1.This study examined the effect of an acute injection of contrast medium on generation of arrhythmias in diseased hearts in man.
2.Subjects were 100 patients in sinus rhythm undergoing cardiac catheterization in whom good quality echocardiograms could be obtained. The subjects comprised 78 males and 22 females aged 37–83 years.
3.Arrhythmia induced by left ventricular angiography ranged from nil to brief bursts of ventricular tachycardia. There was a strongly positive relationship between left ventricular internal dimension in diastole (LVIDd) and induced arrhythmia. Out of 26 patients, 25 developed arrhythmia when LVIDd ⩾ 5 ;cm (96%), but only 24 out of 74 patients developed arrhythmia when LVIDd < 5 ;cm (32%) (P< 0.001). In non-dilated hearts where K+ < 4.0 ;mmol/l, arrhythmia developed in 100% (10 out of 10) of those with left ventricular hypertrophy (LVH), but in only 40% (8 out of 20) without LVH (P< 0.005). Where K+ ⩾ 4.0 ;mmol/l, no arrhythmia occurred in patients with LVH but was present in 52% (31 out of 60) of patients without LVH (P< 0.005). There were no relationships with age, end-diastolic pressure, blood pressure, ischaemic heart disease or sex of patient.
4.These data support the view that acute injection of contrast medium in humans induces arrhythmias dependent upon the underlying state of the heart, with potentially complex interplay between left ventricular dimension, hypertrophy and potassium status, supporting similar observations in experimental animals.