Factors influencing fluoroscopy time and dose-area product values during ad hoc one-vessel percutaneous coronary angioplasty

X-ray exposure during radiologically guided interventional procedures may have some deleterious effects. The aim of our study was to analyse the factors affecting patient dose during percutaneous coronary angioplasty (PTCA). We evaluated radiation dose during coronary angiography followed by one-vessel PTCA in 402 consecutive patients who were treated by three experienced physicians using both femoral and radial techniques. Fluoroscopy time (t) and patient dose measured by a dose-area product (DAP) meter were recorded. A good correlation was observed between t and the DAP (r=0.78, p<0.001). To assess the factors affecting radiation exposure, we studied the differences between operators, arterial catheterization access and stenting strategy. Median (25th to 75th percentiles) values for t were 19 (13 to 26) min and for DAP were 191 (145 to 256) Gy cm(2) for operator 3 compared with t=12 (9 to 18) min and DAP=137 (91 to 208) Gy cm(2) for operator 2 (p<0.005 versus operator 3) and t=13 (9 to 17) min, and DAP=134 (93 to 190) Gy cm(2) for operator 1 (p<0.001 versus operator 3). Differences between the radial and the femoral techniques were: t=17 (13 to 24) min versus 12 (8 to 17) min, (p<0.001) and DAP=175 (128 to 246) Gy cm(2) versus 138 (93 to 197) Gy cm(2), (p<0.001). In comparison with stenting without pre-dilation, direct stenting significantly reduced t and DAP [t=12 (9 to 16) min versus 16 (11 to 22) min, (p<0.001) and DAP=130 (95 to 186) Gy cm(2) versus 163 (119 to 230) Gy cm(2), respectively, (p<0.01)]. Radiation exposure to patients and staff are strongly dependent on operators, stenting strategy and the arterial access chosen for ad hoc one-vessel PTCA.

New insights into septal anterior wall motion velocities at end-systole in normal and hypertrophied left ventricles

AIMS

It was two-fold (1) to define tissue Doppler echocardiographic characteristics of the end-systolic septal anterior motion: passive due to heart translation, or active motion free of translational effects, substantiated by a myocardial velocity gradient. (2) to specify the temporal features of this septal anterior motion on normal and hypertrophied left ventricles since it occurs while the posterior wall contracts during late ejection.

METHODS AND RESULTS

Myocardial velocity gradient was calculated during the anterior motion in simultaneously colour M-mode imaged septal and posterior walls of 21 controls (49+/-12 years) and 17 patients (49+/-13 years) with left ventricle hypertrophy. Timings of septal motion were compared with flow and posterior wall motion. In controls, septal anterior motion started prior to, and overlapped the end of subaortic flow and that of the posterior wall anterior motion. Myocardial velocity gradient was found, exceeding that at the posterior wall (2.5+/-1.6 vs 0.9+/-0.5s(-1), P=0.001). In patients, septal myocardial velocity gradient was lower than in controls (1.2+/-1.04 s(-1)P=0.006). The anterior motion had a longer duration than in controls (75+/-37 vs 50+/-17ms, P=0.003). Myocardial velocity gradient and duration were correlated with septal thickness (P=<0.01).

CONCLUSIONS

The septal anterior motion was active. Patients showed a decreased myocardial velocity gradient, while wall asynchrony increased. Unusual higher septal than posterior wall systolic velocities at tissue Doppler echocardiography may suggest a relaxation pattern, in spite of its end-systolic onset.

Myocardial time intervals preceding left ventricular filling in chronic coronary artery disease: value of a decreased septal ejection time

The aim was to assess the capabilities of a two-segment myocardial recording to recognize patients with an underlying chronic ischemic process as a fast screening from controls, prior to the usual segment-to-segment tissue Doppler echocardiographic assessment of ischemia. Ischemia generates systolic and relaxation abnormalities. A flow Doppler index of global systolic and diastolic myocardial performance was recently drawn from time durations studied by coupling isovolumic relaxation (IR) to preejection (PEP)/ejection (ET) ratio (PEP/ET). We derived a similar tissue Doppler approach to the period preceding the left ventricular filling: PEP', the ejectional inward wall motion representing ET' and the prefilling (PreFg) period ranging from the end of ET' to the onset of the outward wall motion approximating IR, were measured and ratios calculated between variables. Spectral tissue Doppler was applied to septal and posterior walls of 28 patients with proven chronic coronary artery disease and preserved left ventricular function and of 12 age-matched controls. Data were compared with global flow data. Global information did not differentiate both groups, save for IR (sensitivity 32%, specificity 57%). In patients, tissue Doppler mean values of single variables (P=0.004-0.0006) and ratios (P=0.03-0.002) significantly differed from controls. Moreover, septal ET' differentiated 13 patients with one-vessel (219+/-34 ms) from 10 with two-vessel disease (158+/-70 ms, P=0.01). Sensitivity and specificity of a septal ET'<190 ms for a two-vessel disease were 80%. The two-segment tissue Doppler echocardiographic study provided a rapid screening of patients versus controls and helped to predict the number of diseased vessels.

Beating heart revascularization with minimal extracorporeal circulation in patients with a poor ejection fraction

BACKGROUND

Coronary artery bypass grafting with cardioplegia in patients with a low ejection fraction carries a risk of myocardial ischemia. Beating heart surgery is associated with hemodynamic changes when the heart is manipulated. We assessed an alternative: minimal extracorporeal circulation for coronary artery bypass grafting on a beating heart in patients with a poor ejection fraction.

METHODS

From January 2000 to January 2002, 50 patients with an ejection fraction of less than 35%, who represented 10% of all patients undergoing coronary artery procedures, underwent revascularization on a beating heart with assistance. We used a closed cardiopulmonary bypass system with a centrifugal pump without reservoir, and the surgical strategy was modified to avoid aortic cross-clamping and to decrease bypass time.

RESULTS

The main preoperative characteristics were: age (mean +/- SD) of 64 +/- 11.2 years (range, 41-87 years), 35 male patients (70%), mean left ejection fraction of 24.8% +/- 11.2%, and a mean EuroSCORE of 5.8 +/- 2.7. Revascularizations of 146 distal anastomoses (2.9 +/- 0.7 grafts/patient) were completed. Twelve percent were double bypass, 86% were triple bypasses, and 2% were quadruple bypasses; the mean bypass time was 64.2 +/- 26.2 minutes. The mean graft number was 2.9, and the hospital mortality was 2%. Perioperative hematocrit levels were 30.1%, and 26% of patients received transfusions. Postoperative data showed a median extubation time of 9 hours, a median intensive care unit stay of 48 hours, and a hospital stay of 8 +/- 2 days. Postoperative complications included inotropic support (14%), cerebrovascular events (2%), reoperation for homeostasis (4%), delayed sternal closure (2%), and mediastinitis (2%). Peak troponin Ic level remained a low 2.4 +/- 1.9 g/mL. Follow-up at 6 months was complete with 1 late mortality and with a mean ejection fraction of 30.5% +/- 10.8% for the survivors.

CONCLUSIONS

Coronary revascularization on a beating heart with extracorporeal assistance can be done in patients with a low ejection fraction. It avoids the myocardial injury associated with aortic cross-clamping and allows safe and complete coronary revascularization.

[Comparison between radial and femoral approaches in ad hoc coronary angioplasty]

Between September 1999 and June 2001, 591 patients required ad hoc coronary angioplasty. The authors compared the group of patients in whom the approach of first intent was radial (n = 328, 55%) with those in whom the femoral approach had been used (n = 263), in terms of immediate local (haematoma or thrombosis requiring surgical intervention or transfusion) and general complications (myocardial infarction, cerebrovascular accident), and major adverse cardiovascular events (infarction, angioplasty, bypass and death) at 1 year. The dose of ionising radiation during the procedures was also compared prospectively. The conversion rate from the radial (R) to the humeral or femoral (F) approach was 10%. The angioplasty, stenting, and stenting without dilatation failure rates were identical in the two groups (5% versus 5%, 0.6% versus 1.9%, 3% versus 4%, respectively). The average irradiation time was greater in the R group than in the F group (23 +/- 12 min vs 17 +/- 4 min, p < 0.001) as was the irradiation per surface unit (242 +/- 137 Gy.cm2 vs 185 +/- 117 Gy.cm2, p < 0.001). The immediate complication rate was comparable in the two groups (2.5% in group R vs 3.6% in group F) as was the major adverse cardiovascular event rate at 1 year (13% in both groups). The authors observed the same rate of immediate complications and late adverse cardiac events in patients undergoing coronary angioplasty followed by immediate angioplasty by the radial or femoral approaches with an acceptable conversion rate from the radial to the femoral approach. The procedures by the radial approach seem to be associated with a greater time and dosage of ionising radiation.

[Results of heart surgery with extracorporeal circulation in octogenarians]

Cardiac surgery in the octogenarians is increasing in the industrialized countries and therefore represents a growing population. In order to better define the benefits of cardiac surgery in this population, we reviewed all consecutive octogenarians patients operated during the last 10 years. Out of 3,409 patients operated between January 1990 and December 1999, we identified 215 patients (6.3%) aged 80 years or more. Median age was 82.4 +/- 2.45 years, and 52.6% were males. Preoperatively, 52% were in New York Heart Association functional class II, 19.3% in class III, and 28.3% in class IV, with a mean Euroscore score of 7.5 +/- 2.6. Among them, 113 patients (52.5%) had isolated aortic valve replacement, 66 patients (30.6%) had isolated coronary artery bypass graft, 22 patients (10.2%) had aortic valve replacement combined with CABG, and 14 patients (6.5%) had mitral valve operation. The overall hospital mortality was 8%, and multivariate analysis revealed as risk factor for mortality aortic valve replacement combined with coronary artery bypass graft. Median follow up was 36.7 months, with 86% survival at 1 year, 59% at 5 years, and 40% at 7 years. Survival was reduced when aortic valve was combined with revascularisation. Quality of life was improved in 72% of patients. We conclude that for selected octogenarians cardiac surgery can be performed with an acceptable mortality and improves both survival and quality of life.

Comparison of transradial vs. transfemoral approach in the treatment of acute myocardial infarction with primary angioplasty and abciximab

Compared to the femoral approach, the use of radial arterial access has been demonstrated to reduce the incidence of access site bleeding complications in staged procedures. The purpose of this study was to evaluate clinical outcomes comparing radial and femoral approaches in the treatment of acute myocardial infarction with primary angioplasty and the GP IIb/IIIa inhibitor abciximab. Between 15 September 1999 and 15 September 2002, we prospectively enrolled 119 consecutive patients undergoing primary angioplasty with abciximab comparing radial (n = 64) and femoral (n = 55) access. In this nonrandomized study, freedom from major cardiac events at 1-month follow-up occurred in 62 (97%) and 52 (94.5%) patients in the radial and the femoral groups, respectively (P = 0.19). There were no major access site bleeding complications in the radial group, as opposed to three (5.5%) in the femoral group (P = 0.03), all requiring transfusions, with surgical repair necessary in two. Uncomplicated clinical course occurred in 62 (97%) of patients in the radial group and 49 (89%) in the femoral group (P = 0.04). Total hospital length of stay was significantly higher in the femoral group (5.9 +/- 2.1 vs. 4.5 +/- 1.2 days; P = 0.05). Cannulation time (from patient arrival at the catheterization laboratory to the effective placement of arterial sheath) and procedural time were not significantly different in the radial and the femoral group (respectively 8.5 +/- 5.2 vs. 9.0 +/- 5.8 min, P = 0.81, and 42 +/- 28 vs. 44 +/- 27 min, P = 0.74). Nevertheless, time of radiation (23.1 +/- 11 vs. 16.5 +/- 10.9 min; P = 0.01) and dose-area product (28,616 +/- 16,571 vs. 18,819 +/- 10,739 R. cm2; P = 0.01) were significantly higher in the radial group. In patients with acute myocardial infarction treated with primary angioplasty and abciximab, the transradial access is efficacious with fewer major access site complications than transfemoral access. Transradial approach produces a shorter length of stay, as compared to the transfemoral approach, although with longer times of radiation and higher dose-area product.

[Iatrogenic lesions of the left main coronary artery]

Reoccurrence of ischemic events several months after a percutaneous transcutaneous coronary angioplasty is usually due to a restenosis. Coronary angiography rarely shows a new stenosis on another site or on the left main coronary artery. In this series, we report 5 cases of left main coronary artery stenosis which have occurred from 3 to 12 months after a prior percutaneous angioplasty. This phenomenon which has previously been described after direct cannulation of the coronaries ostia during aortic valve replacement in the 70'. This complication is related to intimal damage caused by traumatic manipulation of the left main, which can be either already minimally altered or normal. This complication is rare after percutaneous transcutaneous coronary angioplasty (0.2-1.7%) according to various series. We compare our cases to the published cases in the literature.

Aortic pulse pressure and extent of coronary artery disease in percutaneous transluminal coronary angioplasty candidates

BACKGROUND

Pulse pressure and aortic stiffness are both predictors of coronary artery disease. Whether these parameters are directly related to coronary structural alterations has never been studied.

METHODS

From September 1999 to September 2000, the following data were collected from 99 eligible patients: invasive intra-aortic systolic and diastolic blood pressures (BP), extent of coronary artery disease, cardiovascular risk factors, and the incidence of angiographically documented restenosis after coronary angioplasty.

RESULTS

In the study population, independent determinants of aortic pulse pressure were age, gender, aortic mean BP, heart rate, and extent of coronary artery disease (r2 = 0.57, P < .0001). In univariate analysis, invasive aortic, but not noninvasive brachial, mean pressure (P = .017) and pulse pressure (P = .027) were significantly associated to the extent of coronary artery disease. In a multiple regression analysis, only male gender (P = .013) and the level of aortic pulse pressure (P = .023) were independently associated with the extent of coronary heart disease. Restenosis was angiographically documented in 11 patients (11%). There was a borderline significant association of restenosis to aortic mean BP (P = .05) and to a past history of multiple previous angioplasties (P = .03).

CONCLUSIONS

In this study, aortic pulse pressure was a significant risk factor for the extent of coronary artery disease. There was only a borderline significant association of restenosis to the steady, but not pulsatile, component of aortic BP in the stent era.

[Doppler tissue imaging in the assessment of dilated cardiomyopathy]

Doppler myocardial tissue imaging is a recent technique of objective assessment of wall motion by real time measurement of intra-myocardial velocities. This technique is being evaluated in patients with dilated cardiomyopathy. Doppler myocardial tissue imaging has been used for the quantification of dobutamine stress echocardiography, for the detection of an ischaemic aetiology in patients with dilated cardiomyopathy and for non-invasive estimation of left ventricular filling pressures. At the present time, the recordings have to be analysed a posteriori and only a small number of centres have acquired expertise of these techniques at rest or during stress. Standardisation of a posteriori procedures of image processing and validation of pertinent parameters have yet to be established in this pathology.

Feasibility, safety, cost-effectiveness and 1 year follow-up of coronary stenting without predilation: a matched comparison with the standard approach

BACKGROUND

We evaluated the feasibility, safety, procedural cost-effectiveness, radiation dose and time and 1-year target vessel revascularization rate of direct unprotected mounted stenting without previous balloon dilatation (DS) in native coronary artery lesions.

METHODS

DS was attempted in 119 patients; 39 had a recent myocardial infarction, 62 had unstable angina, and 18 had stable angina. The clinical follow-up was obtained at 14+/-5 months (range 6 to 24 months). These results were compared with those for a consecutive group of 160 patients matched for type and length of lesions and who had a stent only if the post-balloon residual stenosis was >30%.

RESULTS

The feasibility of DS was 112/119 (94%). The number of inflations, the length of the stent/length of the lesion ratio, the time and the dose of radiation were dramatically lower in the DS group (P<0.001). DS conferred a slight reduction in procedure-related cost [$820+/-157 for DS vs. 894+/-427 for standard dilatation (SD) per patient]. The 1-year target vessel revascularization rate was similar in both groups [nine (8%) for DS vs. 17 (11%) patients for SD, ns].

CONCLUSIONS

DS is feasible and safe in selected coronary lesions. This method provides a low rate of repeat revascularization and reduces the time and the dose of radiation compared with the standard approach.

[Coronary subclavian steal syndrome after internal mammary artery bypass grafting. A cause of severe postoperative recurrent myocardial ischemia]

A 65-year-old underwent a triple bypass: internal artery mammary-descending coronary artery, aorta diagonal-lateral coronary (sequential). Three weeks later he started to have severe angina pectoris with ST depression in anterior EKG leads. A left transradial coronary angiography was performed. The examination showed a total occlusion of the left subclavian artery 2 cm after the aortic arch and a retrograde flow in the internal mammary artery (IMA). Via transfemoral approach, angiography showed the patency of the aorto-veinous sequential graft and a retrograde flow through anastomosis in the left mammary artery. The patient underwent a reimplantation of the IMA on the brachiocephalic artery. One month later the patient is doing well without chest pain. A coronary subclavian steal syndrome should be suspected in case of recurrent ischaemia after IMA bypass, particularly if there is more than 20 mmHg systolic pressure differential between the arms. Left transradial approach achieved diagnostic in case of total left subclavian artery occlusion.

Concordance between dobutamine Doppler tissue imaging echocardiography and rest reinjection thallium-201 tomography in dysfunctional hypoperfused myocardium

OBJECTIVE

To evaluate the efficiency of the new technique colour Doppler tissue imaging (DTI) by studying the concordance between dobutamine DTI, standard grey scale echocardiography (SE), and rest-reinjection TI-201 tomography (TI) in dysfunctional myocardium.

PATIENTS

23 patients with chronic wall motion abnormalities and proven coronary artery disease (> 70% diameter stenosis of at least one major coronary artery at angiogram).

METHODS

The contractile reserve and the resting perfusion characteristics of dysfunctional myocardial segments were assessed with low dose dobutamine SE and/or DTI (2.5 up to 20 gamma/kg/min) and TI on a semiquantitative basis. The DTI or SE data were separately compared with TI, on the basis of a 13 segment ventricular model. The resulting score of combined DTI and SE was also compared with TI. Finally the results obtained from DTI were compared with SE.

RESULTS

A total of 142 severely hypokinetic or akinetic segments were visualised. The viability study was feasible in 127 (89%) and 121 (85%) segments with DTI and SE, respectively. TI detected viability more frequently than DTI (84 v 61, p < 0.001) and SE (80 v 50, p < 0.001). However, as many viable segments were detected with combined DTI and SE as with TI (78 v 84, NS). The kappa values between TI and SE, DTI or combined SE and DTI were 0.38, 0.45, and 0.57, respectively, and increased to 0.52 and 0.76, respectively, for SE and DTI versus TI when mid-anterior and mid-inferior segments only were considered. The kappa value between SE and DTI was 0.34.

CONCLUSIONS

DTI is a helpful adjunct to SE, when using low dose dobutamine. This combination revealed as many viable segments as TI and showed a better agreement than DTI or SE alone for the assessment of myocardial viable segments evidenced by TI.

[Occlusion of a coronary endoprosthesis after a negative stress test]

The frequency of early occlusion of coronary stents has fallen with the use of a powerful association of platelet antiaggregants (ticlopidine and aspirin) in the first month. The authors report the case of coronary stent occlusion after a negative exercise stress test, 11 days after implantation in a centre of cardiac rehabilitation. According to the literature, this type of complication would appear to be rare and related to the small size of the stent and the conditions of implantation (acute phase). It would be useful to compile a registry of complications related to coronary angioplasty during rehabilitation to determine their prevalence and, if necessary, change the protocols of physical training of these patients.

[Iatrogenic acute renal failure caused by overdosage of flecainide acetate]

BACKGROUND

Rapid degradation of renal function may occur in patients given drug regimens combining a converting enzyme inhibitor, a diuretic and a nonsteroidal anti-inflammatory drug.

CASE REPORT

A patient given flecainide and an enalapril /hydrochlorothiazide combination in a well-tolerated long-term regimen suddenly developed acute renal failure when a nonsteroidal anti-inflammatory drug was introduced leading to an overdose of the anti-arrhythmic drug.

DISCUSSION

A poor understanding of the elimination routes for anti-arrhythmic drugs and the risks involved when combined with nonsteroidal anti-inflammatory drugs modifying glomerular hemodynamics can lead to dangerous prescriptions and life-threatening situations in patients on multiple drug regimens.

[Doppler tissue imaging of pre-ejection left ventricular wall dynamics in normal subjects]

Pre-ejectional left ventricular wall motion has been demonstrated clinically by angiography. Intramyocardial wall velocities generated by cardiac contraction may be measured by Doppler tissue imaging. The aim of this study was to detect pre-ejectional wall motion and to analyse its sequencer. A long axis M Mode with simultaneous septal and posterior wall imaging was performed in 11 normal subjects (age 37 +/- 15 years) with velocity analysis between the electrocardiographic Q wave and the onset of ejection by digitised analysis between the electrocardiographic Q wave and the onset of ejection by digitised images with automatic velocity extraction (3.8 ms) along a horizontal subendocardial line. The total duration of the pre-ejectional periods in conventional and Doppler tissue imaging are compared. Oscillatory velocimetric appearances with alternate colours of adjacent bands in each wall and a mirror image between walls was observed. The mean and peak velocities of the first four bands were significantly different between the walls (p < 0.001) as were the absolute values between bands 2 (p < 0.02) and 3 (p < 0.006). The duration of band 2, related to motion mainly towards the center of the ventricular chamber exceeded that of the adjacent bands (septum p < 0.02, posterior wall p < 0.001). The correlation coefficient for total duration of the pre-ejectional period between Doppler tissue imaging and conventional Doppler was 0.83, p < 0.05 for the interventricular septum and 0.76, p < 0.04 for the posterior was. The authors conclude that regional pre-ejectional wall motion can be recorded. During isovolumic contraction, there is motion predominantly towards the center of the left ventricular chamber of the two walls, confirming previous angiographic findings. Its timing suggests that wall motion proceeds the increase in ventricular pressure.

[Myocardial Doppler tissue imaging: past, present and future]

The first Doppler spectral and pulsed tissue recordings in 1992 have given way to a new generation of machines which enable cardiologists to study mechanical events of the myocardium during the cardiac cycle by Doppler tissue imaging. This technique provides valuable information about regional function with quantitative analysis of the velocities within the myocardial wall as opposed to the global qualitative or semi-quantitative character of usual echocardiographic data. The velocity mode is the most commonly used in its three different presentations: two-dimensional, M mode and, more traditionally, pulsed spectral modes. Two-dimensional imaging gives a global view of the different myocardial segments and allows a rapid approximation of the differences of velocities between these segments and of myocardial wall thickness; however, it lacks the temporal resolution of pulsed Doppler and M mode. In addition, M mode with automatic programmes of velocity analysis has the advantage of providing a continuous spatio-temporal recording of the velocities within the myocardial wall, layer by layer. There is a physiological gradient of velocities highest at the endocardium and lowest at the epicardium. Despite the present limitations related to the Doppler principle itself, the technology, and the complexity of myocardial architecture, Doppler tissue imaging is a useful complement to information already available concerning pressures, flow and cardiac structures. The future is promising and should exceed this simple complementarity to existing ultrasound methods. Progress in the fields of ultrasound physics, technology, computerisation for acquisition of two- and three-dimensional imaging should provide a new physiopathological approach to the understanding of wall motion changes during cardiac disease.

Right and left isovolumic ventricular relaxation time intervals compared in patients by means of a single-pulsed Doppler method

Right and left isovolumic ventricular relaxation time intervals measurements were obtained as follows: from the peak R wave on the electrocardiogram to either the mitral or the tricuspid pulsed Doppler flow trace onset minus the R to end-ejection zero flow crossing of the subaortic (left side) or pulmonary (right side) D flow trace time interval. A ratio was calculated as a percent difference duration between both isovolumic ventricular relaxation time intervals. The aim was to compare isovolumic ventricular relaxation time interval values in 42 healthy controls and to study the changes induced by heart diseases in 27 patients with (1) controlled hypertension without left ventricular hypertrophy, (2) hypertrophic cardiomyopathy, and (3) Cor pulmonale. Mean values of isovolumic ventricular relaxation time intervals significantly differed at paired and unpaired studies, with right isovolumic ventricular relaxation time intervals shorter than those of the left side in all groups (p < 0.001) except for patients with Cor pulmonale. Isovolumic ventricular relaxation time intervals did not correlate with heart rate and moderately correlated with left ventricular mass and age. No significant difference was found between healthy controls and patients with controlled hypertension. Significant changes were found in patients with hypertrophic cardiomyopathy and Cor pulmonale versus healthy controls for both isovolumic ventricular relaxation time intervals. However, significant changes in the ratio were only found in patients with Cor pulmonale (p < 0.005) because of abnormal similar values for both isovolumic ventricular relaxation time intervals. This Doppler method enabled, for the first time, serial comparison of isovolumic ventricular relaxation time intervals with a homologous method. Both isovolumic ventricular relaxation time intervals significantly lengthened with age and with left ventricular indexed mass, but their ratio remained insignificantly changed except for patients with Cor pulmonale. The concomitant right and left isovolumic ventricular relaxation time intervals lengthening in patients with hypertrophic cardiomyopathy and Cor pulmonale suggests interdependence of both ventricles through the septum. This makes recommendable systematic comparison of both sides. The calculation of a ratio, free from the effect of factors intervening on isovolumic ventricular relaxation time intervals, may, in addition, be of diagnostic help.

Preejectional left ventricular wall motion in normal subjects using Doppler tissue imaging and correlation with ejection fraction

Relations have been demonstrated between the preejection period (PEP) and indexes of left ventricular (LV) systolic function. Doppler tissue M-mode imaging has the capability to measure wall velocities and to display as colored strips within the walls velocity reversals representing changes in direction of wall motion. To document LV preejectional wall motions, this procedure was performed on 16 normal subjects with a twofold purpose: to measure septal and posterior preejectional intramyocardial velocities and durations and to correlate preejectional parameters with LV ejection fraction (LVEF). Parasternal M-mode images of simultaneously recorded walls were digitized. Subendocardial wall velocities were measured every 3.8 ms from the Q wave to the onset of ejection. Total duration measured from Doppler tissue and flow traces was compared in 10 subjects. PEP total duration did not differ between both walls or techniques. Several adjacent velocity reversals with mirror signs in opposite walls were substantiated by 2 to 5 colored strips. Colored strips corresponding to the same sign in each wall had a progressively damped velocity amplitude (septum 19 +/- 8, -21 +/- 10, 15 +/- 7, -8 +/- 5, 4 +/- 2 mm/s; posterior wall -13 +/- 16, 11 +/- 7, -8 +/- 5, 9 +/- 6, -2 mm/s). Peak velocity values of opposite signs significantly differed between both walls (p <0.0001). Absolute values differed only for colored strips 2 and 3 (p <0.009). Strip 2 featured a simultaneous early inward motion of both walls toward the LV cavity with significantly prolonged duration (p <0.0001). The only positive correlation with LVEF was found for peak velocities of strip 2 in the posterior wall (r = 0.71, p <0.006). Thus, the posterior wall and its inward motion velocities have potential for future clinical implications.

[Why so many stents?]

BETTER THAN ANGIOPLASTY: Prolonging inflation with a perfusion balloon decreases the risk of acute coronary occlusion after angioplasty. The longer the artery remains patent, the greater the chances of 0% residual stenosis. This is what the sent allows. Stent act on both mechanisms of stenosis: elastic recoil and fibrous remodeling of the arterial plaque. TARGETTED ACTION: Stents improve angioplasty prevention of acute stenosis. They have a real action on preventing degeneration of the saphenous graft and lead to a significant reduction in the rate of restenosis of the dilated site. There are however two specific complications: subacute occlusion and greater incidence of vascular events. Stents are particularly indicated for the treatment of restenosis and chronic occlusions. TWO IMPROVEMENTS: Risks related to the implantation of a foreign body in the vascular system have been reduced with the use of ticlopidine and high-pressure stent implantation. POSITIVE RESULTS: Stents have produced better angiographic results. They limit restenosis and the number of revascularizations required in treated patients. Several questions concerning indications remain open.

Colour doppler valvar and subvalvar flow diameter imaging versus echo score in mitral stenosis: comparison with type of surgery

OBJECTIVE

To compare the value of echo score with that of Doppler subvalvar flow broadening in deciding the type of mitral stenosis surgery.

PATIENTS

30 patients, mean age 47 years, with severe stenosis undergoing surgery were divided into two groups according to type of surgery: open heart commissurotomy (group 1, n = 12), or prosthesis (group 2, n = 18). A control group of 10 patients with prosthesis served as reference, representing mild stenosis without subvalvar connection.

METHODS

For echo, the score proposed by Wilkins for cross sectional imaging was used. For Doppler, the flow diameters were measured in cm by an independent examiner from the long axis view in early diastole at two levels: (1) at the level of the stenosis (origin flow diameter), and (2) 1.5 cm downstream from the stenosis in the left ventricle (subvalvar flow diameter) with calculation of a Doppler ratio relating these two measurements, expressed as a percentage of broadening. Diagnostic value was compared for both procedures.

RESULTS

There was no significant difference in age, mitral valve areas, or haemodynamics for the two groups. Mean values (SD) were: echo score: group 1, 9.83 (1.26) v group 2, 10.8 (8.1), NS; Doppler ratio %: group 1, 44 (24) v group 2, 12 (21) (P < 0.001); control group: 69 (15). The per cent diagnostic value for an open heart commissurotomy of respective cut off points was: Doppler ratio > 25% (range 71% to 87%); echo score < 10 (range 50% to 75%).

CONCLUSIONS

The new Doppler ratio diagnostic value agreed better with surgical management, repair or prosthesis, in this study. Thus, it appears to better reflect the subvalvar involvement and changes in kinetics than the echo score alone. This easy Doppler method might become a routine examination for follow up of patients with open heart commissurotomy, to avoid performing repeated transoesophageal echocardiography.

Inhibition of substance P-induced microvascular leakage by inhaled methoxamine in rat airways

1. The effect of the inhaled alpha-adrenoceptor agonist, methoxamine (MTX), was studied on experimental airway oedema induced by injection of substance P (SP) in the rat. Sprague-Dawley rats (300-350 g) were anaesthetized with sodium thiopentone, tracheotomized and artificially ventilated. 2. MTX or its vehicle was administered by inhalation. Airway resistance and blood pressure were monitored continuously. Evans Blue dye (EB, 20 mg kg-1) was injected through a jugular catheter 1 min before SP (14.8 nmol kg-1). Airways were dissected out, weighed and placed in formamide for EB extraction and determination by spectrophotometry. 3. EB extravasation induced by SP was significantly reduced in distal intraparenchymal bronchi by inhaled MTX at doses of 50 micrograms kg-1 (58 +/- 9 vs 96 +/- 9 ng EB mg-1 tissue after vehicle, P < 0.001) and 100 micrograms kg-1 (69 +/- 11 vs 137 +/- 26 ng EB mg-1 tissue after vehicle, P < 0.01). Inhaled MTX by itself (100 micrograms kg-1) increased blood pressure: 172 +/- 6 vs 132 +/- 10 mmHg baseline (P < 0.02), but neither induced extravasation nor increased airway resistance. 4. In another set of experiments without SP, MTX was administered intravenously 1 min after EB. At 100 micrograms kg-1, i.v. MTX increased blood pressure to a similar extent as inhaled MTX (180 vs 147 mmHg baseline, P < 0.01), increased airway resistance and caused leakage of plasma proteins in distal intraparenchymal bronchi (79 +/- 7 vs 47 +/- 1 ng EB mg-1 tissue, P < 0.02). 5 Similarly, after sequential i.v. injections of doubling doses of MTX (50-800 microg kg-1), a marked EB extravasation was found in the airways. This was abrogated by pretreatment with prazosin (100 microg kg-1)but not with propranolol (2 mg kg-1).6 These results suggest that microvascular leakage and airway oedema induced by i.v. MTX may be linked to an increase in pressure in the pulmonary circulation, resulting from vasoconstriction of the pulmonary vasculature and acute cardiac dysfunction due to systemic hypertension.7 Our results with inhaled MTX show that direct deposition of MTX at the bronchial vasculature induces a reduction in SP-induced microvascular leakage in rat airways and that inhaled MTX does not share the untoward effect of i.v. MTX inducing airway oedema.