EFFECT OF PROTRACTED DOBUTAMINE INFUSION ON SURVIVAL OF PATIENTS IN CARDIOGENIC-SHOCK TREATED WITH INTRAAORTIC BALLOON PUMPING

The survival of subjects with postmyocardial infarction cardiogenic shock treated with intra-aortic balloon pumping (IABP) differs significantly among various reports. Differences in the criteria for IABP application and in the timing of its initiation have been considered as the main reasons for variations in survival. This study examines whether the way patients in cardiogenic shock are treated prior to IABP may affect their survival. Fifty-five patients in severe postmyocardial infarction cardiogenic shock were classified into three groups according to the rate of dobutamine infusion prior to IABP: the ‘’nondobutamine” (group A, n = 31), the ‘’high-dose dobutamine” (8 to 20 mug-kg-1.min-1, group B, n = 17), and the ‘’low-dose dobutamine” (up to 7 mug-kg-1 -min-1, group C, n = 7). All subjects seen from 1978 to 1983 were recruited for group A, from 1986 to 1990 for group B, and in years 1984, 1985, and 1991 for group C, without using any other classification criteria. It was shown a posteriori that the three groups did not differ in the features of the subjects, in the severity of shock, and in the time length between onset of shock and pumping initiation. None of the 17 subjects of group B could survive under pumping, while 10 of the 31 subjects in group A and 4 of the 7 subjects in group C were weaned off pumping. Conclusions: A protracted, high-dose pre-IABP administration of dobutamine may adversely affect the survival of patients with postmyocardial infarction cardiogenic shock

Reversible symmetric polyneuropathy with paraplegia after heart transplantation

Background, Neurotoxicity is a well-recognized side effect of cyclosporine therapy in transplant recipients. Cyclosporine can cause a wide range of adverse effects on both the central and peripheral nervous systems. Methods. We present a case history of symmetric polyneuropathy with flaccid paraplegia, a rare neurological complication of cyclosporine administration. Results. Blood levels of the drug above the therapeutic range accompanied the neurological manifestations. The syndrome subsided fully with dose reduction. Patients’ symptoms were attributed to axonal degeneration of the peripheral nerves, according to electromyography findings. Conclusions. Cyclosporine neurotoxicity should always be considered in patients with neurological complications following transplantation, The case presented in this article illustrates an additional potential mechanism of this adverse effect, namely, axonal degeneration of the peripheral nerves, causing symmetric polyneuropathy

EFFECTS OF AMIODARONE ON REFRACTORY VENTRICULAR-FIBRILLATION IN ACUTE MYOCARDIAL-INFARCTION - EXPERIMENTAL-STUDY

Objectives. The aim of this study was to evaluate the efficacy of a single dose of intravenous amiodarone in facilitating defibrillation of ventricular fibrillation refractory to lidocaine and epinephrine plus direct current countershocks in experimental acute myocardial infarction. Background. Amiodarone has been hailed as the most effective single antiarrhythmic drug for the treatment of ventricular arrhythmias. However, intravenous amiodarone has only sporadically been used in the defibrillation of ventricular fibrillation in acute myocardial infarction. Methods. Acute myocardial infarction was induced in 60 dogs by ligation of the proximal left anterior descending coronary artery for 2 h. Animals that developed spontaneous ventricular fibrillation were treated with lidocaine and epinephrine plus five direct-current countershocks. Dogs with ventricular fibrillation refractory to this regimen were randomized to further treatment with additional intravenous administration of epinephrine and bolus lidocaine plus less-than-or-equal-to 15 direct-current countershocks (group 1) or administration of amiodarone, 10 mg/kg body weight intravenously, followed by defibrillation with direct-current countershock (group II). Results. Sixteen (27%) of the 60 dogs in which the protocol was attempted developed spontaneous ventricular fibrillation 21 min after ligation and were included in the study. Lidocaine and epinephrine plus five direct-current countershocks succeeded in converting ventricular fibrillation in one dog (6%). The other 15 dogs were randomized to group I (8 dogs) or group II (7 dogs). Defibrillation was achieved in one of the eight dogs in group I and in six of the seven dogs in group II (p < 0.005). Conclusions. In an experimental model of acute ischemia, intravenous amiodarone (10 mg/kg) influences positively the response to defibrillation of ventricular fibrillation refractory to lidocaine and epinephrine plus direct current countershocks

A valveless high stroke volume counterpulsation device restores hemodynamics in patients with congestive heart failure and intractable cardiogenic shock awaiting heart transplantation

The paraaortic counterpulsation device is a round pumping chamber with one valveless opening 20 mm in diameter and a 100 ml stroke volume. The paraaortic counterpulsation device was implanted on the ascending aorta of three male patients with intractable cardiogenic shock. Patients were assisted for 4 hours and 8 and 54 days, respectively; the first patient died as a result of nonresponding peripheral vasodilation and the other two died of septic shock. The two patients who were assisted for 8 and 54 days were conscious and able to function in a limited manner during the mechanical assistance. Discontinuation of the mechanical support for a few seconds was followed by low systolic arterial pressure (30 to 60 mm Hg) and syncopal episodes. Biochemical tests and autopsy results in these patients showed no evidence of blood cell destruction, thrombus formation, brain infarction, or other distal emboli. In conclusion, satisfactory hemodynamic effects, excellent biocompatibility, and simplicity of the implantation procedure in these patients encourage the use of the paraaortic counterpulsation device as a bridge to heart transplantation

Long-term intermittent dobutamine infusion, combined with oral amiodarone for end-stage heart failure - A randomized double-blind study

Study objectives: To examine the effects of long-term intermittent dobutamine infusion, combined with oral amiodarone in patients with congestive heart failure (CHF) refractory to standard medical treatment. Design: Prospective, randomized, double-blind, placebo-controlled clinical trial. Setting: Inpatient and outpatient heart failure clinic in a university teaching hospital. Patients and interventions: Thirty patients with end-stage CHF refractory to standard medical treatment who could be weaned from dobutamine therapy after a first 72-h infusion were randomized in a double-blind manner to receive IV infusions of placebo (group 1; 14 patients) vs dobutamine in a dose of 10 mug/kg/min (group 2; 16 patients) for 8 h every 14 days. All patients received standard medical therapy and also were treated with oral amiodarone, 400 mg/d, which was started at least 2 weeks before randomization. Measurements and results: Kaplan-Meier survival analysis showed a 60% reduction in the risk of death from any cause in the group treated with the combination of dobutamine and amiodarone, compared with the group treated with placebo and amiodarone (hazard ratio, 0.403; 95% confidence interval, 0.164 to 0.992; p = 0.048). The 1-year and 2-year survival rates were 69% and 44%, respectively, in the dobutamine-treated group, vs 28% and 21%, respectively, in the placebo-treated group (p < 0.05 for both comparisons). Median survival times were 574 and 144 days, respectively, for groups 2 and 1. At 6 months, the New York Heart Association functional class was significantly improved in the patients who survived from both groups. Conclusions: Long-term intermittent dobutamine infusion combined with amiodarone added to the conventional drugs improved the survival of patients with advanced CHF that was refractory to conventional treatment

The long-term survival benefit conferred by intermittent dobutamine infusions and oral amiodarone is greater in patients with idiopathic dilated cardiomyopathy than with ischemic heart disease

Background: Intermittent dobutamine infusions (IDI) combined with oral amiodarone improve the survival of patients with end-stage congestive heart failure (CHF). The purpose of the present study was to evaluate whether the response to long-term treatment with IDI+amiodarone is different in patients with ischemic heart disease (IHD) versus idiopathic dilated cardiomyopathy (IDC). Methods: The prospective study population consisted of 21 patients with IHD (the IHD Group) and 16 patients with IDC (the IDC Group) who presented with decompensated CHIF despite optimal medical therapy, and were successfully weaned from an initial 72-h infusion of dobutamine. They were placed on a regimen of oral amiodarone, 400 mg/day and weekly IDI, 10 mu g/kg/min, for 8 h. Results: There were no differences in baseline clinical and hemodynamic characteristics between the 2 groups. The probability of 2-year survival was 44% in the IDC Group versus 5% in the IHD Group (long-rank, P=0.004). Patients with IDC had a 77% relative risk reduction in death from all causes compared to patients with IHD (odd ratio 0.27, 95% confidence interval 0.13 to 0.70, P=0.007). In contrast, no underlying disease-related difference in outcomes was observed in a retrospectively analyzed historical comparison Group of 29 patients with end stage CHIF treated by standard methods. Conclusions: Patients with end stage CHF due to IDC derived a greater survival benefit from IDI and oral amiodarone than patients with IHD. (c) 2005 Elsevier Ireland Ltd. All rights reserved

High stroke volume para-aortic counterpulsation device versus centrifugal pump in cardiogenic shock: Experimental study

During the last decades a number of left ventricular assist devices has been used especially for patients resistant to pharmacologic treatment and to intraaortic balloon pump (IABP) support for left ventricular failure. A high stroke volume para-aortic counterpulsation device (PACD) has been developed utilizing the principle of the diastolic counterpulsation technique. In this study the hemodynamic effects of the valveless PACD were compared to those of the centrifugal blood pump (CBP) in nine dogs in acute experimental cardiogenic shock Hemodynamic measurements were obtained at baseline with both devices off, PACD an and CBP off, or PACD off and CBP on. There was no difference in mean aortic pressure between PACD on (60.0 +/- 11.5 mmHg) and CBP on (69.0 +/- 26.8 mmHg). Similarly, there was no difference in left ventricular end-diastolic pressure with the PACD on (11.9 +/- 5.4 mmHg) versus the CBP on (9.9 +/- 5.2 mmHg) or the cardiac index with the PACD on (84 +/- 36 ml/kg/min) versus the CBP on (77 +/- 36 ml/kg/min). However, the left ventricular systolic pressure (55.0 +/- 19.0 with PACD versus 73.0 +/- 26.0 with CBP, p < 0.001), the tension time index (712 +/- 381 versus 1333 +/- 694, p < 0.01), and the double product (5629 +/- 2574 versus 7440 +/- 3294, p < 0.01) were significantly lower during assistance with the PACD than with the CBP. It was concluded that PACD is at least as effective as CBP for restoring hemodynamic status during acute experimental cardiogenic shock Moreover, the PACD unloads the left ventricle more effectively than CBP, making it suitable for left ventricular mechanical support in cases with reversible myocardial damage

Myocardial salvage by the use of reperfusion and intraaortic balloon pump: Experimental study

Background. Thrombolytic therapy improves left ventricular ejection fraction and survival. The study was undertaken to evaluate the effects of intraaortic balloon pump used in conjunction with reperfusion in reducing infarct size. Methods. Twenty-two dogs were subjected to proximal left anterior descending coronary artery occlusion. In group 1 (n = 7) occlusion lasted for 6 hours. In group 2 (n = 6)2 hours of occlusion was followed by reperfusion. In group 3 (n = 9) after 2 hours of occlusion the dogs were assisted with the intraaortic balloon pump throughout the 4 hours of reperfusion. At the end of 6 hours the infarcted myocardium of the left ventricle was determined and expressed as percentage of the myocardium at risk. Results. In group 1, the infarcted myocardium was 79.3 +/- 9.9% of the myocardium at risk, in group 2, 59.0 +/- 19.9% (p < 0.05 versus group 1), and in group 3, 37.1 +/- 16.7% (p < 0.001 versus group 1 and p < 0.05 versus group 2). Endocardial viability ratio was increased by the intraaortic balloon pump; in group 1 it was 1.02 +/- 0.14, in group 2, 1.25 +/- 0.24, and in group 3, 1.47 +/- 0.31 (p < 0.001 versus group 1 and p < 0.02 versus group 2). Conclusions. Reperfusion and intraaortic balloon pump increased salvage of the ischemic myocardium over that achieved by reperfusion alone in a canine occlusion-reperfusion model