Relation of mechanical dyssynchrony with underlying cardiac structure and performance in chronic systolic heart failure: implications on clinical response to cardiac resynchronization.

AIMS: The aim of this study is to describe the relationship between ventricular mechanical dyssynchrony (VMD) and echocardiographic indices of cardiac remodelling. METHODS AND RESULTS: We evaluated 219 ambulatory patients with chronic systolic heart failure [left ventricular ejection fraction (LVEF) 40 ms and/or inter-VMD > 38 ms). In our study cohort, 59% of patients had evidence of dyssynchrony (including 44% with intra-VMD and 38% with inter-VMD, and 20% with both). Inter-VMD correlated with QRS width (r = 0.48, P < 0.0001) better than intra-VMD (r = 0.24, P < 0.001). Higher inter-VMD was associated with less restrictive filling patterns (rank sums P = 0.012) and larger left ventricular end-diastolic dimension (LVEDD, rank sums P = 0.020), but intra-VMD values were similar across diastolic stages and LVEDD tertiles. CONCLUSION: In chronic systolic heart failure, evidence of mechanical dyssynchrony is prevalent but the underlying cardiac structure and performance may influence the degree of inter-VMD more so than intra-VMD. Our data suggest that the extent of inter-VMD is directly related to the degree of dilatation of the heart but inversely to diastolic dysfunction.

Salvage of nondiagnostic transthoracic echocardiograms on patients in intensive care units with intravenous ultrasound contrast.

Transthoracic echocardiography (TTE) is often technically difficult on patients in intensive care units. Contrast echocardiography can improve left ventricular wall visualization and the assessment of regional and global left ventricular wall motion. Our study undertook to determine what proportion of nondiagnostic TTE studies on patients in intensive care units could be salvaged (i.e., converted to diagnostic studies) with contrast. Ninety-two patients with nondiagnostic TTEs had a repeat study after contrast. Using predefined criteria, 51% of studies were salvaged with contrast. Female gender emerged as the only factor associated with less likelihood of salvaging a study.

Both Sides of the Coin: Randomization from the Perspectives of Physician-Investigators and Patient-Subjects.

Randomization is the "gold standard" design for clinical research trials, and is accepted as the best way to reduce bias. Although some controversy remains over this matter, we believe equipoise is the fundamental ethical requirement for conducting a randomized clinical trial. Despite much attention to the ethics of randomization, the moral psychology of this study design has not been explored. This paper analyzes the ethical tensions that arise from conducting these studies, and examines the moral psychology of this design from the perspectives of physician-investigators and patient-subjects. We conclude with a discussion of the practical implications of this analysis.