Biomedical subjects

N T Skelly

Publications and source records attributed to N T Skelly.

3 recordsLinked to original sources

PubMed1983

Digital subtraction intravenous left ventricular angiography: comparison with conventional intraventricular angiography.

Standard contrast left ventriculography with catheter placement into the left ventricle entails risks and inconvenience. Computer-based digital subtraction techniques now permit high contrast left ventriculography after intravenous administration of contrast medium. To compare the accuracy of intravenous digital subtraction left ventriculography with film-based, standard contrast ventriculography, we assessed left ventricular function by both methods in 32 patients (8 with valvular disease, 22 with coronary disease and 2 with atypical pain). Studies in 31 of 32 patients were considered. Left ventricular ejection fraction by standard contrast ventriculography ranged from 24 to 88%. Digital subtraction angiography was performed with bolus injection of radiopaque contrast material (30 cc at 20 cc/s) into the inferior vena cava. The two methods correlated closely in end-diastolic volume (correlation coefficient [r] = 0.96, probability [p] less than 0.001), end-systolic volume (r = 0.97, p less than 0.001) and ejection fraction (r = 0.98, p less than 0.001). Segmental function was assessed visually; precise agreement existed between the two techniques in 123 (79%) of the 155 segments (p less than 0.001). It is concluded that intravenous digital angiography provides left ventricular images of sufficiently good quality to allow accurate quantitative assessment of global left ventricular function and volumes as well as determination of regional function.

Adult↗

PubMed1983

Exercise left ventriculography utilizing intravenous digital angiography.

Exercise left ventriculography has been shown to be a sensitive and specific tool for the detection of coronary artery disease. At the present time, such studies require radionuclide-base methods. Computer-based techniques recently have been shown to provide high resolution images of the left ventricle when the levophase of an intravenous injection of radiopaque contrast medium is imaged with fluoroscopy. To evaluate the possible efficacy of using "intravenous digital subtraction left ventriculograms" in exercise ventriculography, such ventriculograms were performed at rest and during maximal supine bicycle exercise in 31 patients. Studies that could be analyzed were obtained in 29 patients. In 21 patients with coronary artery disease, ejection fraction was 58% at rest and 45% with exercise (p less than 0.001 vs. rest). In contrast, in seven patients with no coronary artery disease, ejection fraction was 65% at rest and 69% with exercise (difference not significant). In a subgroup of 8 patients with "severe" coronary obstruction, the change in ejection fraction from rest to exercise was -18%, while in the remaining 13 patients with less severe disease, it was -9% (p less than 0.001). All patients with coronary artery disease manifested new or worsening segmental wall abnormality with exercise, compared with two of seven patients without coronary disease (p less than 0.01). Sixteen patients underwent rest and exercise radionuclide cineangiography in addition to digital subtraction angiography. There was a strong correlation between the two techniques for ejection fraction at rest (r = 0.78, p less than 0.001), ejection fraction and with exercise (r = 0.83, p less than 0.001) and change in ejection fraction from rest to exercise (r = 0.88, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1983

Digital angiography in the pediatric patient with congenital heart disease: comparison with standard methods.

Digital subtraction angiography (DSA) permits high-resolution cardiac imaging with relatively low doses of contrast medium and reduced radiation exposure. These are potential advantages in children with congenital heart disease. Computer-based DSA (30 frames/sec) and conventional cutfilm angiography (6 frames/sec) or cineangiography (60 frames/sec) were compared in 42 patients, ages 2 months to 18 years (mean 7.8 years) and weighing 3.4 to 78.5 kg (mean 28.2 kg). There were 29 diagnoses that included valvular regurgitant lesions, obstructive lesions, various shunt abnormalities, and a group of miscellaneous anomalies. For injections made at a site distant from the lesion and on the right side of the circulation, the mean dose of contrast medium was 60% to 100% of the conventional dose given during standard angiography. With injections made close to the lesion and on the left side of the circulation, the mean dose of contrast medium was 27.5% to 42% of the conventional dose. Radiation exposure for each technique was markedly reduced in all age groups. A total of 92 digital subtraction angiograms were performed. Five studies were suboptimal because too little contrast medium was injected; in the remaining 87 injections, DSA and conventional studies resulted in identical diagnoses in 81 instances (p less than .001 vs chance). The remaining six injections made during DSA failed to confirm diagnoses made angiographically by standard cutfilm angiography or cineangiography. We conclude that DSA usually provides diagnostic information equivalent to that available from cutfilm angiography and cineangiography, but DSA requires considerably lower doses of contrast medium and less radiation exposure than standard conventional methods.

Adolescent↗