HEART-RATE-VARIABILITY IN LEFT-VENTRICULAR DYSFUNCTION AND HEART-FAILURE - EFFECTS AND IMPLICATIONS OF DRUG-TREATMENT

Objective-To review the importance of heart rate variability analysis in left ventricular dysfunction and heart failure and to assess the ef fects of drug treatment. In patients with left: ventricular dysfunctio n or heart failure, a low heart rate variability is a strong predictor of a low probability of survival. Because drug treatment in these pat ients has rapidly changed over the past two decades, the effect of the se drugs on heart rate variability needs special attention. Design-A s tudy of published reports to give an overview of heart rate variabilit y in patients with left ventricular dysfunction or heart failure and h ow it is affected by drug treatment. Results-Analysis of heart rate va riability provides an easily obtained early marker for progression of disease. It seems to be more closely related to the degree of neurohum oral activation than to haemodynamic variables. Cardiovascular drugs m ay either stimulate or inhibit the degree of neurohumoral activation, and the effects of pharmacological intervention can be closely monitor ed with this method. Conclusions-The analysis of heart rate variabilit y, including spectral analysis, is a novel non-invasive way to obtain potentially useful clinical information in patients with reduced left ventricular function. The effects of drug treatment on heart rate vari ability are in general consistent with their long-term effects in left ventricular dysfunction and heart failure.