Stroke as the First Manifestation of Atrial Fibrillation

Atrial fibrillation may remain undiagnosed until an ischemic stroke occurs. In this retrospective cohort study we assessed the prevalence of ischemic stroke or transient ischemic attack as the first manifestation of atrial fibrillation in 3,623 patients treated for their first ever stroke or transient ischemic attack during 2003-2012. Two groups were formed: patients with a history of atrial fibrillation and patients with new atrial fibrillation diagnosed during hospitalization for stroke or transient ischemic attack. A control group of 781 patients with intracranial hemorrhage was compiled similarly to explore causality between new atrial fibrillation and stroke. The median age of the patients was 78.3 [13.0] years and 2,009 (55.5%) were women. New atrial fibrillation was diagnosed in 753 (20.8%) patients with stroke or transient ischemic attack, compared to 15 (1.9%) with intracranial hemorrhage. Younger age and no history of coronary artery disease or other vascular diseases, heart failure, or hypertension were the independent predictors of new atrial fibrillation detected concomitantly with an ischemic event. Thus, ischemic stroke was the first clinical manifestation of atrial fibrillation in 37% of younger (<75 years) patients with no history of cardiovascular diseases. In conclusion, atrial fibrillation is too often diagnosed only after an ischemic stroke has occurred, especially in middle-aged healthy individuals. New atrial fibrillation seems to be predominantly the cause of the ischemic stroke and not triggered by the acute cerebrovascular event

Mortality after stroke in patients with paroxysmal and chronic atrial fibrillation - The FibStroke study

Background: Recent studies have reported that patientswith paroxysmal atrial fibrillation (AF) have lower risk of thromboembolism and better prognosis than patients with chronic AF. We sought to address the differences in ischaemic events in patients with paroxysmal AF and chronic AF.Methods: The FibStroke study is a cross-sectional observational multicenter registry that included AF patients with an ischaemic stroke, TIA (transient ischaemic attack) or intracranial bleed during 2003-2012 identified from discharge registries of four Finnish hospitals. Altogether 1448 patients with paroxysmal and 1808 patients with chronic atrial fibrillation suffered a total of 707 TIA-episodes and 2549 ischaemic strokes.Results: Mortality within 30 days after the index event was significantly lower in patients with paroxysmal AF than with chronic AF (7.6% vs 16.9%, p < 0.01). At the onset of event, 62.8% of the patients with paroxysmal AF were in sinus rhythm, and these patients had better prognosis after the event compared to patients with other rhythmthan sinus rhythm(mortality 5.2% vs 15.7%, p < 0.01). In the propensity score matched analysismortality after stroke was significantly lower in patients with paroxysmal AF than in patients with chronic AF (11.6% vs 17.8%, p < 0.01), while mortality after TIA was also lower, but did not reach statistical significance (0.4% vs 1.7%, p = 0.31).Conclusions: Asignificant proportion of strokes in AF patients occur in patients with paroxysmal AF, but they have better prognosis than patients with chronic AF. The prognosis is also significantly better in patients who are in sinus rhythm at the onset of event.

Normative references of heart rate variability and salivary alpha-amylase in a healthy young male population

<p>Abstract</p> <p>Background</p> <p>This study aimed to present normative reference values of heart rate variability and salivary alpha-amylase in a healthy young male population with a particular focus on their distribution and reproducibility.</p> <p>Methods</p> <p>The short-term heart rate variability of 417 young healthy Japanese men was studied. Furthermore, salivary alpha-amylase was measured in 430 men. The average age of the subjects were 21.9 years with standard deviation of 1.6 years. Interindividual variations in heart rate variability indices and salivary alpha-amylase levels were plotted as histograms. Data are presented as the mean, median, standard deviation, coefficient of variation, skewness, kurtosis, and fifth and 95th percentiles of each physiological index.</p> <p>Results</p> <p>Mean recorded values were heart period 945.85 ms, log-transformed high frequency component 9.84 ln-ms², log-transformed low frequency component 10.42 ln-ms², log-transformed low frequency to high frequency ratio 0.58 ln-ratio, standard deviation of beat-to-beat interval 27.17 ms and root mean square of successive difference 37.49 ms. The mean value of raw salivary alpha-amylase was 17.48 U/mL, square root salivary alpha-amylase 3.96 sqrt[U/mL] and log-transformed salivary alpha-amylase 2.65 ln[U/mL]. Log-transformed heart rate variability indices exhibited almost symmetrical distributions; however, time-domain indices of heart rate variability (standard deviation of beat-to-beat interval and root mean square of successive difference) exhibited right-skewed (positive skewness) distributions. A considerable right-skewed distribution was observed for raw salivary alpha-amylase. Logarithmic transformation improved the distribution of salivary alpha-amylase, although square root transformation was insufficient. The day-to-day reproducibility of these indices was assessed using intraclass correlation coefficients. Intraclass correlation coefficients of most heart rate variability and salivary indices were approximately 0.5 to 0.6. Intraclass correlation coefficients of raw salivary markers were approximately 0.6, which was similar to those of heart rate variability; however, log transformation of the salivary markers did not considerably improve their reproducibility. Correlations between sympathetic indicators of heart rate variability and salivary alpha-amylase were not observed.</p> <p>Conclusion</p> <p>Because the sample population examined in this study involved limited age and gender variations, the present results were independent of these factors and were indicative of pure interindividual variation.</p

Mild obstructive sleep apnea does not modulate baroreflex sensitivity in adult patients

Henry Blomster,1 Tomi P Laitinen,2 Juha EK Hartikainen,3,6 Tiina M Laitinen,2 Esko Vanninen,2 Helena Gylling,4,8 Johanna Sahlman,1 Jouko Kokkarinen,5&nbsp;Jukka Randell,5 Juha Sepp&auml;,1 Henri Tuomilehto4,7 1Department of Otorhinolaryngology, Institute of Clinical Medicine, 2Department of Clinical Physiology and Nuclear Medicine, 3Department of Internal Medicine, 4Department of Clinical Nutrition, School of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, 5Department of Respiratory Medicine, 6Heart Center, Kuopio University Hospital, 7Oivauni Sleep Clinic, Kuopio, 8Department of Medicine, Division of Internal Medicine, University of Helsinki, Helsinki, Finland Background: Obstructive sleep apnea (OSA) is a chronic and progressive disease. OSA is associated with increased cardiovascular morbidity and mortality, the risk being more frequently encountered with severe degrees of OSA. Increased sympathetic activation and impaired cardiac autonomic control as reflected by depressed baroreceptor reflex sensitivity (BRS) are possible mechanisms involved in the cardiovascular complications of OSA. However, it is not known at what stage of OSA that changes in BRS appear. The aim of this study was to evaluate BRS in patients with mild OSA. Methods: The study population consisted of 81 overweight patients with mild OSA and 46 body weight-matched non-OSA subjects. BRS, apnea-hypopnea index, body mass index, and metabolic parameters were assessed. The phenylephrine test was used to measure BRS. Results: Patients in the OSA group were slightly but significantly older than the non-OSA population (50.3&plusmn;9.3 years vs 45.7&plusmn;11.1 years, P=0.02). Body mass index, percentage body fat, blood pressure, fasting glucose, insulin, and lipid levels did not differ between the OSA patients and non-OSA subjects. Absolute BRS values in patients with mild OSA and non-OSA subjects (9.97&plusmn;6.70 ms/mmHg vs 10.51&plusmn;7.16 ms/mmHg, P=0.67) and BRS values proportional to age-related and sex-related reference values (91.4%&plusmn;22.7% vs 92.2%&plusmn;21.8%, P=0.84) did not differ from each other. BRS &lt;50% of the sex-specific reference value was found in 6% of patients with mild OSA and in 2% of non-OSA subjects (P=0.29). Conclusion: Patients with mild OSA did not show evidence of disturbed BRS in comparison with weight-matched non-OSA controls. Keywords: obstructive sleep apnea, baroreceptor reflex sensitivit