Biomedical subjects

H Geschwind

Publications and source records attributed to H Geschwind.

At least 19 recordsLinked to original sources

PubMed1996

Sympathetic stimulation overrides flow-mediated endothelium-dependent epicardial coronary vasodilation in transplant patients.

BACKGROUND: Abnormal coronary vasomotor responses have been described in transplant patients. The aim of this study was to evaluate the graft epicardial vasomotor responses to different stimuli that increase coronary blood flow. METHODS AND RESULTS: Twelve heart transplant recipients with angiographically normal epicardial coronary arteries were compared 2.7 +/- 1.2 months after surgery with 6 control subjects. Coronary flow velocity was measured with a guidewire Doppler. Coronary diameter changes of the proximal and midportion of the left anterior descending coronary artery were assessed by quantitative coronary angiography during rapid atrial pacing, cold pressor test, supine exercise, and subselective infusion of papaverine and after intracoronary injection of linsidomine (SIN-1). Catecholamine plasmatic levels were determined at the different stages of the protocol. In 6 other transplant patients, a cold pressor test was performed before and after intracoronary infusion of phentolamine (10 micrograms.kg-1.min-1). Coronary flow velocity increased significantly in both groups during each phase of the protocol. In control subjects, dilation was observed in response to atrial pacing (8.7 +/- 7.6%; P < .05), CPT (8.8 +/- 2.3%; P < .01), exercise (14.5 +/- 9.4%; P < .001), and papaverine infusion (14.2 +/- 6.1%; P < .001) and after injection of SIN-1 (26.8 +/- 11.9%; P < .001). In transplant patients, similar dilation was observed during atrial pacing (8.2 +/- 8.3%; P < .05) and papaverine infusion (14.6 +/- 7.8%; P < .001) and after SIN-1 (25.8 +/- 10.8%; P < .001). CPT and exercise caused slight constriction (-3.5 +/- 4.5% and -2.7 +/- 10.5%, respectively; both P < .001 versus control subjects). Norepinephrine plasmatic levels increased in both groups during CPT and exercise. Slight constriction during the cold pressor test (-4.5 +/- 9.6%) changed to dilation (6.8 +/- 7.0%) after alpha-blockade with phentolamine (P < .001). CONCLUSIONS: These results show that flow-mediated, endothelium-dependent vasodilation is preserved early after trans-plantation. Sympathetic stimulation, which overrides the endothelium-dependent mechanism, can be related to hypersensitivity to catecholamines due to denervation.

Adrenergic alpha-Antagonists↗

PubMed1996

Repeated coronary artery occlusions during routine balloon angioplasty do not induce myocardial preconditioning in humans.

OBJECTIVES: The purpose of the present study was to assess whether brief, repeated coronary artery occlusions during balloon angioplasty induce a myocardial ischemic protective effect. BACKGROUND: In animals, brief coronary artery occlusions preceding a more prolonged occlusion result in reduced infarct size. Whether myocardial protection against ischemia could also occur in humans during angioplasty remains controversial. METHODS: Thirteen patients with a proximal left anterior descending coronary artery stenosis with no angiographic collateral circulation underwent percutaneous transluminal coronary artery balloon angioplasty. Three 120-s balloon inflations separated by a 5-min equilibration period were performed. For each inflation, intracoronary ST segment modifications, septal wall thickening (M-mode echocardiography), left ventricular pressures and time derivatives were measured at baseline and at 30, 60 and 90 s after balloon inflation and 120 s after balloon deflation. RESULTS: Intracoronary electrocardiographic analysis showed that the time course of the maximal ST segment elevation was identical at each inflation, as were wall motion changes assessed by the decrease in septal wall thickening. For the first and last inflations, peak positive dP/dt decreased significantly by 13 +/- 9% (mean +/- SD) and 14 +/- 13%, whereas peak negative dP/dt increased by 23 +/- 15% and 22 +/- 10%, respectively (all p < 0.01 from baseline values). The relaxation time constant, tau, was altered similarly during the different inflations, from 44 +/- 6 to 74 +/- 13 ms and from 57 +/- 13 to 77 +/- 13 ms (all p < 0.001) for the first and last inflations, respectively. Left ventricular end-diastolic pressure increased to the same level after each inflation. In contrast to other hemodynamic variables, tau and left ventricular end-diastolic pressure did not return to baseline values in between the inflations, which may be due to myocardial stunning. CONCLUSIONS: In patients with proximal left anterior descending coronary artery stenosis and no evidence of collateral circulation, brief periods of ischemia, such as those used during routine coronary balloon angioplasty, do not provide any protection against myocardial ischemia.

Aged↗

PubMed1995

Comparison of the effects of exercise and cold pressor test on the vasomotor response of normal and atherosclerotic coronary arteries and their relation to the flow-mediated mechanism.

This study was designed to assess the vasomotor response of coronary arteries to exercise and the cold pressor test, and its relationships with the endothelium-mediated dependent mechanism. Twenty-two patients were entered in the study. Group I was composed of 12 patients with a total cholesterol level < 200 mg/dl associated with angiographically smooth, normal coronary arteries. Group 2 consisted of 10 patients with both a cholesterol level > 240 mg/dl and angiographic luminal irregularities of the left anterior descending coronary artery. Coronary blood flow was assessed by a 0.018-inch tip guidewire during Doppler ultrasonography, and analysis of the coronary arterial dimension of the midportion of the left anterior descending coronary artery was performed by quantitative coronary angiography. Catecholamine concentrations were assessed at the different stages of the protocol. The rate-pressure product increased during both the cold pressure test and exercise (p < 0.001). Coronary blood flow velocity increased during the cold pressor and exercise tests by 24.5 +/- 10% and 72 +/- 42%, respectively (p < 0.001), and by 127 +/- 62% (p < 0.0001) after administration of papaverine. In group 1, the cold pressor test had a more pronounced vasodilating effect on epicardial coronary arteries (+11.2 +/- 16%) compared with group 2 (-2 +/- 9%, p < 0.05). Similarly, exercise had a vasodilating action in group 1 (11.3 +/- 15%) compared with group 2 (-1.9 +/- 8%, p < 0.05). Both responses were highly correlated (r = 0.92, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Improvement of subendocardial myocardial perfusion after percutaneous transluminal coronary angioplasty. A myocardial contrast echocardiography study with correlation between myocardial contrast reserve and Doppler coronary reserve.

BACKGROUND: After angioplasty coronary reserve improves but does not normalize in most patients. The purpose of this study was to examine before and after angioplasty coronary reserve and transmural myocardial blood flow distribution using myocardial contrast echocardiography. METHODS AND RESULTS: Twelve patients with left anterior descending coronary artery stenosis were investigated before and immediately after angioplasty. A Doppler catheter was placed in the proximal segment. Myocardial contrast echocardiography was performed by imaging the septum in M mode in a parasternal view using a 3.0-mL bolus of sonicated amidotrizoate sodium meglumine through the guiding catheter. The gray level before injection was subtracted from the gray level after injection to maximize contrast time-intensity curves. The area under the curve was used as an indicator of myocardial blood flow, and subendocardial/subepicardial ratios were measured. After baseline measurements were obtained, Doppler and echographic data were recorded after a bolus infusion of papaverine into the left main coronary artery. The same protocol was performed in patients after angioplasty and in five control subjects with normal coronary arteries. Before angioplasty, echocardiographic and Doppler coronary reserve were 2.57 +/- 0.48 and 2.54 +/- 0.57, respectively. Both increased after angioplasty to 3.65 +/- 0.57 and 3.36 +/- 0.70, respectively (P < .05). Coronary reserve values obtained in patients with these two methods under the different conditions and in control subjects were correlated (r = .81; P = .0001). Before angioplasty, subendocardial/subepicardial septal ratios decreased from 0.80 +/- 0.48 to 0.60 +/- 0.27 after papaverine (P < .05). However, after angioplasty, these ratios tended to increase, from 0.72 +/- 0.27 to 0.92 +/- 0.45 after papaverine, but they did not change in control subjects (1.11 +/- 0.23 to 0.92 +/- 0.11). CONCLUSIONS: These results show that myocardial contrast echocardiography yields flow reserve values that correlate with values obtained using intracoronary Doppler. This technique may be considered as an accurate tool to assess coronary reserve in humans.

Angioplasty, Balloon, Coronary↗

PubMed1993

Coronary vasodilating action of dobutamine in patients with idiopathic dilated cardiomyopathy.

To assess the coronary hemodynamic effects of dobutamine in patients with idiopathic dilated cardiomyopathy, dobutamine was infused at the incremental infusion rates of 25, 50, 100, and 200 micrograms/min into the left main coronary artery of nine patients undergoing cardiac catheterization. In response to dobutamine infusion, systemic hemodynamic effects were dose related. At the highest infusion rate cardiac index and left ventricular peak positive rate of rise in ventricular pressure increased from 2.33 +/- 0.54 to 2.97 +/- 0.65 L/min/m (p = 0.001) and from 690 +/- 177 to 1157 +/- 275 mm Hg/sec (p = 0.001), respectively. Left ventricular end-diastolic pressure decreased from 17 +/- 8 to 8 +/- 7 mm Hg (p = 0.001) and a trend toward decrease in left ventricular wall stress was observed (from 166 +/- 75 to 148 +/- 66 gm/cm2, not significant). Heart rate and mean arterial pressure remained unchanged. The coronary hemodynamic response to dobutamine infusion was also dose related. At the highest infusion rate coronary sinus blood flow increased from 133 +/- 35 to 179 +/- 47 ml/min (p < 0.01) and was associated with an increase in coronary oxygen blood content from 4.5 +/- 0.6 to 7.8 +/- 1.7 ml per 100 ml (p < 0.01) whereas myocardial oxygen consumption remained unchanged. During dobutamine infusion norepinephrine decreased in the femoral artery and in the coronary sinus from 1.03 +/- 0.34 to 0.641 +/- 0.179 ng/ml (p < 0.05) and from 1.76 +/- 0.98 to 1.38 +/- 0.65 ng/ml (p < 0.05), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Intracoronary linsidomine abolishes acetylcholine-induced vasoconstriction of epicardial coronary arteries.

If the vasodilation of the epicardial coronary arteries caused by linsidomine (SIN-1), the active metabolite of molsidomine, is well established, few data are available concerning the effects of SIN-1 on the acetylcholine (ACh)-induced vasoconstriction of epicardial coronary arteries. Fourteen patients with mild lesions of the left anterior descending artery (LAD) were studied. Intracoronary blood flow velocity was measured by a Doppler probe placed in the proximal segment of the LAD, and cross-sectional arterial area was assessed by quantitative angiography. After initial hemodynamic parameters were measured, 12 mg papaverine was injected into the left main coronary artery. When hemodynamic parameters returned to baseline values, three increasing concentrations of ACh (5 x 10(-7), 10(-6), and 5 x 10(-6) M) were selectively administered into the LAD in a 3 min period for each concentration. While the infusion of ACh 5 x 10(-6) M was continued, 1 mg SIN-1 was injected as a bolus in the ostium of the left coronary artery. After the injection of papaverine, blood flow increased by 197 +/- 8%, with a trend toward vasoconstriction of the proximal and distal segments of the LAD (p = NS). The ACh injection induced a dose-dependent vasoconstriction, reaching 51 +/- 20% on the distal segment of the LAD at the maximum concentration (p < 0.001). After an initial increase in coronary blood flow of 47 +/- 10 and 28 +/- 11% during the first two concentrations of ACh, respectively, the values decreased after the last injection to the level of baseline values. The infusion of SIN-1 antagonized the ACh-induced vasoconstriction, leading to vasodilation of 7.5 +/- 3% (p < 0.005) and 16 +/- 7% (p < 0.001) of the proximal and distal segments of the LAD, respectively; this was associated with an increase in intracoronary blood flow by 42 +/- 8%. We conclude that intracoronary administration of SIN-1 can antagonize the ACh-induced vasoconstriction of epicardial coronary arteries.

Acetylcholine↗

PubMed1993

[Effects of intracoronary injection of SIN-1 on vasoconstriction of epicardial arteries induced by acetylcholine].

Linsidomine or SIN-1, a vasodilator of epicardial arteries, is the active metabolite of Molsidomine which is regularly used for intracoronary injection. Although its vasodilatory action has been demonstrated on the large coronary vessels, it is not known whether this molecule can vasodilate epicardial coronary arteries which have been vasoconstricted with acetylcholine. Twelve patients with left anterior descending artery (LAD) disease were studied. Intracoronary flow velocity was measured with a Doppler catheter (Millar) placed in the proximal segment of the LAD and the diameter of the artery was evaluated by quantitative angiography. After recording the basal haemodynamic parameters, 12 mg of papaverine were injected into the left main coronary artery. After regaining the basal state, three incremental doses of acetylcholine (5 x 10(-7), 1(-6) and 5 x 10(-6) M) were selectively injected into the LAD over a 3 minute period for each injection. Then, during continuous infusion of 5 x 10(-6) of acetylcholine, 1 mg of SIN-1 was injected in a bolus into the left coronary ostium. After the papaverine, the coronary flow velocity increased by 199 +/- 8% associated with a vasoconstrictive tendency in the proximal and distal segments of the LAD (NS). In response to acetylcholine a dose-dependent vasoconstriction vas observed attaining 50 +/- 21% at the last injection in the distal segment of the LAD (p < 0.001). After an initial increase in coronary flow velocity of 46 +/- 11% (p = 0.004) and of 26 +/- 11% (p < 0.05) after the first two doses of acetylcholine, it decreased after the final injection to close to basal values (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

PubMed1993

[Endothelial dysfunction and coronary vasomotricity. Contribution of endocoronary echography].

The regulation of flow and diameter of the coronary arteries depends on many factors. In normal subjects, increased coronary flow is associated with an increase in diameter of the epicardial coronary vessels. The coupling of these two independent variables depends on the integrity of endothelial function. In isolated arteries suppression of the endothelium induces an abnormal vasomotor response to acetylcholine. The presence of atherosclerotic lesions on the coronary vessels also induces the opposite response to the administration of acetylcholine, even in apparently normal segments. Other physiological coronary vasodilator stimuli, especially those which increase the concentration of noradrenaline, become vasoconstrictor in diseased coronary vessels. Finally, increasing coronary blood flow is not associated with increases in coronary diameter in patients with coronary atherosclerosis. This loss of flow-dependent vasodilatation is an early and diffuse phenomenon in subjects with cardiovascular risk factors. The authors have shown that this inversion of vasomotor responses observed by angiographic techniques, may also be documented by endocoronary ultrasonography. Their results demonstrate that the vasodilatation induced by papaverine or by the cold pressor test in 6 normal subjects is lost in 20 patients with coronary atherosclerosis and that the administration of Sin 1 induces a comparable vasodilatation in normal and diseased vessels. This study confirms that endothelial function is globally altered in atherosclerotic coronary artery disease.

Acetylcholine↗

PubMed1993

[Implantation of an endoprosthesis for the repair of stenosis of valved tube between right ventricle and pulmonary artery].

The author report the case of a 35 year old man who had undergone a Rastelli procedure in 1976 for transposition of the great arteries and who required indertion of a stent for stenosis of the valved right ventricular-pulmonary artery conduit. The patient presented with florid signs of right ventricular failure due to degenerescence of the conduit which had a 60 mmHg pressure gradient between the right ventricle and the pulmonary artery. This palliative procedure was decided upon given the high risk of reoperation. The valved conduit was dilated with a balloon catheter before insertion of a Gianturco stent (30 mm diameter and 50 mm long) to cover both conduit and the valvular apparatus. The insertion of the stent was easy with immediate normal expansion and the procedure was well tolerated. After insertion of the stent, the right ventricular-pulmonary artery pressure gradient fell from 60 to 35 mmHg. Angiographic control one month later showed a sustained hemodynamic result with a perfectly patent stent. The patient was pauci-symptomatic when reviewed six months after the procedure.

Adult↗

PubMed1992

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)

Acetylcholine↗

PubMed1992

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)

Acetylcholine↗

PubMed1992

[Primary isolated dissection of the left anterior descending coronary artery].

The authors report the case of a 30 year old Senegalese man admitted with an acute antero-septo-apical myocardial infarction which was fibrinolysed at the 5th hour. Coronary angiography showed dissection of the left anterior descending artery. This young patient with no previous medical history or cardiovascular risk factors had an abnormal skin biopsy showing proliferation of the elastic tissues. Eight months after the infarct the patient is asymptomatic and the appearances of dissection have disappeared. This case is original because the dissection occurred in a man, affecting the left anterior descending artery, with a good outcome after fibrinolysis (4th case), the angiographic regression of the arterial lesion and the possible pathogenetic mechanism of disease of elastic tissues.

Adult↗

PubMed1992

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)

Angioplasty, Balloon, Coronary↗

PubMed1991

Occlusive peripheral vascular disease: a multicenter trial of fluorescence-guided, pulsed dye laser-assisted balloon angioplasty.

Fluorescence-guided, laser-assisted balloon angioplasty was performed in 129 patients with iliac and femoropopliteal artery chronic occlusions (range, 0.5-50.0 cm; mean length, 9.9 cm) after failure of recanalization with standard guide-wire techniques. Laser recanalization and short-term angiographic success were achieved in 101 (72%) and 95 (68%) of 140 occlusions, respectively. Laser and balloon angioplasty failures were encountered in heavily calcified plaques or after perforations and dissections. Complications included perforations (19%), hematomas (5%), thromboses (4%), and distal embolizations (4%). Real-time fluorescence spectroscopy identified thrombus, white fibrous plaque, and media but could not avoid perforations in many cases because laser wire advancement outdistanced fluorescence sensing. Disruption of tissue by means of pressure transients and/or mechanical advancement occurred in at least 36% of lesions where the laser energy was insufficient (less than 0.4 J/cm) to ablate significant tissue. Integration of fluorescence guidance with pulsed dye laser ablation is feasible, but additional refinements are necessary to increase safety and efficacy.

Adult↗

PubMed1991

[Percutaneous transluminal angioplasty of the common trunk during the acute phase of myocardial infarction].

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, Balloon, Coronary↗

PubMed1991

[Results of pulsed laser angioplasty of peripheral arteries guided by spectroscopy].

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)

Adult↗

PubMed1990

[Laser and arterial recanalization].

Interventional cardiorhythmology was born with the invention of electrical catheter ablation of the common atrioventricular bundle of His as a palliative treatment of supraventricular arrhythmias refractory to medicinal treatment. This method is now used as a curative treatment. In Wolff-Parkinson-White syndrome, all accessory pathways, whatever their location, can be destroyed with a very high success rate (96 p. 100) and very low morbidity and mortality rates. Reentrant nodal tachycardias can also be treated by catheter ablation with, however, a low risk of atrioventricular block which, for the moment, limits its indications. In intractable ventricular tachycardias, its indications will certainly be extended and its efficacy will increase since numerous recent studies have identified a limited, slow-conduction area (arrhythmogenic substrate) as being the real target for ablation. Other sources of energy are also used for the same purposes, including radiofrequency currents with results that are promising but vary according to the type of arrhythmia treated. Thus, interventional cardiorhythmology is progressively replacing surgery.

Angioplasty, Laser↗

PubMed1990

Prophylactic intraventricular pumping in high-risk coronary angioplasty.

The 'Hemopump', an axial flow pump, when inserted in the left ventricle brings about mechanical unloading of the ventricle, thus reducing the risk of cardiac arrest during coronary angioplasty. In this study eight very ill patients with unstable myocardial ischaemia and various contraindications for coronary artery surgery were selected for coronary angioplasty with insertion of the hemopump. Anatomical difficulties prevented insertion in three patients, but coronary angioplasty was carried out successfully with the pump in place in the other five. When the pump was working the cardiac index rose by an average of 23% (8-50%) and the pulmonary capillary wedge pressure fell by 17% (0-22%). Though electrocardiographic monitoring showed temporary rhythm instability during angioplasty in four of the five patients, there was no clinical deterioration. Four of the five patients are symptom-free on medical treatment and the other is well after surgical revascularisation.

Aged↗