Concurrent subarachnoid haemorrhage and myocardial injury

Cardiac complications in acute ischemic stroke

Introduction

To characterize cardiac complications in acute ischemic stroke (AIS) patients admitted from an urban emergency department (ED).

Methods

Retrospective cross-sectional study evaluating AIS patients admitted from the ED within 24 hours of symptom onset who also had an echocardiogram performed within 72 hours of admission.

Results

Two hundred AIS patients were identified with an overall in-hospital mortality rate of 8% (n = 16). In our cohort, 57 (28.5%) of 200 had an ejection fraction less than 50%, 35 (20.4%) of 171 had ischemic changes on electrocardiogram (ECG), 18 (10.5%) of 171 presented in active atrial fibrillation, 21 (13.0%) of 161 had serum troponin elevation, and 2 (1.1%) of 184 survivors had potentially lethal arrhythmias on telemetry monitoring. Subgroup analysis revealed higher in-hospital mortality rates among those with systolic dysfunction (15.8% versus 4.9%; P = 0.0180), troponin elevation (38.1% versus 3.4%; P < 0.0001), atrial fibrillation on ECG (33.3% versus 3.8%; P = 0.0003), and ischemic changes on ECG (17.1% versus 6.1%; P = 0.0398) compared with those without.

Conclusion

A proportion of AIS patients may have cardiac complications. Systolic dysfunction, troponin elevation, atrial fibrillation, or ischemic changes on ECG may be associated with higher in-hospital mortality rates. These findings support the adjunctive role of cardiac-monitoring strategies in the acute presentation of AIS.

Dobutamine versus milrinone after subarachnoid hemorrhage

OBJECTIVE

Neurogenic stunned myocardium is a well-recognized complication of subarachnoid hemorrhage. Dobutamine and milrinone are both used for neurogenic stunned myocardium, but there are few data comparing them after subarachnoid hemorrhage.

METHODS

We compared the physiological dose response of dobutamine and milrinone in patients with subarachnoid hemorrhage requiring a pulmonary artery catheter. We located 11 patients who received either inotrope. Physiological data were fitted to a mixed model accounting for drug, dose, and between-patient variation.

RESULTS

There were 11 patients who had 152 pulmonary artery catheter measurements. Two received both inotropes (but not within 4 h of each other), 2 only milrinone, and 7 only dobutamine. The groups had similar clinical and physiological characteristics. After adjustment for vasopressin, milrinone was significantly more potent in increasing cardiac output (P <0.0001) and stroke volume (P=0.03), while decreasing vascular resistance (P <0.0001) and systolic blood pressure (P=0.008), than dobutamine.

CONCLUSION

These data suggest that milrinone and dobutamine should be used in different clinical situations. Milrinone may be more effective in patients with severely depressed systolic function but who have at least normal vascular resistance and blood pressure and in whom raising cardiac output is the primary goal. Dobutamine may be superior when vascular resistance or blood pressure is low.

Pulmonary edema and cardiac dysfunction following subarachnoid hemorrhage

BACKGROUND

Pulmonary edema (PE) can occur in the early or late period following subarachnoid hemorrhage (SAH). The incidence of each type of PE is unknown and the association with ventricular dysfunction, both systolic and diastolic, has not been described.

METHODS

Retrospective chart review of 178 consecutive patients with SAH surgically treated over a three-year period. Patients with pulmonary edema diagnosed by a radiologist were included. Early onset SAH was defined as occurring within 12 hours. Cardiac function at the time of the PE was analyzed using hemodynamic and echocardiographic criteria of systolic and diastolic dysfunction. Pulmonary edema was observed in 42 patients (28.8%) and was more often delayed (89.4%). Evidence of cardiac involvement during PE varied between 40 to 100%.

RESULTS AND CONCLUSIONS

Pulmonary edema occurs in 28.8% of patients after SAH, and is most commonly delayed. Cardiac dysfunction, both systolic and diastolic, is commonly observed during SAH and could contribute to the genesis of PE after SAH.

Non-neurological organ dysfunction in neurocritical care: impact on outcome and etiological considerations

PURPOSE OF REVIEW

Organ dysfunction is an important determinant of outcome in critical care medicine. Patients with life threatening neurologic injury represent a distinct subset of critically ill patients in whom non-neurologic organ dysfunction may develop. In this paper the incidence and impact of non-neurologic organ dysfunction in patients with major neurologic injury will be reviewed. Further, potential etiological considerations will be addressed and management strategies discussed.

RECENT FINDINGS

Non-neurologic organ dysfunction is extremely common in patients with brain injury occurring in 80-90% of patients admitted to intensive-care units. Several studies have now identified this dysfunction as an independent predictor of poor outcome in neurocritical care. This dysfunction may arise as a result of the neurologic injury or secondary to treatment. Massive catecholamine release continues to be the primary etiological theory of non-neurologic organ dysfunction due to brain injury. Currently employed therapies directed at intracranial hypertension such as maintenance of cerebral perfusion pressure and the use of hypothermia or barbiturates predispose non-neurologic organ dysfunction.

SUMMARY

Non-neurologic organ dysfunction is common. This dysfunction independently predicts poor outcome following brain injury and represents a potentially modifiable risk factor. Further study is required to develop optimal management strategies.

Non-neurologic organ dysfunction in severe traumatic brain injury

OBJECTIVE

To describe the incidence of non-neurologic organ dysfunction and its association with outcome in patients with severe traumatic brain injury admitted to intensive care.

DESIGN

Observational cohort study.

SETTING

Foothills Medical Centre, which is the only neurosurgical service in southern Alberta (population approximately 1.3 million).

PATIENTS

Patients were 209 consecutive patients with severe traumatic brain injury.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Non-neurologic organ dysfunction was measured by the maximum modified multiple organ dysfunction score. Organ system failure was defined as a component score of >/=3 on any day during the patient's intensive care unit stay. One hundred and eighty-five patients (89%) developed dysfunction of at least one non-neurologic organ system. Ninety-six organ system failures were identified in 74 patients (35%). Respiratory failure was the most common non-neurologic organ system failure, occurring in 23% of patients, whereas cardiovascular failure occurred in 18%. Eight patients (4%) had failure of the coagulation system. One patient had renal failure, whereas no patient developed hepatic failure. In a multivariate model, non-neurologic organ dysfunction was independently associated with hospital mortality (odds ratio for hospital mortality, 1.63; 95% confidence interval, 1.34, 1.98 for one maximum modified multiple organ dysfunction score point). Non-neurologic organ dysfunction was also independently associated with dichotomized Glasgow Outcome Score, as a measure of neurologic outcome (odds ratio for unfavorable neurologic outcome, 1.53; 95% confidence interval, 1.22, 1.98 for one maximum modified multiple organ dysfunction score point). The timing of the organ dysfunction did not appear to be important in the prediction of outcome.

CONCLUSIONS

Non-neurologic organ dysfunction is common in patients with severe traumatic brain injury and is independently associated with worse outcome.

Age and aneurysm position predict patterns of left ventricular dysfunction after subarachnoid hemorrhage

Cardiac injury, including left ventricular dysfunction, frequently occurs in patients with subarachnoid hemorrhage. Patterns of left ventricular dysfunction often do not follow coronary artery distributions, and may correlate with myocardial sympathetic innervation. Left ventricular dysfunction of the anterior and anteroseptal walls that spares the apex is unusual for patients with myocardial infarction and may represent a neurally mediated pattern of injury. We performed serial echocardiography on 225 patients with subarachnoid hemorrhage and classified those with regional wall-motion abnormalities as following either an apex-sparing (AS) or apex-affected (AA) pattern. Wall-motion abnormalities were found in 61 of 225 patients studied (27%). The AS pattern was found in 49% of these patients. Younger age and anterior aneurysm position were independent predictors of this AS pattern. Both patterns of wall-motion abnormalities appear to be transient, reversible phenomena. The AS pattern may represent a unique form of neurally mediated cardiac injury.

Use of the peak troponin value to differentiate myocardial infarction from reversible neurogenic left ventricular dysfunction associated with aneurysmal subarachnoid hemorrhage

OBJECT

Differentiating myocardial infarction (MI) from reversible neurogenic left ventricular dysfunction (stunned myocardium [SM]) associated with aneurysmal subarachnoid hemorrhage (SAH) is critical for early surgical intervention. The authors hypothesized that the cardiac troponin (cTn) trend and/or echocardiogram could be used to differentiate between the two entities.

METHODS

A retrospective study was conducted for the period between 1995 and 2000. All patients included in the study met the following criteria: 1) no history of cardiac problems; 2) new onset of abnormal cardiac function (ejection fraction [EF] < 40% on echocardiograms); 3) serial cardiac markers (cTn and creatine kinase MB isoform [CK-MB]); 4) surgical intervention for their aneurysm; and 5) cardiac output monitoring either by repeated echocardiograms or invasive hemodynamic monitoring during the first 4 days post-SAH when the patients were euvolemic. Of the 350 patients with SAH, 10 (2.9%) had severe cardiac dysfunction. Of those 10, six were women and four were men. The patients' mean age was 53.5 years (range 29-75 years) and their SAH was classified as Hunt and Hess Grade III or IV. Aneurysm distribution was as follows: basilar artery tip (four); anterior communicating artery (two); middle cerebral artery (one); posterior communicating artery (two); and posterior inferior cerebellar artery (one). The mean EFonset was 33%. The changes on echocardiograms in these patients did not match the findings on electrocardiograms (EKGs). Within 4.5 days, dramatic improvement was seen in cardiac output (from 4.93 +/- 1.16 L/minute to 7.74 +/- 0.88 L/minute). Compared with historical controls in whom there were similar levels of left ventricular dysfunction after MI, there was no difference in peak CK-MB. A 10-fold difference, however, was noted in cTn values (0.22 +/- 0.25 ng/ml; control 2.8 ng/ml; p < 0.001).

CONCLUSIONS

The authors determined the following: 1) that the CK-MB trend does not allow differentiation between SM and MI; 2) that echocardiograms revealing significant inconsistencies with EKGs are indicative of SM; and 3) that cTn values less than 2.8 ng/ml in patients with EFs less than 40% are consistent with SM.

Cardiac manifestations after subarachnoid hemorrhage: a systematic review of the literature

Cardiac alterations associated with subarachnoid hemorrhage (SAH) have been recognized and frequently reported. We systematically reviewed the literature on MEDLINE using the key words: SAH + (heart, cardiac, electrocardiogram, cardiac enzymes, troponin, myoglobin, echocardiography, scintigraphy, Holter, and regional wall motion abnormalities) and included all articles describing cardiac abnormalities in the course of SAH whether spontaneous or secondary. The diagnosis of SAH was established by computed tomography scan, lumbar puncture, or brain autopsy. Cardiac abnormalities were identified by electrocardiogram, enzymatic elevation, Holter monitoring, echocardiography, cardiac scintigraphy, coronary angiography, or autopsy. Despite the considerable literature describing cardiac alterations during the course of SAH, epidemiological, pathophysiological, and prognostic aspects are yet to be clarified. Further studies are needed to evaluate the magnitude of this problem.

Cardiac troponin I release after severe scorpion envenoming by Tityus serrulatus

Eight children aged 2-9 years, with signs and symptoms of severe scorpion envenoming by Tityus serrulatus were studied. All patients showed clinical manifestations of cardiac dysfunction, with ECG and echocardiographic alteration and five developed pulmonary edema. Troponin I levels were normal in all patients on admission, except for two who arrived later, and increased thereafter, with maximum values being observed 24-36 h after the sting. The detection of TnI in patients with severe scorpion envenoming, and the observed temporal pattern and serum levels meet the criteria established for the diagnosis of acute myocardial infarction. The rapid reversibility of cardiac dysfunction, together with the normalization of the enzymatic, ECG and echocardiographic data, indicates the occurrence of an acute myocardial lesion without underlying or associated coronary disease.

Sympathetic nervous activity and myocardial damage immediately after subarachnoid hemorrhage in a unique animal model

BACKGROUND AND PURPOSE

Obvious cardiac dysfunction, including ECG abnormalities and left ventricular asynergy, is known to develop after subarachnoid hemorrhage (SAH). To clarify the close relationship between myocardial damage and sympathetic nervous activity immediately after SAH, a novel experimental animal model was used.

METHODS

SAH was provoked by perforation of the basilar artery with the use of a microcatheter inserted through the femoral artery in 18 beagle dogs. Hemodynamic changes were recorded, and plasma concentrations of noradrenaline, adrenaline, and 3-methoxy-4-hydroxy-phenylethylene glycol (MHPG) and serum levels of creatine kinase-MB (CK-MB) and troponin T were measured at 0, 5, 15, 30, 60, 120, and 180 minutes after SAH.

RESULTS

Noradrenaline (pg/mL), adrenaline (pg/mL), and MHPG (ng/mL) increased abruptly from 120+/-70, 130+/-70, and 1.3+/-0.5 before SAH to 1700+/-1200, 5600+/-3500, and 3.2+/-1.2 at 5 minutes after SAH, respectively. Aortic pressure, left ventricular wall motion, and cardiac output increased by 60%, 40%, and 30%, respectively (P<0.001) at 5 minutes and then decreased by 50%, 55%, and 40%, respectively (P<0.001) >60 minutes after SAH compared with baseline values. The peak value of CK-MB correlated positively with the peak values of noradrenaline and adrenaline (r=0.730 and r=0.611, respectively). The peak value of troponin T also correlated positively with the peak values of noradrenaline and adrenaline (r=0.828 and r=0.792, respectively).

CONCLUSIONS

These results suggest that the elevated activity of the sympathetic nervous system observed in the acute phase of SAH induced myocardial damage and contributed to the development of cardiac dysfunction.