Hemorrhagic infarct of the brain during cardiogenic shock]

The paper deals with the possible mechanism in the development of a hemorrhagic brain infarction during myocardial infarction, complicated by a cardiogenic shock of the III degree. The results of a postmortal study of the brain, its major arteries, as well as the vessels of the Willis circle, permit to assume that the mechanism of realization of this cerebral vascular complication is in a joint metabolic and microcirculatory disorders accompanying the shock. Besides, there is also a stenosing atherosclerotic process, with prevalent lesion of the intracranial part of the magistral arteries, supplying the brain.     

Current status of post-infarction cardiogenic shock and revascularization

Despite improved management of myocardial infarction, the incidence of cardiogenic shock remains constant at about 7.5% of cases. Patients who develop cardiogenic shock are older and much more often women. The site of infarction is usually anterior, transmural with greater left ventricular systolic dysfunction and a higher increase in cardiac enzymes. Diastolic intra-aortic balloon pumping is the usual treatment but survival only seems to be increased in patients undergoing revascularisation. Surgical revascularisation and circulatory assist devices have been proposed but patient selection in these studies was biased and optimised the results. The effect of thrombolysis was analysed in a subgroup of patients in the GISSI study. The 30 day mortality was 69.9% in 146 patients treated by streptokinase and 70.1% in patients given placebo. Thrombolysis only benefitted patients with an anterior myocardial infarction aged less than 65 and treated within 6 hours of the onset of pain. Although there are no randomised studies of the value of angioplasty in patients in cardiogenic shock. Several uncontrolled series suggest that this type of procedure reduces short and long-term mortality. However, the prognosis is not as good when unselected consecutive groups of patients are studied in whom infarction is complicated by cardiogenic shock immediately and who undergo "aggressive" revascularisation: 72% of patients die in hospital and there are few long-term survivors. The prognosis appears to be particularly poor in patients over 70 years of age with a previous history of myocardial infarction or who undergo prolonged pre-hospital cardiopulmonary resuscitation. However, the implantation of coronary stents associated with circulatory assist devices seems to improve the prognosis of infarction complicated by cardiogenic shock by ensuring adequate coronary flow and reducing the risk of reocclusion.     

Mechanical assistance in cardiogenic shock after cardiac surgery

With [14C]oleate-labeled phosphatidylcholine as a substrate for phospholipase D the hydrolytic activity was measured by phosphatidic acid formation and the transphosphatidylation activity was measured by the phosphatidylethanol formed in the presence of ethanol. The pH optimum was 6.5 with dimethylglutarate as the buffer. EGTA inhibited the transphosphatidylation activity to a greater extent than the hydrolytic activity. In contrast CaCl2, BaCl2, MgCl2 and SrCl2 stimulated the hydrolytic activity without effecting the transphosphatidylation activity. BeCl2 another member of the group IIa transition metals was a very potent inhibitor of both the hydrolytic and transphophatidylation activity. GTP gamma S, an activator of G protein-mediated events, was an inhibitor of both activities.     

Magnesium deficiency and cardiogenic shock after cardiopulmonary bypass

Magnesium is an important cation that has a key role in cellular processes of energy transfer and utilization involving adenosine triphosphate, and influences cell membrane functions. Its antiarrhythmic properties are well-known and it is widely recognized as an adjunct for the treatment of arrhythmias after myocardial infarction and cardiopulmonary bypass. Magnesium may influence hemodynamic performance through its effects on vascular tone, modulation of intracellular calcium, regulation of catecholamine activity, and its essential role in adenosine triphosphate metabolism. The potential for magnesium deficiency to affect cardiovascular performance may be especially relevant in ischemic states. We report a case of cardiogenic shock developing after cardiopulmonary bypass that was initially unresponsive to therapeutic intervention, but that resolved promptly after magnesium administration. The potential role of magnesium in enhancing hemodynamic performance is discussed, with a review of its cellular metabolic properties and activities.     

Advances in the treatment of cardiogenic shock (author's transl)

Advances in the conservative treatment of cardiogenic shock have been achieved by a combination of the use of drugs (dopamine, furosemide, prednisolone), artificial ventilation and parenteral nutrition (to avoid a negative energy situation). Basic requisites for such therapy are the continuous monitoring of haemodynamic parameters (pulmonary wedge pressure, cardiac index) and of laboratory results (blood gas analysis, pO2, pCO2, osmolarity, blood glucose level). Assisted circulation (IABP) should be started immediately if it becomes apparent that little or no effect has been achieved by medical treatment. Protection is provided by the IABP for further investigation of the patient by selective coronary angiography and surgical intervention whenever possible.     

Hemodynamics of pancreatic ischemia in cardiogenic shock in pigs

BACKGROUND & AIMS: Previous studies have shown that the renin-angiotensin axis plays a pivotal role in vasoconstriction of the gastric, intestinal, and hepatic circulations during cardiogenic shock. The aim of this study was to evaluate the fundamental hemodynamic mechanism of pancreatic ischemia during cardiogenic shock induced by pericardial tamponade. METHODS: Cardiogenic shock was induced by pericardial tamponade. Cardiac output (and total peripheral vascular resistance) was determined by thermodilution. Pancreatic blood flow (and vascular resistance) was determined with radiolabeled microspheres. RESULTS: Graded increases in pericardial pressure produced corresponding decreases in cardiac output to 42% +/- 1% and arterial pressure to 67% +/- 3% of baseline and increases in total peripheral vascular resistance to 146% +/- 5% of baseline. Pancreatic blood flow decreased disproportionately to 30% +/- 3% of baseline, because of a disproportionate increase in pancreatic vascular resistance to 220% +/- 19% of baseline. Previously confirmed blockade of the renin-angiotensin axis ablated this response, whereas confirmed blockade of the alpha-adrenergic system or vasopressin system had no significant effect. Without shock, central intravenous infusions of angiotensin II closely mimicked this selective vasoconstriction. CONCLUSIONS: Angiotensin-mediated selective pancreatic vasoconstriction results in significant pancreatic ischemia during cardiogenic shock.     

Mechanical circulatory support for post cardiotomy cardiogenic shock in infants

Eleven infants weighing 2.3 to 7.8 kg underwent mechanical circulatory support for post cardiotomy cardiogenic shock. Initiated pre-operatively in two patients, extracorporeal membrane oxygenation was used in a total of eight patients aged 6 days to 3 months in association with repair of cyanotic congenital heart disease with increased pulmonary blood flow or with a right sided obstructive lesion. Ventricular assist devices were used in three other patients: a centrifugal left ventricular assist device in Patient 1 (10 months, 5.7 kg) after repair of the anomalous left coronary artery, and a pneumatic biventricular assist device (stroke volume 12 ml) in Patient 2 (6 months, 7.0 kg) for cardiac arrest after closure of ventricular septal defect and in Patient 3 (10 months, 7.8 kg) for post transplant graft failure. Duration of extracorporeal membrane oxygenation duration ranged from 26 to 192 hr (mean, 88 hr). Three patients were weaned from extracorporeal membrane oxygenation and two survived. Two others were separated from extracorporeal membrane oxygenation because of bleeding, but both subsequently died. Patient 1 was weaned from the left ventricular assist device after 192 hr and discharged from the hospital. Support was discontinued after 45 hr in Patient 2 who exhibited irreversible brain damage. Patient 3 was weaned from a biventricular assist device after 174 hr, but suffered recurrent graft failure. Our results show that an appropriate circulatory support system should be selected according to the cardiac anatomy in infants.     

Incidence and prognosis of early primary cardiogenic shock in myocardial infarction

The aim of this retrospective study was to analyse the results of coronary reperfusion on the incidence and short and medium term prognosis of early primary cardiogenic shock in acute myocardial infarction. Of 339 consecutive patients admitted within 6 hours of the onset of acute myocardial infarction, 25 (7.4%) had cardiogenic shock from the onset. The majority of patients (18) underwent direct angioplasty with a successful result in 16 cases. Intravenous thrombolysis was instituted in 5 cases followed by emergency coronary angiography leading to "rescue" coronary angioplasty in 3 cases, which was successful in 2 cases. Two patients had no coronary revascularisation because of a double contra-indication to thrombolysis and catheterization by the femoral approach. Intra-aortic balloon pumping was used in 17 cases. Complementary emergency surgical revascularization was necessary in 5 patients (20%). In all, early reperfusion of the infarct-related artery was obtained in 80% of cases (20 patients). The hospital mortality was 72% (18 patients) due to refractory cardiac failure in nearly all cases. After an average follow-up of 17 months, 3 of the 7 survivors of the hospital period have died and of the 4 remaining patients, 2 are in the NYHA classes III or IV. Recent therapeutic advances have not influenced the incidence of cardiogenic shock but have significantly increased the proportion of very early cardiogenic shock, whereas the late cardiogenic shocks of more progressive onset, have nearly disappeared (4/339, 1.2% in this series). The prognosis of these early shocks, caused by severe myocardial damage, remains catastrophic and hardly improved by emergency coronary reperfusion by angioplasty and intraaortic balloon pumping.(ABSTRACT TRUNCATED AT 250 WORDS)     

Non occlusive mesenteric ischemia: a late complication of cardiogenic shock

The case of a diabetic 62-year-old man with a past history of myocardial infarction, developing a cardial arrest followed by successful cardiopulmonary resuscitation, is reported. In the late clinical course, the patient displayed abdominal signs related to mesenteric ischaemia. The pathophysiology of non-occlusive mesenteric ischaemia is discussed. Risk factors such as diabetes, cardiovascular disease, hemodialysis, the use of digoxine or alpha-adrenergic drugs are listed. Non-occlusive mesenteric ischaemia is not an infrequent complication of cardiac failure in high risk patients.     

Undetected cardiogenic shock in patients with congestive heart failure presenting to the emergency department

The purpose of this study was to examine the use of lactic acid levels and continuous central venous oxygen saturation (central venous oximetry) to stratify and treat patients with acutely decompensated end-stage chronic congestive heart failure (CHF) presenting to the emergency department. This prospective, convenience, non-outcome study was performed at an urban tertiary care hospital. Patients with end-stage CHF with an ejection fraction <30% presenting in decompensated CHF were eligible for the study. Patients were assessed using the Killip classification and New York Heart Association criteria. After lactic acid levels were obtained, patients were managed according to a standardized protocol guided by central venous oximetry. The patients were divided into high lactic acid (n = 22), low lactic acid (n = 5), and control groups (stable patients presenting to a cardiology clinic, n = 17) for comparison. There was no statistical difference in vital signs, or Killip and New York Heart Association criteria among the 3 groups. Central venous oxygen saturation was significantly lower in the high lactic acid group (32 +/- 12%) than in the normal lactic acid (51 +/- 13%) and control groups (60 +/- 6%) (p < 0.001). After treatment there was a significant decrease in lactic acid (-3.65 +/- 3.65 mM/L) and an increase in central venous oxygen saturation (32 +/- 13%) in the high lactic acid group compared with the normal lactic acid group (p < 0.001). A significant subset of patients with decompensated end-stage CHF present to the emergency department in occult shock and are clinically indistinguishable from patients with mildly decompensated CHF and stable CHF. Once identified, these patients require aggressive alternative management and disposition. Further study is necessary to identify whether this intervention impacts morbidity, mortality, and health care resource consumption.     

Changing practice patterns in the management of acute myocardial infarction complicated by cardiogenic shock: elderly compared with younger patients

BACKGROUND: Cardiogenic shock continues to be an ominous complication of acute myocardial infarction (AMI). Evidence from retrospective analyses, registries and observational studies suggests that aggressive management using emergent revascularization strategies can bring about significant improvement in survival in this setting. Several studies have identified age as an independent predictor of survival. OBJECTIVE: To study retrospectively the possible changes in practice patterns in the management of patients with AMI complicated by cardiogenic shock in a tertiary care referral centre, and to determine what effect these changes may have had on survival of the patients, stratified by age. METHODS: From 1989 to 1995, 115 patients fulfilled the study criteria of cardiogenic shock based on pump failure and of presenting within 48 h of onset of shock. Prespecified data were extracted from medical records. All available coronary angiograms (n = 72) were analyzed by two experienced angiographers and consensus of findings was obtained. RESULTS: The study revealed a significant increase in the use of cardiac catheterization, interventional procedures and intra-aortic balloon pump (IABP) support in patients in the age groups 65 years or less, 66 to 75 years, and older than 75 years in 1989 to 1990, through 1991 to 1992, to 1993 to 1995. Significantly fewer patients aged older than 75 years received cardiac catheterization, coronary intervention and IABP support throughout the study period and even in the final period analyzed. In-hospital survival improved from 4% in 1989-90 to 33% in 1991-92, and 44% in 1993-95 (P = 0.001). Patients aged 65 years or less improved from 10% in 1989-90 to 59% in 1993-95 (P = 0.032). Only 20% of patients aged older than 75 years survived in the 1993-95 period. By univariate analysis, use of coronary angiography (catheterization 46% versus no catheterization 5%; P < 0.0001), coronary intervention procedures (percutaneous transluminal coronary angioplasty or coronary artery bypass grafting) (intervention 48% versus no intervention 9%; P < 0.0001) and IABP support (IABP 41% versus no IABP 18%; P = 0.0096) were all associated with improved in-hospital survival. Use of thrombolytic therapy showed possible survival benefit only in patients aged older than 75 years (thrombolysis 33% versus no thrombolysis 5%; P = 0.10). Patients who underwent coronary intervention were younger (P = 0.002), had a lower incidence of previous myocardial infarction (P = 0.0002), lower heart rate (P = 0.04), higher peak creatine phosphokinase (P = 0.04) and fewer vessels with at least 70% stenosis (P < 0.0001). On multivariate analysis only lower age, lower heart rate and presence of coronary intervention procedures were found to have an independent effect on survival. CONCLUSIONS: Use of invasive treatment strategies has increased significantly since 1989-90 in the management of patients with AMI complicated by cardiogenic shock. This increase has been associated with improved in-hospital survival in all age groups except possibly the very elderly. Patients undergoing coronary interventional procedures are significantly different in baseline clinical characteristics from patients not undergoing these procedures. These observations underscore the need for randomized trials to define the optimal treatment strategies in these patients. Efficacy of invasive treatment strategies in elderly patients aged older than 75 years-deserves special attention.