title: Pressure gradient and blood flow in human arm veins--a proposed explanation of the pumping mechanism.
abstract: In a patient with mitral stenosis we previously found a negative periphero -central pressure gradient (P-C PG) despite a forward peripheral venous blood flow velocity ( PVBFV ) during supine leg exercise. The present study was undertaken to confirm this finding and elucidate its mechanism. In 6 patients with congestive heart failure, P-C PG was reversed from -2.4 to -18.7 cm H2O for 1 to 5 minutes during exercise. PVBFV , measured simultaneously with peripheral venous pressure (Pv) in 8 subjects, remained positive; 5 of these were patients with a negative P-C PG. The effect of intravenous lidocaine(1-26 mg) was studied in 13 patients: In 4 of 13 patients the change in Pv by saline injection was smaller than that after lidocaine (2-5 mg) injection (-0.5 +/- 0.5, 3.9 +/- 0.8 cm H2O, mean +/- SE, respectively) (p less than 0.02). In 13 patients Pv rose after a small dose of lidocaine. After a larger dose the rate of rise of Pv decreased or Pv dropped. No significant change was observed in the central venous pressure. In 6 patients who performed Valsalva's maneuver, the rate of rise of Pv during the test decreased or unchanged after lidocaine injection. The probability of a pumping mechanism in superficial human arm veins was discussed.
mesh_terms: D000328:Adult; D000368:Aged; D001132:Arm / Q000098:blood supply*; D001281:Atrial Fibrillation / Q000503:physiopathology; D001783:Blood Flow Velocity; D002496:Central Venous Pressure / Q000187:drug effects; D003911:Dextrans / Q000494:pharmacology; D005260:Female; D006333:Heart Failure / Q000503:physiopathology; D006801:Humans; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000503:physiopathology; D005082:Physical Exertion; D011660:Pulmonary Heart Disease / Q000503:physiopathology; D014636:Valsalva Maneuver; D014680:Veins / Q000502:physiology; D014690:Venous Pressure / Q000187:drug effects
chemical_list: D003911:Dextrans; D008012:Lidocaine