No abstract

Simultaneous clearance of 99Tcm from the gastrocnemius and quadriceps muscles has been studied in 74 limbs of 62 patients with claudication and in 20 normal limbs of 15 volunteers. The local decay curve for 10 min at rest and for 20 min after a 3-min treadmill walk at 4.5 km/h was recorded. The changes in blood flow which occurred after exercise were characteristic of the arteriographic lesions and they explain the haemodynamics of claudication.

The effect of local controlled cooling on the digital systolic blood pressure in the hand was studied in 25 In an effort to make objective measurements in patients with primary or secondary Raynaud's syndrome, several workers have studied blood flow in the hand ( I , 2) before and after local cooling, blood viscosity ( 3 ) changes at low temperatures and photoelectric measurement of pulse amplitude (4) during stepwise cooling. Nielsen ( 5 ) suggested that photoplethysmography was unsuitable for detecting pulsation when finger systolic pressure was less than 30-40mmHg. He described a method (5,6) of indirectly measuring finger systolic pressure at different temperatures using a proximal occluding cuff and a proximal cooling cuff, and strain gauge plethysmography to detect distal pulsation. However, although Nielsen achieved objective pressure measurements that separated normals from patients with primary Raynaud's disease (5,7), he found it necessary to use body cooling with a cooling blanket at an ambient room temperature of 22°C to achieve this separation. We have adopted his method of local finger cooling, using photoplethysmography instead of strain gauge plethysmography to detect distal pulsation. and a lower ambient room temperature of 17.5-18 "C instead of total body cooling. The aim of our study was to measure and attempt to identify any difference in the response to cooling in controls and patients with Raynaud's syndrome. Patients and methodsTwenty-five normal volunteers (21 women, 4 men: age 20-40 years) acting as controls and 25 patients (20 women, 5 men: age 22-67 years) with Raynaud's syndrome were studied. Seven patients had systemic sclerosis. 2 had Buerger's disease and in 14 the diagnosis was unknown. In each subject the brachial systolic blood pressure and the systolic blood pressure of the cooled middle finger and of the noncooled (reference) index finger were measured. This was achieved using a thermostatically controlled culT, which could be pressurized and simultaneously perfused with water at 30°C or 10°C. on the middle digit. a non-cooled cuff pressurized by air at ambient room temperature on the index finger and photoplethysmographic (PPG) probes to detect the distal pulse on the tip of each finger. A commercially available digit cooling machine (Medimatic, Copenhagen, Denmark) was used. Both cuffs were capable of being pressurized and deflated simultaneously; cuff pressure was monitored via an Akers transducer (AE 840) and amplifier and recorded on a pen recorder (Watanabe MC611). The PPG probes (Medasonics PH77). placed on the pulp of each digit, were connected via a Photo Pulse Adaptor (Medasonics PA13) and the tracings were recorded on the same pen recorder. Thus, there were simultaneous recordings of cuff pressure and distal pulses.The pre-test conditions for all subjects involved no tobacco or alcohol (in the preceding 2 hours) and a light meal only, and for the test all were rested for 20 minutes in light clothing at a room temperature maintained at 17.5-18 "C. Cuffs on both fing...

Usually, venous insufficiency affecting an extremity results from elevated pressure, whereas arterial insufficiency usually is caused by reduced pressure energy. Except when caused by arteriovenous fistulae, elevated venous pressures are caused by obstruction to outflow and/or by incompetence of the venous valves, particularly at popliteal level and in the calf perforator veins. In the lower extremity, such elevated venous pressures can result in chronic changes that cause symptoms and/or signs that range from “tired legs” to ulceration. Although mild venous hypertension may constitute only a relative inconvenience such as varicose veins, more severe cases can lead to debilitating ulceration that may demand a change in lifestyle. Assessing an extremity for venous valvular insufficiency means detecting venous reflux. This work describes the plethysmographic, continuous-wave Doppler, and duplex ultrasound imaging modalities that can be used for detecting venous reflux in the deep, superficial, and perforating veins. Although plethysmographic and continuous-wave Doppler modalities have been supplanted largely by duplex ultrasound imaging, they have been included for completeness because they can continue to fulfill a role in overall functional assessment. Whatever the testing modality used to assess venous reflux, it is essential to verify the patency of the deep veins before any intervention in the superficial venous system.

No abstract