SUBENDOCARDIAL HAEMORRHAGE AND E.C.G. CHANGES IN INTRACRANIAL BLEEDING

Cardiovascular Manifestations of Acute Intracranial Lesions: Pathophysiology, Manifestations, and Treatment

The objective of this article was to review the effects of acute intracranial lesions on myocardial function. The authors reviewed scientific and clinical literature retrieved from a computerized MEDLINE search from January 1965 through January 2002. Pertinent literature was referenced, including clinical and laboratory investigations, to demonstrate the effects of acute intracranial lesions on the cardiovascular system. The literature was reviewed to summarize the mechanisms of cardiac damage and clinical manifestations and treatment of cardiovascular dysfunction caused by acute intracranial lesions. Myocardial damage and rhythm disturbances were shown to occur with acute intracranial neurological disease. The subgroup of patients used in this study formed a substantial pool of cardiac donors for cardiac transplantation. The pathophysiology of myocardial dysfunction and the optimal management continues to be a source of debate. In this article, the authors will review the anatomy, the available evidence of the pathophysiology, and the management of this complex group of patients. They will also discuss areas that need to be further investigated. Cardiovascular effects of acute intracranial lesions are common and contribute to increased morbidity and mortality.

Myocarditis in patients with subarachnoid hemorrhage: A histopathologic study

Cardiac abnormalities after subarachnoid hemorrhage (SAH) such as electrocardiographic changes, echocardiographic wall motion abnormalities, and elevated troponin levels are independently associated with a poor prognosis. They are caused by catecholaminergic stress coinciding with influx of inflammatory cells into the heart. These abnormalities could be a sign of a myocarditis, potentially giving insight in pathophysiology and treatment options. These inflammatory cells are insufficiently characterized, and it is unknown whether myocarditis is associated with SAH. Myocardium of 25 patients who died of SAH and 18 controls was stained with antibodies identifying macrophages (CD68), lymphocytes (CD45), and neutrophil granulocytes (myeloperoxidase). Myocytolysis was visualized using complement staining (C3d). CD31 was used to identify putative thrombi. We used Mann-Whitney U testing for analysis. In the myocardium of SAH patients, the amount of myeloperoxidase-positive (P < .005), CD45-positive (P < .0005), and CD68-positive (P < .0005) cells was significantly higher compared to controls. Thrombi in intramyocardial arteries were found in 22 SAH patients and 1 control. Myocytolysis was found in 6 SAH patients but not in controls. Myocarditis, consisting of an influx of neutrophil granulocytes, lymphocytes, and macrophages, coinciding with myocytolysis and thrombi in intramyocardial arteries, occurs in patients with SAH but not in controls. These findings might explain the cardiac abnormalities after SAH and may have implications for treatment.

Neurogenic stunned myocardium after acute hydrocephalus

Neurogenic stunned myocardium (NSM) is a syndrome of cardiac stunning after a neurological insult. It is commonly observed after aneurysmal subarachnoid hemorrhage but is increasingly being reported after other neurological events. The underlying mechanism of NSM is believed to be a hypothalamic-mediated sympathetic surge causing weakened cardiac contractility and even direct cardiac myocyte damage. The authors report 2 cases of NSM in pediatric patients after acute hydrocephalus. Both patients experienced severe cardiac dysfunction in the acute phase but ultimately had a good neurological outcome and a full cardiac recovery. The identification, treatment, and outcome in 2 rare pediatric cases of NSM are discussed, and the history of the brain-cardiac connection is reviewed.

Electrocardiographic findings in subarachnoid hemorrhage. A population study

The prevalence of ECG abnormalities and their prognostic value in subarachnoid hemorrhage (SAH) were analysed in patients from an epidemiological study on SAH. The analysis was based on ECGs recorded during the first 72 hours after bleeding. An ECG recording was obtained in 29% of patients dying within 7 days after SAH, and in 64% of those surviving longer. Tachycardia over 100 beats/min, P mitrale, and ST segment depression greater than 1.0 mm or elevation greater than 2.5 mm were statistically significantly more common among patients dying within 7 days after bleeding. ECG changes reflecting myocardial ischemia or a compromised hemodynamic state observed during the first 3 days after SAH seem to have an untoward effect on the prognosis.

Pheochromocytoma: an endocrine stress mimicking disorder

A pheochromocytoma is an endocrine tumor that can uniquely mimic numerous stress-associated disorders, with variations in clinical manifestations resulting from different patterns of catecholamine secretion and actions of released catecholamines on physiological systems.

Ampulla cardiomyopathy associated with aneurysmal subarachnoid hemorrhage: report of 6 patients

BACKGROUND

The authors report 6 cases of aneurysmal SAH associated with ampulla cardiomyopathy, which has been considered a unique type of stunned myocaridum.

CASE DESCRIPTION

All patients were female, ranged from 35 to 79 years, and their echocardiograms revealed typical cardiac wall motions: the hypokinesia in the apical area of the left ventricle associated with the hyperkinesia in the basal area. In all, the cardiac function started to recover in the first few days; however, associated pulmonary congestions delayed aneurysmal surgeries in 3 patients. Among 3 patients whose surgeries were delayed, one died due to rerupture of aneurysm and another due to severe pneumonia. The other 4 patients recovered well, although one had left ventricular mural thrombus, which was treated successively with anticoagulant.

CONCLUSIONS

It is considered highly important for neurosurgeons to be familiar with this clinical entity, since this transient cardiac function disturbance can be diagnosed at the initial presentation with a unique wall motion. The significance and clinical features of ampulla cardiomyopathy are discussed.

Neurogenic stunned myocardium: an unusual postoperative complication

OBJECTIVE

In this report of myocardial dysfunction in a pediatric patient after a neurosurgical procedure, we highlight the need for high clinical suspicion for neurogenic stunned myocardium.

DESIGN

Case report.

SETTING

A tertiary pediatric intensive care unit.

PATIENT

A 7-yr-old boy with a history of Chiari malformation type 1, undergoing his fourth surgical procedure, who developed signs of myocardial infarction in the immediate postoperative period.

INTERVENTIONS

Serial echocardiograms, a rest-stress myocardial perfusion study, and coronary angiography were performed. Serial troponins were followed.

RESULTS

The troponin level normalized 6 days after the initial event, and he was discharged home on a limited course of lisinopril, propanolol, and aspirin and without signs or symptoms of cardiac dysfunction.

CONCLUSIONS

Neurogenic stunned myocardium is an uncommon event after neurosurgical procedures in children. Pediatric intensivists need to consider this diagnosis in a patient with signs of myocardial dysfunction in the neurosurgical postoperative period. The management of neurogenic stunned myocardium involves close monitoring and establishing the absence of other causes of myocardial ischemia.

Negative Myoglobin Staining in Hemiplegic Muscle of Acute Stroke Patients Predicts Functional Recovery [Retracted]

OBJECTIVE

There is little information on skeletal muscle changes in patients with acute stroke, despite the repeated observation that levels of serum creatine kinase (CK) and myoglobin (Mb) increase in the initial phase of strokes. It is also not clearly known whether the CK and Mb are derived from skeletal muscle or myocardium.

DESIGN

Biceps muscle biopsies of the hemiplegic side were obtained from 157 ischemic stroke patients on the second day of stroke onset and were examined for immunoreactivity to Mb, and measurements of Mb, total CK, troponin T, epinephrine, and norepinephrine were made on the same day. The degree of disability of patients was assessed at 7 days and at 12 mos after stroke using the Barthel index and the Scandinavian Stroke Scale. The control group consisted of 159 healthy volunteers matched in age and sex.

RESULTS

Lack of Mb immunoreactivity was observed in 109 patients. The prevalence of negatively stained muscle fibers ranged from 0.0% to 22.0%, with a mean of 5.9% +/- 6.0%. The mean values of serum Mb, CK, troponin T, and norepinephrine were higher in patients than those in the control group (P < 0.0001 for all indices; percentage differences were 658% for Mb, 529% for CK, and 258% for norepinephrine). A positive correlation was observed between the prevalence of negative Mb immunostaining in fibers and the Mb (r2 = 0.968, P < 0.0001), CK (r 2= 0.910, P < 0.0001), and norepinephrine levels (r2 = 0.835, P < 0.0001). During the 12-mo study period, Barthel index and Scandinavian Stroke Scale values improved. The percentage change of the Barthel index and Scandinavian Stroke Scale correlated positively with the prevalence of negative Mb immunostaining in fibers.

CONCLUSIONS

It was speculated that ischemia, resulting from vasoconstriction induced by an increase in norepinephrine, may be responsible for the occurrence of fibers with negative immunoreactivity for Mb. Patients with higher negative immunostaining for Mb fibers had poor functional recovery of hemiplegia 12 mos after stroke onset. This implies that these muscular alterations may hamper functional recovery.

Management of patients with stunned myocardium associated with subarachnoid hemorrhage

Cardiac complications are well known after aneurysmal subarachnoid hemorrhage. Electrocardiographic changes occur in 50% to 100% of such cases. Arrhythmias, left ventricular dysfunction, and frank myocardial infarction are infrequently observed. Myocardial infarction must be differentiated from neurogenic stunned myocardium, which is a reversible condition. From 1996 to 2001, 105 patients with aneurysmal subarachnoid hemorrhage underwent endovascular treatment at the University of Michigan. Of these, four patients with no history of cardiac disease experienced cardiac failure related to neurogenic stunned myocardium. All had signs of left ventricular dysfunction, electrocardiographic changes, and elevated cardiac enzymes. Three had pulmonary edema at presentation. All were diagnosed with myocardial infarction. One underwent coronary angiography, which was normal. All were considered poor surgical candidates and underwent endovascular treatment of the aneurysms. Three of four patients developed symptomatic vasospasm, and two required balloon angioplasty. Three patients achieved good outcomes. The eldest died from severe vasospasm that was unresponsive to angioplasty. Reversible cardiac failure associated with subarachnoid hemorrhage may be due the neurogenic stunned myocardium. Frequent symptomatic vasospasm occurs, possibly related to poor cardiac output and the inability to optimize hyperdynamic hypervolemic therapy, particularly with compromised volume status. These patients can be treated with endovascular therapy of the aneurysms and balloon angioplasty as needed. With aggressive management, patients can recover from these reversible cardiac complications.

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.

Creatine kinase-MB elevation after stroke is not cardiac in origin: comparison with troponin T levels

BACKGROUND AND PURPOSE

Creatine kinase-MB (CK-MB) increases in some patients with stroke, with no clear evidence of an acute coronary syndrome. Its elevations have been suggested to represent a biological marker for stroke-related myocardial injury. Troponin T has superior sensitivity and specificity to CK-MB in revealing minor myocardial injury. Therefore, we studied troponin T levels after stroke to determine whether troponin T increases in parallel to CK-MB.

METHODS

We made daily measurements of CK-MB, myoglobin, total creatine kinase (total CK), and troponin T levels up to day 5 in 32 patients with large hemispheric infarction and with no history of coronary heart disease. The daily enzyme levels were compared with those of a control group of 22 patients with neurological diseases other than stroke.

RESULTS

Serum CK-MB, myoglobin, and total CK levels were elevated above the cutoff value in 11, 26, and 20 patients with stroke, respectively. These enzyme levels gradually increased within the first 3 days and declined afterward. Troponin T did not exceed the reference range in any patients. One patient had elevated myoglobin and 3 had elevated total CK in the control group. The difference between groups was significant for CK-MB, myoglobin, and total CK at various time points.

CONCLUSIONS

Troponin T, a more specific biochemical marker of myocardial injury, does not increase after stroke. Normal troponin T along with elevated CK-MB signifies that CK-MB is not the biological marker for myocytolysis. CK-MB elevations in stroke patients are likely to be noncardiac in origin.

Myocardial dysfunction associated with brain death: clinical, echocardiographic, and pathologic features

BACKGROUND

The sequelae of severe brain injury include myocardial dysfunction. We sought to describe the prevalence and characteristics of myocardial dysfunction seen in the context of brain-injury-related brain death and to compare these abnormalities with myocardial pathologic changes.

METHODS

We examined the clinical course, electrocardiograms, head computed tomography scans, and echocardiographic data of 66 consecutive patients with brain death who were evaluated as heart donors. In a sub-group of patients, we compared echocardiographic findings with pathologic findings.

RESULTS

Echocardiographic systolic myocardial dysfunction was present in 28 (42%) of 66 patients and was not predicted by clinical, electrocardiographic, or head computed tomographic scan characteristics. Ventricular arrhythmias were more common in the patients with, compared to those without, myocardial dysfunction (32% vs 0%; p < 0.001). Myocardial dysfunction was segmental in all 8 patients with spontaneous subarachnoid or intracerebral hemorrhage. In these patients, the left ventricular apex was often spared. Myocardial dysfunction was either segmental or global in 17 patients who suffered head trauma and in 3 patients who died of other central nervous system illnesses. In 11 autopsied hearts, we found poor correlation between echocardiographic dysfunction and pathologic findings.

CONCLUSIONS

Systolic myocardial dysfunction is common after brain-injury-related brain death. After spontaneous subarachnoid or intracerebral hemorrhage, the pattern of dysfunction is segmental, whereas after head trauma, it may be either segmental or global. We found poor correlation between the echocardiographic distribution of dysfunction and light microscopic pathologic findings.

Myocardial stunning secondary to aneurysmal subarachnoid hemorrhage

BACKGROUND

Although subarachnoid hemorrhage (SAH) is often associated with electrocardiographic abnormalities, profound effects on cardiac performance are rare.

CASE DESCRIPTION

A 57-year-old woman who developed loss of consciousness, respiratory distress, severe hypotension, and left ventricular hypokinesis with minimal coronary artery disease is described. Despite normal appearance of the coronary arteries on angiography, left ventricle function was so severely depressed that she required intra-aortic balloon pump support for 24 hours. Mental status changes prompted a head computed tomographic (CT) scan, which showed severe SAH and an intraventricular hemorrhage (IVH). Cerebral angiography demonstrated a basilar apex aneurysm. An echocardiogram done on hospital day 6 was normal. A left frontal ventriculostomy catheter was placed. This was later changed to a lumbar subarachnoid (SA) drain. The patient underwent an orbito-zygomatic craniotomy and aneurysm clipping. Although several serious medical problems occurred during her hospitalization, at follow-up, her sole neurological impairment was a minimal and resolving oculomotor paresis.

CONCLUSION

This patient's respiratory failure and severe hypotension were initially thought to be due to a chemical pneumonitis or a cardiomyopathy. However, her symptoms ultimately proved to be secondary to a ruptured basilar apex aneurysm. The complex relationship of SAH to myocardial stunning, as illustrated by this patient, is discussed.

Severe ventricular dysfunction secondary to subarachnoid hemorrhage

A 39-year-old man was brought to the emergency department in a coma. The electrocardiogram showed partial left bundle-branch block and ST elevation in precordial leads, and serum creatinine kinase activity was elevated. Two-dimensional echocardiography revealed severe biventricular dysfunction. Autopsy demonstrated the presence of subarachnoid hemorrhage. Coronary arteries and the myocardium were macroscopically normal.

Electrocardiographic markers of abnormal left ventricular wall motion in acute subarachnoid hemorrhage

A reversible and presumably neurogenic form of myocardial dysfunction may occur following subarachnoid hemorrhage (SAH), but the relationship of this finding to electrocardiographic abnormalities remains unclear. To clarify this issue, serial electrocardiograms (ECGs, mean 6.2 per patient) and echocardiograms (mean 3.4 days after SAH) were obtained in 57 SAH patients without preexisting cardiac disease. The goal was to determine which specific electrocardiographic changes, if any, reflect abnormal left ventricular wall motion in acute SAH. Wall motion abnormalities were identified in five (8%) of 57 patients. Four of these affected patients experienced hypotension (systolic blood pressure < 100 mm Hg) and three exhibited pulmonary edema within 6 hours of SAH, compared to none of the 52 patients with normal wall motion (p < 0.0001). Patients with abnormal wall motion were more likely than patients with normal echocardiograms to have symmetrical T wave inversion (five of five vs. seven of 52, p < 0.001) and severe (> or = 500 msec) QTc segment prolongation (five of five vs. three of 52, p < 0.001) on serial ECGs. These associations maintained their significance with analysis limited to single ECGs performed on or near the day of echocardiography. Abnormal wall motion was also associated with borderline (2% to 5%) creatine kinase MB elevation (five of five vs. three of 52, p < 0.001) and poor neurological grade (p < 0.0001). Although no combination of findings on a single ECG resulted in 100% sensitivity for abnormal wall motion, the presence of either inverted T waves or severe QTc segment prolongation on serial ECGs was associated with 100% sensitivity and 81% specificity. These results demonstrate an association between reduced left ventricular systolic function, mild creatine kinase MB elevation, and electrocardiographic repolarization abnormalities in acute SAH. Symmetrical T wave inversion and severe QTc segment prolongation best identified patients at risk for myocardial dysfunction and may serve as useful criteria for echocardiographic screening following SAH.

Heterogeneity of myocardial blood flow

Myocardial blood flow is heterogeneous, whether considered by chamber, by layers of the ventricular walls, or by microregions within layers. There is also variability of myocardial flow reserve, particularly in layers and microregions, even when the heart is arrested. The variability of flow during arrest may be associated with the resistance pathways to each region, but the variability of flows in the beating heart with vascular tone is probably due to regional differences in work and thus oxygen demand. Heterogeneity by layer may be responsible for the subendocardial ischemia that is common to many forms of heart disease. Microheterogeneity may account for the patchy necrosis that occurs with chronic ischemia.

Left ventricular wall motion abnormalities in patients with subarachnoid hemorrhage: neurogenic stunned myocardium

OBJECTIVES

The purpose of this study was to determine whether a relation exists between electrocardiographic (ECG) abnormalities and left ventricular wall motion in patients with subarachnoid hemorrhage.

BACKGROUND

Although ECG changes simulating acute myocardial infarction are frequently seen in patients with subarachnoid hemorrhage, their relation to left ventricular wall motion has not been established.

METHODS

Twelve patients with subarachnoid hemorrhage were classified according to the presence of ST segment elevation in at least two consecutive leads on admission: seven patients with ST segment elevation (group I) and five patients without ST segment elevation (group II). No patients had a previous history of heart disease. Left ventricular regional wall motion was evaluated by the centerline method. The mean (+/- SEM) duration from onset of subarachnoid hemorrhage to left ventriculography was 9 +/- 3 h in group I and 10 +/- 1 h in group II. Coronary angiography was performed to rule out wall motion abnormalities due to coronary artery disease while the ST segment was still elevated. Two-dimensional echocardiography was used to evaluate wall motion thereafter.

RESULTS

All patients in group I showed ST segment elevation in ECG leads V4 to V6. Wall motion of the left ventricular apex was significantly reduced in group I compared with group II (-2.48 +/- 0.41 vs. -0.45 +/- 0.72, p < 0.02). No patients showed organic stenosis or vasospasm, or both, of epicardial coronary arteries. Wall motion abnormalities decreased echocardiographically in all patients, but one patient in group I died in hospital at 2 or 3 weeks after the onset of subarachnoid hemorrhage, when the T wave was inverted in leads V4 to V6.

CONCLUSIONS

These findings suggest that patients with subarachnoid hemorrhage and ST segment elevation may demonstrate transient corresponding regional wall motion abnormalities. The mechanism of neurogenic stunned myocardium was not clearly elucidated in the present study.

ST segment depression detected by continuous electrocardiography in patients with acute ischemic stroke or transient ischemic attack

BACKGROUND AND PURPOSE

Forty percent of patients with a history of ischemic stroke or transient ischemic attack (TIA) have concomitant coronary artery disease. ST segment depression, detected by continuous electrocardiography, is associated with increased cardiac morbidity and mortality in patients with known coronary artery disease. While electrocardiographic changes have been associated with acute stroke, the etiology and significance of these changes remain unclear. In this pilot study we report the prevalence of ST segment depression and ventricular arrhythmias in patients with acute ischemic stroke or TIA monitored by continuous electrocardiography. Clinical predictors of ST segment depression and ventricular arrhythmia are also identified.

METHODS

Consecutive patients presenting with acute ischemic stroke or TIA were enrolled within 72 hours of hospital admission and monitored by continuous electrocardiography for 48 hours. The electrocardiographic results were analyzed for periods of ST segment depression and ventricular arrhythmias.

RESULTS

Of 51 patients with ischemic stroke or TIA, 15 (29%) had episodes of ST segment depression (95% confidence interval, 15% to 43%), and 18 (35%) had ventricular arrhythmias (95% confidence interval, 21% to 49%). In logistic regression analysis, increasing age (P < .02) and a left-sided neurological event (P < .01) were significant predictors of ST segment depression. Increasing numbers of atherosclerotic risk factors, a history of cardiac disease, and increasing or decreasing mean arterial pressure were not predictive of ST segment depression.

CONCLUSIONS

Patients with acute ischemic stroke or TIA have a 29% prevalence of ST segment depression within the first 5 days after their event. In comparison, the prevalence of ST depression is 2.5% to 8% in asymptomatic adults and 43% to 60% in patients with symptomatic coronary artery disease. The association of ST segment depression with left-sided neurological events suggests that the electrocardiographic changes are in part neurologically mediated. Further study is necessary to better define the brain-heart interaction and to determine whether ST segment depression in patients with ischemic stroke or TIA reflects underlying coronary artery disease.

Subarachnoid haemorrhage: a cause of left bundle branch block?

We describe what we believe to be the first reported case of documented de novo left bundlebranch block in association with acute subarachnoid haemorrhage.

Electrocardiographic and echocardiographic changes associated with malignant catatonia

We describe a case of malignant catatonia manifested by catatonic symptoms, fever, hemodynamic instability, and acute neurologic decline that was associated with electrocardiographic and echocardiographic abnormalities similar to those noted in patients with other central nervous system processes. The patient's electrocardiographic and echocardiographic abnormalities resolved after successful electroconvulsive therapy for the underlying neuropsychiatric disorder. The theoretic, physiologic, and clinical significances of this case are discussed.

Electrocardiographic changes associated with acute cerebrovascular disease: a clinical review

Patients with acute vascular disorders of the CNS demonstrate an abundance of both rhythm and morphologic changes in their ECG. Of these a few will demonstrate myocardial dysfunction and or damage. The value of the ECG in evaluating and predicting which patients will have myocardial dysfunction or damage is questionable. One would assume the echocardiogram would be of more help than the ECG in identifying patients with myocardial damage; however, little data are available. The reason for the poor correlation between ECG findings and clinical correlates has not been explained to date, but it is possible to postulate a theory. There are two mechanisms that might mediate ECG changes in these patients, ie, autonomic neural stimulation from the hypothalamus or elevated circulating catecholamines. Hypothalamic stimulation may cause ECG changes without associated myocardial damage whereas elevated catecholamines may result in myocardial damage. This might explain why so many patients have ECG changes and very few have demonstrable myocardial damage in general, or ischemic damage in particular. That cardiac antiischemic therapy does not change mortality may relate to the fact that treatment has been directed towards patients with ECG changes, which in turn do not correlate with myocardial damage. Better patient selection for such therapy might rest upon demonstration of wall motion abnormalities on echocardiogram. The weakness of this strategy is that many patients with stroke have preexisting coronary disease and wall motion abnormalities and thus echo findings may only document remote infarction rather than acute ischemia.

Haemodynamic, intracranial pressure and electrocardiographic changes following subarachnoid haemorrhage in rats

Experimental induction of subarachnoid haemorrhage in rats resulted in acute haemodynamic changes. Heart rate decreased concomitantly with a rise in arterial blood pressure. Intracranial pressure increased and consequently cerebral perfusion pressure dropped. These changes as well as the observed electrocardiographic (ECG) changes were comparable to those reported in patients. Apart from blood also saline, when introduced into the cisterna magna, was able to elicit such abnormalities. The haemodynamic and electrocardiographic changes, which result from subarachnoid haemorrhage, may even become aggravated, when repetitive injections of blood or saline are given into the cisterna magna and when cerebral angiography is performed prior to induction of the subarachnoid haemorrhage. Chronic intracranial pressure monitoring during the 48 hours following subarachnoid haemorrhage revealed no significant rise in pressure. A thorough control of the experimental conditions is thus of utmost importance in order to give a valid interpretation of the observed anomalies.

Insular cortex stimulation produces lethal cardiac arrhythmias: a mechanism of sudden death?

The rat posterior insular cortex has recently been shown to possess cardiac chronotropic organization and therefore may be involved in cortical mechanisms of sudden death. In order to assess the potential of this region for cardiac arrhythmogenicity, phasic microstimulation of tachycardia zones was undertaken in the urethane-anesthetized rat. The insular stimulus was triggered by the R wave of the electrocardiogram (ECG) and delayed so that resultant putative cardiac sympathetic nerve activity would be synchronous with the T wave of the ECG. This resulted in increasing degrees of heart block leading to escape rhythms, ventricular ectopics and ultimately death in asystole. Heart block was associated with elevated plasma norepinephrine levels and myocardial damage. Such effects have not been previously demonstrated for a cortical site. These data suggest that pathophysiological activation of the insular cortex by stroke, epileptic seizure, or under conditions of severe emotional stress could predispose to ECG changes, cardiac arrhythmias and sudden death.

Electrocardiographic abnormalities in cerebrovascular accidents

The electrocardiographic abnormalities found in 100 patients with acute cerebrovascular disease and previously normal hearts are described. The abnormalities were more often seen in patients with intracerebral and subarachnoid hemorrhages. The most common changes were Q-Tc Prolongation and ST segment and T wave abnormalities. The mechanisms of these electrocardiographic abnormalities appear to be multiple.

Serial electrocardiographic recording in aneurysmal subarachnoid hemorrhage

We prospectively studied serial electrocardiograms in 61 patients with aneurysmal subarachnoid hemorrhage. Electrocardiographic changes were related to the initial level of consciousness, to subsequent events, and to outcome after 3 months. All 61 patients had at least one abnormal electrocardiogram, but cardiac disease did not contribute directly to morbidity or mortality. Fast rhythm disturbances, ischemic changes, or both on the electrocardiograms were significantly correlated with poor outcome but not with specific outcome events, particularly not with rebleeding or cerebral ischemia. The Glasgow Coma Scale score on admission and the amount of cisternal and (to a lesser extent) intraventricular blood on the initial computed tomogram were also significantly correlated with poor outcome, but these factors only partially confounded the relation between electrocardiographic abnormalities and poor outcome. We conclude that in patients with aneurysmal subarachnoid hemorrhage, electrocardiographic abnormalities do not herald impending cardiac disease but indirectly reflect adverse intracranial factors. Electrocardiographic abnormalities may therefore have some independent value in predicting poor outcome.

T wave inversion associated with severe theophylline toxicity

Adverse cardiovascular effects are commonly seen in severe theophylline poisoning. Primary ST-T wave changes have not been described previously. We report T wave inversion associated with severe theophylline toxicity in a 33-year-old woman with no evidence of organic heart disease. The T wave inversion resolved after treatment. Physicians should be alerted to possible T wave abnormalities in patients with severe theophylline poisoning.

Dopamine treatment of locally procured donor hearts: relevance on postoperative cardiac histology and function

Administration of catecholamines can lead to myocyte damage. Dopamine treatment is often used in potential cardiac donors to attain hemodynamic stability. Donor hearts exposed to dopamine are rejected or selected for transplantation without clearly defined criteria. A prospective study was undertaken to analyze the clinical relevance of dopamine-induced myocardial lesions in 25 hearts (21 male, 4 female; 15-40 years, mean: 26 +/- 7) that were later used for transplantation. Donors were divided into those who had received dopamine and those who had not. Dopamine doses ranged from 2-12.5 micrograms/kg/min (mean: 6.3 +/- 3). Time of administration was 3-26 hours (mean: 16 +/- 8). Use of dopamine was unrelated to donor electrocardiographic findings, intra- or postoperative death, or difficulty coming off by-pass. Postoperatively, filling pressures were similar in both groups of patients at 2 and 10 days postoperatively. Left ventricular ejection fraction was similar in the two groups. Dopamine requirements were significantly higher in the dopamine-treated hearts (P = 0.05). Histologic findings at first biopsy revealed infiltration and cell damage in a similar proportion of patients in both groups.

IN CONCLUSION

donor hearts exposed to dopamine can be accepted for transplantation if doses ranging from 2-12.5 micrograms/kg/min have been administered up to 24 hours.

Left ventricular wall motion abnormalities in subarachnoid hemorrhage: an echocardiographic study

Although electrocardiographic (ECG) abnormalities and autopsy evidence of myocardial necrosis are associated with subarachnoid hemorrhage, their relation to in vivo measures of left ventricular function in this condition has not been established. Thirteen patients with subarachnoid hemorrhage and no prior history of heart disease were studied by two-dimensional echocardiography, performed initially 10 to 48 h (mean 18) after admission and serially for less than or equal to 14 days. Serum creatine kinase (total and myocardial isoenzyme) was determined 5 times over the first 48 h; ECGs were performed daily. Neurologic state was assessed with the use of a standard grading system. Four patients (Group I) exhibited left ventricular wall motion abnormalities in one to eight segments. In two of these patients there was also left ventricular apical mural thrombus that embolized in one patient, leading to further neurologic deterioration. The initial creatine kinase myocardial isoenzyme was higher in Group I than in Group II (patients without wall motion abnormalities) (10.3 versus 2.1 U/liter, p less than 0.001), initial heart rate was higher (91 versus 61 beats/min, p less than 0.01), neurologic grade was higher (2.5 to 4.5 versus 1 to 2, p less than 0.001) and inverted T waves were more common (4 of 4 versus 1 of 9). Three of the four patients in Group I died; two of the three underwent autopsy and were found to have no significant coronary artery disease. No other patients died.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased intracranial pressure elicits hypertension, increased sympathetic activity, electrocardiographic abnormalities and myocardial damage in rats

Intracranial pressure was increased in 59 rats by inflating a subdural balloon to a total mass volume of 0.3 ml. The increase in intracranial pressure ranged from 75 to greater than 500 mm Hg. With few exceptions, mean arterial pressure increased to as high as 227 mm Hg during the increase in intracranial pressure. Significant increases in plasma catecholamines, major electrocardiographic changes and a considerably shortened survival time were observed only in the rats that demonstrated an increase in mean arterial pressure greater than 50 mm Hg. A perfusion study with liquid silicone rubber (Microfil) revealed dilated irregular myocardial vessels with areas of focal constriction consistent with microvascular spasm. Histologic examination of the myocardium revealed widespread patches of contraction band necrosis and occasional contraction bands in the smooth muscle media of large coronary arteries. These observations suggest that myocardial damage after suddenly increased intracranial pressure resulted both from exposure to toxic levels of catecholamines and from myocardial reperfusion. Extension of these studies to humans suggests that a detailed assessment of myocardial function should be performed in victims of severe brain injury. Myocardial dysfunction may be a major determinant of the patient's prognosis or may render the heart unsuitable for transplantation.

Torsades de pointes: atypical rhythm, atypical treatment

For the present, treatment of the acquired Torsades de Pointes consists of removal of the causative agent, correction of the underlying electrolyte imbalance, and initiation of direct therapy. Unresponsive dysrhythmias may need magnesium therapy or cardioversion.

Transmural myocardial perfusion

The predilection for subendocardial underperfusion and ischemia is great and must be considered in the management of any patient, especially if there is coronary artery disease or ventricular hypertrophy. Although the mechanisms of subendocardial ischemia remain to be fully defined, they are clearly associated with the transmural distribution of intramyocardial systolic pressures. Even though almost all the myocardium is perfused in diastole, a reduction of diastolic perfusion pressure or duration will result in subendocardial ischemia. The factors that produce subendocardial ischemia are all associated with a reduction or loss of coronary flow reserve, and as our ability to measure flow reserve in humans improves, it is likely that we will be able to select medical or surgical therapy that will minimize or abolish subendocardial ischemia. For example, it will someday become possible to choose a time for valve replacement in an asymptomatic patient to obtain maximal protection of the myocardium or to select the right combination of therapies for the immediate post-operative period so that as much myocardium as possible will be spared. The more we learn to understand the mechanisms of subendocardial ischemia, the sooner will we be able to achieve these desired ends.