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Biomedical subjects

W Rutishauser

Publications and source records attributed to W Rutishauser.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Immediate results of coronary endoprosthesis in threatening or occlusive dissections complicating angioplasty; the Geneva experience].

Between April 1988 and September 1993, 123 patients (average age 60.4 +/- 8.9 years) underwent coronary stenting for threatening or occlusive dissection complicating angioplasty. The anterograde coronary flow was disturbed in 51% of cases (TIMI-0-2). The artery concerned was the left anterior descending in 59% of cases, the right coronary in 28% of cases, the circumflex in 12% and a coronary bypass graft in 1% of cases. Technically, the stenting was successful in 118 cases (98%) and, in 21 cases, complete stenting of the dissection required the insertion of several stents. The minimal coronary diameter after expansion of the stent was 3.1 +/- 0.6 mm. During hospital follow-up, 3 deaths (3%) and 7 Q-wave infarcts were observed. Twenty-eight patients (23%) developed a haemorrhagic complication, including 2 retroperitoneal and 2 intracerebral bleeds. Eight patients (6%) underwent coronary bypass grafting, as an emergency in 4 cases and semi-electively in another 4 cases. One hundred and five patients (89%) survived the intra-hospital period without major complications (death, Q-wave infarction, emergency coronary bypass surgery or severe haemorrhage). Coronary stenting for threatening or occlusive dissection complicating angioplasty seems to be a reasonable solution and a usually definitive one. The frequency of haemorrhagic complications underlines the need for strict clinical and biological surveillance.

Aged↗
PubMed1993

[Delay in management and treatment of patients with suspected acute myocardial infarction: role of the public, of extra- and intra-hospital structures and transportation methods].

The potential impact of thrombolytic agents on mortality and morbidity from coronary artery disease is weakened by in- and out-of-hospital delays occurring in the management of acute myocardial infarction. The goals of this study were to review the situation 5 years after the publication of the GISSI study. From October 1, 1991 to March 31, 1992, all the events occurring between symptom onset and in-hospital treatment were analyzed for 620 consecutive patients with suspected myocardial infarction seen in the emergency ward of the University Hospital, Geneva. Among them, 189 (30.5%) had myocardial infarction and 144 (23%) unstable angina. Mean and median delay between symptom onset and hospital arrival for the 620 patients were 10 h 02 min and 2 h 55 min respectively; 117 (19%) patients came straight to the hospital alone, with the risk of arrhythmic complications en route to the emergency ward but with shorter time delays (mean delay: 6 h 13 min; median delay: 2 h 30 min) than the 503 (81%) patients who called out-of-hospital services (mean delay: 10 h 55 min; median delay: 3 h; p < 0.04). The latter patients accounted for 47% of mean out-of-hospital delay and the out-of-hospital services for 53%. Minimization or ignorance of symptoms, waiting for relief from medication and attempts to reach relatives were responsible for long patients' decision times.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

[Coronary angioplasty in octogenarians].

Coronary balloon angioplasty was performed on 33 lesions during 28 procedures in 23 octogenarians (median age 83, range 80 to 87 years) between January 1989 and December 1991. 96% of the patients had grade III-IV angina pectoris. The median left ventricular ejection fraction was 64% (range: 38-85%). Single vessel coronary artery disease was present in 43% and multivessel coronary artery disease in 57%. Angioplasty was performed on 1 vessel in 85% of the procedures and on 2 vessels in 15%. Primary angiographic success was 97% for 33 attempted lesions with one failure to recanalize an old occlusion. One patient underwent emergency intracoronary stent implantation after failed angioplasty. None underwent emergency coronary bypass surgery. One patient (4%) had a myocardial infarction and 2 patients (7%) died during hospitalization, the first because of abrupt vessel closure during angioplasty, the second due to acute retroperitoneal bleeding on the 8th day post-angioplasty while fully anticoagulated for an intracoronary stent. Follow-up (median 17, range 8 to 39 months) was obtained for all patients. Out of the 21 patients with primary angioplastic success, 3 (14%) had died (1 cardiac and 2 non-cardiac). At 1 year actuarial survival was 86%, and survival free from myocardial infarction or coronary bypass surgery was 81%. Further angioplasty for either restenosis or another lesion was performed in 5 patients (24%). These results confirm that coronary angioplasty is an effective means of controlling anginal symptoms in a selected group of severely symptomatic octogenarians. However, when complications do occur they are linked to a significant mortality rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Implications of coronary angiography in patients with suspected or known coronary artery disease.

The study analyzes the incidence of coronary lesions and their implications on the treatment offered in 500 consecutive non-selected patients (406 males (81%), age 60 +/- 10 (+/- 1 standard deviation), range 21-88 years) undergoing coronary angiography for suspicion or confirmation of coronary artery disease (excluding patients with congenital and pure valve disease, or cardiomyopathy). A history of myocardial infarction was present in 205 patients (41%). There were no prior cardiac procedures in 334 patients (67%). There was prior coronary angioplasty in 82 patients (16%), coronary artery bypass grafting in 44 (9%) and both in 4 (1%). A total of 36 patients (7%) had had prior coronary angiography only. Mean left ventricular ejection fraction was 61 +/- 12 (18-83%) and mean left ventricular end diastolic pressure was 12 +/- 6 (2-37) mmHg. Angiographically normal coronary arteries were present in 61 patients (12%) and non-significant coronary lesions in 70 patients (14%). One vessel disease was present in 169 patients (34%), two vessel disease in 97 (19%), three vessel disease in 88 (18%) and left main coronary artery disease in 15 (3%). In single vessel disease, involvement of the left anterior descending coronary artery was seen in 82 patients (49%), left circumflex coronary artery in 38 (22%) and right coronary artery in 49 (29%). In two vessel disease, involvement of the left anterior descending coronary artery and left circumflex coronary artery was present in 30 patients (31%), left anterior descending coronary artery and right coronary artery in 36 (37%) and left circumflex coronary artery and right coronary artery in 31 (32%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Effect of altered loading conditions during haemodialysis on left ventricular filling pattern.

Changes in the circulating volume associated with haemodialysis result in modification of left ventricular loading conditions. To determine the influence of haemodialysis on Doppler indices of left ventricular filling, 12 patients (mean age 40.8 +/- 2.7 (SEM) years) with renal insufficiency but without overt heart disease were studied by Doppler-echocardiography immediately before and after haemodialysis. Haemodialysis resulted in a decrease in body weight from 68.0 +/- 3.8 kg to 65.0 +/- 3.7 kg (P < 0.01). Heart rate and blood pressure did not change significantly during haemodialysis. Left ventricular diastolic dimension (M-mode) decreased from 53.5 +/- 1.1 mm to 49.5 +/- 1.9 mm (P < 0.05), whereas the shortening fraction did not change. Haemodialysis elicited marked changes in the early diastolic rapid filling wave (E wave) recorded by pulsed Doppler at the level of the mitral annulus. Peak velocity of the early rapid filling phase (peak E) decreased significantly from 95.3 +/- 8.2 cm.s-1 to 63.0 +/- 5.7 cm.s-1 (P < 0.001) and mid-diastolic deceleration of transmitral velocity decreased from 437.3 +/- 54.2 cm.s-2 to 239.7 +/- 54.4 cm.s-2 (P < 0.01). The peak filling velocity during atrial contraction (peak A) did not change (79.7 +/- 6.3 cm.s-1 vs 74.1 +/- 4.7 cm.s-1; P = NS). The ratio peak E/peak A decreased from 1.19 +/- 0.06 to 0.85 +/- 0.04 (P < 0.01) during haemodialysis. The results provide further evidence for the pronounced preload-dependence of Doppler indices of left ventricular diastolic function.

Adult↗
PubMed1993

Cine gradient-echo MR imaging in the evaluation of cardiovascular diseases.

The contributions of cine gradient-echo (GRE) magnetic resonance imaging were compared with those of spin-echo (SE) imaging for the evaluation of morphologic, functional, and flow alterations in 78 cases of congenital and acquired cardiac diseases. High temporal and spatial resolution cine GRE images (256 phase-encoding steps, 256 x 256 acquisition matrix interpolated to 512 x 512 for display, 16-64 frames per cycle) and SE images were acquired in each case. Cine GRE images provided a better diagnostic evaluation than SE images in several cases: (a) both masses and thrombi could be differentiated from flow artifacts; (b) abnormalities in cardiac function, such as infarction, abnormal wall motion, and ventricular dysfunction, could be evaluated; (c) small defects, shunts, and abnormal communications could be clearly seen; and (d) valvular regurgitations, poststenotic flow alterations, and aortic coarctation could be assessed. Cine GRE imaging was also valuable for postoperative evaluations. The authors believe that cine GRE imaging is a useful addition to SE sequences, especially for the assessment of blood flow and cardiac function.

Adolescent↗
PubMed1993

Effects of dialysate composition during hemodialysis on left ventricular function.

To determine the effects of dialysate composition during hemodialysis on left ventricular systolic and diastolic function, 12 patients treated by chronic hemodialysis (mean age 40.8 +/- 2.7 years), without overt heart disease, were studied by Doppler-echocardiography successively before and after acetate hemodialysis (AHD), bicarbonate hemodialysis (BHD), and acetate-free biofiltration (AFB). The three types of hemodialysis resulted in a comparable decrease of the body weight. Mean arterial blood pressure decreased by 5 mm Hg (NS), 8 mm Hg (NS) and 10 mm Hg (P < 0.05) during AHD, BHD and AFB, respectively. There was a significant increase of the heart rate and the shortening fraction of the left ventricular diameter after AHD, but not after BHD and AFB. Mean total systemic resistance increased by 20% after AHD, 18% after BHD and by 7% after AFB (all changes NS). During each type of hemodialysis there was a significant reduction of the peak velocity of the early diastolic rapid filling wave (peak E) without change of the peak filling velocity during atrial contraction (peak A). During AHD and BHD the pressure half-time of the early filling phase (TP/2) increased, and the velocity-integral of the early diastolic filling phase (E-area) decreased. However, TP/2 and E-area did not change significantly after AFB.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed1992

[Regional coronary flow in ml/min measured with conventional coronarography].

We have developed a new method of measuring absolute coronary blood flow (CBF) in all major branches of the coronary circulation using computer analysis of conventional cineangiograms. A coronary cineangiogram is obtained in any biplane projections at 50 fps and digitized into a 512 x 512 x 8 matrix. The artery is reconstructed in 3D using the x-ray projection matrices calculated from a cube filmed in the same projections. All diameters along the artery are automatically determined. The arterial volume is calculated from the 3D reconstructed true arterial length and diameters. The absolute flow is obtained by dividing the arterial volume filled by contrast medium during the first cardiac cycle following the injection by the duration of that cycle. The method was validated in vivo by comparing LAD flow measured by angiography with great cardiac vein flow simultaneously measured by thermodilution. Ten patients were studied at baseline and during pacing-induced hyperemia at 100 and 120/min. Mean flow was 52.1 ml/min (range 28-93) by angiography and 51.5 ml/min (range 11-115; NS) by thermodilution. The two methods correlated well: r = 0.82, SE = 9.8 ml/min, n = 27, p less than 0.0001. Thus, absolute CBF can be measured by computer analysis of conventional biplane coronary cineangiograms.

Aged↗
PubMed1992

[Consequences of circadian variability for the treatment of ischemic heart disease].

The incidence of ischemic cardiac events is highest in the early morning hours (symptomatic and asymptomatic cardiac ischemia, myocardial infarction, and sudden death). Quantitatively, however, most of them occur during the rest of the day; therefore, an ideal therapy should be established in the early morning hours and be efficient all day long. We recommend that nitrates should be taken as early as possible after a dose-is-free interval during the night. Patients taking beta-blockers do not show a circadian rhythm of the incidence of ischemic cardiac events. Compliance can be improved with the never long-acting agents. Therapy should be tailored individually for each patient. It is not yet known whether calcium blockers influence the circadian rhythm. The efficacy of the never preparations is comparable to the older ones. Aspirin can be taken at any time of the day because of its long duration of action.

Angina Pectoris↗
PubMed1992

Morphometry versus densitometry--a comparison by use of casts of human coronary arteries.

Geometric and densitometric methods for quantitative coronary arteriography have generally been compared by use of phantoms simulating arteries with circular lumina ('Hole phantoms'). We have used more adequate phantoms obtained by casting disease-free and atheromatous human coronary arteries. The phantoms, filled with contrast medium, were imaged digitally (1024 x 1024 x 10 matrix) under experimental conditions simulating routine coronary angiography. The angiographic 'diameters' and the densitometric cross-sectional areas of 59 marked lumina were determined in single plane and orthogonal biplane raw images. Geometric calibration was performed by help of a 7F coronary catheter. For the densitometric calibration, we used a 'hole phantom' attached to the image intensifier. The obtained luminal areas were compared to their true values determined previously by planimetry. The mean absolute error of single plane cross-sections obtained geometrically was 1.53 mm2. Biplane imaging reduced it by a factor 2.4 to 0.64 mm2. The corresponding mean absolute errors for densitometry were 0.56 mm2 and 0.51 mm2. Single plane 'diameter' measurements appear thus of very limited value for hemodynamic conclusions. In contrast, biplane geometric quantification was not markedly inferior to single plane and biplane densitometry.

Absorptiometry, Photon↗
PubMed1992

3D-reconstruction of coronary arteries in view of flow measurement.

An angiographic method for measurement of absolute coronary blood flow in patients was developed. It is based on 3D-reconstruction of the left or right coronary tree from digitized biplane coronary cineangiograms. The apparatus is presently composed of a 35 mm cinefilm projector with a video camera and a 512 x 512 x 8 bits image array processor controlled by a VAX-11/750 computer. First, the parameters of the two angiographic projections are determined in form of two 4 x 3 matrices from a pair of cineframes showing a 4 cm cube bearing markers. The cube is filmed after the coronary injection, with unchanged geometric configuration. The coronary arteries of interest are then 3D-reconstructed from a pair of cineframes showing them fully opacified. This allows to compute the intravascular volumes needed for flow determination. In vitro experiments showed that the obtained volume are reasonably accurate. For the measurement of coronary flow, the concentration of contrast medium along the involved arteries is computed (in arbitrary units) from two cineframes taken one (or two) cardiac cycle after onset of the injection. This yields a 'concentration-distance' curve per artery. The volume of fluid (contrast medium mixed with blood) which flows into the arteries during this (or these two) cardiac cycle is determined by applying a concentration threshold to the obtained concentration-distance curves. Measurements performed on a constant flow model were satisfying. Preliminary measurements in 12 patients showed that flow values obtained angiographically into the left anterior descending coronary artery correlate well with the values measured simultaneously by thermodilution in the great cardiac vein (Qangio = 0.83 x Qthermo + 16.1 ml, r = 0.87, n = 29).

Cineradiography↗
PubMed1992

Abnormal left ventricular filling pattern in patients with single vessel coronary artery disease: effect of angioplasty.

To study the effect of coronary angioplasty (PTCA) on left ventricular (LV) diastolic filling, mitral Doppler flow tracings of 15 patients with isolated stenosis of the left anterior descending coronary artery (LAD) and normal systolic LV function were recorded before PTCA as well as 24 h and 3 months after successful PTCA. Compared to control subjects, patients with LAD stenosis exhibited an abnormal LV filling velocity pattern before PTCA. The day following PTCA, the ratios of the early peak diastolic velocity to the peak late diastolic velocity and of the time velocity integral of the early diastolic filling phase to the time velocity integral of the late diastolic filling phase were unchanged. Despite the absence of clinical evidence of restenosis, LV filling remained abnormal 3 months after PTCA. The results suggest that abnormalities of the LV filling velocity in patients with isolated LAD stenosis and normal systolic function may persist as long as 3 months after PTCA.

Angioplasty, Balloon, Coronary↗
PubMed1991

Spatial reconstruction of coronary arteries from angiographic images.

A method for 3D reconstruction of coronary arteries from two angiographic projection views is presented (cinefilm 35 mm, 50 images/s). The geometric information defining the two projections is secured by filming a cube bearing 15 steel markers in the approximate location of the heart. For 3D reconstruction, a pair of images of the cube and two simultaneous images of the coronary tree are digitized on a computer assisted system. Two matrices describing the two projections are obtained from the 15 x 2 x 2 image coordinates of the cube markers. Next, the operator draws with a mouse the approximate centre lines of the coronary arteries to be 3D reconstructed. The program then determines the centre lines and the edges of the vessels in the two images accurately. The 3D centre lines are reconstructed and the true local vessel diameters determined. Intravascular volumes are obtained by summation of elementary volumes. The reconstructed arteries are visualized on a colour TV monitor. Measurements on various phantoms have shown that lengths of a few centimetres can be measured with typically 2% error. The accuracy of volume determination was somewhat less due to the inaccuracy of lumen determination. For real coronary arteries the volume error is estimated to be about 15% because of the poorer image quality.

Angiography↗
PubMed1990

Long-term results of successful and failed angioplasty for chronic total coronary arterial occlusion.

The results over a mean period of 2 years of successful percutaneous transluminal coronary angioplasty (PTCA) in 100 consecutive patients with chronic total coronary occlusion were compared with those in 100 consecutive patients whose PTCA was unsuccessful. The groups were comparable in terms of gender, age and arteries attempted. A control angiography in the group with successful PTCA was performed in 62 patients and showed a restenosis in 28 (45%). Repeat PTCA was performed in 21 versus 1 patient with failed PTCA (p less than 0.0001). At follow-up, in the group with successful PTCA, there were 57 symptom-free patients versus 26 patients in the group with failed PTCA (p less than 0.0001). Coronary artery bypass surgery was performed in 7 versus 37 patients (p less than 0.0001), and there were 5 versus 3 deaths (difference not significant), respectively. In the group with successful PTCA, 27 of 82 patients (33%) had positive stress test results, compared with 49 of 85 patients (58%) in the group with unsuccessful PTCA (p less than 0.001). The double product (beats/min x mm Hg/100) in patients with successful PTCA improved from 247 +/- 57 before PTCA to 277 +/- 61 (p less than 0.001) at follow-up, whereas it did not significantly change in patients with failed PTCA. The work load (W) in patients with successful PTCA improved from 95 +/- 34 before PTCA to 124 +/- 40 at follow-up (p less than 0.001). In patients with failed PTCA, work load improved less significantly, from 98 +/- 37 before PTCA to 108 +/- 34 at follow-up (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1990

[Acute myocardial infarction and thrombolysis: analysis of the delay in arrival at the hospital].

Since the duration of precordial pain plays a key role in the indication for thrombolytic treatment in acute myocardial infarction, a retrospective study was made of the last 200 infarctions at Monthey Hospital with particular reference to the factors influencing this duration (distance, type of transport, prior intervention by a physician, loss of time in hospital). These factors were compared with other studies, and ways of influencing the time factor are proposed.

Aged↗
PubMed1990

Nonselective preoperative digital subtraction angiography of internal mammary arteries.

In preparation for coronary bypass surgery, digital subtraction angiography (DSA) was used to assess the caliber of the left and right internal mammary arteries and to exclude stenoses of their feeding arteries. In 100 patients (86 males, mean age 56 +/- 9 years) DSA was performed with a Siemens Digitron 2 device. A frontal projection was used in 18 patients, and a 10-20 degree right anterior oblique projection was used in 82 patients. The flow was 10 to 25 ml/sec; 20 ml was injected in 45 patients, 30 ml in 41, 40 ml in 5, 50 ml in 8, and 60 ml in 1 patient. Judged on the proximal third, visualization of the left and the right internal mammary artery was good in 80 and 72, fair in 17 and 20, and bad in 3 and 8 arteries, respectively. The diameter (mm) was 2.7 +/- 0.4 (range 1.8-3.4) and 2.7 +/- 0.3 (range 2.0-3.5), and visible length (cm) was 8 +/- 5 (range 1-24) and 9 +/- 4 (range 2-22) for the two arteries, respectively. The 10-20 degree right anterior oblique view separated the left internal mammary artery better from the descending aorta than the frontal view. In more pronounced right anterior oblique views the ascending aorta interfered with the right internal mammary artery. The quality was not different with 20 ml or 30 ml injections. The feeding arteries could not be assessed in 4 patients. One left subclavian artery was found occluded at the orifice. Incidentally, 2 distal right subclavian stenoses and 2 carotid stenoses were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography, Digital Subtraction↗
PubMed1990

Congenital intrathoracic left ventricular diverticulum in an adult.

A 53-year-old woman without any risk factors for coronary artery disease was found to have a congenital intrathoracic left ventricular diverticulum with a narrow long connection to the left ventricular cavity. Coronary angiography revealed normal coronary arteries. The diverticulum was resected and showed three normal cardiac layers. This is an extremely rare finding in the adult population.

Diagnosis, Differential↗