International journal of cardiology
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Randomized Controlled Trial
Blunted heart rate recovery is improved following exercise training in overweight adults with obstructive sleep apnea.
Obstructive sleep apnea (OSA) predisposes individuals to cardiovascular morbidity, and cardiopulmonary exercise test (CPET) markers prognostic for cardiovascular disease have been found to be abnormal in adults with OSA. Due to the persistence of OSA and its cardiovascular consequences, whether the cardiovascular adaptations normally conferred by exercise are blunted in adults not utilizing established OSA treatment is unknown. The aims of this study were to document whether OSA participants have abnormal CPET responses and determine whether exercise modifies these CPET markers in individuals with OSA. ⋯ These results suggest that individuals with OSA have autonomic dysfunction, and that exercise training, by increasing HRR and VO2 peak, may attenuate autonomic imbalance and improve functional capacity independent of OSA severity reduction.
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Current European guidelines recommend the use of sensitive or high-sensitivity cardiac troponin assays to reduce the minimal sampling interval from 6 to 3h. ⋯ Rule-in and rule-out of non-STEMI may be accomplished comparably effective at 3 or 6h. For rule-in, absolute kinetic changes perform better than relative changes at all time points. ROC-optimal absolute δ-change was 6.95 ng/L at 3h and 8.9 ng/L at 6h.
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It remains unclear which echocardiographic measure is most suitable for serial measurement in real-world aortic stenosis (AS) follow-up. We determine whether the dimensionless index (DI) between aortic valve and left ventricular outflow tract velocities is measured more consistently using velocity-time-integral (VTI) or peak velocities (V(peak)) in real life. ⋯ Serially-followed variables require minimal noise to maximise detection of genuine change. For AS surveillance, calculating DI--or effective orifice area--from the ratio of V(peak) rather than VTIs would reduce 95% confidence intervals from ± 51% to a still-disappointing ± 25%. Guidelines recommend noisy surveillance measures, causing conscientious echocardiographers to 'peek' at previous values, and impairing clinicians' faith in echocardiographically-observed changes when making clinical decisions. For us in echocardiography to improve our ability to contribute to AS follow-up requires us to first acknowledge and discuss this honestly.
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Fragmented QRS complexes (fQRS) correlate with myocardial scar, and may predict arrhythmias in patients with repaired tetralogy of Fallot (TOF). We investigated the relationship between fQRS in operated TOF patients with right ventricular (RV) dysfunction and RV outflow tract (RVOT) aneurysm. ⋯ The presence of fQRS on the ECG is significantly associated with RV dysfunction and RVOT aneurysms in repaired TOF patients. Increasing burden of fragmentation, especially in the anterior leads, is associated with increasing RV dysfunction.
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In rodent models of pulmonary hypertension (PH) and right ventricular hypertrophy (RVH), the QTc interval is prolonged, reflecting downregulation of repolarizing Kv channels in RV myocytes. The significance of QTc prolongation in human PH is unknown. We hypothesized that QTc prolongation occurs in human PH, is associated with RVH and decreased RV function, and predicts adverse prognosis. ⋯ QTc prolongation in PH patients reflects the status of the RV and is an independent predictor of mortality.