Mechanisms and how to treat heart failure.
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Angiotensin-Converting Enzyme Inhibitors↗
Biomedical subjects
W Rutishauser
Publications and source records attributed to W Rutishauser.
Doppler assessment of left ventricular diastolic filling during brief coronary occlusion.
To assess left ventricular diastolic filling in patients with single-vessel coronary artery disease, Doppler-derived transmitral velocity was studied in 22 normal subjects and in 15 patients with isolated proximal stenosis of the left anterior descending coronary artery (LAD) and normal systolic function of the left ventricle. Transmitral velocity was recorded before and after balloon inflation during coronary angioplasty. At baseline the transmitral velocity pattern in patients with LAD stenosis differed from that of normal subjects with a significant (p at least less than 0.05) decrease in the early diastolic filling phase (E area 0.094 +/- 0.022 m in normal subjects vs 0.078 +/- 0.008 m in patients) and an increase in the late diastolic filling phase (A area 0.034 +/- 0.007 m vs 0.042 +/- 0.008 m). Correspondingly the ratio E area/A area decreased (2.7 +/- 0.51 vs 1.9 +/- 0.4) and the ratio A area/total area increased (0.28 +/- 0.04 vs 0.35 +/- 0.05). During coronary occlusion the E area and the ratio E area/A area decreased further, whereas the A area and the ratio A area/total area increased. The results suggest that patients with single-vessel disease and normal systolic function often exhibit an altered pattern of transmitral velocity even in the absence of overt ischemia, and that during acute regional ischemia early diastolic filling is further compromised with compensatory enhancement of the late diastolic filling phase.
Adult↗
Morphometric versus densitometric assessment of coronary vasomotor tone--an overview.
The main advantage of the morphometric approach is that the spatial orientation of the vessel with respect to the image intensifier is not very important. Its most severe limitations are that reasonable accuracy can only be obtained with circular lumina, and that accuracy decreases rapidly with the vessel diameter. The densitometric approach is much less dependent on the shape of the lumen and on the correct identification of the vessel wall in the image. A further essential advantage is that one measures directly the cross-sectional area of the vessel instead of a 'diameter' of low haemodynamic relevance. Severe requirements must however be met if the potential accuracy of densitometry is to be fully exploited. The morphometric approach seems thus preferable for absolute or relative diameter measurements on intact vessels, while densitometry is superior in case of irregular or small lumina. Morphometric calibration using the injection catheter can induce non-negligible errors in both approaches. Grid calibration is probably more accurate, but also more tedious. In the densitometric approach, '3D-calibration' by help of a cube of known size allows also determination of the spatial orientation of the vessel in space. This solution requires however biplane imaging.
Angiography, Digital Subtraction↗
Spatial reconstruction of coronary arteries from biplane coronary angiograms.
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Computer Graphics↗
Clinical experience with the Monorail balloon catheter for coronary angioplasty.
The Monorail balloon catheter is distinctly different from other current balloon catheters: the guidewire passes through the balloon itself, exits the catheter proximal to the balloon, and runs alongside its small shaft (3 French) through the guiding catheter. Monorail coronary angioplasty was attempted in 61 patients on 73 lesions with balloons from 2.0 to 3.7 mm. Angiographic success was obtained in 66 lesions (90%). For 15 lesions, balloon exchanges were needed. In three lesions, the Monorail balloon failed to cross the lesion, while a standard balloon succeeded; two lesions could not be crossed with any balloon. Vessel occlusion occurred in four patients: two had emergency surgery without infarct (one died suddenly 4 days later and one had a stroke 1 day later), one was recanalized with a standard balloon, and one had a myocardial infarct. Continuous infusion of urokinase was used until patient 3 in whom problems with the delivery system led to cardiocerebral air embolization (with complete recovery). No thrombotic complications were observed in the subsequent 58 patients with only a bolus of 10,000 U of heparin. The Monorail balloon facilitates contrast injections and balloon exchanges but appears more difficult to pass through tight lesions. Omission of the previously recommended infusion with a thrombolytic agent proved safe.
Adult↗
Silent ischemia: a relevant problem in patients with coronary artery disease?
Awareness of silent myocardial ischemia has greatly increased during the last few years in the medical community. Methods for its detection include exercise testing, Holter monitoring, and, more specifically, Thallium-201 scintigraphy, 2D-echocardiography, and multigated radionuclide ventriculography with phase analysis, all during rest and exercise. Cohn's classification of silent ischemia has proven very useful in highlighting the magnitude of the problem. It can be estimated that about 2% to 4% of apparently healthy middle aged males in industrialized European countries are prone to asymptomatic ischemic episodes. Prognosis of silent myocardial ischemia has been evaluated in prospective and retrospective studies. Most authors come to the conclusion that ischemia is the key finding, whether painful of asymptomatic. Even present understanding of pain perception from the ischemic myocardium is incomplete; the high prevalence and the relation with myocardial infarction and sudden cardiac death make silent myocardial ischemia one of today's most relevant problems.
Coronary Disease↗
Assessment of regional coronary flow reserve by digital angiography in patients with coronary artery disease.
Digital angiography provides a convenient means to quantify the progression of a contrast medium bolus injected into a coronary artery throughout the myocardium, which in turn yields information on myocardial perfusion. Sixteen patients presenting a single critical proximal stenosis (estimated diameter reduction greater than 80%) on either the left anterior descending coronary artery (LAD) or the left circumflex coronary artery (LCX) were studied. First, 12 consecutive end-diastolic images of an ECG-triggered intracoronary injection of 4 ml of iopamidol were acquired on 60 degree left anterior oblique projection under basal conditions. This was repeated 30 s after intracoronary injection of 12 mg of papaverine. For each image sequence, a densogram was computed in each pixel by fitting a curve through its 12 consecutive intensity values. The 'time of maximal pixel opacification' (TMAX) and the 'mean ascending time' (TMAT), expressed in cardiac cycles, were determined from each curve. Two myocardial regions of interest (ROI) were defined for each patient, one in the perfusion bed of the LAD, the other in the bed of the LCX. The mean values of TMAX and TMAT in each ROI were computed, at rest and during hyperemia. At rest, the mean values of TMAX and TMAT obtained from the ROI associated to the stenosis artery were not significantly different from the values obtained in the ROI associated with the intact artery. During hyperemia, a significant decrease of the mean TMAX and TMAT was observed in the normally perfused regions (p less than 0.001). The rest to hyperemia ratios of both TMAX and TMAT mean values were considered to be indices of coronary flow reserve.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Restenosis and repeat coronary angioplasty in Geneva.
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Angioplasty, Balloon↗
Acute complications of elective coronary angioplasty: a review of 500 consecutive procedures.
In 500 consecutive procedures of elective coronary angioplasty attempted at a centre with a primary success of 86%, one or more major acute complications occurred in 34 cases (6.8%). Twenty four patients (4.8%) sustained an acute myocardial infarction (in six this was despite emergency coronary artery bypass surgery) and two patients (0.4%) had emergency coronary bypass without myocardial infarction. Ventricular fibrillation was a complication without sequelae in five (1.0%) patients; one (0.2%) patient died because of refractory ventricular fibrillation and ensuing electromechanical dissociation. "Benign" coronary artery rupture occurred in one (0.2%) patient, and one (0.2%) patient had elective coronary surgery to retrieve the tip of a fractured guide wire after an otherwise successful angioplasty. Despite a low mortality, coronary angioplasty is associated with major complications in about one of 14 procedures; the complication is usually acute myocardial infarction caused by occlusion of the vessel.
Adult↗
Clinical and angiographic follow-up after coronary recanalization during acute myocardial infarction.
Coronary angiography followed by percutaneous transluminal coronary angioplasty and/or intracoronary streptokinase infusion was performed in 50 patients 288 +/- 162 min after the onset of symptoms of acute myocardial infarction. Subocclusion of the infarct-related vessel was found in 5 patients, all of whom had angioplasty of the residual stenosis. Recanalization was achieved in 37 patients (success rate 82%). There was no procedure-related death. One patient died 4 days after the intervention. Control coronary angiography 5 +/- 2 months after the procedure in 35 of 42 patients with recanalization documented recurrence of stenosis or reocclusion in 8 (23%). Comparison of preintervention and control angiograms in 33 patients showed an increase in left ventricular ejection fraction from 55 +/- 8 to 61 +/- 13%, p less than 0.001, in patients with collaterals to the infarct-related vessel and/or recanalization within 180 min after the onset of pain, and from 55 +/- 9 to 59 +/- 8%, nonsignificant, in patients with recanalization later than 180 min and without collaterals. At follow-up 7 +/- 4 months after the procedure, 1 patient had died and 36 (86%) were asymptomatic. Good long-term results can be achieved at a reasonable risk by coronary angioplasty with or without thrombolysis in evolving myocardial infarction. Left ventricular function is better preserved in patients with collaterals and/or early recanalization.
Angiography↗
Potential protective effect of high coronary wedge pressure on left ventricular function after coronary occlusion.
To assess the potential of coronary collateral circulation to protect myocardium after occlusion of a coronary vessel, the mean coronary wedge pressure, the angiographic grade of collateral channels, and the left ventricular function were studied in 47 consecutive patients with mechanical recanalization of totally occluded coronary arteries. Coronary wedge pressure measurements were obtained 39 +/- 51 days (range, 2 hours to 361 days) after the presumed time of occlusion. The patients were divided into two groups: 31 with a coronary wedge pressure more than 30 mm Hg (group 1) and 16 with a coronary wedge pressure of or less than 30 mm Hg (group 2). Patients in group 1 had a significantly higher mean global left ventricular ejection fraction than those in group 2 (63 +/- 9% vs. 49 +/- 7%, p less than 0.001). Regional left ventricular function (artery-related area change) was also superior in group 1 compared with group 2 (47 +/- 11% vs. 36 +/- 10%, p less than 0.01). Global left ventricular function was significantly correlated to coronary wedge pressure (r = 0.51, p less than 0.001) but not to the angiographic presence of collaterals. The data suggest that a high coronary wedge pressure is associated with improved left ventricular function after coronary artery occlusion and that coronary wedge pressure more accurately reflects the physiological role of collaterals than their angiographic presence.
Angiography↗
[Digitalized angiography in coronary disease].
In cardiology, digital subtraction angiography after intravenous injection of contrast medium allows only the visualization of relative large structures as the ventricles and the great vessels. Subselective intra-arterial injections are attractive, but do not provide an appreciable reduction of the injected amount of contrast medium. A reduction is possible with selective injections, but good subtraction is only possible for non-moving arteries or for arteries with truly periodic movement (ECG gated subtraction). With the improvement of spatial and temporal resolution, digital angiography (without image subtraction) could replace conventional angiography, provided that the main problem of prohibitive costs associated to the stockage of image sequences with high spatial (1024 x 1024) and temporal (25 images/s) resolution is solved. At the present, however, the cinefilm 35 mm is still unbeaten in density of information, handling and costs. In interventional cardiology, the visualization of small coronary branches and of fine, fast moving guide-wires is improved by the digitalization of the images at the source, pulsed fluoroscopy, progressive scanning of the TV camera with temporary stockage of image sequences and the selective reinforcement of the image contrast in real time. Digital angiography is also more attractive than the cinefilm in view of a better exploitation of the information contained in angiographic sequences by sophisticated, computer assisted methods. For instance, parametric imaging for analysis of the contraction and relaxation of the left ventricle, or for the visualization of the progression of contrast medium to investigate the coronary circulation, condensing in one single image the information looked for, are fields where digital angiography has given new impulses to cardiologic research.
Coronary Angiography↗
Radiation exposure during diagnostic catheterization and single- and double-vessel percutaneous transluminal coronary angioplasty.
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Angiography↗
[Percutaneous coronary angioplasty in unstable angina and acute infarction].
Unstable angina represents an indication for percutaneous transluminal coronary angioplasty (PTCA) provided it is based on a significant fixed lesion. A primary success rate of about 90% can be expected, but in 5% to 10% the intervention will cause a myocardial infarction. Mortality is higher than in patients with stable angina and does not differ from that of bypass surgery; however, it is still below 1%. At 1 year, 50% to 90% of the patients treated with initial success are asymptomatic if redilatations for recurrences (occurring in about one third) are included. - Acute myocardial infarction was introduced as an indication for PTCA in about 1980. PTCA was first used for failures, then for incomplete successes of intracoronary streptokinase therapy, and finally in patients without pretreatment. Currently, PTCA is being evaluated in multicenter studies as an adjunct to early intravenous fibrinolysis with clot specific agents (e.g., tissue-type plasminogen activator). PTCA achieves adequate initial reperfusion in about 80% irrespective of concomitant fibrinolytic therapy. It is complicated by occlusion of an already partially recanalized vessel in 4%. Late reocclusions occur in 15%, half of them accompanied by reinfarction. Intrahospital mortality is about 5% and increases by 1% up to 1 year. PTCA has its place in the treatment of unstable angina and acute infarction. In the latter it may be advantageous to precede it with early intravenous fibrinolysis.
Angina Pectoris↗
[Long-term prognosis of patients with silent ischemia].
To study the long-term evolution in patients with silent ischemia we investigated 242 coronary patients showing ischemic signs on exercise T1-201 scintigraphy. The findings in a group of 106 patients with angina were compared with those in a group of 136 patients without angina during exercise and followed up for an average of 60 months. Multiple comparisons of clinical features, ECG, hemodynamic and angiographic data showed no significant differences between the two groups. However, the extent of ischemia detected by T1-201 was significantly smaller in patients with silent ischemia although their work-load and double product were higher.--During the follow-up cardiac mortality (11% vs 11%), unstable angina (27% vs 20%) and myocardial infarction (23% vs 20%) were found with the same frequency in patients with angina compared with those with silent ischemia. Bypass surgery was performed more frequently (55% vs 37%) in patients with symptomatic ischemia. Long-term evolution in our coronary patients with episodes of silent ischemia was similar to that in patients with ischemia accompanied by angina, and showed numerous complications. Therefore, we should try to treat not only angina but also, and especially, ischemia.
Angina Pectoris↗
Angiographic follow-up after multivessel percutaneous transluminal coronary angioplasty.
In 100 consecutive patients undergoing multivessel percutaneous transluminal coronary angioplasty (PTCA), dilation was attempted in 207 arteries. Primary success was achieved in 85 patients. Complications occurred in 8 patients: acute myocardial infarction in 5 and need for emergency coronary artery bypass surgery in 5. Control angiography was done in 77 of 85 patients (91%) with primary success at a mean of 12 +/- 6 months. Complete revascularization had been achieved in 59 patients and incomplete revascularization in 18. Angiographic restenosis was found in 39 of 77 patients (51%) and in 47 of 143 arteries (33%) at 9 +/- 7 months. The restenosis rate was 57% for chronic total occlusions (8 of 14) and 30% for stenoses (39 of 129). The restenosis rate was significantly higher for the left anterior descending coronary artery (40%) than for the left circumflex coronary artery (21%). However, the significance was lost after exclusion of chronic total occlusions. A higher residual stenosis and a high coronary wedge pressure were predictors for restenosis. Restenosis was clinically silent in 14 patients (18%). Repeat PTCA was done in 19 patients with recurrence and elective surgery in 8. Clinical follow-up was available in all patients at 24 +/- 12 months. Patients with incomplete revascularization had less favorable clinical follow-up results than patients with complete revascularization: 44% (8 of 18) vs 81% (48 of 59) were asymptomatic (p less than 0.005), and 28% (5 of 18) vs 5% (3 of 59) had undergone elective bypass surgery during follow-up (p less than 0.005). Most patients with restenosis after multivessel PTCA had only 1-vessel restenosis and only 7% had restenosis of all lesions.
Angiography↗
[Change in indications for coronary angiography in a decade].
To characterize the changes in indications for coronary angiography we compared indications and therapeutic conclusions of cardiac catheterization, including coronary angiography, in 100 consecutive patients in 1975 and 100 consecutive patients in 1985. The baseline characteristics of the patients in the two groups were similar, except for age (50 +/- 10 vs 56 +/- 9 years, p less than 0.0001) and prior angioplasty (0 vs 12, p less than 0.0001). The main indications for coronary angiography in the two groups were (1975 vs 1985) chest pain in 67 vs 62 (n.s.), myocardial infarction in 10 vs 17 (n.s.), prior coronary surgery in 3 vs 0 (n.s.), major arrhythmias in 1 vs 1 (n.s.), and incidental (coronary pathology not the primary issue) in 19 vs 8 (p less than 0.05). We further analyzed each of the main indications in the two groups. Chest pain: angina ruled out in 21% vs 26% (n.s.), stable angina 64% vs 61% (n.s.), unstable angina 15% vs 13% (n.s.), positive non-invasive tests 39% vs 44% (n.s.). Myocardial infarction: acute intervention 0 vs 12% (n.s.), angina after infarction 20% vs 47% (n.s.), positive non-invasive tests after myocardial infarction 20% vs 41% (n.s.). Incidental: valvular heart disease 57% vs 63% (n.s.), cardiomyopathy 26% vs 13% (n.s.), congenital heart disease 11% vs 0 (n.s.), aortic dissection 5% vs 25% (n.s.), other 5% vs 0 (n.s.). Overall, clinical suspicion of coronary artery disease was confirmed and documented in 80% (65/81) vs 77% (61/79) of patients (n.s.), and normal coronary arteries were found in 20% (16/81) vs 23% (18/79) of patients respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Two-dimensional exercise echocardiography. Comparison with electrocardiography, myocardial scintigraphy with thallium 201 and coronary angiography].
Biapical two-dimensional echocardiograms were obtained immediately before and after a bicycle exercise test in 54 patients referred for coronary angiography. Images of adequate quality were recorded in 47 cases (87%), 39 of whom had significant coronary artery disease. All patients also underwent a stress electrocardiogram. In 22 subjects echocardiography and bicycle stress test in the supine position were combined. 23 patients underwent scintigraphy with thallium-201. The sensitivity of rest and exercise echocardiography for the diagnosis of coronary artery disease was 90% and the specificity 63%, compared to 82% and 75% respectively for the electrocardiogram. The sensitivity for the detection of jeopardized myocardium, defined by angiographic criteria, was 75% for the exercise echocardiogram and 65% for the exercise electrocardiogram in the 28 patients without myocardial infarction. In 19 patients with infarction echocardiography detected jeopardized myocardium with a sensitivity of 73%, compared to 53% for the electrocardiogram. In the subgroup of 23 patients studied by thallium-201 scintigraphy, sensitivity for identification of multivessel disease (8 patients) was comparable for both rest and exercise scintigraphy (6/8) and echocardiography (7/8). The specificities were 88% and 94% respectively. Jeopardized myocardium was detected in this subgroup with a sensitivity of 82% by echocardiography, 76% by thallium scintigraphy and 65% by electrocardiography. In conclusion, this study demonstrates that two-dimensional echocardiography can be combined with exercise electrocardiography in one stress test. This improves the diagnosis of coronary artery disease, detection of jeopardized myocardium and identification of patients with multivessel disease.
Adult↗