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J Escaned

Publications and source records attributed to J Escaned.

48 records · Page 3Linked to original sources
PubMed1993

Experimental validation of geometric and densitometric coronary measurements on the new generation Cardiovascular Angiography Analysis System (CAAS II).

Computer-assisted contour detection and videodensitometric cross sectional area assessment of coronary artery obstructions on the CAAS II system were validated in vitro and in vivo by angiographic cinefilm recording and automated measurement of stenosis phantoms (luminal diameter 0.5, 0.7, 1.0, 1.4, 1.9 mm) which were first inserted in a plexiglass model and then serially implanted in swine coronary arteries. "Obstruction diameter" (OD) and "obstruction area" (OA) values obtained from 10 in vitro and 19 in vivo images at the site of the artificial stenoses were compared with the true phantom dimensions. The in vitro assessment of OD yielded an accuracy of 0.00 +/- 0.11 mm (correlation coefficient: r = 0.98, y = 0.18 + 0.82x, standard error of estimate: SEE = 0.08), whereas the in vivo measurement of OD gave an accuracy of -0.01 +/- 0.18 mm (r = 0.94, y = 0.22 + 0.82x, SEE = 0.15). The assessment of OA gave an accuracy of -0.08 +/- 0.21 mm2 in vitro (r = 0.97, y = 0.08 + 0.99x, SEE = 0.22) and -0.22 +/- 0.32 mm2 in vivo (r = 0.95, y = 0.21 + 1.01x, SEE = 0.33). The mean reproducibility was +/- 0.09 mm for geometric measurements and +/- 0.21 mm2 for videodensitometric assessments, respectively. Thus, due to inherent limitations of the imaging chain, the reliability of geometric coronary measurements is still far superior to videodensitometric assessments of vessel cross sectional areas.

Absorptiometry, Photon↗
PubMed1993

Quantitative angiography during coronary angioplasty with a single angiographic view: a comparison of automated edge detection and videodensitometric techniques.

Little information is available on the reliability of coronary luminal measurements obtained from quantitative analysis of a single angiographic view, an approach that is central to the practical use of on-line quantitative angiography. In the present study we investigated the contribution of two different techniques of quantitative angiography, edge detection (ED) and videodensitometry (VD), to the application of this concept during coronary angioplasty. Forty-six balloon angioplasty procedures were included in this study, all of them performed in a stenosis located in the mid right coronary segment. This coronary location was chosen to optimize data collection on luminal morphology and to minimize the number of factors that may adversely affect quantitative analysis with both techniques. In all cases two orthogonal angiographic projections were obtained before, after balloon dilatation, and at follow-up. Correlation coefficients and differences between orthogonal measurements obtained with each technique were used to evaluate the agreement between orthogonal readings at every stage of the procedure. The obtained correlation coefficients and mean differences (MD) between orthogonal measurements were as follows: before percutaneous transluminal coronary angiography (PTCA), 0.67 (MD 0.01 +/- 0.47 mm2) and 0.57 (MD 0.05 +/- 0.64 mm2) for ED and VD, respectively (Pitman's test for SD, p < 0.05); after balloon dilatation, 0.32 (MD -0.56 +/- 1.53 mm2) and 0.53 (MD -0.15 +/- 1.43 mm2) for ED and VD, respectively (paired t test for MD, p < 0.05); and at follow-up 0.79 (MD -0.15 +/- 0.97 mm2) and 0.73 (MD 0.17 +/- 1.16 mm2) for ED and VD, respectively (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1993

Clinical and histological determinants of smooth-muscle cell outgrowth in cultured atherectomy specimens: importance of thrombus organization.

BACKGROUND: Coronary atherectomy provides a unique opportunity to obtain plaque tissue from a wide variety of clinical syndromes. We investigated the relation between the clinical status and histopathological substrate of tissue retrieved during directional coronary atherectomy and the proliferative and migratory potential of smooth-muscle cells judged from successful outgrowth during cell culture. METHODS: After directional coronary atherectomy, tissue samples were examined macroscopically, divided into two equal pieces, and separately subjected to cell culture and histopathological study. Cell culture was performed using an explant technique. In-vitro smooth-muscle cell outgrowth was related to clinical and histological variables. RESULTS: Atherosclerotic tissue was obtained from 98 consecutive atherectomy procedures. Histological examination revealed a broad spectrum of appearances, ranging from complex atheroma containing dense fibrous tissue, calcium deposits, macrophages, and necrotic debris to neointimal proliferation and organized thrombi. Smooth-muscle cell outgrowth was observed in 43 of the 98 samples (44%). Although not affected by any of the clinical variables, cell outgrowth was influenced by histological variables, in particular the presence of organizing thrombi. Outgrowth was successful in eight out of 10 samples with thrombus (80%) and in only 35 out of 88 (40%) without (P = 0.03). CONCLUSION: The presence of organizing thrombi in the retrieved tissue facilitates smooth-muscle cell outgrowth and suggests an enhanced proliferative and migratory potential. These findings may be relevant to the understanding of neointimal proliferation in coronary syndromes where mural thrombosis is likely to occur.

Angina Pectoris↗
PubMed1992

Pleural effusion following coronary perforation during balloon angioplasty: an unusual presentation of the postpericardiotomy syndrome.

We report on the development of features of the postpericardiotomy syndrome following coronary perforation during balloon angioplasty, in a patient that was managed conservatively. The case illustrates that while cardiac tamponade does not invariably follow coronary perforation, late consequences derived from this complication may occur. It also widens the spectrum of conditions where the postpericardiotomy syndrome has been observed.

Angina Pectoris↗
PubMed1991

Evaluation of a theoretical Doppler index to noninvasively estimate peak dP/dt using continuous wave Doppler ultrasound of ascending aortic flow in man.

A theoretical formula for calculation of peak dP/dt was derived using parameters obtained from continuous wave Doppler echocardiography signals of aortic blood flow. The direct proportional relationship between the main variables of this formula and invasively measured peak dP/dt was validated in 20 patients undergoing routine diagnostic cardiac catheterization. Doppler signals of aortic flow were obtained simultaneously to invasive pressure recordings with a 2 MHz continuous wave transducer via the suprasternal echocardiographic window. The Doppler signals were recorded on magnetic tape and measurements were made with digital calipers by two independent, blinded observers. The following parameters were measured: peak velocity (V) and time from onset of ejection to peak velocity (T). V2/T, the variable of the derived formula, was calculated for each of the observer's measured parameters and showed a very high interobserver correlation. The two observers' measurements of each parameter were averaged for each patient and the resulting mean was used in calculating the V2/T and mean acceleration. 4. A good correlation of V2/T with invasively measured peak dP/dt was obtained. Our derived index of left ventricular function showed a higher correlation with peak dP/dt compared to other Doppler indices of ventricular function. V2/T may provide a noninvasive method for estimating peak dP/dt.

Aorta↗
PubMed1991

Changes in Doppler indices of cardiac function during and after percutaneous transluminal coronary angioplasty.

OBJECTIVE: To assess the sensitivities of Doppler indices to changes in global cardiac function during and after controlled myocardial ischaemia induced by coronary angioplasty. DESIGN: Continuous wave Doppler signals of aortic flow were recorded during coronary angioplasty. The following Doppler indices of cardiac function were measured before, during, and after balloon inflation: V (peak velocity), MA (mean acceleration), V2/T (T = time from onset to peak ejection), and MD (minute distance corrected for baseline heart rate). SETTING: A tertiary care cardiological unit in a university hospital. PATIENTS: Sixteen patients undergoing coronary angioplasty of the left anterior descending coronary artery. Eight patients had multivessel disease. MAIN OUTCOME MEASURES: The primary outcome measures were planned before data collection began. RESULTS: 12 patients showed a significant fall of three or more Doppler indices from their baseline values during balloon inflation. This occurred in all patients with multivessel disease. The Doppler indices V2 T, MD, V, and MA fell by 43.7%, 37.7%, 27.4%, and 23% respectively from their baseline values (p less than 0.0001). The relative sensitivities of the Doppler indices to ischaemia were V2/T greater than MD (p less than 0.02), MD greater than (p less than 0.001), and V greater than MA (p less than 0.01). The impairment of global left ventricular function resulting from brief balloon inflation during single vessel angioplasty was reversible in all the patients. CONCLUSIONS: The Doppler indices V2/T, MD, V, and MA are all sensitive, in order of magnitude, to falls in global cardiac function resulting from ischaemia. They may prove useful for assessing cardiac function during ischaemia in the clinical setting.

Adult↗
PubMedDate not supplied

Predictors of failure in direct stenting in the real world.

INTRODUCTION: Stent implantation without predilation simplifies a large proportion of coronary intervention procedures, with a significant reduction in costs and procedure time. OBJECTIVES: To determine the variables associated with a higher probability of failure in direct stent implantation in daily practice in a wide range of clinical contexts and types of lesions. POPULATION AND METHODS: Over a period of 28 months, direct implantation of 931 stents was attempted in our Center (811 patients, 83% male, mean age 62 +/- 12 years; 1.1 stent per patient). In 59 patients (7.3%), balloon predilation was necessary, and the factors associated with direct implant failure were determined. RESULTS: The vessels treated were: anterior descending (373 lesions: 40.1%), right coronary artery (306 lesions: 32.9%, circumflex (210 lesions: 22.6%), saphenous vein (35 lesions: 3.8%), left main (5 lesions: 0.4%) and internal mammary artery (2 lesions: 0.2%). 54% of the lesions were of type B2/C (ACC/AHA classification). The characteristics significantly associated with, or with statistical tendency towards, a lower success rate in direct stent implantation were: Lesion in the circumflex (11% vs. 5.5%, p = 0.012); reference vessel diameter less than 3.0 mm (9.8% vs. 6.2%, p = 0.097); age over 65 years (8.5% vs. 4.5%, p = 0.017); left main disease, irrespective of the vessel treated (23.5%% vs. 6.5%, p = 0.023); B2/C lesion (7.8%, vs. 4.8%, p = 0.086); calcification (9.9% vs. 4.9%, p = 0.012); vessel angulation greater than 45 degrees (9.9% vs. 4.9%, p = 0.009); and Express stent implant (19.6% vs. 6.0%, p < 0.001). On multivariate analysis, independent predictors of failure in direct stent implantation were: left main lesion (RR 6.6; 95% CI 1.73-24.93; p = 0.013), presence of calcium (RR 1.9; 95% CI 1.02-3.37; p = 0.049), vessel curvature (RR 2.0; 95% CI 1.13-3.64; p = 0.018), reference vessel diameter less than 3 mm (RR 2.2; 95% CI 1.15-4.32; p = 0.023), lesion type B2/C (RR 1.9; 95% CI 1.0-3.52; p = 0.044) and Express stent (RR 2.7; 95% CI 1.07-6.79; p = 0.05). CONCLUSION: In a large and heterogeneous series of patients, direct stenting was not possible in 7.3% of cases, which required balloon predilation. Certain clinical and angiographic features can predict when this is more like to occur.

Equipment Failure↗