No abstract

Background: The impairment of short-term heart rate regulation in patients with heart failure with preserved ejection fraction (HFpEF) can cause acute hemodynamic collapse. Detrended fluctuation analysis (DFA) is a useful tool for the diagnosis of heart diseases and the prediction of mortality. In DFA, the short-term scaling exponent a is decreased in heart failure. However, its change in HFpEF patients remains unclear. Methods: Twenty patients diagnosed with HFpEF [defined as brain natriuretic peptide (BNP) >100 pg/ mL, ejection fraction (EF) !50%, and without significant valvular disease], 20 diagnosed with non-HFpEF (BNP > 100 pg/mL and EF < 50%), and 20 control subjects generally matched for age and gender were enrolled. Holter electrocardiography was performed, and heart rate variability was calculated. In the DFA, the scaling exponents in 1000 beats were calculated for each 15-min segment and the average of all segments was used. We compared both the short-term (<11 beats, a1) and long-term (!11 beats, a2) scaling exponents among the three groups.Results: In the HFpEF, non-HFpEF, and control groups, a1 was 0.73 AE 0.27, 0.66 AE 0.29, and 1.01 AE 0.20 (p < 0.01), and a2 was 0.95 AE 0.08, 0.88 AE 0.11, and 0.96 AE 0.07 (p < 0.01), respectively. The a1 exponent was significantly decreased in the HFpEF group (p < 0.01 vs. control) and the non-HFpEF group (p < 0.01 vs. control), while the a2 exponent was significantly decreased in the non-HFpEF group only (p < 0.05 vs. HFpEF and control).Conclusions: Short-term heart rate regulation is impaired in patients with HFpEF, while patients with non-HFpEF have both short-term and long-term impairment.

No abstract

SummaryThe usefulness of coronary magnetic resonance angiography (cMRA) has been reported, although the difference in the diagnostic accuracy of different protocols has not been established.We compared conventional coronary angiography (CAG) and cMRA, conducted within 6 months in 24 consecutive patients between September 2012 and July 2014. Three cMRA protocols were examined, cMRA1, free-breathing wholeheart coronary angiography (WHCA) without contrast; cMRA2, free-breathing WHCA with contrast; and cMRA3, breath-hold steady-state free precession with contrast using a 3.0 T scanner. Image quality was graded on a 4-point scale: 1) nonassessable; 2) assessable, fair vessel contrast; 3) assessable, good vessel contrast; and 4) assessable, excellent vessel contrast. Significant narrowing of the coronary arteries was visually assessed.Stenosis was observed in 34 segments, with a prevalence of 10.3%. For cMRA1, cMRA2, and cMRA3, the numbers of assessable segments were 245 (74.2%), 287 (87.0%), and 164 (49.7%), respectively (P < 0.001 by the McNemar test). For assessable segments, the sensitivity, specificity, positive predictive value, and negative predictive value were 89.3%, 99.1%, 92.6%, and 98.6% for cMRA1, 90.0%, 98.1%, 84.4%, and 98.8% for cMRA2, and 76.5%, 93.9%, 59.1%, and 97.1% for cMRA3, respectively. For the assessable segments, the image quality score was better with cMRA2 than with the other two protocols.cMRA is a useful modality to rule out coronary artery disease, especially the cMRA2 protocol, which performed better than the other two protocols. (Int Heart J 2016; 57: 535-540) Key words: Whole-heart coronary angiography, Steady-state free precession, Coronary artery disease X -ray coronary angiography (CAG) is the current gold standard for the assessment of coronary artery disease (CAD), but it carries the risk of complications because it is an invasive procedure. However, magnetic resonance (MR) imaging technology is noninvasive and radiationfree.1) The ability to evaluate the coronary arteries using electrocardiogram (ECG)-gated MR imaging was first reported in 1987;2) however, only the proximal coronary arteries can be evaluated using this method. One of the major limitations of coronary MR angiography (cMRA) is the need to effectively suppress respiratory motion. Breath-hold imaging is one of the protocols used to solve this problem,3) in addition to freebreathing and 3-dimensional cMRA, 4,5) which result in better image quality than breath-hold imaging.Improvements in cMRA image quality have also been achieved by using gradient performance, radiofrequency-receiving coils, and advanced data acquisition techniques. However, whole heart cMRA requires a long acquisition time, whereas in the clinical setting, evaluation of only the main branch or the proximal portion of the coronary artery is sometimes required. 3T MRI has a better signal-to-noise ratio and higher spatial resolution than 1.5T MRI. On the other hand, cMRA is particularly useful for the assessment of coronary arteries. In addition, 3T MR...

It is feasible to treat AMI patients with prasugrel. HTPR is a significant independent risk factor for adverse events in AMI patients receiving prasugrel after primary PCI.