; Majid Mukadam; Jonathan D W Evans; Roger Beadle; Bernadette O Fernandez; Robert S Bonser; Martin Feelisch; Melanie Madhani; Michael P Frenneaux Journal: Circ Heart Fail Date: 2015-04-02 Impact factor: 8.790