Biomedical subjects

S P Graham

Publications and source records attributed to S P Graham.

4 recordsLinked to original sources

PubMed1991

Comparison of angiographic findings and demographic variables in patients with coronary artery disease presenting with acute pulmonary edema versus those presenting with chest pain.

One hundred nineteen patients admitted to the coronary care unit with pulmonary edema were retrospectively reviewed to identify the demographic characteristics and underlying cardiac disorders of this population. The patients with pulmonary edema were compared with 119 patients admitted to the coronary care unit with chest pain. Cardiac catheterization in 71 patients with pulmonary edema and 93 with chest pain showed left main and 3-vessel coronary artery diseases to be equally common in both groups, although anginal pain was infrequent in patients with pulmonary edema (n = 28, 24%). Left ventricular function was reduced in the patients with pulmonary edema compared with those with chest pain (mean ejection fraction 42 vs 59%; p less than 0.001). More patients with pulmonary edema were black, and had diabetes and preexisting hypertension than those with chest pain. The results of cardiac catheterization were the same for black and white patients with pulmonary edema. In conclusion, patients with pulmonary edema have a high incidence of cardiac disease, and pulmonary edema may be 1 manifestation of silent myocardial ischemia. Important demographic differences exist between patients admitted with pulmonary edema and those who present with chest pain.

Adult↗

PubMed1990

Estimation of coronary flow reserve by intracoronary Doppler flow probes and digital angiography.

This prospective study investigated two different methods used clinically to estimate coronary flow reserve during cardiac catheterization. First, the relationship between simultaneous digital angiography and intracoronary Doppler velocity measurements was determined in 61 patients. The correlation coefficient for 233 simultaneous pairs of papaverine-induced flow reserve was 0.70 (Doppler = 0.41 digital + 0.93, P less than 0.0001). Repeated basal flow determinations showed little variability (Doppler: 2 +/- 5% (mean +/- 95% confidence intervals); digital: 3 +/- 10%). Repeated hyperemic flow estimates by the Doppler technique were more reproducible (10 +/- 2%) than those by the digital method (26 +/- 6%). Second, estimates of coronary flow reserve by side-mounted and end-mounted Doppler catheters were compared in vitro and in patients. In vitro measurement of blood velocity was linear for both catheter designs and was highly correlated with volume flow determined by electromagnetic flow meter (r = 0.99 side-mounted; r = 0.96 end-mounted). In patients (n = 20), average coronary flow reserve for the side-mounted Doppler crystal was 2.64 +/- 0.15 and for the end-mounted Doppler crystal was 2.40 +/- 0.14 (P less than 0.02). When flow reserve was determined twice for each catheter, there was greater variability in repeated measurements using the side-mounted Doppler crystal (21 +/- 10%, n = 14) than using the end-mounted Doppler crystal (12 +/- 4%, n = 32).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Accelerated aortic stenosis.

A 56 year-old woman presented in congestive heart failure 4 weeks after cardiac catheterization. By repeat catheterization, the mean gradient across the native aortic valve had progressed from 10 mm Hg to 51 mm Hg. In patients with calcific-degenerative valvular disease, the rapid worsening of aortic stenosis should be considered in the differential diagnosis of recurrent heart failure.

Aortic Valve Stenosis↗

PubMed1989

Clinical percutaneous imaging of coronary anatomy using an over-the-wire ultrasound catheter system.

This manuscript describes initial applications of a unique new intravascular ultrasound imaging catheter. This 5.5F catheter uses an over-the-wire design and incorporates a phased array transducer at its tip. There are no moving parts. A 360 degree image is produced perpendicular to the catheter axis using a 20 MHz center frequency. A dedicated minicomputer is used for initial image processing, as well as enhancement and analysis. Initial studies using phantoms demonstrated excellent accuracy for linear dimensions (r = 0.99, range 3.0 to 7.6 mm, image = 1.0 phantom + 0.1). Serial imaging of the same arterial segment in vitro showed good reproducibility (coefficients of variance 2.5-5.2%). Likewise, intra- and inter-observer variability in image analysis was minimal (r = 0.92-0.99). Initial in vivo studies were performed in dogs. The catheter was easily passed over a wire into mesenteric, cerebral and coronary vessels without evidence of significant vessel trauma. Subsequently, 20 patients had percutaneous coronary imaging performed during cardiac catheterization. Cardiac motion was rarely a problem and acceptable images were obtained in all but two patients. Areas of calcification, mild stenoses, branching vessels and graft atherosclerosis could be identified. We conclude that intracoronary ultrasound imaging will be useful for assessing vascular pathology, for studying both rapid change in vessel size as well as chronic progression or regression of atherosclerosis, and for assisting with new therapeutic interventions.

Angioplasty, Balloon↗