[Multicentric experience with the use of Sheathless 6.5 French-size catheter in coronary angioplasty for bifurcation lesions: feasibility and safety]. / Expérience multicentrique de l'utilisation du Sheathless 6.5 French dans l'angioplastie coronaire des lésions de bifurcation : faisabilité et sécurité

BACKGROUND: Transradial intervention of coronary lesion is increasing in frequency and is associated with lower major vascular access site complications. However, the small size of the radial artery is a major limitation of this technique, especially for bifurcation lesions, because 6-French guiding catheters are necessary to optimize the technique. A Sheathless guiding catheter has recently been introduced, optimizing a large lumen with a small size. OBJECTIVES: The aim of this study is to report our preliminary experience performing bifurcated transradial interventions using a 6.5 French Sheathless guide catheter. PATIENTS AND METHODS: From March 2009 to February 2012 in three hospitals, 46 consecutive patients were enrolled in this study who underwent transradial approach (TRA) for percutaneous bifurcation coronary interventions using the 6.5 French Sheathless Eaucath guiding catheter system because of small radial artery caliber. RESULTS: In this study, 46 patients were enrolled with mean age of 72.13 ± 16.41 years. The majority of patients were females with sex-ratio 0.53. Procedural success using the 6.5 French Sheathless guide catheter system was 100 % with no cases requiring conversion to a conventional guide and catheter system. During procedures, adjunctive devices used in this cohort included IVUS (2 patients), 35 bifurcated lesions were treated with a kissing-balloon technique in the group of 46 patients undergoing bifurcation PCIs, one patient required rotational atherectomy, thrombus-aspiration catheters had used in four patients, FFR-guided angiography in four patients. We report one case of chronic total occlusion bifurcated lesion successfully treated using this hydrophilic catheter. There were no radial artery site complications. CONCLUSION: The treatment of coronary bifurcation lesions with 6.5 French Sheathless guiding catheter by transradial approach is feasible and appears safe in this multicenter study.

[Assessment of myocardial function and perfusion by MRI two days and four months after acute myocardial infarction revascularised by primary angioplasty]. / Evaluation par IRM de la fonction et de la perfusion myocardique à deux jours et quatre mois de l'infarctus aigu du myocarde revascularisé par angioplastie primaire.

The extent of gadolinium enhancement assessed by cardiac MRI is an accepted marker of myocardial necrosis. The correlation between late enhancement and other parameters of infarct size after myocardial infarction have previously been described. However, the prognostic value of the extent of late enhancement in terms of myocardial recovery remains controversial especially in revascularised infarcts analysed by early MRI. In order to clarify this question the authors compared the results of MRI at two days and four months after myocardial infarction benefiting from early revascularisation. Between July 2002 and November 2004, the authors included patients with myocardial infarction treated by primary angioplasty and examined by MRI (Siemens Symphony 1.5 T) at two days and three to five months after myocardial infarction. The left ventricular ejection fraction, volume, mass and wall thickness were measured. Perfusion at first passage (PP) and late enhancement were analysed after injection of 20 cc of gadolinium. An eight segment short axis model was used for PP and analysis of late enhancement. Each segment was assessed for transmural or subendocardial hypoperfusion for PP assessment and the wall thickness with late enhancement (1-25%, 26-50%, 51-75%, and 76-100%) was measured to calculate the percentage of myocardial mass showing late enhancement. Thirty-nine patients (thirty three men) were included. The average age was 59 +/- 10 years. TIMI III flow was obtained in all but one (TIMI II) patient. Cardiac MRI was performed 2.1 +/- 1.5 days and 4.6 +/- 1.7 months after myocardial infarction. The ejection fraction increased from 48.7 +/- 12.6% to 54.2 +/- 11.1%, p<0.05, and was related to infarct size (p<0.01). Forty-eight per cent of dysfunctional segments at the initial MRI improved their contractility and the extent of transmural late enhancement was inversely correlated with wall thickening at initial (p<0.01) and four month MRI (p<0.01). The PP improved significantly (regression from 9.5 +/- 8.2% to 2.8 +/- 4.1% of segments with abnormal myocardial perfusion, p<0.01). The late enhancement with respect to total myocardial mass decreased from 20.0 +/- 10.7% to 13.0 +/- 8.1%, p<0.01). Despite restoring TIMI III flow, early myocardial reperfusion is incomplete and improves in the medium term. The authors also observed a reduction in late enhancement at four months, indicating that the results immediately after myocardial infarction may overestimate the infarct size and that this sign does not represent necrotic tissue alone but also viable myocardium with a potential for recovery.

Effects of time and previous acute rejection episodes on coronary vascular reserve in human heart transplant recipients.

OBJECTIVES: This study examined whether previous rejection episodes may have deleterious effects on coronary vascular reserve of heart transplant recipients months after transplantation. BACKGROUND: Coronary reserve has been demonstrated to be within the normal range in long-term transplant patients without previous episodes of rejection. Conversely, acute rejection is associated with a dramatic reduction of coronary reserve, which is rapidly restored after therapy. METHODS: Coronary flow velocity was measured by intracoronary Doppler catheter before and after a maximally vasodilating dose of intracoronary papaverine in 16 control subjects and in 59 transplant patients classified into three groups with respect to time after transplantation: 1 to 6 months (group 1, n = 17), 7 to 18 months (group 2, n = 22) and > 18 months (group 3, n = 20). Coronary vascular reserve was evaluated through peak/rest coronary flow velocity ratio and minimal coronary vascular resistance index. All patients had normal findings on left ventricular angiography and coronary arteriography and a normal left ventricular mass. RESULTS: Arterial pressure was normal in all groups. Heart rate in the three groups of transplant patients, mean aortic pressure in groups 1 and 2, left ventricular systolic pressure in group 2 and rate-pressure product in groups 1 and 2 were higher than in control subjects. Average number of rejection episodes per patient was similar in the three groups of patients (group 1, 2.4 +/- 1.4; group 2, 2.5 +/- 1.9, and group 3, 2.1 +/- 1.3). Results showed no difference between each group of transplant patients and control subjects for peak/rest coronary flow velocity ratio (control subjects, 5.2 +/- 0.8; group 1, 5.3 +/- 1.5; group 2, 4.9 +/- 1.2, and group 3, 4.4 +/- 1.6) and for minimal coronary vascular resistance index (control subjects, 0.18 +/- 0.03; group 1, 0.18 +/- 0.04; group 2, 0.20 +/- 0.06, group 3, 0.23 +/- 0.11). In addition, patients with zero or one rejection episode had similar values of peak/rest coronary flow velocity ratio and minimal coronary vascular resistance index (4.3 +/- 1.3 and 0.23 +/- 0.10, respectively, n = 22) as did those with one or two rejection episodes (5.1 +/- 1.5 and 0.19 +/- 0.07, respectively, n = 24), and those with four or more episodes (5.2 +/- 1.4 and 0.19 +/- 0.05, respectively, n = 13). CONCLUSIONS: This study showed that coronary vascular reserve remains within normal range and is independent from the number of previous episodes of rejection until late after transplantation in human heart transplant patients with angiographically normal coronary arteries.

[Coronary vascular reserve in heart transplantation. Normalization after therapy for rejection]. / Réserve vasculaire coronaire dans la transplantation cardiaque. Normalisation après traitement du rejet.

Acute rejection is associated with severe impairment of coronary reserve in heart transplants. To evaluate the effects of rejection therapy, coronary reserve was assessed in 6 patients before and after treatment of an acute episode of rejection. Coronary reserve was significantly enhanced after rejection therapy (4.7 +/- 0.8, vs 2.3 +/- 0.5, P less than 0.001) and was not significantly different from that of transplanted patients without rejection (5.4 +/- 0.8). This study provides evidence that alterations of coronary reserve due to acute rejection are reversible after treatment of the rejection episode.

[Coronary disease in patient following heart transplantation]. / La maladie coronaire du transplanté cardiaque.

Coronary artery disease is a common and particularly severe complication of cardiac transplantation because it may cause progressive destruction of the graft by acute or chronic ischemia. The ischemia is usually silent because of cardiac denervation. Cardiac failure related to graft dysfunction, asymptomatic infarction on the ECG, or sudden death, are sometimes the only signs of severe coronary disease. The prevalence of coronary lesions has been evaluated by coronary angiography at nearly 25% at 2 years and 50% at 5 years. The distribution and morphology of the lesions are characteristic: diffuse concentric, irregular and occlusive, predominantly distal stenoses, without a distal and usually without a collateral circulation. The histological features are variable: the association of medial necrosis, severe endothelial lesions and intense parietal inflammation are suggestive of acute arteriolitis, often present during acute rejection, may be related to a common pathological process. Diffuse obliterative arteriolar lesions with concentric proliferation of medial smooth muscle are the usual appearances in transplant patients who have died or been retransplanted. There is no non-invasive diagnostic method sufficiently sensitive of specific which justifies the practice of many groups of systematic annual coronary angiography in transplanted patients. The pathogenesis is poorly understood and probably multifactorial: disorders of lipid metabolism, immunological factors, the atherogenic role of Cytomegalovirus infection. The absence of an identifiable risk factor makes preventive measures difficult. The evolutive risk justifies retransplantation in selected patients, the results of which are less satisfactory but which reduces the risk of acute coronary events and sudden death.(ABSTRACT TRUNCATED AT 250 WORDS)

[Myocardial mass index in the diagnosis of acute rejection of allogeneic heart transplants]. / Intérêt de déterminer la variation d'un indice de masse myocardique dans le diagnostic du rejet aigu d'une greffe cardiaque allogénique.

Changes in an index of left ventricular mass were evaluated in the diagnosis of acute cardiac transplant rejection in a prospective study involving 28 transplant patients by comparison with the histology of endomyocardial biopsy. The surface of a ring of left ventricular myocardium obtained from a 2D echocardiographic examination was used as an index of mass. Eighty-three pairs of results--biopsy and index of mass--recorded within a 12 hour interval were obtained between the first day and 10th month of transplantation over a period of 12 consecutive months. Echocardiographic diagnosis of acute rejection was made when the index of myocardial mass increased by over 7 per cent compared with baseline values recorded during the first 3 days of transplantation or during a new period of equilibrium after an episode of rejection. Two groups of patients were identified from the results of biopsy, taken as the reference: in 16 patients with mild or moderate histological signs of rejection the variation of the index of mass was 18.3 +/- 9.1%; endomyocardial biopsy was negative in the 12 other patients and the change in index of mass was -1.5 +/- 5.2% (p less than 0.001). The overall concordance in the 83 successive results was good with a Kappa coefficient of 0.71. The other parameters which have been reported to be useful in diagnosing rejection (relaxation, antegrade diastolic mitral flow, acoustic density of myocardium) present a number of problems in routine practice related either to difficulties with the recording of the data or to its interpretation.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of plasma volume expansion on hemodynamics and atrial natriuretic factor release in heart-transplant recipients.

Plasma atrial natriuretic factor (ANF), plasma cyclic guanosine monophosphate (cGMP), plasma aldosterone, plasma-renin activity (PRA) and hemodynamic parameters were measured in heart-transplant recipients and control patients (chest pain syndrome) during right-sided heart catheterization under basal conditions and in response to an intravenous saline load. Basal plasma ANF and cGMP were higher in heart-transplant recipients than in control patients, whereas PRA and plasma aldosterone did not differ. The high plasma ANF levels in heart-transplant recipients did not result from high atrial pressures but appeared to be related with elevated atrial dimensions and cyclosporine-induced renal failure. During volume expansion, plasma ANF increased in control patients and remained elevated during the postinfusion period. In heart-transplant recipients, the changes in plasma ANF were less marked despite identical increases of atrial pressures. The sluggish response of plasma ANF in this group was associated in the postinfusion period with a nonreturn of the hemodynamic parameters to their basal values in contrast with what was observed in control patients.

Recovery of a normal coronary vascular reserve after rejection therapy in acute human cardiac allograft rejection.

During acute rejection, coronary vascular reserve is severely impaired in human orthotopic heart transplants. To evaluate the effects of rejection therapy on coronary vascular reserve, the ratio of peak-to-resting coronary flow velocity was assessed with a coronary Doppler catheter and a maximally vasodilating dose of intracoronary papaverine (12 mg) in nine allograft recipients without rejection (group 1) and in six recipients before and after treatment of an acute episode of rejection (group 2). All the patients had normal epicardial coronary arteries and were free of left ventricular hypertrophy. In group 2 during rejection, the coronary vascular reserve was significantly lower than in group 1, in which all the patients had a peak-to-resting coronary flow velocity ratio greater than 4 (2.3 +/- 0.5 vs. 5.4 +/- 0.8, respectively, p less than 0.001). In group 2 after treatment of rejection, the peak-to-resting coronary flow velocity ratio was similar to that of group 1 (4.7 +/- 0.8). Heart rate, left ventricular volumes and pressures, hemoglobin concentration, and arterial oxygen pressure were similar in the two groups. This study provides evidence that alterations of coronary vascular reserve because of acute rejection were reversible after treatment of the rejection episode.

Onset and development of cyclosporin A effects on lymphocytes of cardiac patients before heart transplantation.

The effects of cyclosporin A (CSA) in low dosage (4 mg/kg/24 h i.v.) were studied in 17 patients awaiting heart transplantation. The lymphocyte subsets were typed, enumerated, and their proliferation measured before CSA perfusion, after infusion (over 24 h), and then again after two further 24 h intervals (T0 h, T24 h, T48 h, and T72 h). No significant change was found in T or B enumerations although lymphocyte function was markedly modified. For all 17 patients, there was a significant decrease in lymphocyte proliferation that was, however, re-established after 72 h for 14 of the patients, but not for the remaining 3. Inhibition of the proliferative response was found to occur rapidly, to be potent although rapidly reversible in most cases, while yet subject to wide interindividual variability. These four features suggest that (a) CSA in fixed doses may later the balance between helper and suppressor cells in varying degrees according to the patient, and that (b) CSA given immediately or shortly after heart transplantation could be beneficial.

Coronary vasodilation induced by intracoronary enalaprilat: an argument for the role of a local renin-angiotensin system in patients with dilated cardiomyopathy.

Although indicated by several experimental studies, the presence of a renin-angiotensin system has not been demonstrated in the human heart. The influence of a local renin-angiotensin system on the coronary vessels may be difficult to establish after oral or intravenous administration of an angiotensin converting-enzyme inhibitor, since coronary blood flow depends greatly on the loading conditions of the left ventricle. To avoid such a situation, our study consisted in a direct bilateral intracoronary infusion of enalaprilat in patients with dilated cardiomyopathy and normal coronary arteries (mean ejection fraction = 32 +/- 11%, n = 12). This intracoronary infusion (0.05 mg min-1, 1 ml min-1 in each coronary artery) resulted in no significant change of the systemic resistances (20.6 +/- 5.6 to 22.0 +/- 5.1 mmHg l-1 min), rate-pressure product (10,974 +/- 2630 to 10,214 +/- 2486) or myocardial oxygen consumption (21.08 +/- 6.37 to 22.10 +/- 6.42 ml min-1). Despite these steady haemodynamic conditions, intracoronary enalaprilat provoked a significant elevation of coronary sinus blood flow (181 +/- 73 to 214 +/- 79 ml min-1, P less than 0.001) with a reduction of coronary resistance (0.51 +/- 0.17 to 0.41 +/- 0.15 mmHg ml-1 min, P less than 0.001), and no significant alteration in plasma renin activity or plasma aldosterone. The results of this intracoronary infusion of enalaprilat demonstrate that this angiotensin converting-enzyme inhibitor has significant coronary vasodilator properties, which can be evidenced without stimulating the peripheral renin-angiotensin system.(ABSTRACT TRUNCATED AT 250 WORDS)

Maximal coronary vasodilator capacity of orthotopic heart transplants in patients with and without rejection.

In cardiac allograft rejection, histopathologic changes suggesting that myocardial ischemia is a component of the rejection process have been documented. To further define the coronary vascular reactivity of human heart transplant, coronary sinus blood flow and coronary resistance were measured before and after intravenous dipyridamole within the first year after transplantation in 8 patients without rejection (group II) and in 5 patients with rejection (group III). All had normal coronary arteriograms. Results were compared to those of 8 control subjects (group I). After dipyridamole, coronary sinus blood flow was increased in groups I, II and III by 303, 212 (p less than 0.01 vs group I) and 45%, respectively (p less than 0.001 vs groups I and II). Coronary resistance was reduced by 77, 73 (not significant vs group I) and 36%, respectively (p less than 0.001 vs groups I and II). Concomitantly, coronary sinus blood oxygen content was increased by 172, 145 (not significant vs group I) and 78%, respectively (p less than 0.001 vs group I, not significant vs group II). Thus, the coronary flow reserve evaluated by the dipyridamole/basal coronary sinus blood flow ratio and the coronary resistance reserve evaluated by the basal/dipyridamole coronary resistance ratio were dramatically impaired in group III (1.56 +/- 0.09 and 1.63 +/- 0.30, respectively, p less than 0.001 vs groups I and II). In contrast, they were almost normal in group II (3.11 +/- 0.42 vs 4.03 +/- 0.52 in group I, p less than 0.02, and 3.83 +/- 0.78 vs 4.45 +/- 0.81 in group I, difference not significant). Thus, the impairment of coronary reserve during heart rejection should be linked to abnormalities of the coronary microvaculature. This emphasizes the important involvement of the coronary circulation in the rejection process.

[Enoximone and the therapeutic strategy in patients awaiting emergency cardiac graft]. / Enoximone et stratégie thérapeutique chez des patients en attente d'une greffe cardiaque en urgence.

Enoximone is a positive inotropic agent belonging to the group of phosphodiesterase F-III inhibitors. The drug was tested in 34 patients uncontrolled by sympathomimetic drugs and referred to our department for urgent heart transplantation or circulatory assistance. After insertion of a Swan-Ganzgatheter and a radial artery catheter for haemodynamic monitoring, enoximone was administered as a 15-minute intravenous bolus injection of 1 to 2.5 mg/kf every 8 hours, in addition to sympathomimetic agents. Clinical and haemodynamic improvement was observed after thirty minutes in 30 patients. The cardiac index rose from 1.82 to 2.67 l/min/m2 and the pulmonary wedge pressure fell from 30.8 to 18.9 mmHg. Systemic arterial resistance decreased from 2170 to 1520 dyn. s. cm-5, and pulmonary resistance from 5.5 to 4.6 Wood units (p less than 0.01 for all values). Four patients had no haemodynamic improvement and were put on circulatory assistance, using a Jarvik 7 total artificial heart in 3 of them and heterotopic circulatory assistance in one. After clinical investigation for contra-indication to heart transplantation, and as their improved haemodynamic status permitted, 12 of the 30 patients were considered suitable (group B) for heart transplantation. Transplantation was performed within a week of admission in 11 patients without any need for mechanical assistance. One of the group B patients who required implantation of a Jarvik 7 artificial heart died after 12 hours of assistance. Eighteen patients were considered unsuitable for transplantation (group A) and treated medically.(ABSTRACT TRUNCATED AT 250 WORDS)

[Cardiac transplantation in an extreme emergency]. / La transplantation cardiaque en super urgence.

Urgent cardiac transplantation in very unstable patients, kept alive in intensive care unit, is a significant (34 percent) part of the Henri-Mondor's transplantation program. Nineteen patients received a donor graft from january 1986 to october 1988. Sixteen were bridged pharmacologically as 5 received a mechanical bridge. Time on waiting list ranged from 12 to 21 days. Six patients died in the first post-operative month. Death was due to uncontrolled preoperative problems in 5, donor graft failure in one. The survival rate at one year was 52 percent, to be opposed to 76 percent in stable patients. These figures must be considered when selecting the priority of the transplantation candidates.

[Early angioplasty in unstable angina. Results apropos of 60 consecutive patients]. / L'angioplastie précoce dans l'angor instable. Résultat à propos de 60 patients consécutifs.

Transluminal coronary angioplasty (TCA) is an attractive means of suppressing ischaemia in patients (pts) with unstable angina. Sixty consecutive pts underwent TCA 6 +/- 2.5 days on average after their admission. Only the ischaemic vessel was dilated (mean stenosis 79 p. 100). Primary success was obtained in 53 pts (88 p. 100) with 31 p. 100 of residual stenosis after TCA. Two pts underwent emergency surgery for extensive dissection; failure of traversing the stenotic segment occurred in 2 pts; 3 pts had myocardial infarction (MI) less than 1 h after TCA, 2 arteries have been recanalized by intracoronary streptokinase with persistence of a satisfactory result of TCA, the 3rd patient had occlusion of a secondary side branch. During their stay in hospital, 2 pts had coronary bypass for recurrent angina. After a follow-up period of 6 to 16 months (mean 10 months) early recurrence of angina was observed in a number of cases (before the sixth month in 7 pts). One pt developed MI during the fourth month. At six month, 10 or the initial 60 pts had undergone coronary bypass, 1 undilated pt was asymptomatic; out of 49 dilated pts (47 with one single TCA), 39 were symptom-free but 6 had a positive exercise test, 7 pts were in class II and one in class IV. At control coronary arteriography (46 pts) restenosis was present in 39 p. 100: 5 new TCA and 2 aorto-coronary bypasses were performed. At one year 28 pts had been followed up: 1 was in class IV and 1 in class II, the others being asymptomatic.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacological bridge to cardiac transplantation.

From September 1985 to August 1988, 32 patients were referred from various intensive care units throughout Paris for urgent cardiac transplantation or for a mechanical bridge to transplantation. At time of admission, under maximal sympathomimetic therapy, the cardiac index (CI) was 1.81 +/- 0.26 l/min per m2, the pulmonary capillary wedge pressure (PCWP 31 +/- 7 mmHg), systemic vascular resistances (SVR) 2053 +/- 469 dynes s cm-5. In 25, diuresis was less than 25 ml/h. Five were anuric. Prior to any final decision, a new inotropic agent, enoximone, was infused in addition to previous treatment as a 10 min bolus iv 1.5-2 mg/kg every 8 h. In 3, the situation further deteriorated, leading to a Jarvik 7-70 implantation within 12 h. In 29 however, within 3 h, the Cl increased to 2.69 +/- 0.56 as SVR dropped to 1410 +/- 453 and PCWP to 18 +/- 7. Diuresis increased to more than 100 ml/h in all. This permitted an indepth evaluation of the transplant candidates leading to contraindications to transplantation in 16. Nine patients could be weaned off iv enoximone. Four of these are still living (NYHA class III) with a follow up of 6-17 months. In 11, transplantation was performed within 2 days. Four died within a month, 2 with multiple organ failure. One patient died after 5 months. Six are back to normal life, NYHA class I (follow up 10 months-2.5 years). This protocol suggests that in patients with extreme heart failure, immediate survival may be increased by iv enoximone therapy, permitting a better selection of the recipients, more efficient pre-transplantation intensive care and consequently a decrease in the indications for a temporary mechanical bridge to a staged transplantation.

Severe impairment of coronary reserve during rejection in patients with orthotopic heart transplant.

The present study analyzed coronary sinus blood flow alterations after dipyridamole induced coronary vasodilation in seven patients whose endomyocardial biopsies evidenced no sign of rejection (group 1) and in five patients with histologic signs of rejection (group 2) after orthotopic heart transplantation. All patients were treated with cyclosporine and prednisone and some with azathioprine and had normal coronary arteriograms. Coronary sinus blood flow and coronary resistance were measured before and after intravenous dipyridamole (0.18 mg/kg/min over 4 minutes). Basal values were similar in groups 1 and 2 for coronary sinus blood flow (166 +/- 34 compared with 181 +/- 39 ml/min, respectively), coronary resistance (0.62 +/- 10 compared with 0.52 +/- 13 mm Hg/ml/min, respectively), coronary sinus blood oxygen content (5.7 +/- 1.6 compared with 4.5 +/- 0.9 ml/100 ml, respectively) and arterial-coronary sinus blood oxygen difference (10.6 +/- 1.3 compared with 10.3 +/- 1.8 ml/100 ml, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Combined heart and kidney transplantation using the same donor.

A 45-year-old man received a combined heart and kidney transplant provided by the same donor. The patient was in the terminal stage of renal failure and was submitted to 3 sessions of haemodialysis per week for 2 years before transplantation. A dilated cardiomyopathy with severe impairment of left ventricular (LV) function was discovered, precluding renal transplantation alone. In the postoperative course, a cardiac rejection episode was detected by echocardiography and documented by endomyocardial biopsy; no simultaneous rejection of the kidney could be detected. The patient was discharged after 2 months, and he resumed a normal and active life. The specific problems raised by the management of such multi-organ transplantation are briefly reviewed.

Direct myocardial and coronary effects of enalaprilat in patients with dilated cardiomyopathy: assessment by a bilateral intracoronary infusion technique.

Angiotensin II elicits contractile responses in the coronary arteries and myocardial tissue, which suggests that blockade of the renin-angiotensin system by specific agents should lead to both coronary vasodilation and an alteration of left ventricular inotropism. The present work was designed to delineate--independently from its systemic effects--the intrinsic actions of an angiotensin converting-enzyme inhibitor on the coronary circulation and left ventricular function. To minimize peripheral effects, a bilateral intracoronary infusion of enalaprilat (0.05 mg.min-1, 1 ml.min-1 in each coronary artery) was performed in 16 patients with dilated cardiomyopathy. All patients had normal coronary arteriograms. In 12 patients (group I) the intracoronary infusion of enalaprilat resulted in minimal peripheral changes, with a 5% reduction in the mean aortic pressure (p less than .05) and no significant alteration in indexes of preload, i.e., left ventricular end-diastolic pressure and volume, or of afterload, i.e., left ventricular end-systolic stress and systemic resistances. Myocardial oxygen consumption was also unaffected by the intracoronary infusion of enalaprilat. Coronary vasodilation was demonstrated by a significant elevation of coronary sinus blood flow (+19%, from 181 +/- 73 to 214 +/- 79 ml.min-1, p less than .001) and a reduction of coronary resistance (-18%, from 0.51 +/- 0.17 to 0.41 +/- 0.15 mm Hg.ml-1.min, p less than .001), with a parallel increase in coronary sinus oxygen content and pressure (both p less than .05). Oxygen extraction by the myocardium was reduced (p less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)