USEFULLNESS OF ELECTROCARDIOGRAM IN HEART FAILURE PROGNOSIS
Authors: Dan Dărăbanțiu
Electrocardiogram is an usual, noninvasive investigation performed frequently in heart failure patients. Although ECG changes in heart failure are usually related to underlying heart disease or comorbid conditions, there are some changes that can provide useful prognostic informations.
QRS duration is important to be determined, one third of heart failure patients having intraventricular conduction disturbances, most of them as left bundle branch block. Experimental studies have shown a positive correlation between QRS duration and myocardial fibrosis. Also, it seems that left bundle branch block contributes to the vicious circle of increased wall stress, LV dilation and progressive alteration of ventricular function. QRS duration increase is associated with increased mortality, including sudden death, in patients with systolic dysfunction, is prognostic value in patients with preserved ejection fraction being lower.
QRS duration follow-up in patients with heart failure is also important, its increase being a predictor of poor prognosis.
The presence of left bundle branch block is a criteria for cardiac resyncronization therapy, the beneficial effect of resyncronization in patients with right bundle branch block being less clear.
Other ECG changes that can have prognostic implications are QRS microvoltage, the presence of premature ventricular beats, R’ wave duration in right bundle branch block.