The use of echocardiography in the critical care setting.

Echocardiography has become an invaluable tool in the management of critically ill patients. Its safety and portability allow for use at the bedside to provide rapid, detailed information regarding the cardiovascular system. Echocardiography can elucidate cardiac structure and mechanical function. Recently, the power of clinical echocardiography has been augmented by the use of Doppler techniques to evaluate cardiovascular hemodynamics. An in-depth understanding of the proper use of echocardiography is a prerequisite for the intensivist.

The low-density lipoprotein cholesterol-lowering effect of pravastatin and factors associated with achieving targeted low-density lipoprotein levels in an African-American population.

STUDY OBJECTIVES: To describe the low-density lipoprotein cholesterol (LDL)-lowering effect of pravastatin in African-American patients and to identify factors associated with achieving National Cholesterol Education Program (NCEP)-defined target levels. DESIGN: Retrospectively defined cohort study. SETTING: Large, government-owned, teaching hospital. PATIENTS: Eighty-four African-American patients starting therapy with pravastatin in October-November 1997. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Whether or not target LDL concentrations were achieved was used to measure efficacy. Stepwise logistic regression identified the target LDL, baseline LDL, and baseline high-density lipoprotein cholesterol (HDL) as significant predictors of achieving the target. The proportion of patients achieving their target LDL when that target was below 160, below 130, and 100 mg/dl or below was 64%, 32%, and 13% (p=0.004), respectively. Medical record review identified the reasons for not achieving target as incorrect drug regimen, inadequate lipid monitoring, and noncompliance. CONCLUSION: These results indicate that substantial numbers of patients receiving lipid-lowering therapy are not meeting NCEP-defined targets and that with increased drug monitoring and compliance, improvements in achieving NCEP target LDL levels could be realized.

Low high density lipoprotein levels are associated with an elevated blood viscosity.

Low levels of high density lipoprotein (HDL) have been inversely correlated with blood viscosity and plasma viscosity; however, the contribution of concomitant hypertriglyceridemia may confound this association. This study evaluated the relationship between blood viscosity and HDL cholesterol in 70 subjects with fasting levels of total cholesterol <5.2 mmol/l (200 mg/dl) and triglycerides <2.3 mmol/l (200 mg/dl). Viscosity (mPa x s) was measured at 37 degrees C with a coaxial cylinder microviscometer. HDL cholesterol was inversely associated with corrected blood viscosity at 100 s(-1) (beta = -0.49, P<0.00005) and 20 s(-1) (beta = -0.38, P = 0.001) but not at 1 s(-1) (beta = -0.05, P = 0.69) using stepwise multivariate analyses. Low HDL levels are associated with an elevated blood viscosity, and this rheological abnormality may contribute to cardiovascular risk in subjects with isolated low HDL levels.

Comparison of MPEG digital video with super VHS tape for diagnostic echocardiographic readings.

BACKGROUND: Digital recording of echocardiographic studies is on the clinical horizon. However, full digital capture of complete echocardiographic studies in traditional video format is impractical, given current storage capacity and network bandwidth. To overcome these constraints, we evaluated the diagnostic image quality of digital video by using MPEG (Motion Picture Experts Group) compression. METHODS AND RESULTS: Fifty-eight complete, consecutive studies were recorded simultaneously with the use of MPEG-1 and sVHS videotape. Each matched MPEG and sVHS study pair was reviewed by two from a total of six readers, and findings were recorded with the use of a detailed, computerized reporting tool. Intrareader and interreader discrepancies were characterized as major or minor and analyzed in total and for specific subgroups of findings (left and right ventricular parameters, valvular insufficiency, and left ventricular regional wall motion). Intrareader discrepancies were reviewed by a consensus panel for agreement with either MPEG or sVHS findings. There was an exact concordance between MPEG and sVHS readings in 83% of findings. The majority of discrepancies were minor, with major discrepancies in only 2.7% of findings. There was no difference in the rate of consensus panel agreement with MPEG or sVHS for instances of intrareader discrepancy, either in total or for any subgroup of findings. Interreader discrepancy rates were nearly identical for both MPEG and sVHS. CONCLUSIONS: MPEG-1 digital video is equivalent to sVHS videotape for diagnostic echocardiography. MPEG increases the range of practical options for digital echocardiography and offers, for the first time, the advantages of digital recording in a familiar video format.