Cardiovascular Tests for Risk Assessment in Asymptomatic Adults and Implications for Pilots.

BACKGROUND: This study aims to examine which marker or testing protocols have been suggested for cardiovascular disease (CVD) risk assessment in asymptomatic populations, at which CVD risk level, and how this can be implemented for CVD risk assessment in pilot populations. METHODS: A systematic search was performed using Systematic Reviews Subset on PubMed; the OvidSP interface, including all EBM reviews and EMBASE databases; and the G-I-N International Guideline Library. From each recommendation, we extracted data on consideration of the use of a marker or test for cardiovascular risk assessment in asymptomatic populations. RESULTS: Included were 45 guidelines, systematic reviews, or meta-analyses relevant to cardiovascular risk assessment in asymptomatic populations. The majority (9/12) of the citations recommend coronary artery calcium score (CACS) for CVD risk assessment in intermediate-risk (10-yr CVD risk score of 10-20%) asymptomatic adults. Other cardiac and vascular tests that may also be considered include the measurements of carotid-intima media thickness, supplemented by carotid plaque, and the ankle brachial index for prevention of peripheral artery disease and stroke. Stress myocardial perfusion scan is the potential cardiac functional test to be used with pilots with 5-yr risk of ≥15%. Among laboratory markers, only hs-CRP has a potency to be used in CVD risk assessment in intermediate-risk asymptomatic adults; however, the strength of the recommendation is not adequate. DISCUSSION: Among the cardiac and vascular testing available, CACS is the most frequently suggested test. The implications of findings for CVD risk assessment in airline pilots are highlighted in this paper.Wirawan IMA, Griffiths RF, Larsen PD. Cardiovascular tests for risk assessment in asymptomatic adults and implications for pilots. Aerosp Med Hum Perform. 2018; 89(7):648-656.

Differences in the characteristics of induced and spontaneous episodes of ventricular fibrillation.

AIMS: The degree of organization of ventricular fibrillation (VF) can be examined in terms of the regularity of the electrical activity within the ventricle. Using electrograms (EGMs) stored within implanted cardioverter defibrillators (ICDs), we examined the hypothesis that the degree of organization, or regularity, was different if the VF was induced by electrical stimulation as opposed to occurring clinically due to ischemia or scar. METHODS AND RESULTS: We compared the statistical characteristics of EGMs recorded by ICDs during spontaneous episodes with those induced during device testing in the laboratory in nine subjects. Regularity of the VF EGM signals was quantified using autocorrelation, Shannon entropy (derived from cycle to cycle activation complexes), and Kolmogorov entropy (derived from eight second long episodes of VF). All three measurements showed a statistically greater degree of regularity for induced VF than in spontaneous episodes. CONCLUSION: Analysis of VF EGMs using these techniques is novel and robust, providing a new way for assessing electrical organization during VF. The clinical significance and utility of differences in VF waveform regularity is unclear at this stage.