Simultaneous records of the pulse waves were obtained from the right common carotid artery and the right femoral artery by means of piezo-electric microphones in 26 per= sons whore ages ranged from 15 to 92 years. The time difference between the foot points of the waves from them two sites was termed Tar.A significant correlation was found between ToS and age, be= tween TOP and the systolic blood pressure and between Top and As described by Miller and White (1) and Geddes and Hoff (2), the pulse wave can be recorded by means of piezo-electric microphones placed externally above the artery. If T is the time difference between the foot points of two pulse waves recorded a t varying distances from the heart and D the length of the segment, the pulse wave velocity = D/T.

After introduction of a catheter into the aorta, the pressure wave velocity was measured in 26 subjects whose ages ranged from 9 to 68 years. The first site of registration was approximately 10 cm from the aortic valve, and the second was 50 cm distal to the first. At both sites the time difference was measured between the R‐wave of the electrocardiogram and the foot of the pressure wave (TProx. and TDist.). The time difference T50 (TDist. – TProx.) and the distance between the sites of registration (50 cm) were used for the calculation of the pressure wave velocity (PWV). Four of the 26 subjects were normal; the others had some form of heart disease, including disease of the valves, hypertension and aortic atherosclerosis. Nevertheless, the values found for pressure wave velocity were in agreement with those stated in literature. A significant correlation was found between T50 and age (r = —0.788), between T50 and the proximal systolic blood pressure (r = −0.537), and between T50 and the proximal pulse pressure (r = −0.491), but not between T50 and the cardiac output and peripheral arterial resistance. There was no correlation between the proximal diastolic blood pressure and T50, possibly owing to the fact that all the patients had a diastolic blood pressure below 100 mm Hg. There was no significant difference between the coefficient of correlation for T50 and age (−0.788) and the multiple coefficient of correlation for T50 and age and systolic blood pressure proximal in the aorta (−0.811). Four patients had arteriographic aortic atherosclerosis. Two of these had lower T50 values than would be expected according to the proximal systolic blood pressure and the pulse pressure, but after exercise the values were within the normal range (±2 s.d.) Owing to the dominating influence of age on T50 and the considerable spreading of these values, it is not likely that the determination of pulse wave velocity will be of clinical value, for example, in the diagnosis of atherosclerosis.

The relation between the flow in the superior vena cava and inferior vena cava has been measured on ten normal subjects both at rest and during exercise using the results of the oxygen saturation determinations on blood samples drawn from the pulmonary artery, superior vena cava and inferior vena cava. The result is that, with a doubling of the cardiac output caused by exercise using the lower extremities, the flow in the inferior vena cava is increased from 48% to 75% of the total flow. The importance of this for the calculation of the size of the shunt both at rest and during exercise in patients with atrial septal defects is discussed.

In a retrospective study of patients admitted for acute myocardial infarction ( A M ) during six years, sinus node dysfunction (SND) was detected in 29 (1.04%). Twelve had persistent sinus bradycardia, 11 sinotrial block or sinus arrest and six bradytachy syndrome. Symptoms occurred in 17 patients, 12 of whom required temporary pacing for periods up to three weeks. A permanent cardiac pacemaker was implanted in three patients with brady-tachy syndrome. Three patients died during the primary admission and six during the observation period. Follow-up after a mean observation period of 34 months showed continuous signs of SND in 11 out of 19 patients. The arrhythmia caused symptoms in five patients, two of whom had a cardiac pacemaker and two received medical treatment. It is concluded that SND appearing during an AM1 persists in a high number of these patients.

A retrospective study covering all admissions during a 6-year period revealed 128 patients with sinus node dysfunction (SND). The patients were grouped according to the ECG criteria chosen: group I 3 3 patients with sinus bradycardia, group I1 37 with sinoatrial block/sinus arrest, group I11 58 with brady-tachy syndrome. Additional heart disease, predominantly ischaemic, was found in 56%. The frequency and severity of symptoms increased from group I to group 111. Pacemaker treatment was given to 40% of the cases, while medical treatment alone was successful in 17%. A follow-up including 104 patients was carried out after a mean observation period of approximately three years. Sixteen patients had died. The cause of death may have been SND per se in only one case. Five patients died of apoplectic insults or complications to such. In total, nine possible or proven systemic embolic events were found-all occurring in patients with brady-tachy syndrome. A progression of the ECG abnormality from a lower to a higher group took place in nine patients during the observation period. It is concluded that SND is a condition with a broad clinical spectrum and a stationary or slowly progressive course. In general, it carries a good prognosis. A substantial number of deaths or disabilities in patients with brady-tachy syndrome may be ascribed to systemic embolism. Long-term anticoagulant therapy is proposed in this subgroup of patients with SND. Key Liwrds: sinus node dysfunction, syncopal attacks, pacemaker treatment. systemic embolism. Acta Med Scand 208: 343. 1980.An increasing number of publications o n sinus node dysfunction (SND) have appeared during the last decade, the main objects of interest being electrophysiological phenomena (2, 3, 8) and the possibility of treatment (12, 15, 17). T h e syndrome is accompanied by symptoms varying considerably in severity. There are only a few reports regarding the clinical spectrum (7, 15. 16), and these include smaller numbers of patients A study of 128 patients is presented in an attempt a t defining the difference between patient groups, obtained from ECG criteria with regard t o the occurrence of symptoms. need of treatment, risk of progression, and prognosis. P A T I E N T S A N D M E T H O D SThe study comprises 128 patients (74 men and 54 women), selected retrospectively by means of a survey of the case reports of all admissions to Medical Department B, Odense University Hospital, from April I , 1972 to Dec. 31, 1977. Telemetry, but not Holter technique, was employed in detection of arrhythmia and in evaluation of antiarrhythmic therapy. The patients were selected on the basis of ECG findings in accordance with the criteria mentioned below. Excluded from the study were patients with acute myocardial infarction or SND caused by antiarrhythmic treatment.The patient series was divided into three groups on the basis of the following ECG criteria: Group 1. Persistent and in other respects unexplainable sinus bradycardia with a heart rate of less than 50/m at rest. Group fI. Sinu...