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Many treatments aim at making a patient feel better due to symptom relief or improved quality of life. Other treatments are given in order to prevent future complications, non-fatal or fatal. There are methodological difficulties in assessing subjective symptoms and quality of life. To document reduced risk of complications takes large, long-term, costly clinical trials. Thus, the use of a surrogate marker to document benefit may seem appealing. A well-validated surrogate marker can demonstrate benefit of a given treatment with fewer patients in a shorter time and at considerably lower cost. It is much easier to show in a 12-week study that a new compound lowers blood pressure than to show that it lowers the risk of stroke, myocardial infarction or renal impairment. One problem with surrogate markers is that very few are well-validated, another is that even those which are cannot be expected to reflect adverse effects, expected or unexpected, and are thus of limited value in the global assessment of benefit vs. risk. It is recommended that results obtained with surrogate markers be regarded as preliminary until results of large trials with clinically relevant outcomes are available.

A randomized, double-blind study was carried out in 24 patients with stable angina pectoris to compare the efficacy of nadolol, a new beta-adrenoceptor antagonist, and propranolol. After a period on placebo, 14 patients received nadolol once daily and 10 patients propranolol 4-times daily over a 10-week dose-ranging period followed by a maintenance period of 4 weeks. Optimal daily dosage for nadolol was 100 mg, and 112 mg for propranolol. Parameters used for evaluation of therapeutic effects included the number of anginal attacks, number of nitroglycerine tablets needed, time before onset of chest pain during exercise test, exercise time, and overall clinical impression of response. The results indicated that nadolol given once daily was equally as effective as propranolol 4-times daily in treating angina pectoris.

The P wave of the ECG, recorded with both conventional and special techniques, was compared with left atrial (LA) pressure and volume in 22 patients with mitral valve disease. The patients were also compared with 2 groups of normal subjects as to the P wave, recorded with the special technique. Changes in the P wave, such as increased duration, increased bipeak interval or P terminal force were significantly more common in the patients than in normal subjects. Among the patients, no significant correlations were found between degree of LA pressure elevation, LA enlargement and P wave changes. It is concluded that for the diagnosis of increased LA load it is more useful to study the terminal vector of the P wave than signs of increased atrial asynchrony. Recordings with high amplification and paper speed as in the present special technique are of advantage for such measurements. However, the special leads by themselves were not ideal for study of an increased terminal vector directed to the left and backwards.

Electrocardiograms were registered with a special technique during attempts at cardioversion in 22 patients with atrial fibrillation or flutter. The registrations permitted analysis of the electrocardiogram 0.1-0.5 s after the electrical discharge. Mean values indicate that there is no compensatory pause after the d.c. shock. After 29 of the 42 synchronized d.c. shocks the first QRS complex was aberrant.

The atrial activity was studied at rest and during exercise in 6 patients with atrial flutter and in 7 patients with atrial fibrillation. In the latter, a special recording technique was used which permitted identification of the f-waves. No increase in the frequency of the atrial waves was found. Thus the increase of the ventricular rate during work in patients with atrial flutter or atrial fibrillation seems to be caused by a change in the atrio-ventricular conduction.

Serum lipoproteins, apolipoproteins and intravenous fat tolerance were studied in 22 male athletes and compared with healthy age and weight-height matched controls. All of the subjects were non-smokers. Athletes had lower serum, very low density lipoprotein (VLDL) and low density lipoprotein (LDL) triglycerides, lower serum VLDL and LDL cholesterol and an increase in apolipoprotein A I. High density lipoprotein (HDL) cholesterol was similar in both groups. The clearance of i.v. injected triglyceride emulsion was faster in athletes. This suggests that the lower serum and VLDL triglycerides in athletes are at least in part due to a more rapid triglyceride clearance.

ECG tracings from 16 patients with spontaneous onset and/or termination of supraventricular tachyarrhythmias (SVTA) were studied. Of these recordings, 13 were made with a special technique which gives a high resolution of the atrial waves. At the onset of SVTA, the first atrial wave invariably had an aberrant configuration. The coupling index (coupling interval (P-1P) preceding cycle length) was 0.05 or less in 9 of 16 cases but more than 0.60 in 4 cases. In the 5 cases of onset of atrial fibrillation, the intervals between the first few atrial waves corresponded to a frequency of 300-350 per minute. Acceleration of the atrial activity occurred within the first 30 seconds. At the termination of SVTA, no successive modification of the atrial activity was found. The termination often did not occur at or shortly after a QRS complex. It is concluded that a premature atrial beat--even a single one--with a short coupling interval may well intiate a circus-movement SVTA, while an ectopic atrial beat with a long coupling interval apparently must be followed by repeated rapid discharges from the ectopic focus in order for SVTA to ensue. The functional conditions of the atria may then determine which kind of SVTA eventually results.