Variability in obstructive sleep apnea: Analysis of pacemaker-detected respiratory disturbances.

Background: Obstructive sleep apnea (OSA) is associated with several cardiovascular conditions. Some pacemakers feature specific algorithms detecting respiratory cycles and deriving indices well correlated with the identification of polysomnography-confirmed severe OSA.

Objectives: The purposes of this study were to analyze respiratory disturbances measured by a validated algorithm in clinical practice and to describe their variability over time and their association with atrial fibrillation.

Acoustic cardiac triggering: a practical solution for synchronization and gating of cardiovascular magnetic resonance at 7 Tesla.

Background: To demonstrate the applicability of acoustic cardiac triggering (ACT) for imaging of the heart at ultrahigh magnetic fields (7.0 T) by comparing phonocardiogram, conventional vector electrocardiogram (ECG) and traditional pulse oximetry (POX) triggered 2D CINE acquisitions together with (i) a qualitative image quality analysis, (ii) an assessment of the left ventricular function parameter and (iii) an examination of trigger reliability and trigger detection variance derived from the signal waveforms.

Results: ECG was susceptible to severe distortions at 7.