Biomedical subjects

Jim Kirkpatrick

Publications and source records attributed to Jim Kirkpatrick.

2 recordsLinked to original sources

PubMed2003

Biplane stress echocardiography using a prototype matrix-array transducer.

BACKGROUND: Rapid image acquisition after cessation of exercise is essential for accurate stress echocardiography. Recently, a prototype matrix-array transducer has been developed that allows simultaneous acquisition of 2 imaging planes (biplane [BP] imaging). METHODS: In all, 19 healthy volunteers underwent 2 separate stress echocardiographic studies. Images were acquired in traditional 2-dimensional or BP format pre-exercise and postexercise. RESULTS: Total image acquisition time for 2-dimensional stress echocardiography was 38 +/- 8 seconds versus 29 +/- 8 seconds for BP imaging (P <.05). Heart rates were acquired closer to age-predicted maximum with BP imaging in the apical 3- and 2-chamber and parasternal long- and short-axis views (82%, 75%, 70%, 70% for BP vs 76%, 72%, 68%, 66% for 2-dimensional, respectively). CONCLUSION: BP imaging using a recently developed matrix-array probe allows more rapid imaging postexercise, resulting in acquisition of poststress images at higher heart rates without compromising image quality.

Acoustics↗

PubMed2003

Normal values of left ventricular systolic and diastolic function derived from signal-averaged acoustic quantification waveforms: a multicenter study.

Automated border-detection techniques such as acoustic quantification have proven accurate and useful for quantifying left ventricular (LV) function. We acquired LV acoustic quantification waveforms from the parasternal short-axis window in 140 healthy patients in the age range of 16 to 78 years. Signal-averaged waveforms were analyzed for parameters of systolic and diastolic performance. The average fractional area change was 54 +/- 12%, and there were no significant changes in LV systolic function in the age range studied. There were significant changes in diastolic parameters with aging. The percentage of contribution to total LV filling occurring during atrial filling nearly tripled during the 6 decades studied, from 13% in the youngest cohort to 36% in the eighth decade of life. This study provides normal reference values for systolic and diastolic parameters of LV function determined from signal-averaged acoustic quantification waveforms acquired from the parasternal short-axis view in adult and adolescent patients over a wide age range.

Adolescent↗