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Cardiac diagnostics and imaging

40 articles

Physiological factors

Physiological factors (R-HSA-5578768) is a Reactome human pathway on natriuretic peptide regulation of cardiovascular homeostasis, within Cardiac conduction; it covers NPPA expression, corin processing, NPR1/NPR2 binding, and sacubitril metabolism.

Pulsus paradoxus

Pulsus paradoxus: inspiratory systolic blood pressure fall over 10 mmHg, a sign of cardiac tamponade, constrictive pericarditis, severe asthma, and COPD; named by Kussmaul in 1873.

Radionuclide ventriculography

Radionuclide ventriculography (RNV, MUGA, gated blood pool scan, ERNA) is a nuclear medicine test measuring ventricular ejection fraction with Tc-99m labeled red cells and ECG-gated gamma camera imaging, by first-pass or equilibrium methods; once the main nuclear cardiology technique, now used when echo or MRI are unsuitable.

Revised Cardiac Risk Index

Revised Cardiac Risk Index (RCRI, Lee index): 1999 six-point perioperative cardiac risk score for noncardiac surgery, derived from 2893 patients; threshold above 1 marks elevated MACE risk; weak in vascular surgery.

Split S2

Split S2: auscultated separation of the second heart sound into aortic (A2) and pulmonic (P2) components. Normally split on inspiration, single on expiration; fixed split suggests atrial septal defect, reverse split LBBB or aortic stenosis.

Third heart sound

Third heart sound (S3, ventricular gallop): low-frequency early-diastolic sound 120–180 ms after S2 from rapid filling deceleration; normal under ~40, otherwise marks heart failure, with 51% sensitivity and 90% specificity for reduced ejection fraction.

Troponin

Troponin: cardiac regulatory protein complex (TnC, TnI, TnT) of striated muscle; its cardiac subunits cTnI and cTnT are the standard blood biomarkers for diagnosing myocardial infarction, now measured with high-sensitivity assays.

Troponin I

Troponin I (cTnI) is the inhibitory subunit of the troponin complex and a cardiac-specific biomarker for myocardial infarction; released 4-10 h after injury, measured by high-sensitivity immunoassays against the 99th percentile cutoff.

Valsalva maneuver

Valsalva maneuver: forced expiration against a closed airway, first described by Antonio Maria Valsalva in 1704 for clearing the middle ear; now used in autonomic testing, murmur diagnosis, SVT treatment, and ear clearing.

Venous hum

Venous hum (cervical venous hum): a continuous, innocent murmur of the internal jugular veins, loudest in the supraclavicular area, common in children, right-sided, louder sitting and in diastole, abolished by jugular compression or lying down.