Gapless Electrocardiogram-Monitoring in stroke at high risk of atrial fibrillation.

BACKGROUND AND PURPOSE: Previous studies investigating prolonged electrocardiogram (ECG)-monitoring after ischemic stroke had significant gaps between the index event and the beginning of long-term monitoring. Atrial fibrillation (AF) detection might be higher if prolonged cardiac rhythm documentation is performed with a gapless approach without any interruption of monitoring time. METHODS: This investigator-initiated, prospective study included patients with acute ischemic stroke or transient ischemic attack at three study centers. Participants received gapless ECG-monitoring via telemetry during stroke-unit admission until implantation of an insertable cardiac monitor (ICM) within the first days after the index event. Patients acted as their own controls and also received standard 24-72-h Holter ECG. RESULTS: A total of 110 patients were included, of whom 86 (78.2%) had an embolic stroke of unknown source, 14 (12.7%) had small-vessel disease, and 10 (9.1%) had large-artery disease. AF was newly diagnosed in 17 (15.5%) patients via ICM monitoring, compared to one (0.9%) patient via Holter ECG during 6 months of follow-up (p < 0.001). The detection rate of AF within the first 30 days was 10.0%, which accounted for 64% of all new AF diagnoses. The median duration of the detected episodes was 1.7 (interquartile range = 0.2-4.7) h. All patients with new onset AF were treated with oral anticoagulation. CONCLUSIONS: Gapless ECG-monitoring is an effective strategy to significantly increase the detection rate of AF after ischemic stroke. This finding supports the use of long-term ECG-monitoring with a gapless approach without any interruption in monitoring time as the gold standard for clinical practice.

Temporal Trends of Functional Outcome in Patients With Acute Ischemic Stroke Treated With Intravenous Thrombolysis.

BACKGROUND: Intravenous thrombolysis improves functional outcome in patients with acute stroke and frequencies of r-tPA (recombinant tissue-type plasminogen activator) treatment have been increasing over time. We aimed to assess whether functional outcome in r-tPA-treated patients improved over time and to investigate the influence of clinical variables on functional outcome. METHODS: We analyzed data of r-tPA-treated patients in the Austrian Stroke Unit Registry from 2006 to 2019. Favorable functional outcome was defined as modified Rankin Scale score of 0 to 2. Frequencies of modified Rankin Scale score of 0 to 2 were assessed for the overall population and in prespecified subgroups; multivariable logistic regression analysis was performed to assess associations of baseline characteristics including clinically relevant interactions, and outcome. RESULTS: Overall, 4865 out of 9409 r-tPA-treated patients (51.7%) achieved favorable functional outcome 3 months post stroke. Between 2006 and 2019, frequencies of favorable functional outcome increased from 45.9% to 56.8%. In multivariable logistic regression analysis, year of treatment (adjusted odds ratio [adjOR], 1.08 [95% CI, 1.01-1.15]) was associated with favorable functional outcome. Stroke severity (National Institutes of Health Stroke Scale, adjOR, 0.86 [95% CI, 0.85-0.87]), age (61-70 years: adjOR, 0.67 [95% CI, 0.55-0.80], 71-80 years: adjOR, 0.42 [95% CI, 0.35-0.50], >80 years: adjOR, 0.16 [95% CI, 0.13-0.20]), female sex (adjOR, 0.89 [95% CI, 0.79-0.99]), and various comorbidities (eg, atrial fibrillation, prior stroke, diabetes) were negatively associated. Inclusion of interaction terms into the multivariable logistic regression model suggests a positive effect of year of treatment and endovascular treatment by increasing stroke severity on functional outcome (interaction between year of treatment and National Institutes of Health Stroke Scale: adjOR, 1.01 [95% CI, 1.00-1.02], interaction between National Institutes of Health Stroke Scale and endovascular treatment: adjOR, 1.02 [95% CI, 1.01-1.03]). CONCLUSIONS: Frequencies of favorable functional outcome in r-tPA-treated patients have been increasing over time, likely driven by improved outcome in patients with more severe strokes receiving endovascular treatment. However, some subgroups are still less likely to achieve functional independency and deserve particular attention.

Cardiovascular effects of fentanyl and propofol on hemodynamic function in rabbits.

OBJECTIVE: To evaluate short-term cardiovascular effects after IV administration of boluses of fentanyl in rabbits. ANIMALS: 6 healthy New Zealand White rabbits. PROCEDURES: Each rabbit was anesthetized with propofol (4.0 to 8.0 mg/kg, IV); anesthesia was maintained by administration of propofol (1.2 to 1.3 mg/kg/min, IV). Subsequently, 3 injections of fentanyl (0.0053 mg/kg) were administered. Before and for 10 minutes after injections, the following variables were measured: vessel diameter, peak systolic blood flow velocity, minimum diastolic blood flow velocity, end-diastolic blood flow velocity, time-average blood flow velocity, mean volumetric flow (VFmean), resistance index (RI), and pulsatility index for the left common carotid artery after the first injection and abdominal aorta after the third injection; mean arterial pressure (MAP); heart rate (HR); arterial oxygen saturation; end-tidal partial pressure of carbon dioxide; and body temperature. Echocardiography was performed after the second injection. RESULTS: Fentanyl injections caused a transient and significant decrease in diameter and VFmean of the abdominal aorta and end-diastolic blood flow velocity of the left common carotid artery and an increase in peak systolic blood flow velocity and RI of the left common carotid artery. Also, MAP, HR, and body temperature decreased significantly after injections. CONCLUSIONS AND CLINICAL RELEVANCE: Fentanyl injections induced a short-term decrease of vessel diameter in the abdominal aorta and increased resistance in the distal distribution area of the left common carotid artery. Results revealed decreases in MAP, HR, and body temperature, with an increasing effect after the third bolus injection, which indicated a cumulative drug effect.

Cardiovascular effects of dipyrone and propofol on hemodynamic function in rabbits.

OBJECTIVE: To evaluate the short-term cardiovascular effects of IV administration of dipyrone (metamizole) as an intraoperative analgesic during total IV anesthesia with propofol. ANIMALS: 6 healthy female New Zealand White rabbits. PROCEDURES: Anesthesia was induced with propofol (4.0 to 8.0 mg/kg, IV) and maintained with the same drug (1.2 to 1.3 mg/kg/min, IV). After induction, 3 doses of dipyrone (65 mg/kg each) were administered IV at 25-minute intervals. Before and for 10 minutes after each dipyrone injection, the following vascular and hemodynamic variables were recorded at the left common carotid artery every minute after the first injection: vessel diameter; peak systolic, minimum diastolic, end-diastolic, and mean blood flow velocities; mean volumetric flow; resistance and pulsatility indices; mean arterial blood pressure (MAP); heart rate; arterial oxygen saturation (SpO(2)); and end-tidal partial pressure of CO(2) (PETCO(2)). Echocardiography was performed after the second injection. The same variables were measured at the abdominal aorta (AA) after the third injection. RESULTS: Dipyrone injections caused a significant, transient decrease in the resistance index at the AA. Also detected were a minor decrease in pulsatility index at the left common carotid artery and a minor increase in end-diastolic blood flow velocity at the AA. The MAP, heart rate, SpO(2), and PETCO(2) did not significantly change after injections. A comparison of HR and MAP after the first and third bolus injections revealed only minor changes. CONCLUSIONS AND CLINICAL RELEVANCE: Dipyrone used with propofol anesthesia in rabbits appeared not to significantly impair cardiovascular and hemodynamic function.

Accounting for biological variation in differential display two-dimensional electrophoresis experiments.

Variation of protein expression levels was investigated in the heart, lung and liver from an inbred (C57/BL6) and an outbred (CD-1) mouse line. Based on the measured inter-individual variation, optimal sample sizes for two-dimensional electrophoresis experiments were determined by means of power analysis. For both lines, the level of protein expression variation was in the range of technical variation. Thus, although the differences in protein expression variation were significant between organs and mouse lines, optimal sample sizes were very similar (between 8 for heart proteins from C57/BL6 and 10 for liver proteins of the same line). Proteins with organ expression bias (higher expression in one organ as compared to the other two organs) exhibited higher variation of expression and the proportion of these proteins in each organ explained at least partly inter-organ differences in protein expression variation. The results suggest that proteomic experiments using more heterogeneous mouse samples would not require much larger sample sizes than those using narrowly standardized samples. Experiment designs encompassing a broader genetic variation and thus affording increased relevance of the results can be accessible to proteomics researchers at still affordable sample sizes.

Effects of medetomidine-midazolam-fentanyl IV bolus injections and its reversal by specific antagonists on cardiovascular function in rabbits.

The objective of this study was to investigate the short-term cardiovascular effects of intravenous (IV) medetomidine-midazolam-fentanyl (MMF) injections in the rabbit using vascular ultrasonography and echocardiography.Anesthesia with MMF was induced intramuscularly (IM) in 8 female New Zealand White rabbits before 3 defined bolus injections of MMF were given IV. Before and for 10 min after each MMF injection the following vascular variables [at the left common carotid artery (ACC) after the first injection and at the abdominal aorta (AA) after the second injection]: vessel diameter (D), peak systolic, minimum diastolic, end-diastolic and average blood flow velocities (psBFV, mdBFV, edBFV, Vave), average volumetric flow (VFave), resistance index (RI) and pulsatility index (PI) and other clinical variables: mean arterial pressure (MAP), heart rate (HR), peripheral arterial oxygen saturation and end-tidal CO2 were recorded. Echocardiography was used after the third injection to investigate changes in cardiac parameters. Additionally, hemodynamic effects were observed at the ACC after complete subcutaneous antagonism of anesthesia by atipamezole-flumazenil-naloxone (AFN) until recovery of the animals.Medetomidine-midazolam-fentanyl IV caused a significant decrease of blood flow velocity in both investigated vessels which was associated with a significant decrease of HR and cardiac performance indicated by the decrease of FS and average volumetric blood flow. Mean arterial pressure significantly increased after each MMF injection; whereas, it significantly decreased after AFN injection. Therefore, MMF and AFN should be carefully used in rabbits and may not be suitable in patients with ventricular dysfunction.

Effects of ketamine-xylazine intravenous bolus injection on cardiovascular function in rabbits.

The direct effects of ketamine-xylazine (KET-XYL) on vascular function have not been investigated in rabbits. The short-term cardiovascular effects of intravenous (IV) KET-XYL bolus injection, therefore, should be investigated using vascular ultrasonography.In this prospective experimental study, KET-XYL anesthesia was induced IV in 9 female New Zealand White rabbits before 3 defined test bolus injections of KET-XYL were given IV. Before and for 10 min after each KET-XYL injection vascular and hemodynamic variables were recorded at the left common carotid artery (ACC) after the 1st injection, and at the abdominal aorta (AA) after the 2nd injection. Echocardiography was performed after the 3rd injection to investigate changes in cardiac parameters.Ketamine-xylazine IV caused a significant increase in vessel diameter at the ACC and AA. Average volumetric flow significantly decreased at the ACC and pulsatility index significantly decreased at the AA. Fractional shortening (FS) and heart rate significantly decreased, while mean arterial blood pressure initially increased.Bolus injections of KET-XYL IV produced a transient vasodilatation at the ACC and AA. Despite central vasodilatation, bradycardia, and decrease of FS and average volumetric flow (VFave), mean arterial blood pressure did not significantly decrease indicating well-preserved cardiovascular compensatory mechanism after the ratio and doses of KET-XYL IV bolus injections used in this study.