Cardiac Problems in Patients with Neurologic Disease

Takotsubo cardiomyopathy induced by dobutamine infusion during hypertensive therapy for symptomatic vasospasm after subarachnoid hemorrhage -case report-

A 65-year-old female with subarachnoid hemorrhage (SAH) developed takotsubo cardiomyopathy induced by dobutamine infusion for vasospasm 9 days after onset of SAH. She underwent neck clipping of the ruptured cerebral aneurysm on day 1. Course after surgery was uneventful, but she developed motor aphasia on day 9. Hypertensive therapy was carried out under the diagnosis of symptomatic vasospasm. Half an hour after initiation of dobutamine infusion at 6 microg/kg/min, sudden symptoms of takotsubo cardiomyopathy developed. Fortunately, her symptoms recovered in a few days with supportive therapy without any consequences. Takotsubo cardiomyopathy is one pattern of cardiac dysfunction occasionally encountered after SAH. Possible mechanisms of this disorder include epicardial catecholamine cardiotoxicity. Therefore, generally, cardiac function is worst at the early stage of SAH, when sympathetic activity is highest, and recovers thereafter. Dobutamine infusion seems to have triggered the takotsubo cardiomyopathy in the present patient even 9 days after onset of SAH. Inotropic agents including dobutamine are often used during the course of SAH, and since takotsubo cardiomyopathy can occur in patients with SAH, this complication must be considered.

Safety and efficacy of carvedilol therapy for patients with dilated cardiomyopathy secondary to muscular dystrophy

BACKGROUND

By the age of 20 years, almost all patients with Duchenne's or Becker's muscular dystrophy have experienced dilated cardiomyopathy (DCM), a condition that contributes significantly to their morbidity and mortality. Although studies have shown carvedilol to be an effective therapy for patients with other forms of DCM, few data exist concerning its safety and efficacy for patients with muscular dystrophy. This study aimed to evaluate the safety and efficacy of carvedilol for patients with DCM.

METHODS

A clinical trial at an outpatient clinic investigated 22 muscular dystrophy patients, ages 14 to 46 years, with DCM and left ventricular ejection fraction (LVEF) less than 50%. Carvedilol up-titrated over 8 weeks then was administered at the maximum or highest tolerated dose for 6 months. Baseline and posttreatment cardiac magnetic resonance imaging (CMR), echocardiography, and Holter monitoring were recorded.

RESULTS

Carvedilol therapy was associated with a modest but statistically significant improvement in CMR-derived ejection fraction (41% +/- 8.3% to 43% +/- 8%; p < 0.02). Carvedilol also was associated with significant improvements in both the mean rate of pressure rise (dP/dt) during isovolumetric contraction (804 +/- 216 to 951 +/- 282 mmHg/s; p < 0.05) and the myocardial performance index (0.55 +/- 0.18 to 0.42 +/- 0.15; p < 0.01). A trend toward improved shortening fraction, E/E' ratio, and isovolumetric relaxation time also was observed. Two patients had runs of nonsustained ventricular tachycardia exceeding 140 beats per minute (bpm) before carvedilol administration. Ventricular tachycardia exceeding 140 bpm was not observed after carvedilol therapy. Carvedilol was well tolerated, and no serious adverse events were identified.

CONCLUSIONS

Carvedilol therapy appears to be safe for patients with DCM secondary to muscular dystrophy and produces a modest improvement in systolic and diastolic function.

Neurocardiogenic injury in neurovascular disorders

cardiac injury occurs frequently after stroke; and the most widely investigated form of neurocardiogenic injury is aneurysmal subarachnoid hemorrhage. Echocardiography and screening for elevated troponin and B-type natriuretic peptide levels may help prognosticate and guide treatment of stroke. Cardiac catheterization is not routinely recommended in subarachnoid hemorrhage patients with left ventricular dysfunction and elevated troponin. The priority should be treatment of the underlying neurologic condition, even in patients with left ventricular dysfunction. Cardiac injury that occurs after subarachnoid hemorrhage appears to be reversible. In contrast to subarachnoid hemorrhage patients, patients with ischemic stroke are more likely to have concomitant significant heart disease. For patients who develop brain death, cardiac evaluation under optimal conditions may help increase the organ donor pool.

Anaesthesia for endovascular management of cerebral aneurysms

Subarachnoid haemorrhage due to rupture of cerebral aneurysms is a multisystem disease. Treatment of the condition in the past has relied on craniotomy and clipping of the aneurysm to prevent a recurrent haemorrhage. There is now emerging evidence to suggest that endovascular treatment of cerebral aneurysms may reduce the morbidity associated with open surgery. The anaesthetic management of interventional neuroradiology also creates new challenges due to the novel approach to treatment. Anaesthetists need to be familiar with this procedure and the management of potential complications. This review provides an overview such considerations.

Cardiopulmonary complications of brain injury

Cardiac and pulmonary complications following acute neurologic injury are common and may be a cause of morbidity and mortality in this population. Examples include hypertension, arrhythmias, ventricular dysfunction, pulmonary edema, shock, and sudden death. Primary neurologic events are represented by stroke, subarachnoid hemorrhage, traumatic brain injury, epilepsy, and encephalitis and have been frequently reported. Given the high frequency of these conditions, it is important for physicians to become familiar with their pathophysiology, allowing for more prompt and appropriate treatment.

Plasma B-type natriuretic peptide levels are associated with early cardiac dysfunction after subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Serum B-type natriuretic peptide (BNP) is elevated after subarachnoid hemorrhage (SAH), as well as in the setting of congestive heart failure and myocardial infarction. The aim of this study was to prospectively quantify the relationship between BNP levels and cardiac outcomes after SAH.

METHODS

Plasma was collected for BNP measurements as soon as possible after enrollment; a mean of 5+/-4 days after SAH symptom onset. On days 1, 3, and 6 after enrollment, troponin I (cTi) was measured and 2-dimensional echocardiography was performed. The following cardiac variables were collected and treated dichotomously: left ventricular ejection fraction (LVEF), regional wall motion abnormalities (RWMA), diastolic dysfunction, pulmonary edema, and cTi.

RESULTS

There were 57 subjects. The median BNP level was 141 pg/mL (range, 0.8 to 3330 pg/mL). Higher mean BNP levels were present in those with RWMA (550 versus 261 pg/mL; P=0.012), diastolic dysfunction (360 versus 44; P=0.011), pulmonary edema (719 versus 204; P=0.016), elevated cTi (662 versus 240; P=0.004), and LVEF <50% (644 versus 281; P=0.015).

CONCLUSIONS

Early after SAH, elevated BNP levels are associated with myocardial necrosis, pulmonary edema, and both systolic and diastolic dysfunction of the left ventricle. These findings support the hypothesis that the heart releases BNP into the systemic circulation early after SAH.

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.

Cardiac Injury after Subarachnoid Hemorrhage Is Independent of the Type of Aneurysm Therapy

OBJECTIVE:

Subarachnoid hemorrhage (SAH) is associated with cardiac injury and dysfunction. Whether aneurysm clipping versus coiling has a differential effect on the risk of troponin release and left ventricular (LV) dysfunction after SAH is unknown. It is hypothesized that aneurysm treatment does not affect the risk of developing cardiac injury and dysfunction.

METHODS:

The study included 172 consecutive SAH patients who underwent clipping (n = 109) or coiling (n = 63) aneurysm therapy. Hemodynamic data were collected, cardiac troponin I was measured, and echocardiography was performed on the 1st, 3rd, and 6th days after enrollment. A cardiac troponin I measurement of more than 1.0 μg/L was considered abnormal. For each echocardiographic examination, a blinded observer measured LV ejection fraction (abnormal if &lt;50%) and quantified LV regional wall motion abnormalities. The incidence of cardiac outcomes in the treatment groups was compared using odds ratios (ORs).

RESULTS:

The coiled patients were older than the clipped patients (mean age, 59 ± 13 yr versus 53 ± 12 yr; t test, P &lt; 0.001) and were more likely to have posterior aneurysms (33% versus 18%; χ2 test, P = 0.019). There were no significant between-group differences in the risk of cardiac troponin I release (coil 21% versus clip 19%; OR = 0.89, P = 0.789), regional wall motion abnormalities (33% versus 28%; OR = 0.76, P = 0.422), or LV ejection fraction lower than 50% (16% versus 17%; OR = 1.06, P = 0.892). No patient died of cardiac causes (heart failure, myocardial infarction, or arrhythmia).

CONCLUSION:

Surgical and endovascular aneurysm therapies were associated with similar risks of cardiac injury and dysfunction after SAH. The presence of neurocardiogenic injury should not affect aneurysm treatment decisions.

Electrocardiographic changes in patients with ischaemic stroke and their prognostic importance

We investigated prognostic importance of electrocardiographic (ECG) changes in ischaemic stroke patients without primary heart disease because of the limited evidence. This study consisted of 162 patients (92 male, age 64 +/- 14 years) with first ischaemic stroke presenting to hospital during 18 months. One-month mortality was analysed by means of ischaemia-like ECG changes, long QT and arrhythmia. Ischaemia-like ECG changes were observed in 79% of stroke patients and long QTc in 26% and arrhythmias in 44%. Early mortality rate was 27% (n = 44). Age, ST-segment change and abnormal U wave were univariate predictors of early mortality (each p < 0.05). In multivariate analysis, age > 65 years (OR = 1.4, p = 0.02) and presence of ST-segment change (OR = 2.6, p = 0.01) were only independent predictors. Although sensitivity and specificity of ST-segment change were relatively low to identify patients at risk of death, its negative predictive value was 82%. The ECG changes are frequently seen in selected patients with ischaemic stroke. Regardless of origin, ST-segment change can be a predictor of early mortality.

Predictors of neurocardiogenic injury after subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage (SAH) frequently results in myocardial necrosis with release of cardiac enzymes. Historically, this necrosis has been attributed to coronary artery disease, coronary vasospasm, or oxygen supply-demand mismatch. Experimental evidence, however, indicates that excessive release of norepinephrine from the myocardial sympathetic nerves is the most likely cause. We hypothesized that myocardial necrosis after SAH is a neurally mediated process that is dependent on the severity of neurological injury.

METHODS

Consecutive patients admitted with SAH were enrolled prospectively. Predictor variables reflecting demographic (age, sex, body surface area), hemodynamic (heart rate, systolic blood pressure), treatment (phenylephrine dose), and neurological (Hunt-Hess score) factors were recorded. Serial cardiac troponin I measurements and echocardiography were performed on days 1, 3, and 6 after enrollment. Troponin level was treated as a dichotomous outcome variable. We performed univariate and multivariate analyses on the relationships between the predictor variables and troponin level.

RESULTS

The study included 223 patients with an average age of 54 years. Twenty percent of the subjects had troponin I levels >1.0 microg/L (range, 0.3 to 50 microg/L). By multivariate logistic regression, a Hunt-Hess score >2, female sex, larger body surface area and left ventricular mass, lower systolic blood pressure, and higher heart rate and phenylephrine dose were independent predictors of troponin elevation.

CONCLUSIONS

The degree of neurological injury as measured by the Hunt-Hess grade is a strong, independent predictor of myocardial necrosis after SAH. This finding supports the hypothesis that cardiac injury after SAH is a neurally mediated process.

Neurogenic cardiac injury

Cardiac injury may occur following many types of brain injury, although the most widely investigated form of neurocardiogenic injury is subarachnoid hemorrhage (SAH). Echocardiography may help prognosticate and aid in the treatment of SAH if left ventricular (LV) dysfunction is suspected or if troponin levels are elevated. Cardiac catheterization, however, is not routinely recommended in SAH patients with LV dysfunction and elevated troponin. The priority should be treatment of the underlying neurological condition, even in the setting of LV dysfunction. Cardiac injury that occurs following an SAH appears to be reversible. For patients that develop brain death cardiac evaluation under optimal conditions may help increase the donor pool.

Regional myocardial perfusion after experimental subarachnoid hemorrhage

BACKGROUND AND PURPOSE

The pathophysiology of cardiac injury after subarachnoid hemorrhage (SAH) remains controversial. Data from animal models suggest that catecholamine-mediated injury is the most likely cause of cardiac injury after SAH. However, researchers also have proposed myocardial ischemia to be the underlying cause, as a result of coronary artery disease, coronary artery spasm, or hypertension and tachycardia. To test the hypothesis that SAH-induced cardiac injury occurs in the absence of myocardial hypoperfusion, we developed an experimental canine model that reproduces the clinical and pathological cardiac lesions of SAH and defines the epicardial and microvascular coronary circulation.

METHODS

Serial ECG, hemodynamic measurements, coronary angiography, regional myocardial blood flow measurements by radiolabeled microspheres, 2D echocardiography, and myocardial contrast echocardiography were performed in 9 dogs with experimental SAH and 5 controls.

RESULTS

Regional wall motion abnormalities were identified in 8 of 9 SAH dogs and 1 of 5 controls (Fisher's Exact Test, P=0.02) but no evidence was seen of coronary artery disease or spasm by coronary angiography and of significant myocardial hypoperfusion by either regional myocardial blood flow or myocardial contrast echocardiography.

CONCLUSIONS

In this experimental model of SAH, a unique form of regional left ventricular dysfunction occurs in the absence of myocardial hypoperfusion. Future studies are justified to determine the cause of cardiac injury after SAH.