Single-lead VDD-pacing system incorporating high impedance stimulation: a multicentre study.

AIM: The purpose of this study was to evaluate the performance of a new VDD pacing system incorporating a high impedance, single-pass VDD lead. The new lead is a bipolar, steroid-eluting, high impedance lead with a full-ring atrial dipole. METHODS AND RESULTS: The system was implanted in 46 patients with high degree atrioventricular (AV) block. Patients were followed at pre-discharge, 6 weeks, and 3 months. The mean measured P-wave amplitude was stable, with values between 1.18 and 1.43 mV. Atrial sensing was reliable during short-term evaluation at rest and in the sitting position, with AV-synchronous stimulation between 98.79 +/- 6.90% and 99.73 +/- 1.47%. Holter recordings after 6 weeks demonstrated AV-synchronous stimulation in 99.57 1.03% of all P-waves. Lead impedance was stable during follow-up, with mean values between 1000 and 1167 Q. Mean ventricular pacing thresholds (at 0.5 ms) were 0.47 V at implant, 0.49 V at pre-discharge, 0.74 V at 6 weeks, and 0.72 V at 3 months. R-wave amplitude remained stable between 14.9 and 16.7 mV during follow-up. CONCLUSION: This new single-pass VDD lead system provided reliable atrial sensing and stable high impedance stimulation during a 3-month follow-up period.

[Implantable defibrillators. Role of the defibrillator in treatment and prevention of sudden death]. / Les défibrillateurs implantables. Le rôle du défibrillateur en traitement et en prévention de la mort subite.

PROVEN EFFICACY: Several studies have demonstrated that implantable defibrillators improve survival in patients with a very high risk of sudden death. INDICATIONS FOR PRIMARY PREVENTION: The most obvious indication is for young patients with severe recurrent rhythm disorders and generally good left ventricular function. However, most of the candidates have severe left ventricular dysfunction due to post infarction ischemia or dilated cardiomyopathy who develop syncopal or hemodynamically poorly tolerated ventricular tachycardia or who have survived a first episode of sudden death. PROPHYLACTIC INDICATIONS: Automatic defibrillation should be proposed for patients with factors of risk of sudden death such as left ventricular dysfunction or infarction sequelae.

[Implantable defibrillators. Sudden death: high risk]. / Les défibrillateurs implantables. La mort subite: un risque certain.

INCIDENCE: The incidence of sudden death remains high. The basic causes are related to ischemic heart disease and heart failure. Automatic defibrillation is the best treatment, as first conceived and implanted by Mirovski twenty years ago. MARKERS OF RISK OF SUDDEN DEATH: Left ventricular dysfunction, functional class and spontaneous and induced ventricular hyperexcitability identify a high-risk population. THERAPEUTIC APPROACH: Drug treatments used in the post infarction period or for heart failure (beta-blockers, converting enzyme inhibitors and amiodarone) have demonstrated a certain efficacy in preventing sudden death. However, different therapeutic trials comparing the efficacy of defibrillators and drug treatments have demonstrated the 20 to 46% superiority of defibrillation in terms of reduced mortality.

Diagnostic value of stored electrograms in single-lead VDD systems.

UNLABELLED: Evaluation of the quality of atrial sensing is indispensable to monitor the performance of VDD single-lead systems. In addition to counters, a new VDD system offers storage of intracardiac electrograms (EGMs). The clinical contribution of stored EGMs in a VDD pacemaker was prospectively examined in a multicenter study, and the reliability of its counters was evaluated on the basis of EGM information. METHODS: A VDD system (Pulsar 870, Guidant Co.) was implanted in 46 patients with atrioventricular block. EGM storage was activated upon detection of ventricular tachycardia (VT), recurrent premature ventricular complexes (PVCs), and mode switch ("atrial tachy reaction," ATR). Stored EGMs were retrieved before discharge of the patients from the hospital, and at 6-week, 3-month, and 6-month follow-up. RESULTS: A total of 440 stored EGMs were retrieved and analyzed. Of 30 VT episodes detected, 2 (7%) were confirmed, and all others were attributable to ventricular oversensing. One postmortem interrogation documented VT as the cause of sudden death. Of 175 EGMs stored upon detection of PVCs, 43 episodes (25%) were confirmed and 124 (70%) showed intermittent atrial undersensing with spontaneous AV conduction; in 8 episodes (5%) no abnormality was observed. Of 235 episodes stored upon ATR, 82 (35%) were confirmed and 153 were due to atrial oversensing. CONCLUSIONS: (1). Stored EGMs indicated a high percentage (69%) of event misdiagnosis by the pacemaker. Thus, pacemaker counter information without the availability of stored EGMs should be interpreted with caution. (2). Misclassified events are of high clinical importance since they unmask otherwise unsuspected intermittent under- or oversensing.

[Hypertrophic obstructive cardiomyopathy and double-chamber pacing. Long-term results in a consecutive series of 22 patients]. / Cardiomyopathie hypertrophique obstructive et stimulation cardiaque double chambre. Résultats à long terme d'une série consécutive de 22 patients.

The authors report their experience with dual-chamber pacing in hypertrophy obstructive cardiomyopathy. 22 patients (14 women and 8 men) mean age 60 +/- 13 years were implanted between 1992 and 1998. The criteria for pace-maker implantation were the presence of severe symptoms related with hypertrophy obstructive cardiomyopathy (dyspnea, angina, syncope) and left ventricular outflow tract gradient at mean 30 mmHg. Before pacing, all patients received a medical therapy which included beta-blockers or calcium inhibitors. This treatment was considered as ineffective or responsible of side effects. Patients were followed-up at mean 35.1 +/- 20.3 months. During this period, symptoms improved (mean NYHA class 2.7 +/- 0.5 before pacing vs 1.4 +/- 0.5 after pacing) and left ventricular outflow tract lowered from 95.4 +/- 40.8 to 39.3 +/- 20.5 at 6 months. 34.3 +/- 23.4 at one year and 26.5 +/- 21 at the end of follow-up. Seven patients had RF ablation of atrio-ventricular junction for paroxysmal atrial fibrillation or for lack of hemodynamic improvement with pacing. This procedure permits a significative lowering of gradient and a better ventricular filling. In conclusion, dual-chamber pacing is effective for treatment of hypertrophy obstructive cardiomyopathy when medical therapy is ineffective or bad tolerated at condition of: perfect pacing with permanent ventricular capture and optimal AV delay; RF ablation of AV junction in one third of cases; medical therapy systematically associated in all patients.

Chronic irregular idiopathic ventricular tachycardia with myocardial dysfunction suppressed by verapamil in an adult.

We report a case of an almost permanent ventricular tachycardia that occurred in a 39-year-old man a few weeks before admission to the hospital. This arrhythmia was noticeable by its total irregularity and its association with a left ventricular dysfunction. The precise nosological frame for the arrhythmia was difficult to define. This case presented as an idiopathic left ventricular tachycardia, the features of which could be consistent with an atypical parasystole. The rapid abolition of the rhythm disturbance by oral verapamil without recurrence at 6 months resulted in normalization of the contractile function.

Effects of piroximone on the right ventricular function in severe heart failure patients.

OBJECTIVES: To assess the effects of piroximone, a phosphodiesterase inhibitor, on right ventricular function in patients with heart failure. DESIGN: Randomized study: patients were randomly assigned to the piroximone infusion rate of 5 or 10 micrograms/kg/min. SETTING: Cardiologic intensive care unit. PATIENTS: 12 consecutive patients with severe heart failure. INTERVENTIONS: Right heart catheterization was performed using a Swan-Ganz ejection fraction thermodilution catheter. MEASUREMENTS AND RESULTS: Measurements of right ventricular ejection fraction (RVEF), end-diastolic and end-systolic right ventricular volumes were obtained using the thermodilution principle. To determine contractility indexes, the relationships between end-systolic pulmonary arterial pressure (ESPAP) over right ventricular end-systolic volume (RVESV) and ESPAP over RVEF were calculated during the infusion of prostacyclin at incremental infusion rates of 2, 4, 6 and 8 ng/kg/min. The slope of the relation between ESPAP over RVESV shifted during piroximone therapy from 7.635 +/- 1.632 to 1.975 +/- 0.432 (p < 0.01) and from 6.092 +/- 1.99 to 1.028 +/- 0.853 (p < 0.05) at 5 and 10 micrograms/kg/min piroximone infusion, respectively. The slope of the relation between ESPAP over RVEF decreased from -0.414 +/- 0.296 to -0.821 +/- 0.257 (p < 0.01) and from -0.127 +/- 0.048 to - 0.533 +/- 0.135 (p < 0.05) at 5 and 10 micrograms/kg/min piroximone infusion, respectively. CONCLUSIONS: This study suggests a positive action of piroximone on right ventricular contractility at these 2 dosages. This approach using this type of catheter allowed us to determine right ventricular inotropic indexes.

Additive haemodynamic effects of piroximone and prostacyclin in severe chronic heart failure.

This study was undertaken to assess the haemodynamic effects of the combined infusion of prostacyclin and piroximone, a phosphodiesterase inhibitor, in 18 patients with severe congestive heart failure. Right heart catheterization was performed with a Swan-Ganz thermodilution catheter and arterial blood pressure was monitored using a radial line. After baseline haemodynamic measurements, prostacyclin was administered in all patients at the incremental infusion rate of 2, 4, 6 and 8 and 10 ng.kg-1.min-1 during 15 min each. After recovery of baseline haemodynamics, patients were randomly assigned to the piroximone infusion rate of 5 or 10 micrograms.kg-1.min-1 or placebo. After 24 h piroximone or placebo infusion, the same prostacyclin protocol was applied. Prostacyclin infusion added to piroximone resulted in a significant improvement in haemodynamics, as compared to the group receiving prostacyclin added to placebo. As compared to the curve observed with the placebo infusion, 10 ng.kg-1.min-1 prostacyclin infusion resulted in a further increase in cardiac index, by 41 and 38% (P < 0.01) at the piroximone-infusion rates of 5 and 10 micrograms.kg-1.min-1, respectively, whereas systemic vascular resistance decreased by 25 and 21%, respectively (P < 0.01). Additionally, a further decrease in pulmonary capillary wedge pressure by 13 and 11% (P < 0.05) and in pulmonary vascular resistance by 21 and 19% (P < 0.05) was observed at the piroximone-infusion rates of 5 and 10 micrograms.kg-1.min-1, respectively. Consequently, stroke work index increased significantly, as compared to the group receiving prostacyclin added to placebo. This haemodynamic improvement occurred without significant changes in heart rate and mean arterial pressure. Thus, this study shows that in patients with severe congestive heart failure, short-term infusion of prostacyclin is safe and has additive haemodynamic effects on phosphodiesterase inhibitors.

Hemodynamic effects of a new calcium antagonist, SR 33557, in patients with coronary artery disease and normal left ventricular function.

SR 33557 is a new calcium antagonist which in vitro demonstrated selectivity for smooth muscle over cardiac muscle. To assess the hemodynamic effects of SR 33557 in humans, SR 33557 was administered intravenously (i.v.) in 9 patients with normal systolic left ventricular function [LV ejection fraction (EF) = 63.7 +/- 8%] undergoing right and left catheterization. Baseline measurements were recorded before and during right atrial pacing (100 beats/min), after which 5 mg SR 33557 was infused in 10 min and hemodynamic parameters were continuously recorded until 30 min after discontinuation of the infusion. Effects of SR 33557 were evident from discontinuation of the infusion, maximal between the tenth and twentieth min after discontinuation of the infusion. Without atrial pacing, the main effect of SR 33557 infusion was to decrease heart rate (HR) from 77.7 +/- 10.7 to 61.9 +/- 9.3 beats/min (p < 0.001). Cardiac index (CI) did not change; stroke volume index (SVI) increased from 44.2 +/- 13 to 50.4 +/- 15 ml.m-2, (p < 0.05). Mean arterial pressure (MAP) decreased from 104.7 +/- 29.6 to 94.3 +/- 22.9 mm Hg (p < 0.05) with no change in filling pressures or systemic vascular resistance (SVR). Consequently, rate-pressure product (RPP) decreased from 8,211 +/- 3,092 to 5,906 +/- 2,025 mm Hg.beat-1 (p < 0.01). Peak positive LVdP/dt decreased from 1,711 +/- 257 to 1,533 +/- 194 (p < 0.01). During the pacing phase, none of the hemodynamic parameters differed from baseline; especially peak positive LVdP/dt remained unchanged. SR 33557 has negative chronotropic action but shows no direct negative inotropic effect in patients with normal systolic LV function.

[Hemodynamic study of intravenous milrinone in 26 patients with NYHA class III or IV cardiac failure]. / Etude hémodynamique de la milrinone par voie intraveineuse chez 26 patients en insuffisance cardiaque de classe III ou IV de la NYHA.

The hemodynamic effects of milrinone (WIN 47203) were studied in 26 NYHA Class III or IV patients. The compound was administered intravenously using a protocol including an initial push dose of 50 micrograms/kg in 10 min, followed by a 24 hour infusion at the dose of 0.5 microgram/kg/min. Maximal response was obtained after 15 min and persisted during the infusion: cardiac index increased from 2.08 +/- 0.36 l/min/m2 to 3.09 +/- 0.68 l/min/m2, while capillary pressure fell from 25 mmHg to 16-17 mmHg. These variations were significant (p = 0.01). Heart rate was stable. Mean peripheral blood pressure fell modestly (6%). Systemic vascular resistance fell by 30% and pulmonary vascular resistance by 20%. All these results confirmed the beneficial effect of this inotropic agent administered intravenously. The increase in ventricular premature contractions noted by many justifies the careful surveillance of these patients by monitoring.

Evaluation of bepridil efficacy by electrophysiologic testing in patients with recurrent ventricular tachycardia: comparison of two regimens.

The purpose of the study was to evaluate this effect of different doses of intravenous and oral bepridil on the induction of ventricular tachycardia. Thirty-eight patients underwent electrophysiologic evaluation for recurrent ventricular tachycardia (VT). Sustained monomorphic VT was induced by programmed ventricular stimulation, using up to three extrastimuli in all patients. The effects of intravenous bepridil (2 mg/kg) were evaluated during the initial study. Intravenous bepridil prevented the induction of sustained VT in eight patients (21%). Electrophysiologic study was repeated after oral bepridil. In six patients the study was stopped because of adverse effects or VT recurrence. Thirty-two patients underwent repeat study 7 days later, taking oral bepridil, 500 mg/day (n = 16) or 900/day (n = 16). A dose of 500 mg/day of bepridil prevented the induction of sustained VT in only one patient. A dose of 900 mg/day of bepridil prevented the induction of sustained VT in eight patients. There were no significant clinical adverse effects, except in one patient receiving intravenous bepridil. The response to intravenous bepridil did not predict the response to oral bepridil. The response to intravenous or oral bepridil was not related to the plasma level of bepridil but was related to a higher left ventricular ejection fraction. Eight patients (21%) in whom VTs were noninducible on oral bepridil were discharged on 300 mg/day of bepridil if their initial loading dose was 500 mg/day or on 600 mg/day if their initial loading dose was 900 mg/day. They remained free of VT during a follow-up of at least 6 months.(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.

Acute postinfarction septal rupture: long-term results.

From 1973 to 1989, 66 patients received early surgical repair for acute postinfarction ventricular septal rupture. Mean age was 64 +/- 7 years (range, 45 to 80 years). Ventricular septal rupture occurred soon after acute myocardial infarction (3.4 +/- 4 days), and the first medical treatment occurred 6.7 +/- 7 days after onset of acute myocardial infarction. Three patients had a previous myocardial infarction. The site of the rupture was anterior in 38 patients (57%) and posterior in 28 (43%). Forty-four patients (67%) were in shock at the time of admission. Intraaortic balloon pumping was used preoperatively in 28. Operation was performed at the time of maximal efficacy of medical treatment. The same technique was used in all cases. Associated procedures included coronary bypass grafting in 5 patients and valvar operation in 5. The patients have been carefully followed up for up to 16 years. Hospital mortality was 45% (30 patients) and was cardiac related or due to acute renal failure in 25 patients (83%). No correlation could be revealed between early death and age, sex, preoperative intraaortic balloon pumping, or year of operation. Location of the ventricular septal rupture (early mortality of 57% for posterior versus 37% for anterior ventricular septal rupture) and shock at the time of admission (52% versus 32%) showed a trend toward significance (0.08 less than or equal to p less than 0.10). Response to initial active therapy has a strong predictive value (mortality of 70% in unresponsive patients versus 14% in responders; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Physiologic assessment of milrinone therapy in severe heart failure patients.

To assess the inotropic, vasodilator, and after-load-reducing effects of intravenous milrinone in patients with severe congestive heart failure, a simple noninvasive echocardiographic study coupled with a right catheterization was performed in 12 patients. Milrinone was administered intravenously as a 50 micrograms.kg-1 bolus followed by a 24-h milrinone infusion at a rate of 0.5 mg.kg-1.min-1 [corrected]. Echocardiographic left ventricular end-diastolic diameter (Ded), end-systolic diameter (Des), and wall thickness were measured at baseline and at 24 h of milrinone infusion, before and after a sublingual nitrate administration (0.8 mg of nitroglycerin) that induced load variations. Hemodynamic measurements were performed simultaneously. Left ventricular end-systolic meridional wall stress (Ses) was then calculated. The slopes of percent fractional shortening (percent FS)/Ses and Ses/Des, obtained during sublingual nitrate administration, were traced. Both end-systolic relations are an index of the contractile state. Milrinone therapy improved hemodynamics in all patients, resulting in stabilized hemodynamic conditions between 12 and 24 h of continuous milrinone infusion. At these times, the cardiac index increased to 30% while the capillary pulmonary wedge pressure and systemic vascular resistance decreased to 26 and 24%, respectively (all p less than 0.01). The average slope of Ses/Des shifted upward from 47.5 +/- 30 to 69.25 +/- 34 (p less than 0.05) and the average slope of (percent FS)/Ses shifted from -0.032 +/- 0.025 to -0.082 +/- 0.061 (p less than 0.01), both variations attesting the inotropic effect of milrinone.(ABSTRACT TRUNCATED AT 250 WORDS)

[Medical strategy in patients awaiting emergency heart transplantation]. / Stratégie médicale chez les patients en attente de greffe cardiaque en urgence.

Cardiac transplantation is theoretically the optimal final treatment of terminal cardiac failure but the indications, especially in the emergency situation, should be carefully considered. Sympathomimetic agents are of limited use in patients with severe cardiac failure partly because of the down regulation of the myocardial beta-receptors. The phosphodiesterase inhibitors, represented by enoximone, are valuable because of their action on the cardiac muscle (inotropic and lusitropic) and their direct systemic vasodilator effect. Enoximone can be administered by intravenous bolus resulting in a rapid onset of action (peak at 30 minutes) with a prolonged effect due to its hepatic metabolites. The authors' experience in this indication dates over 5 years and over 50 patients were included. A preliminary study in 34 patients with cardiac failure resistant to betamimetic drugs, referred to the intensive care unit for urgent cardiac transplantation, or, in the absence of a donor, circulatory assistance is reported. A Swan Ganz catheter and radial artery canula were inserted for haemodynamic monitoring and enoximone was administered in an intravenous bolus over 15 minutes every 8 hours in addition to sympathomimetic agents. A haemodynamic improvement was observed after the 30th minute in 30 patients. The cardiac index increased from 1.82 to 2.67 l/mn/m2 and the pulmonary capillary pressures decreased from 30.8 to 18.9 mmHg. Systemic arterial resistances fell from 2,170 to 1,520 dynes.s.cm-5. No haemodynamic improvement was observed in 4 patients who were treated by mechanical ventricular assistance. After investigations to detect contra-indications to cardiac transplantation, 12 of the 30 patients remained candidates for cardiac transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Pre-hospital thrombolysis, is it useful?

Thrombolytic treatment efficacy is greater when the delay between onset of pain and treatment is short. One way to shorten this delay is to give treatment at home, but one cannot recommend this technique if it has not been demonstrated first, that pre-hospital thrombolysis is feasible and safe, and second, that it is useful. We have been able to demonstrate that pre-hospital thrombolysis with APSAC is feasible and safe. Our findings are similar to those of other teams using other drugs. Whether pre-hospital thrombolysis is useful has not been adequately assessed; and we consider that first, the benefit of pre-hospital vs in-hospital thrombolysis must be determined, and second, the results of a study involving many centres, with various levels of training, practicing pre-hospital thrombolysis must be examined. Two large scale studies are currently being performed. One in Seattle, uses left ventricular ejection fraction as the major end-point, whereas the other, the European Myocardial Infarction Project, (EMIP) is using total mortality. Data currently available indicate that pre-hospital thrombolysis with APSAC is feasible, easy and safe. We hope that we will very soon be able to answer the last question: is it useful?

[Dipyridamole echocardiography test during the acute phase of lower myocardial infarction]. / Echographie sous dipyridamole à la phase aiguë d'un infarctus du myocarde inférieur.

Two-dimensional echocardiography with intravenous injection of dipyridamole (0.56 mg/kg) was performed in 33 consecutive patients with acute (2 +/- 2 days) postero-inferior myocardial infarction for semiquantitative segmental wall motion analysis. The results were compared with those of coronary angiography which was carried out during the hospital period. After a second evaluation of the recordings the following results were obtained: feasibility: 94 per cent with 85 per cent of segments analysed. Residual ischaemia in the first days of myocardial necrosis was common (70%). The ischaemia was often clinically silent including during the investigation (61%). When pain occurred, it always followed changes in regional wall motion. The dipyridamole test suggested multivessel disease with a sensitivity of 72 per cent and a specificity of 90 per cent, and residual arterial stenosis with a sensitivity of 75 per cent ans specificity of 80 per cent the secondary effects were minor. The main limitation of the test is related to the distinction between pharmacological and physiologic ischaemia. A positive test was associated with lesions justifying myocardial revascularisation (coronary bypass or angioplasty) in 19 out of 23 cases but with a very poor correlation with the topography of the coronary lesions. A negative test indicated arterial occlusion, residual stenosis with extensive myocardial damage or a normal coronary angiogram. Therefore, the dipyridamole echocardiography test may help identify a group of patients with little or no myocardial ischaemia in whom invasive investigations could be deferred; these patients contrast with the group with a positive test indicating residual ischaemia in which the coronary lesions should be documented by coronary angiography.

Prehospital use of APSAC: results of a placebo-controlled study.

Thrombolytic treatment efficacy is greater when the delay between onset of pain and treatment is short. To give treatment before admission to a coronary care unit, responsibility needs to be transferred from cardiologists to other physicians working in mobile care units. We conducted a 2-part feasibility study to investigate this strategy. Part 1 evaluated the diagnostic accuracy of mobile care unit physicians. Results from this study indicate that with regard to the diagnosis of acute myocardial infarction, the risk of a wrong diagnosis is low. Part 2 was a placebo-controlled trial involving 100 patients in which 57 received anisoylated plasminogen streptokinase activator complex (APSAC) (30 U) at home and 43 received placebo at home. Patients receiving placebo at home were reevaluated on arrival in a coronary care unit and received APSAC (30 U) if indicated. The main results were that (1) diagnostic accuracy was good--all patients had an acute coronary syndrome and 97 of 100 patients had myocardial infarction; (2) time gain was approximately 60 minutes; (3) coronary patency rate was 72%; (4) ejection fraction was higher in the prehospital group (56.7%) than in the control group (53.4%), but the difference was not significant; (5) there was no rhythmic or bleeding complication related to the prehospital treatment; (6) 5 patients died from cardiogenic shock--2 between home and hospital and 3 in the hospital (3 received thrombolytic treatment at home and 2 received placebo at home and APSAC in the hospital); and (7) prehospital administration of APSAC did not induce a delay in arrival to the coronary care unit.(ABSTRACT TRUNCATED AT 250 WORDS)

[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)