Prediction of mortality in patients with right bundle branch block referred for pharmacologic stress echocardiography

Exercise left ventricular ejection fraction predicts events in right bundle branch block

OBJECTIVE

Interpretation of the electrocardiogram (ECG) during exercise is not easy in patients with right bundle branch block (RBBB). Also, the value of exercise echocardiography (ExE) for predicting outcome in them has not been addressed. We sought to assess its prognostic value in patients with RBBB and known/suspected coronary disease.

DESIGN

Retrospective analysis of data on 703 patients with RBBB who were submitted to a clinically-indicated ExE. The end points were overall mortality and combined myocardial infarction and cardiovascular mortality.

RESULTS

During follow-up (4.1 ± 4.5 years) there were 130 deaths and 108 combined events. Independent predictors of combined events were history of coronary artery disease (hazard ratio [HR] = 2.37, 95% Confidence Interval [CI] = 1.24-4.52, p = 0.009) resting wall motion score index (HR = 2.14, 95% CI = 1.12-4.10, p = 0.02), metabolic equivalents (HR = 0.89, 95% CI = 0.93-0.97, p = 0.007), Δ in double product with exercise (HR = 0.96, 95% CI = 0.92-1.00, p = 0.036) and Δ in left ventricular ejection fraction (LVEF) with exercise (HR = 0.97, 95% CI = 0.94-0.99, p = 0.01). Neither positive clinical nor ECG exercise testing was predictive. Combined event rates were 3.3% in patients with ΔLVEF > 5%, 4.7% in those with ΔLVEF between 1-5% and 8.2% in those with no increase (Δ < 1%).

CONCLUSIONS

A decrease in LVEF during exercise is predictive of serious events in patients with RBBB.

Hypertrophies and intraventricular conduction defects: causes, presentation, and significance

There is an increasing need for nurses to interpret a 12-lead electrocardiogram, both in critical care units and in other areas. This can be a challenging task, especially in the presence of hypertrophies, bundle-branch blocks, and fascicular blocks. This article reviews the pathophysiology of intraventricular blocks and hypertrophy, characteristics found in the 12-lead electrocardiogram, and discusses what the significance of these findings may be.

Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC)

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. Among different stresses of comparable diagnostic and prognostic accuracy, semisupine exercise is the most used, dobutamine the best test for viability, and dipyridamole the safest and simplest pharmacological stress and the most suitable for combined wall motion coronary flow reserve assessment. The additional clinical benefit of myocardial perfusion contrast echocardiography and myocardial velocity imaging has been inconsistent to date, whereas the potential of adding - coronary flow reserve evaluation of left anterior descending coronary artery by transthoracic Doppler echocardiography adds another potentially important dimension to stress echocardiography. New emerging fields of application taking advantage from the versatility of the technique are Doppler stress echo in valvular heart disease and in dilated cardiomyopathy. In spite of its dependence upon operator's training, stress echocardiography is today the best (most cost-effective and risk-effective) possible imaging choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

The use of stress echocardiography for prognostication in coronary artery disease: an overview

PURPOSE OF REVIEW

Stress echocardiography has a high accuracy for the detection of coronary artery disease. Additionally, it provides clinically useful prognostic information, such as resting left ventricular function, myocardial viability, stress-induced ischemia, vascular extent of wall motion abnormalities, and changes in end-systolic volume and ejection fraction with stress.

RECENT DEVELOPMENTS

The timing, extent, and severity of the stress-induced wall motion abnormalities are important determinants of long-term prognosis. Previous studies have shown the efficacy of stress echocardiography in predicting long-term cardiac events in mixed patient groups and the value of this test in selected patient subsets.

SUMMARY

This review attempts to define the role of stress echocardiography for prognostication in coronary artery disease, pointing out the ability of this technique to identify low-risk and high-risk subsets among patients with known or suspected coronary artery disease and thus guide patient management decisions.

Prognostic stratification of patients with right bundle branch block using dobutamine stress echocardiography

The presence of a right bundle branch block (RBBB) is associated with increased mortality. We studied the role of dobutamine stress echocardiography for the prognostic stratification of patients with RBBB. The presence of an abnormal dobutamine stress echocardiography was the strongest predictor of cardiac events and provided incremental prognostic information to clinical and stress test data.