Angiology

In a first group of experiments, control and ischemic blood was sampled from healthy male volunteers before and 3 hours after the administration of a single 40-mg oral dose of flunarizine or placebo. The blood samples were stored for 24 hours at 0°C to induce partial transformation of discocytes into echi nocytes (crenation). The effect of the drug on the degree of crenation was evaluated by scanning electron microscopy. In control blood, flunarizine treat ment significantly suppressed the discocyte-echinocyte transformation. Similar results were obtained with ischemic blood, although individual variability was greater.

In a second group of experiments still in progress, control blood was taken from patients with intermittent claudication before and 24 hours after the first oral dose of flunarizine (4 × 20 mg) or placebo. The results again indicated that in patients flunarizine significantly reduced the echinocyte formation in stored blood samples.

Based on the results of earlier studies it is postulated that flunarizine exerts its effect at the plasma membrane of the erythrocyte by inhibiting excessive influx of extracellular Ca²⁺. This mechanism of action, by which the compound suppresses echinocyte formation, may be similar to that by which it reduces hyperviscosity and possibly improves red blood cell (RBC) deformability.

The problems of applying mercury strain gauge venous occlusion plethys mography in quantitative measurements of high blood flow rates were studied in the extremities of humans and animals. The fast-acting ECG-controlled pneumatic Periflow system opens the possibility of measurements with reduced restriction of arterial inflow. In animal experiments the arterial inflow rate (about 0.25 vol%/min) during the arterial occlusion period was estimated by an indicator dilution technique. The accuracy of the perfusion rate estimation of a limb by plethysmography was tested in controlled perfused extremities of large dogs weighing about 60 kg. Strain gauges with different positions showed dif ferent—but for each filament quite proportional—relations to real values. The nonuniform venous capacities of the different segments of a limb, which have been shown by injections of a known volume and recording of pressure volume curves, may complicate blood flow measurements by volume displacements from low-compliance regions to high-compliance regions of the vein system. Estimations of the length resistance relation of mercury strain gauges agreed well with the theoretically expected function. If an inextensible part is inserted into the circumferential arrangement of the filament, a correcting calculation of volume changes is necessary.

Screening is successful in detecting hypertension, but reducing morbidity and mortality depends on achieving patient compliance. Cardiovascular disease has declined significantly since the thiazide diuretics have become generally available and provided effective and safe treatment of hypertension. More people are now aware of their blood pressure, and more hypertensive people are under treatment than ever before. Unfortunately many are not being treated— or if treated, they are not receiving adequate therapy.

After several years of experimentation in screening, the concept of per manent site hypertension evaluation with an automatic recording device was instituted in a pharmacy. Detection during the first year in 926 people revealed that 51 % were hypertensives. There were 17% with mild hypertension, 9% with moderate hypertension, and 25% under treatment. Those under treatment were assumed to be hypertensive—normal being considered 140/90, and hyperten sive 160/100. Those between were considered mild hypertensives. After the second year, 1726 people had been screened and hypertension was detected in 48%; 18% had mild hypertension, 10% had more severe hypertension, and 20% were being treated.

Compliance was measured in two groups of patients. Short-term compliance (up to 6 months) was measured in 441 patient revisits: initially 16% were normotensive, but on revisit after 6 months, 37% were normotensive—a reduc tion in mild hypertension from 52% to 33%. Long-term compliance (6 months to 2 years) was measured in 402 patient revisits: initially 19% were normotensive, and on revisit 32%—an increase in compliance with a reduction from 48% to 35% in mild hypertension.

A new method, permanent site hypertension evaluation with patient revisits, is suggested as a new way of increasing patient compliance. The presence of normotension is assumed to mean compliance. The easy availability of per manent sites may induce the patient to return regularly, or the patient may be testing the medication or his physician. Whatever the case, normotension is the aim of compliance.