No abstract

There was close agreement between whole-body impedance cardiography and thermodilution in the measurement of cardiac output in patients with coronary artery disease without cardiac shunts and valvular lesions. The repeatability of the impedance method was significantly better than the repeatability of thermodilution. Whole-body impedance cardiography can be recommended for the assessment of cardiac output and its changes in the resting state. Whole-body impedance cardiography is a feasible and handy method for noninvasive and continuous measurement of cardiac output.

This investigation studied the effect of 50 Hz electric and magnetic fields on the human heart. The electrocardiograms of 27 transmission-line workers and 26 male volunteers were recorded with a Holter recorder both in and outside the fields. The measurements took from half an hour to a few hours. The electric field strength varied from 0.14 to 10.21 kV/m and the magnetic flux density from 1.02 to 15.43 microT. Analysis of the ECG recordings showed that extrasystoles or arrhythmias were as frequent outside the field as in the field. In some cases a small decrease in heart rate was observed after field exposure.

Aim To retrospectively assess the indications for and findings on 24‐hour electrocardiographic (Holter) monitoring in newborns, focussing on bradycardias and extrasystoles. Methods Data included 337 term‐born infants. Holter indications were categorised into bradycardias below 80 beats per minute, extrasystoles, any tachycardia and other. Heart rate below 60 beats per minute, pathological atrioventricular conduction, supraventricular or ventricular tachycardia, or either atrial premature contractions over 10% or ventricular premature contractions over 5% of total beats were defined as significant arrhythmia on Holter. Results The median age was 6 days (range: 2–62 days). Bradycardia (42%) or extrasystoles (32%) were the most common Holter indications. Fifty‐three infants (16%) had significant arrhythmia on Holter. Heart disease or 12‐lead electrocardiogram expressing extrasystoles or conduction abnormalities were associated with significant arrhythmias (p = 0.046 and p < 0.001, respectively). Twenty‐seven of 109 infants (25%) with extrasystoles as a Holter indication had abnormal Holter results, but only seven (6.4%) had significant arrhythmia on Holter if the 12‐lead electrocardiogram was normal. No pathology was found behind bradycardias below 80 beats per minute in the absence of heart disease. Conclusion Among term newborns with extrasystoles or bradycardias, Holter monitoring could be targeted to infants with heart disease or abnormal electrocardiograms.