Holter monitoring in patients with transient focal cerebral ischemia

Is ambulatory electrocardiography useful in the evaluation of patients with recent stroke?

This study was designed to determine whether ambulatory electrocardiography in patients with recent stroke would lead to a change in clinical management or outcome and to express these findings in terms of cost benefit. A prospective, consecutive sample of patients (n = 100) with recent stroke referred from the neurology or medical services for ambulatory electrocardiography was identified. Ambulatory electrocardiograms were reviewed to identify patients with potentially important bradyarrhythmias, tachyarrhythmias, or atrial fibrillation. Patients were then followed up without interference with ongoing care to determine whether these findings led to changes in clinical management that might influence patient outcome. Of the 100 patients, 16 had an index "important" arrhythmia. No significant bradyarrhythmias were noted. Nonsustained ventricular tachycardia (> or = 6 complexes) in two patients and supraventricular tachycardia (> or = 10 complexes) in seven patients did not lead to management changes. Four patients had a history of atrial fibrillation who were in sinus rhythm; anticoagulation had been addressed in three; the fourth patient died before the issue could be addressed. Of three patients in atrial fibrillation, there was a history of atrial fibrillation and a decision regarding anticoagulation in each before monitoring. The cost of these 100 ambulatory electrocardiograms was about $55,000. In conclusion, these findings do not support the routine use of ambulatory electrocardiography in the evaluation of patients with stroke.

Activity of peripheral sympathetic efferent nerves in experimental subarachnoid haemorrhage. Part I: Observations at the time of intracranial hypertension

The origin and pathomechanism of vegetative disturbances in patients suffering from subarachnoid haemorrhage are not completely clarified. Since some of these alterations in vegetative functions may well be attributed to acute changes in sympathetic activity, we initiated a study to investigate this modality in experimentally induced subarachnoid haemorrhage. Experiments were performed on 51 cats, anaesthetized with alpha-chloralose and urethane, immobilized and artificially ventilated. Compound electrical discharges of the left vertebral, cardiac and renal sympathetic nerves, ECG, EEG, end-tidal CO2, systemic arterial blood pressure and intracranial pressure were recorded on a polygraph. Subarachnoid haemorrhage was simulated by the injection of 1-5 ml of fresh, autologous blood into the cisterna magna. Mock cerebrospinal fluid was also injected as a control. Our results showed that in induced subarachnoid haemorrhage, not the blood itself but the intracranial pressure elevation might be responsible for the strong increase in sympathetic efferent activity. With the direct recording of the electrical activity of the three sympathetic nerves, we were able to verify the sympathetic overactivity underlying the cardiovascular disturbances during intracranial pressure elevation. Regarding the mechanism of the overactivity, most probably not the ischaemia or hypoxia, but the mechanical distortion of the medulla could be the adequate stimulus of the sympathetic overactivity and the Cushing response during intracranial pressure elevation.

[Malaise and loss of consciousness in the elderly patient: prospective evaluation of methods of investigation]

60 consecutive patients (mean age: 80,7 yrs; s.d.: 6,1 yrs; range 70-94 yrs) referred to a geriatric medicine department with syncope or dizziness were proposectively compared with 40 age and sex matched controls. A battery of non-invasive investigations including tilt-test, glycemia, 12 lead ecg., eeg, 24 hour ambulatory ecg recording,. M--mode echocardiogram and cervical Doppler velocimetry was applied blindly to patients and controls. The proportion of abnormalities was similar in both groups having sick sinus syndrom or complete atrio-ventricular block versus no control (p less than 0.05). By contrast history-case was of great predictive value: 6 of 13 patients reporting abrupt syncope had a 24 ecg recording showing sick sinus syndrom or complete atrio ventricular block, versus 2 of 47 other patients (p less than 0,01); 11 of 14 patients reporting orhostatic dizziness or syncope had a tilt-test consistent with orthostactic hypotension versus 6 of 46 other patients (p less than 0,01).

Potential sources of emboli in patients with presumed transient cerebral or retinal ischaemia

Potential sources of emboli were sought by non-invasive techniques and, where appropriate, by angiography in 117 consecutive patients referred to a neurological service with symptoms of transient cerebral or retinal ischaemia. The non-invasive tests were also applied to 104 age and sex matched controls. 32% of the patients had structural cardiac abnormalities, 32% had arrhythmias on 24 h electrocardiographic monitoring, 15% had evidence of ischemic heart disease, and 34% were or had been hypertensive. The proportions of these abnormalities in the control group were 14%, 28%, 12%, and 10%, respectively. 37% of the patients who had carotid angiograms had significant arterial lesions. Some patients had both cardiac and carotid lesions but 25% of the patients who had complete investigations had no detectable evidence of any cardiovascular disease.

Cerebral ischemia in young adults

56 cerebral ischemia patients up to the age of 40 were investigated using a strict clinical and instrumental protocol in order to elicit the relative importance of the various iatrogenic factors involved. In addition to atherosclerosis risk factors (smoking, hypertension, ischemic heart disease, diabetes, dyslipidemia) other possible causes of cerebral ischemia were sought (arteritis, migraine, head injury, oral contraceptives, coagulation disorders, cardiogenic embolism, etc.). 50% of the patients examined had at least two atherosclerosis risk factors and 55% had other causes singly or in association with atherosclerosis.