First-pass left ventriculograms were obtained using digital subtraction angiography in 24 patients after intravenous injection of 30 to 40 ml of iodinated contrast material. An image processing computer was used to enhance the iodine signal in the image relative to the background soft tissue by digitizing each new frame of the fluoroscopic exposure and subtracting from it a stored "mask" image. Digital left ventriculograms were obtained in the 30-degree right anterior oblique (RAO) position using high fluoroscopic exposure levels [8 mA and 70 to 90 kVp] and compared to 30-degree RAO cineangiograms obtained at cardiac catheterization. Standard cineanglograms were performed in 33 patients at cardiac catheterization but six (18%) were excluded because of runs of ventricular tachycardia initiated by the standard intraventricular injection of 40 ml of contrast media. Digital subtraction angiography was attempted in the 33 patients and left ventriculograms of clinically useful quality were obtained in 30 (91%). There were close correlations between end-diastolic volumes (r = 0.82), end-systolic volums (r = 0.93), and ejection fractions (r = 0.96). Multiple premature ventricular contractions occurred in a total of 10 of 33 (30%) patients during standard intraventricular cineangiography but did not occur in any patients during the intravenous first-pass technique. Wall motion abnormalities were visualized as well by digital angiography as by the standard method. Digital angiography appears to be an important new addition to diagnostic cardiology because it provides a less invasive outpatient method for obtaining contrast left ventriculograms which have much greater spatial resolution than radionuclide cineangiograms.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine