Obstructive sleep apnea and electrocardiographic P-wave morphology.

INTRODUCTION: Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder with important cardiovascular implications. Left atrial abnormality can be identified by electrocardiographic P-wave morphology and is considered an important risk for atrial fibrillation (AF) and stroke, both of which have been associated with OSA. We hypothesized that severity of OSA would be associated with more abnormal electrocardiographic P-wave morphology as indicated by P-wave terminal force in V METHODS: Patients who underwent clinically indicated polysomnography and had 12-lead ECG were identified through medical record review. Logistic regression was used to determine the associations between the measures of OSA severity (apnea hypopnea index [AHI] and mean nocturnal oxygen [O RESULTS: A total of 261 patients (mean age: 57 years old, male: 52%) were included in the study. Multivariate analysis showed that AHI was associated with abnormal PTFV CONCLUSION: In a sleep clinic cohort, there was significant association between OSA severity and ECG-defined left atrial abnormality

Simplified Post Processing of Cine DENSE Cardiovascular Magnetic Resonance for Quantification of Cardiac Mechanics

BACKGROUND: Cardiovascular magnetic resonance using displacement encoding with stimulated echoes (DENSE) is capable of assessing advanced measures of cardiac mechanics such as strain and torsion. A potential hurdle to widespread clinical adoption of DENSE is the time required to manually segment the myocardium during post-processing of the images. To overcome this hurdle, we proposed a radical approach in which only three contours per image slice are required for post-processing (instead of the typical 30-40 contours per image slice). We hypothesized that peak left ventricular circumferential, longitudinal and radial strains and torsion could be accurately quantified using this simplified analysis. METHODS AND RESULTS: We tested our hypothesis on a large multi-institutional dataset consisting of 541 DENSE image slices from 135 mice and 234 DENSE image slices from 62 humans. We compared measures of cardiac mechanics derived from the simplified post-processing to those derived from original post-processing utilizing the full set of 30-40 manually-defined contours per image slice. Accuracy was assessed with Bland-Altman limits of agreement and summarized with a modified coefficient of variation. The simplified technique showed high accuracy with all coefficients of variation less than 10% in humans and 6% in mice. The accuracy of the simplified technique was also superior to two previously published semi-automated analysis techniques for DENSE post-processing. CONCLUSIONS: Accurate measures of cardiac mechanics can be derived from DENSE cardiac magnetic resonance in both humans and mice using a simplified technique to reduce post-processing time by approximately 94%. These findings demonstrate that quantifying cardiac mechanics from DENSE data is simple enough to be integrated into the clinical workflow

Very late presentation in ST elevation myocardial infarction: Predictors and long-term mortality

Background: Despite improvements in ST elevation myocardial infarction (STEMI) care, total ischemic time remains long in patients who present late. Our goal was to identify predictors of very late presentation (≥12 h) of STEMI and determine long-term mortality. Methods: We retrospectively examined consecutive patients admitted with STEMI to our institution using the ACTION Registry™. Time of symptom onset to first medical contact (FMC) was calculated and categorized as <12 h or ≥12 h. Predictors of very late presentation were determined. Results: Compared to patients who presented <12 h (n = 365), those who presented ≥12 h (n = 49) after symptom onset were more likely women, diabetics, and those with prior coronary revascularization. In addition, patients who presented ≥12 h had worse ventricular function, were less likely to report chest pain, and were less likely to be transported by ambulance and to undergo coronary angiography. Late presenters had higher rates of heart failure, longer hospitalizations, and were less likely to be discharged home. Diabetes, female sex, and absence of chest pain were strong predictors of late presentation. Long-term survival was significantly lower in late presenters (73% vs. 93%, p = 0.007). Conclusions: Female sex, diabetes, and absence of chest pain are strong predictors of presentation delay, and long-term mortality is significantly increased in those presenting very late. Keywords: Late presentation, STEM