[Calculation of the slope of the ST/HR segment]. / Cálculo de la pendiente segmento ST/FC.

Several methods for evaluation of exercise stress testing (EST) have been described in order to analyze the relationship between ST segment changes and heart rate. The ST/HR slope has demonstrated to be worthwhile in identifying severe coronary artery disease (CAD). We applied this method in patients catalogued as borderline in the traditional exercise test to find out if they could be considered to have a severe CAD. The patients were divided into two groups: the A, which included 41 patients with borderline EST, and the group B with 41 patients with normal EST. Age, risk factors, double product and ST/HR slope were evaluated. The testing was done on a treadmill with the Bruce protocol. Four patients in group A had ST/HR slope greater than 6.0 mu Volt/beat/min (two of them with borderline EST). Whereas all patients in group B had ST/HR slope values less than 6.0. We concluded this is a sensitive method for discrimination between normal and borderline EST. We found no correlation among age, sex, risk factors, double product and ST/HR slope. Approximately 10 percent of borderline EST would be underestimated with the traditional method. The calculation of the slope obtained its maximum applicability in patients with almost maximum EST.

Prevalence and prevention of deep venous thrombosis of the lower extremities in high-risk pulmonary patients.

Information is lacking about the prevalence of, and the best method of preventing deep venous thrombosis (DVT) of the lower extremities in patients forty years or older with pulmonary disease that keeps them in bed for three consecutive days or more and who are thus at high risk of developing DVT or pulmonary embolism (PE). In this study, 192 high-risk patients, aged forty to ninety-two, received 125I fibrinogen and had daily radioactive scans, venous Doppler, and strain gauge plethysmography. Four preventive methods were used until patients became ambulatory: graded compression stockings (GCS) in 39, elastic bandages (EB) in 33, subcutaneous administration of 5,000 USP units of heparin (HEP) bid in 39, and oral administration of 0.5 g of acetylsalicyclic acid (ASA) bid in 35. Results were compared with those in 46 patients in a control group (CG). Twelve patients in CG, none in GCS, 4 in EB, 1 in HEP, and 2 in ASA developed DVT proved by contrast venography. There was a statistically significant difference between GCS and CG (P less than 0.0003), HEP and CG (P less than 0.0022), and ASA and CG (P less than 0.0148) but not between EB and CG (P greater than 0.10); no significant differences were found between any pair of prophylaxis groups. The significant differences could not be attributed to differences in age, sex, or length of stay in bed. PE occurred in 3 patients in CG and 1 in EB. Hemorrhagic complications occurred in 7 patients in HEP and 4 in ASA, requiring exclusion of 2 patients and 1 patient, respectively, from the study.(ABSTRACT TRUNCATED AT 250 WORDS)