28 research outputs found
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