[Delays of treatment of acute myocardial infarction with ST elevation admitted to the CCU (coronary care unit) in Alsace]. / Délais de prise en charge de l'infarctus aigu du myocarde avec sus-décalage persistant du segment ST admis dans les USIC d'Alsace.

OBJECTIVE: to determine the time delay from symptom onset to diagnosis and treatment of patients with persistant ST segment elevation myocardial infarction (STEMI). DESIGN: prospective observational study. METHOD: patients with symptoms onset < 24 h admitted in all 10 cardiac intensive care units in one French administrative region (Alsace). Data were recorded by doctors on duty soon after hospital admission. Patients with STEMI during hospital stay or as a complication of cardiac interventional procedure were excluded. The Kruskal-Wallis test was used to assess statistical differences between the groups (p value < 0.05). RESULT: from April to October 2004, 326 patients were admitted for STEMI. Median time between the symptoms onset and the patient's call for medical help was 60 minutes. General practitioners were the first medical contact in 41%. The time from symptoms onset to first medical intervention and from first medical intervention to coronary care unit admission were markedly shorter in patients who had directly called the Emergency Medical Services (group 15-110 patients i.e. 33% of the study population): 44 min vs 75 min otherwise (p=0,003). Median transport time was 60 min. Sixty two percent of the pts were transported by the Emergency Medical Services. The median time from symptoms onset to initiation of reperfusion therapy was 240 min. It was significantly lower in group 15 (170 min vs 286 min - p < 0,001) and for thrombolytic therapy (190 min versus 245 min for primary angioplasty, p=0,007). When thrombolysis (THL) was used, 89% of the pts could be treated during 6 hours of symptoms onset and 44% in 3 hours. For angioplasty only 4% of the pts were treated in the first 90 minutes, 9% in the 2 hours and 30% in the 3 hours of symptoms onset. If the time delay is evaluated from the 1 st medical intervention, call to reperfusion intervention was significatly shorter for THL: 91 versus 157 min, p< 0,003. Angioplasty represented 75% of reperfusion strategy in our area and THL alone only 2,7% and combine therapy 5,4%. CONCLUSION: our study documents the beneficial effect of a direct call to Emergency Medical Services. Our results also underscore the need for an effort to reduce the time to offer the best appropriate reperfusion techniques in STEMI pts: speed up the admission in the cath-lab, think about pre-hospital thrombolysis followed by coronary angioplasty if necessary.

Effects of infusion of L-arginine into the left anterior descending coronary artery on acetylcholine-induced vasoconstriction of human atheromatous coronary arteries.

Hypercholesterolemia and atherosclerosis are conditions associated with impaired endothelium-dependent relaxation. In hypercholesterolemic animals, intravenous administration of L-arginine, the precursor of nitric oxide, normalizes endothelium-dependent vasodilator activity. In the present study, we questioned whether intracoronary administration of L-arginine in patients with coronary artery disease could improve coronary vascular reactivity to acetylcholine. Thirteen hypercholesterolemic patients with diffuse coronary atherosclerosis but nonstenotic lesions of the left anterior descending (LAD) coronary artery were investigated. Quantitative coronary angiography and subselective intracoronary Doppler flow velocity measurements were performed to determine LAD diameters and coronary blood flow. Intracoronary infusion of acetylcholine was performed during 3 consecutive 3-minute periods at incremental rates adjusted to achieve estimated final concentrations of 5 x 10(-7), 10(-6) and 5 x 10(-6) M. After evaluation of the response to acetylcholine, L-arginine was infused into the LAD at the rate of 25 mg/min (10(-3) M) and the same stepwise 3-minute infusions of acetylcholine were repeated during infusion of L-arginine. Infusion of acetylcholine induced a dose-dependent reduction of distal epicardial LAD diameter reaching -48.5 +/- 17% at 5 x 10(-6) M (p < 0.01 vs control values). L-arginine alone had no effect on the distal LAD diameter but attenuated acetylcholine-induced vasoconstriction to -21 +/- 9% at 5 x 10(-6) M acetylcholine (p < 0.01). Coronary blood flow showed a biphasic response to acetylcholine, increasing by 41 +/- 12% at 5 x 10(-7) M (p < 0.01) and decreasing by 21 +/- 13% at 5 x 10(-6) M (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in hemodynamics and coronary blood flow during left ventricular assistance with the Hemopump.

The Hemopump, a catheter-mounted left ventricular assist device, has been demonstrated to be effective in supporting patients with potentially reversible cardiac failure. The mechanism of recovery of the hearts with this device is not fully understood. The effects of the Hemopump on hemodynamics and coronary blood flow with and without myocardial ischemia and failure have been studied in 8 anesthetized open-chest dogs. Coronary blood flow in the left circumflex artery was assessed with an intracoronary Doppler catheter. Myocardial ischemia was induced by ligation of the left anterior descending and diagonal branches. The effects of maximum support were compared with those of minimum support. The effects of the Hemopump varied according to cardiac function. When cardiac dysfunction was mild, the Hemopump support slightly reduced myocardial O2 demand (assessed by pressure-work index) by volume unloading. When cardiac dysfunction was severe, total bypass was achieved and myocardial O2 demand decreased by 45%, owing to both volume and pressure unloading. Coronary blood flow was incompletely auto-regulated, and the ratio of blood flow to O2 demand increased.

Coronary hemodynamics during hemopump left-intraventricular assistance.

Hemopump left intraventricular pumping (HP) can permit percutaneous transluminal angioplasty (PTCA) in high-risk patients. Benefits may be related to left ventricular unloading or myocardial perfusion improvement, or both. Direct ultrasonic measurements of coronary blood flow were made in the dilated vessel after a successful PTCA in five patients. A 3 Fr intracoronary Doppler catheter was placed in the coronary artery to measure flow velocities (maximal or diastolic velocity; minimum or systolic velocity and mean velocity). A SwanGanz catheter was used to measure the cardiac index and pulmonary capillary wedge pressure. Mean aortic pressures were monitored through an 8 Fr guiding catheter. Measurements were made after a 5-min period of minimal speed (T0) of the HP to avoid retrograde regurgitation through the turbine; during the increase from minimum to maximal speed (T1); after a 5-min period of maximal HP flow (3l/min) (T2) and after HP was pulled back (T3). From T0 to T2, cardiac index rose from 1.93 +/- 0.38 to 3.26 +/- 0.35 l/min/m2 and capillary wedge pressure decreased from 18 +/- 6 to 13 +/- 5 mmHg (p less than 0.05); from T2 to T3, cardiac index decreased to 2.4 +/- 0.4 while capillary wedge pressure increased to 17 +/- 5 (p less than 0.05). Mean arterial pressure and heart rate did not change significantly throughout the study. When the hemopump flow was raised to high speed, coronary blood flow increased immediately but returned shortly to baseline values.(ABSTRACT TRUNCATED AT 250 WORDS)

Length of docked tail and the incidence of rectal prolapse in lambs.

A multistate cooperative study was conducted to study the current issue of tail length in docked lambs and its relationship to incidence of rectal prolapse. A total of 1,227 lambs at six locations were randomly allocated to two or three tail dock treatments: 1) short--tail was removed as close to the body as possible, 2) medium--tail was removed at a location midway between the attachment of the tail to the body and the attachment of the caudal folds to the tail, and 3) long--tail was removed at the attachment of the caudal folds to the tail. Short-docked lambs had a greater (P < 0.05) incidence of rectal prolapse (7.8%) than lambs with a medium (4.0%) or a long (1.8%) dock. Female lambs had a higher (P < 0.05) incidence of rectal prolapse than male lambs. At two stations, lambs were finished either in a feedlot on a high-concentrate diet or on pasture with no grain supplementation. At one station, with a very low incidence of rectal prolapse, there was no difference in incidence between lambs finished in the feedlot or on pasture; however, at the station with a relatively high incidence of rectal prolapse, lambs in the feedlot had a higher (P < 0.05) incidence than lambs on pasture. The half-sib estimate of heritability for the incidence of rectal prolapse was low (0.14). The results of this study strongly implicate short dock length as a cause of rectal prolapse in lambs finished on high-concentrate diets. Furthermore, the results of this study and the only other study known conducted on this issue strongly suggest that docking lambs at the site of the attachment of the caudal folds to the tail will result in a negligible incidence of rectal prolapse.

[Results of pulsed laser angioplasty of peripheral arteries guided by spectroscopy]. / Résultats de l'angioplastie par laser pulsé guidé par spectroscopie des artères périphériques.

Seventy-six patients with complete occlusion of the iliac, femoropopliteal or distal arteries underwent laser angioplasty after failure of attempted mechanical recanalization by conventional angioplasty. The energy source was a dye pulsed laser emitting at 480 nm, 2 microseconds, 35 to 50 mJ/pulse and 5 Hz. The laser was coupled with an optical fiber of 200 microns diameter covered by a metallic spring. In order to center the laser in the arterial lumen, the fibre optic was introduced with a balloon catheter or a modified Van Andel catheter with a tapered and curved distal end with controlled torsion to direct the laser towards the lesion to be treated. The therapeutic laser was connected to a diagnostic Helium-Cadmium laser emitting at 325 nm, 50 ms and 5 mW, for the induction of tissue fluorescence analysed by a multichannel detector, itself connected to a computer programmed to differentiate atheromatous from normal tissues. The therapeutic laser was only activated when atheromatous tissue was in contact with the distal tip of the fiber optic. After vaporizing a narrow pilot channel conventional balloon angioplasty was performed. The immediate success rate was 83%; it was higher in iliac than in femoral arteries. This was less dependent on the length of occlusion than on the presence of calcification which was a common cause of failure. The complications were immediate reocclusion, perforation due to the sharp tip of the fibre and dissections without major clinical consequences. After 18 months, 64% of the arteries remained patent.(ABSTRACT TRUNCATED AT 250 WORDS)

[Percutaneous transluminal angioplasty of the common trunk during the acute phase of myocardial infarction]. / Désobstruction du tronc commun par angioplastie à la phase aiguë de l'infarctus.

The prognosis of cardiogenic shock in the acute phase of myocardial infarction has been transformed since the introduction of techniques of myocardial revascularisation. We report the case of a patient in cardiogenic shock after a large anterior myocardial infarct in whom failure of early thrombolytic therapy led to referral for emergency percutaneous transluminal coronary angioplasty. The success of the procedure on the patient's haemodynamic condition was life-saving. The originality of this case resides in the fact that revascularisation concerned the left main coronary stem.

[Angioplasty or surgery in the patient with multivessel disease]. / Angioplastie ou chirurgie chez le patient pluritronculaire.

The aims of myocardial revascularisation are to treat angina, reduce ischaemia and improve life expectancy. Patients with multivessel disease have a poor prognosis, especially when the lesions are proximal, when the preseptal left anterior descending artery is involved and when left ventricular dysfunction is present. In this particular group of patients, coronary bypass surgery has been shown to improve 10 year survival. Coronary angioplasty has been compared with surgical treatment in many clinical trials. The medium-term survival is the same in both groups, but with a higher number of repeat procedures except in diabetic patients in whom mortality is higher after angioplasty. The use of coronary stents should reduce the number of post-angioplasty procedures. Constant technical improvements, the introduction of surgery without cardiopulmonary bypass, combined revascularisation procedures, new antiplatelet drugs, the absence of long-term comparative results, all this results in a personalized choice of revascularisation procedure based on the overall clinical and angiography features of each particular case.

[The value of recording the pulmonary insufficiency flow by continuous Doppler for the evaluation of systolic pulmonary artery pressure]. / Intérêt de l'enregistrement du flux d'insuffisance pulmonaire en doppler continu pour l'estimation de la pression artérielle pulmonaire systolique.

Systolic, diastolic and mean pulmonary artery pressures can be evaluated by Doppler recordings of the maximal velocity of tricuspid regurgitation and early and late diastolic pulmonary regurgitant flow. The aim of this study was to assess the reliability of the calculation of systolic pulmonary artery pressure from pulmonary regurgitant flow by comparing the values with those obtained from the tricuspid regurgitant flow in the same patient. With this objective in mind, we investigated 70 patients with an average age of 45 +/- 34 years, in sinus rhythm, all of whom had tricuspid and pulmonary regurgitant jets which could be recorded with continuous wave Doppler. Systolic pulmonary artery pressure was calculated as follows: from tricuspid regurgitation: maximum pressure gradient + 10 mmHg; from pulmonary regurgitation: 3 x early diastolic gradient - 2 x late diastolic gradient + 10 mmHg. The systolic pulmonary artery pressures calculated from tricuspid and pulmonary regurgitation were: 42 +/- 16 mmHg and 43 +/- 17 mmHg respectively (r = 0.97) with an estimated standard error of 4.7 mmHg. These results show that the recording of pulmonary regurgitation by continuous wave Doppler allows accurate estimation of pulmonary artery pressures. The calculation by the two methods using tricuspid and pulmonary regurgitant jets increases the reliability of the results and provides a means of internal validation of the Doppler technique.

Percutaneous coronary mid-infra-red laser angioplasty.

A pilot study was performed to determine the safety and efficacy of coronary pulsed mid-infra-red laser angioplasty. The laser was coupled with a novel 2.0 mm multifiber catheter consisting of 37 optical fibers of 150 microns each arranged concentrically around a 0.018-inch central lumen and a soft leading tapered distal tip to maintain coaxial alignment and position plaque in front of fibers. The laser was operated at 500 millijoules/pulse, 3.5 Hz, and 250 microseconds/pulse. Twenty-three patients with stenosis or occlusion of the left anterior descending or right coronary artery were selected for laser treatment. In three patients the catheter could not be positioned against the obstruction. In the 20 remaining patients laser angioplasty increased the diameter of the lumen from 0.3 +/- 0.3 mm to 1.4 +/- 0.3 mm and reduced the stenosis from 91 +/- 8% to 57 +/- 10%. In three patients "stand-alone" laser treatment was sufficient. In 17 patients balloon dilatation further reduced the stenosis to 20 +/- 18%. In two patients who had previously undergone unsuccessful balloon angioplasty with high inflation pressure, laser angioplasty allowed subsequent successful dilatation with low inflation pressure. There were no deaths, perforations, dissections, or arrhythmias. One patient had abrupt reclosure 24 hours after the procedure. Spasm occurred in four patients, and six patients had chest sensations during laser emission. Thus mid-infra-red pulsed coronary laser angioplasty is safe and effective for recanalization of stenosed and totally occluded arteries. The efficacy may be sufficient for "stand-alone" laser treatment. The technique may improve the efficacy of balloon angioplasty in cases of unsuccessful primary dilatation.

Effects of Hemopump support on left ventricular unloading and coronary blood flow.

The effects of the Hemopump (HP) on left ventricular (LV) and coronary hemodynamics, with and without myocardial ischemia, were studied in an acute, anesthetized, open-chest dog preparation (n = 6). Coronary blood flow velocity in the left circumflex was assessed with an intracoronary Doppler catheter. Measurements were made at two pump speeds (minimal = HP1 and maximal = HP7) before coronary ligation (control), after ligation of the LAD (ischemia), and after induction of cardiac failure by multiple ligations of the diagonal branches (failure). Changing from HP1 to HP7 resulted in 1) Increased total cardiac output in ischemia and failure; 2) Increased mean aortic pressure and systemic vascular resistance in control, ischemia, and failure; 3) Decreased LV external work (LV systolic pressure X stroke volume) in control, ischemia, and failure; 4) Decreased LV end diastolic pressure in ischemia; 5) Decreased LV systolic pressure and pressure-rate product in failure; and 6) Increased coronary blood flow/O2 demand ratio in failure. Hemopump support reduced O2 demand by LV decompression, and improved blood flow/O2 demand ratio in the nonoccluded coronaries of ischemic, failing hearts.

Restoration of coronary blood flow in severely narrowed and chronically occluded coronary arteries before and after angioplasty: implications regarding restenosis.

The restenosis rate after recanalization of chronic totally occluded coronary arteries is high. This may be due to a competitive flow or a low coronary flow velocity. This study was designed to assess differences in coronary blood flow velocity between severely narrowed and occluded arteries before and after successful percutaneous transluminal coronary angioplasty. Thirty-five patients were studied including 12 with an occluded vessel (group 1) and 23 with a stenosis (group 2). Rest and peak hyperemic (papaverine) coronary blood flow velocities were measured. Before successful percutaneous transluminal coronary angioplasty, velocity was lower in occlusions than in stenoses (3.8 +/- 2.1 vs 7.9 +/- 4.8 cm/sec; p < 0.02), whereas resistance was higher (31.7 +/- 20.8 vs 13.7 +/- 7.0 mm hg/cm/sec, respectively; p = 0.0009). There was no significant difference in vasodilator reserve between the two groups. After successful percutaneous transluminal coronary angioplasty, the velocity increased in both groups and the resistance index decreased. Velocity and resistance were similar in the two groups. The vasodilator reserve did not change after the procedure. It was concluded that the coronary flow velocity achieved after successful recanalization of chronic totally occluded arteries is similar to that observed after dilation of stenoses. These results do not support the hypothesis that the high rate of restenosis in recanalized chronically occluded vessels is due to differences in post-percutaneous transluminal coronary angioplasty blood flow velocity.

Results and follow-up after percutaneous pulsed laser-assisted balloon angioplasty guided by spectroscopy.

BACKGROUND: Few data are available on the long-term outcome of patients who undergo laser-assisted balloon angioplasty for recanalization of occluded peripheral arteries. Because the cost of laser angioplasty is high, the value of the method should be carefully analyzed before it can be considered a routine method for recanalization. The purpose of this study was to evaluate the early and late results of laser-assisted balloon angioplasty in patients who could not be recanalized by conventional techniques. METHODS AND RESULTS: Laser angioplasty was performed in 66 patients with total occlusion of the iliofemoral artery in whom mechanical techniques failed to recanalize the obstructed vessel. The system consisted of a pulsed dye laser operated at 480 nm, 2 microseconds/pulse, 5 Hz, 50 mJ/pulse coupled into a 0.021-in. laser catheter. The treatment laser was connected with a diagnostic laser to induce tissue fluorescence for spectroscopic analysis via the same fiber. The treatment laser was emitted only when atheromatous tissue was recognized. After a pilot hole was created by laser emission, dilatation was performed to enlarge the channel. The mean length of occlusion was 8.8 +/- 6.1 cm. The primary success rate was 82%. It did not depend on the length of occlusion but was greater in non-calcified than in calcified lesions (88% versus 71%, p less than 0.03). Complications included seven early reocclusions that could be recanalized and eight perforations without clinical sequelae. At a mean 18-month follow-up, 64% of the laser-treated arteries remained patent. The rate of patency was related neither to the length of the occlusion nor to calcifications but was lower in patients who had early reocclusion (p less than 0.02). CONCLUSIONS: Pulsed dye laser-assisted balloon angioplasty is effective for recanalization of totally occluded arteries that cannot be treated by conventional means. The efficacy is limited by calcifications. The long-term patency rate is acceptable given the severity of the lesions.

L-arginine improves endothelium-dependent relaxation of conductance and resistance coronary arteries in coronary artery disease.

To assess the ability of L-arginine to improve endothelium-dependent vasodilation in atheromatous coronary arteries, we determined whether intracoronary infusion of L-arginine could improve coronary vascular reactivity to acetylcholine (ACh) examining both conductance and resistance vessels. Coronary blood flow velocity was assessed by positioning a 3 Fr Doppler catheter into the proximal coronary artery segment (six left anterior descending and one circumflex coronary artery). Computed quantitative angiography allowed the measurement of distal diameters. After baseline measurements, ACh was infused at incremental infusion rates through the Doppler lumen catheter (3 min period each) to obtain the estimated concentrations of 5 x 10(-7), 10(-6), and 5 x 10(-6) M. After returning to baseline, L-arginine was infused at the rate of 25 mg/min (10(-3) M) through the Doppler lumen catheter. Infusion of ACh was then repeated according to the same protocol than in the absence of L-arginine. The heart rate and mean arterial blood pressure did not change at any step of the protocol. Infusion of ACh induced dose-dependent vasoconstriction of coronary distal segments with a reduction in coronary distal segments by 39 +/- 15% at 5 x 10(-6) M (p < 0.01). During infusion of L-arginine, the coronary diameter was reduced by only 16 +/- 10% (p < 0.05) at the highest ACh dose. The coronary blood flow velocity increased by 100 +/- 15% at 5 x 10(-7) M ACh (p < 0.05) but only to 16 +/- 15% at 5 x 10(-6) M ACh (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Is pulsed Doppler echocardiography an adequate method to evaluate left ventricular function during filling in hypertensive patients?

Pulsed Doppler tracings of the mitral inflow are often proposed to describe left ventricular function during filling in hypertensive patients. The tracings are determined by the complex interaction of left atrial pressure and left ventricular relaxation, diastolic compliance and contractility of the left atrium. They strongly depend on preload and, thus, do not allow precise characterization of the left ventricle. In addition, they vary with age, heart rate and the site of measurement. The modifications caused by the presence of hypertensive hypertrophy are not specific: similar changes are seen for example, in the presence of hypertrophic cardiomyopathy or coronary heart disease, but are absent in highly trained athletes in spite of very significant physiologic hypertrophy.