Objective:To evaluate the relationship between sudden cardiac death, ventricular arrhythmias and left ventricular hypertrophy in patients with hypertension.Data identification:Epidemiological studies assessing the importance of left ventricular hypertrophy as a risk factor for sudden cardiac death, studies assessing the prevalence of arrhythmias in left ventricular hypertrophy and studies assessing whether there is an electrophysiological substrate in the hypertrophied myocardium for ventricular dysrhythmias.Results of data analysis:Current evidence indicates that left ventricular hypertrophy is a risk factor for sudden cardiac death and that ventricular arrhythmias are more prevalent in hypertensive patients with than in those without left ventricular hypertrophy. However, there is a lack of evidence that these dysrhythmias are important as an underlying mechanism for sudden cardiac death, and there is no clear evidence that the hypertrophied myocardium is, itself, an arrhythmogenic substrate for malignant ventricular dysrthyhmias. One possible mechanism for sudden cardiac death is myocardial ischaemia, either as a consequence of asssociated coronary disease or due to left ventricular hypertrophy, but this remains unproved.Conclusions:There is currently no evidence that the ventricular ectopic activity seen in patients with hypertensive left ventricular hypertrophy is a marker for sudden cardiac death. Clarification of the mechanisms involved in sudden cardiac death will help in selecting appropriate preventive and therapeutic strategies for these patients.