Hemodynamics in essential hypertension at rest and during exercise--a 20-year follow-up study

In connection with a mass screening of the Bergen population 93 patients with essential hypertension and 48 normotensive controls were studied in 1965-66. Blood pressure (BP) was recorded intraarterially, cardiac output (CO), by dilution method, heart rate (HR) by ECG and oxygen consumption (VO2) by Douglas bag/Scholander technique. Studies were performed during rest and 50, 100 and 150 watt steady state exercise. The most important initial findings were: Although CO and HR were higher in the youngest hypertensive group (17-29 yrs) than in normotensive age matched controls VO2 was also increased and no true luxury perfusion was demonstrated. Exercise stroke index (SI) did not increase to the same level as in normotensives and total peripheral resistance index (TPRI) during exercise was increased. Cross-sectional data showed a reduction in SI and CI and an increase in TPRI with increasing age - at rest as well as during exercise. 10-year follow-up: 28 subjects initially below 40 years were completely untreated. During the first 10 years there was a fall in CI and SI of approximately 15% and TPRI increased by 20%. The same changes were seen at rest as well as during exercise. Resting blood pressure was practically unchanged. Nearly all patients greater than 40 yrs were treated. 20-year follow-up: Between the 10 year and 20 year follow-up DAP rose to 100 mmHg or more in most of the subjects less than 40 yrs and treatment had to be started. Generally diuretics, betablockers or a combination of the 2 were used. Before the 20 year follow-up, treatment was withdrawn for 2 months.(ABSTRACT TRUNCATED AT 250 WORDS)